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It's under the southern polar ice cap (https://www.bbc.com/news/science-environment-44952710).

Ladies and gentlemen, we have a native Martian habitat.  Whether anything's in it remains to be seen, but dayamn.

Is this mentioned in the Bible?  How can we know it's true then?

Sorry, I'm still reeling from the recent Mouse invasion.

Quote from: SGOS on July 25, 2018, 03:41:48 PM
Is this mentioned in the Bible?  How can we know it's true then?

Sorry, I'm still reeling from the recent Mouse invasion.

Yeah, I get it.  But didn't we already know there was ice there?

Quote from: Cavebear on July 25, 2018, 03:47:52 PM
Yeah, I get it.  But didn't we already know there was ice there?

Hmmm.  I guess I better read the link.

Quote from: SGOS on July 25, 2018, 03:54:49 PM
Hmmm.  I guess I better read the link.

Ah ha!  It's water in it's liquid state, not just the ice you would expect.

Quote from: SGOS on July 25, 2018, 03:56:22 PM
Ah ha!  It's water in it's liquid state, not just the ice you would expect.

Ice + low pressure = water.  OK.

What am I missing here?

Quote from: Cavebear on July 25, 2018, 04:00:14 PM
Ice + low pressure = water.  OK.

What am I missing here?

There's a 20 km body of liquid water just been found.

I predict they won't find any sort of life there, but I hope I'm wrong.

Quote from: Unbeliever on July 25, 2018, 04:17:02 PM
I predict they won't find any sort of life there, but I hope I'm wrong.

I suspect there might be water slime all over the universe.  But not a jellyfish.  And if a jellyfish, not a fish.  But if something like a mammal, intelligence.

I doubt seriously that there's anything even remotely approaching a microbe. No life of any kind.

But remember, I'm a pessimist.

Quote from: Unbeliever on July 25, 2018, 04:26:33 PM
I doubt seriously that there's anything even remotely approaching a microbe. No life of any kind.

But remember, I'm a pessimist.

I would be insanely happy with a microbe.  A mere suggestion of an RNA structure would make me at least giddy.

This tells the story of how it was found:


https://www.youtube.com/watch?v=b8eNOOqi258

Quote from: Unbeliever on July 25, 2018, 05:54:58 PM
This tells the story of how it was found:


https://www.youtube.com/watch?v=b8eNOOqi258

I hereby name it Lake Hillary.  Let Trump go nuts, LOL!

Well, it is where you'd expect to be able to find water on Mars â€" underneath something rather solid.

Quote from: Cavebear on July 25, 2018, 05:59:52 PM
I hereby name it Lake Hillary.  Let Trump go nuts, LOL!

I like it! Lake Hillary - I wonder how you could spread the idea? :-)

Quote from: Unbeliever on July 25, 2018, 07:05:19 PM
I like it! Lake Hillary - I wonder how you could spread the idea? :-)

If you have the Curiosity, the Spirit and the Opportunity you could find a way.

Quote from: Hakurei Reimu on July 25, 2018, 07:00:31 PM
Well, it is where you'd expect to be able to find water on Mars â€" underneath something rather solid.

There is liquid water well under Antarctica, not just the ice shelves.

Quote from: Unbeliever on July 25, 2018, 07:05:19 PM
I like it! Lake Hillary - I wonder how you could spread the idea? :-)

An icy dame with wet ideas?

Quote from: Cavebear on July 25, 2018, 04:51:07 PM
I would be insanely happy with a microbe.  A mere suggestion of an RNA structure would make me at least giddy.

I'd be even happier with an information-carrying molecule that isn't anything like RNA or DNA.  Something completely alien.  That would be completely mindblowing.

Quote from: trdsf on July 25, 2018, 08:10:45 PM
I'd be even happier with an information-carrying molecule that isn't anything like RNA or DNA.  Something completely alien.  That would be completely mindblowing.

I'd be more pleased with a close match to DNA. We've found RNA "precursors" (right word?) in the spectra of distant stars, hinting at a ubiquity of the stuff. I think that we find another intelligent species it will be sharing some characteristics with us. (Murray Leinster's "First Contact" comes to mind.)

Quote from: SGOS on July 25, 2018, 03:41:48 PM
Is this mentioned in the Bible?  How can we know it's true then?

Sorry, I'm still reeling from the recent Mouse invasion.

I just looove your reply!

Quote from: Cavebear on July 25, 2018, 05:59:52 PM
I hereby name it Lake Hillary.  Let Trump go nuts, LOL!

Yeh!
An old ice cold,dried up, crumbling rock, with some salt water deep in her interior!

Quote from: Cavebear on July 25, 2018, 04:00:14 PM
Ice + low pressure = water.  OK.

What am I missing here?

Actually, high pressure

Quote from: Gawdzilla Sama on July 26, 2018, 06:37:04 AM
I'd be more pleased with a close match to DNA. We've found RNA "precursors" (right word?) in the spectra of distant stars, hinting at a ubiquity of the stuff. I think that we find another intelligent species it will be sharing some characteristics with us. (Murray Leinster's "First Contact" comes to mind.)

The two reasons I don't want to see DNA/RNA on Mars are:

• We could never be sure if it was the result of one abiogenetic event or two.  We know material has transferred between the Earth and Mars.  ALH84001 is probably the best-known example (https://en.wikipedia.org/wiki/List_of_Martian_meteorites) of Martian material reaching the Earth; while we've found several meteorites on Mars (https://en.wikipedia.org/wiki/List_of_rocks_on_Mars), of course we don't have the equipment in place to test their origins, but the same process that allows Martian ejecta to reach Earth allows Terrestrial ejecta to reach Mars.
  So if we find RNA/DNA based life on Mars, it could have come from Earth, or Earth life could have come from Mars, or both could have come from elsewhere.  As a side note, I don't like panspermia as a theory of how life came to Earth.  It seems to me to be a punt on the question of how abiogenesis occurs.  It's possible, but I hope research rules it out some day.
• Martian DNA/RNA wouldn't de-parochialize biology.  We'd still be studying life as we (more or less) know it, when it would be much more interesting to study life as we don't know it.

Of course, it's entirely possible that DNA/RNA are the most easily formed information-carrying molecules on which to base life, but Mars can't answer that question for us because we know there's been a transfer of material between Earth and Mars.  Current DNA/RNA based life on Mars only tells us that once life gains a foothold, it doesn't let go easily.

If, on the other hand, we find DNA/RNA life on the outer moons, especially Enceladus and Titan, that would strongly suggest DNA/RNA are the most likely data-carrying molecules because there is no plausible model for cross contamination between those moons and either the Earth or Mars.  Alternately, it would be a data point in favor of panspermia, also because cross-contamination with the inner worlds isn't an option.

Whether or not it's DNA/RNA-based, however, I think you're right about sharing physical characteristics with other intelligent life.  We should expect to see extensions capable of fine manipulation, multiple sensory organs, a brain or brains protected by an exo- or endoskeleton of some sort, and a means of locomotion.  There are good evolutionary reasons to expect a cluster of sensory organs to be on an elevated scanning platform of some sort, because of the advantages in detecting predators that arrangement gives -- we call ours our heads, what the poet Russell Edson evocatively referred to as a "teetering bulb of dread and dream".

I don't think we can go much farther than that, though.  There are too many other variables â€" first environmental, then after the rise of intelligence also social â€" to be able to predict more than with the broadest strokes.  I would expect them to be physically symmetric in some way, but not necessarily bilaterally as we are.  I would expect them to be self-sealed (as we are by skin), but wouldn't care to guess if by skin/hide, chitin, or exoskeleton, or some means that hasn't appeared in Terrestrial biology.  They would have a means of communication with each other, but I wouldn't expect it to have to be by means of forcing air through vibrating meat.

I would not be surprised if they're pattern matchers like we are, but only because I can't think of another plausible route from instinct to intelligence.  So by the same token, I also would not be surprised if there's something else they're innately good at instead of pattern matching.

I would also not be surprised if they had (or still have) religion(s), or something analogous to them, nor would I be surprised if there are broad similarities between theirs and some of the ones practiced here.  I would be shocked if they were similar in detail to just one Terrestrial religion â€" while yes, that might indicate a divine power at work, it also can indicate cultural cross-contamination through the intervention of a third and unknown intelligent species.  Since that latter explanation does not require stepping out of the universe for an explanation, it's the more likely.  I'm still not sure how you differentiate between a god and an extremely advanced alien, Clarke's Law being perfectly applicable here.

Finding ANY life on Mars would be HUGE. I won't ask too much of the event.

In any case, let's all pray they find extraterrestial life.


...

Oh, shit. Wait!

My dream is that they find intelligent life. Somewhere.

My dream is to find intelligent life on Earth.

Quote from: Unbeliever on July 26, 2018, 01:40:59 PM
My dream is to find intelligent life on Earth.

Come back in a few million years.

One step closer to making Mars viable for habitation then.

Quote from: Shiranu on July 26, 2018, 02:15:20 PM
One step closer to making Mars viable for habitation then.

True, you can move ice in open trucks there, so the water situation seems to be resolved. Once we distill out the perchlorates, that is.

(https://upload.wikimedia.org/wikipedia/commons/thumb/4/45/A_small_cup_of_coffee.JPG/275px-A_small_cup_of_coffee.JPG)

I wouldn't mind a nice steaming cup of perchlorates...

Wait, you're talking about coffee, right? ;-)

Living on Mars is going to be a lot tougher than is generally believed:


https://www.youtube.com/watch?v=ESQ1bKd7Los

Tell it to Columbus, Magellan, etc.

Tell them what, exactly?

Quote from: Unbeliever on July 26, 2018, 05:43:24 PM
Tell them what, exactly?

Going to the New World is a terrible idea.

Quote from: Unbeliever on July 26, 2018, 04:29:24 PMLiving on Mars is going to be a lot tougher than is generally believed:

Yeah, but ya gotta start somewhere.  If humanity doesn't take these first few steps out, we might never leave the cradle.  No rush or anything, but have you noticed how unstable things are at home?  What happens when the unthinkable happens?

We're too late. We can't possibly colonize Mars soon enough to save any significant fraction of Earth's biosphere. And we'd need the biosphere, we can't just haul a bunch of humans to Mars and expect them to survive.

Quote from: Unbeliever on July 26, 2018, 06:14:52 PM
We're too late. We can't possibly colonize Mars soon enough to save any significant fraction of Earth's biosphere. And we'd need the biosphere, we can't just haul a bunch of humans to Mars and expect them to survive.

I'm not talking full terraforming and Noah's Ark-ing the Earth, I'm just talking about have a small but permanent presence outside the Earth.  Think ISS just a lot further away.

Just the simple act of seriously attempting to make it happen might trigger some profound changes on Earth.  International cooperation.  Prioritizing science again.  Spinoff technologies like you wouldn't believe.  Looking towards the future with hope again.

And it all starts with a small step for man.

Sounds good, I just think it's too optimistic. If we had a colony on Mars it could not be made self-sustaining. If the Earth were to be unable to send supplies, etc. on a regular basis the colony would die. It may not be long before the civilizations of earth will collapse, making it impossible to sustain a Mars colony.

But I'm a pessimist, so I could be wrong.

Maybe it would be a good first step to put a permanent settlement on the moon first.  Work out some bugs and then think of Mars. 

That's an idea that may work. It seems the height of hubris to think Mars is the next step, when we've barely even been to the Moon. That's why God put it there, after all!

On both the Moon and Barsoom we may be living in old lava tubes. Practice on Luna so we don't have to guess on Mars.

Quote from: Shiranu on July 26, 2018, 02:15:20 PM
One step closer to making Mars viable for habitation then.

Is that you, Elon?  I am not sure even fleeing that far will help you escape your fraud.

Quote from: Gawdzilla Sama on July 26, 2018, 05:40:41 PM
Tell it to Columbus, Magellan, etc.

They had air and water aplenty, and plants and animals, when they arrived.

Quote from: Unbeliever on July 26, 2018, 06:14:52 PM
We're too late. We can't possibly colonize Mars soon enough to save any significant fraction of Earth's biosphere. And we'd need the biosphere, we can't just haul a bunch of humans to Mars and expect them to survive.

Good way to do a Darwin experiment on Democrats ;-)

Quote from: Unbeliever on July 26, 2018, 07:12:07 PM
That's an idea that may work. It seems the height of hubris to think Mars is the next step, when we've barely even been to the Moon. That's why God put it there, after all!

Stop dropping your drawers at me already!

Quote from: Gawdzilla Sama on July 26, 2018, 06:04:34 PM
Going to the New World is a terrible idea.

It was, for the humans already here.  Is that you Smallpox Sama?

Quote from: Unbeliever on July 26, 2018, 06:38:36 PM
Sounds good, I just think it's too optimistic. If we had a colony on Mars it could not be made self-sustaining. If the Earth were to be unable to send supplies, etc. on a regular basis the colony would die. It may not be long before the civilizations of earth will collapse, making it impossible to sustain a Mars colony.

But I'm a pessimist, so I could be wrong.

The Vikings in Greenland weren't pessimistic enough to go back to Iceland.

Quote from: Mike Cl on July 26, 2018, 06:56:23 PM
Maybe it would be a good first step to put a permanent settlement on the moon first.  Work out some bugs and then think of Mars.

Debugging might take longer than expected ...

https://www.youtube.com/watch?v=8WP1hUxbNs8

Quote from: Hydra009 on July 26, 2018, 06:09:45 PM
Yeah, but ya gotta start somewhere.  If humanity doesn't take these first few steps out, we might never leave the cradle.  No rush or anything, but have you noticed how unstable things are at home?  What happens when the unthinkable happens?

Happened already.  Agriculture invented.  Overpopulation commences.

Quote from: Gawdzilla Sama on July 26, 2018, 07:21:01 PM
On both the Moon and Barsoom we may be living in old lava tubes. Practice on Luna so we don't have to guess on Mars.

Well, hell, why don't we ask John Carter; I'm sure he'd let us stay in Helium.

We'll have to use Trump's Space Force to defeat Ming the Merciless before we can occupy Mars.

;-)

Quote from: Mike Cl on July 26, 2018, 07:37:56 PM
Well, hell, why don't we ask John Carter; I'm sure he'd let us stay in Helium.

My voice would be squeaky high ;-)

I like retro sci fi ...

https://www.youtube.com/watch?v=nlvYKl1fjBI

https://www.youtube.com/watch?v=zH7KZD5vGBY

Quote from: Baruch on July 26, 2018, 08:02:38 PM
My voice would be squeaky high ;-)

I like retro sci fi ...

https://www.youtube.com/watch?v=nlvYKl1fjBI

https://www.youtube.com/watch?v=zH7KZD5vGBY

The books are better.

Quote from: Unbeliever on July 26, 2018, 04:29:24 PM
Living on Mars is going to be a lot tougher than is generally believed:

With that attitude we'd still be living in the trees.

You could easily make a list of 5 reasons why bipedal locomotion is a bad idea.

Quote from: Jason78 on July 27, 2018, 03:33:17 PM
With that attitude we'd still be living in the trees.

You could easily make a list of 5 reasons why bipedal locomotion is a bad idea.

Says a cute doggie ;-)

Quote from: Unbeliever on July 25, 2018, 07:05:19 PM
I like it! Lake Hillary - I wonder how you could spread the idea? :-)

Mention it on Facebook.  Everyone trusts Facebook.  LOL!

Ooh, ooh, say that TRUMP named it Lake Hillary!

Quote from: Cavebear on August 01, 2018, 07:50:55 AM
Mention it on Facebook.  Everyone trusts Facebook.  LOL!

Ooh, ooh, say that TRUMP named it Lake Hillary!

Anything T.rump says is flake news.

Quote from: Gawdzilla Sama on August 01, 2018, 07:56:00 AM
Anything T.rump says is flake news.

Not to his followers (all 200 of them at Fox News).  If HE (deity capitals) says it is, it is.

Quote from: Cavebear on August 01, 2018, 07:50:55 AM
Mention it on Facebook.  Everyone trusts Facebook.  LOL!

Ooh, ooh, say that TRUMP named it Lake Hillary!

Hope you didn't loose a wad of cash with Super-Zuckerberg last week.  Facebook is a guaranteed investment!  Just like Tesla.

I hear Elon Musk in doing OK.

Quote from: ferdmonger on August 01, 2018, 09:50:44 PM
I hear Elon Musk in doing OK.

Ah, not his finances ... he was so hard up, he was asking for a loan from Zuckerberg ;-)

Don't touch that water. Be forewarned. I watched Doctor Who. I know what happens next.

I like Isaac Arthur's videos, they're very informative:


https://www.youtube.com/watch?v=9TteoCHmXTc

I think we'll have to get over our planetary chauvinism (https://republicoflagrangia.org/category/planetary-chauvinism/) if we really expect to colonize space in a big way. Any planet we want to live on will have to be terraformed, which is very expensive and time consuming. It's a lot cheaper to build our own habitats that can be as comfortable as we'd like them to be.

Quote from: Unbeliever on August 03, 2018, 04:06:07 PM
I think we'll have to get over our planetary chauvinism (https://republicoflagrangia.org/category/planetary-chauvinism/) if we really expect to colonize space in a big way. Any planet we want to live on will have to be terraformed, which is very expensive and time consuming. It's a lot cheaper to build our own habitats that can be as comfortable as we'd like them to be.

We'll have to pound ice balls into Mars and generate greenhouse gases.

We can live in the lava tubes, but I'd colonize Valles Marineris first, the deepest parts, over three miles below the surface, will get the first dense atmospheres.  Damn up a few deep spots and you have a "Hab" without a roof.

That could work for a small number of people, but I doubt many could live there. Maybe a few thousand?

Quote from: Unbeliever on August 03, 2018, 05:19:27 PM
That could work for a small number of people, but I doubt many could live there. Maybe a few thousand?

You do realize that Valles Marineris is the length of the US, from New York to LA, with numerous side canyons? We start with small canyons, only a hundred miles long, and expand as the atmosphere gets thicker. We'd alway be below the mean surface level of Mars, so the air wouldn't "get away". Living in the cliff walls make instant "skyscrapers" and radiation shelters.

So where does the new atmosphere come from, comets? How hard would it be to capture enough comets to add a significant amount of nitrogen/oxygen to Mars? How long would that take? How much would it cost?

Quote from: Unbeliever on August 03, 2018, 05:34:21 PM
So where does the new atmosphere come from, comets? How hard would it be to capture enough comets to add a significant amount of nitrogen/oxygen to Mars? How long would that take? How much would it cost?

We're terraforming a PLANET. /hint

Quote from: Unbeliever on August 03, 2018, 05:34:21 PM
So where does the new atmosphere come from, comets? How hard would it be to capture enough comets to add a significant amount of nitrogen/oxygen to Mars? How long would that take? How much would it cost?

More than a bankrupt humanity can afford.

Quote from: Unbeliever on August 03, 2018, 03:50:13 PM
I like Isaac Arthur's videos, they're very informative:


https://www.youtube.com/watch?v=9TteoCHmXTc

I am The Mule.  Your Foundation has cracks in it.

Quote from: Gawdzilla Sama on August 03, 2018, 05:23:21 PM
You do realize that Valles Marineris is the length of the US, from New York to LA, with numerous side canyons? We start with small canyons, only a hundred miles long, and expand as the atmosphere gets thicker. We'd alway be below the mean surface level of Mars, so the air wouldn't "get away". Living in the cliff walls make instant "skyscrapers" and radiation shelters.

Martian Anasazi ;-)

It would be so massively cool to find a any type of microbe.

I agree it is very unlikely, but man... if we did, life is suddenly everywhere.

Quote from: ferdmonger on August 03, 2018, 09:04:18 PM
It would be so massively cool to find a any type of microbe.

I agree it is very unlikely, but man... if we did, life is suddenly everywhere.

It is everywhere.  But not as we define it.

Just out of curiosity, if Mars couldn't hold an atmosphere earlier on its own, what makes anyone think it could hold a terraformed one?  I've never understood that part.  It isn't the atmosphere that is the problem.  It's the lack of size and (maybe) lack of magnetic core.

Quote from: Cavebear on August 04, 2018, 01:25:46 AM
Just out of curiosity, if Mars couldn't hold an atmosphere earlier on its own, what makes anyone think it could hold a terraformed one?  I've never understood that part.  It isn't the atmosphere that is the problem.  It's the lack of size and (maybe) lack of magnetic core.

Mars slowly lost its atmosphere over a few million years or so according to the models I've seen. Erosion by solar wind isn't fast.  If we got a new atmosphere up it should last at least that long.

Quote from: Gawdzilla Sama on August 04, 2018, 06:09:47 AM
Mars slowly lost its atmosphere over a few million years or so according to the models I've seen. Erosion by solar wind isn't fast.  If we got a new atmosphere up it should last at least that long.

OK, but doesn't it also take a long time to CREATE an atmosphere?  We need to find a way for one to stay.  Asteroid bombardment?  Comets?  Planetary core heating?

Quote from: Cavebear on August 04, 2018, 07:00:42 AM
OK, but doesn't it also take a long time to CREATE an atmosphere?  We need to find a way for one to stay.  Asteroid bombardment?  Comets?  Planetary core heating?

Comets, or icy bodies in the inner solar system. Probably don't need to go further than Jupiter or Saturn for beau coup ice. It will be expensive, a scaled-up Manhattan Project.

Quote from: Gawdzilla Sama on August 04, 2018, 07:04:47 AM
Comets, or icy bodies in the inner solar system. Probably don't need to go further than Jupiter or Saturn for beau coup ice. It will be expensive, a scaled-up Manhattan Project.

But I will say again, could Mars HOLD an atmosphere for as long as it would take to create one?  There is an aspect of perpetual motion if you can't.  I mean, suppose you had to crash down asteroids that could add to a Mars atmosphere to maintain it.  Dodging asteroids isn't fun.

Total Recall.

Quote from: Cavebear on August 04, 2018, 07:10:49 AM
But I will say again, could Mars HOLD an atmosphere for as long as it would take to create one?  There is an aspect of perpetual motion if you can't.  I mean, suppose you had to crash down asteroids that could add to a Mars atmosphere to maintain it.  Dodging asteroids isn't fun.

It took millions of years to lose it, it might take a hundred years to get a new one going. Not only does crashing icy bodies into Mars provide water and other gases, like nitrogen, it also adds a wee bit of heat, and every little bit helps.

We could have a "daisy chain" of pusher ships that get the bodies going in the right direction and then go to the next one on their list, repeat as needed. A hundred of those might deliver a thousand bodies a month, depending on the orbital dynamics. Again, expensive, but extinction is cheap.

A gunny sergeant once asked me how fast I could run?

"How scared am I?"

Quote from: Cavebear on August 04, 2018, 07:00:42 AM
OK, but doesn't it also take a long time to CREATE an atmosphere?  We need to find a way for one to stay.  Asteroid bombardment?  Comets?  Planetary core heating?

You are killing the meme ... let the space cadets play ;-)

https://www.youtube.com/watch?v=UU7TdtLzPrA

Quote from: Cavebear on August 04, 2018, 07:10:49 AM
But I will say again, could Mars HOLD an atmosphere for as long as it would take to create one?  There is an aspect of perpetual motion if you can't.  I mean, suppose you had to crash down asteroids that could add to a Mars atmosphere to maintain it.  Dodging asteroids isn't fun.

Since Mars is geologically inert -- no apparent continental drift of any sort anymore -- and has a minimal magnetic field, it hasn't a way to both retain and regenerate its atmosphere.  Now, there's a speculative plan that an artificial magnetic shield at Mars' L1 point with the Sun would both provide the necessary magnetic shielding to prevent the atmosphere being stripped by the solar wind, but also allow the planet to warm enough to release the CO₂ at the poles, which would then allow it to warm enough to melt the remaining water (https://www.popularmechanics.com/space/moon-mars/a25493/magnetic-shield-mars-atmosphere/).

The problem then becomes one of Martian gravity -- it can hold a nitrogen-oxygen atmosphere (barely), but it can't retain water (https://en.wikipedia.org/wiki/Atmospheric_escape), even if the surface temperature and pressure are raised to something approximating that of Earth.  So there would probably be atmospheric resupply missions every few centuries, capturing a comet or some such and bringing it in very carefully or in small chunks.  Alternately, adding mass to the planet so the escape velocity rises would turn the trick, or some combination of the two.

Maintaining the atmosphere would be minor compared to establishing it.

For a SWAG let's say 0.01% of the atmosphere is lost every hundred years. How hard would it be to bring that back up to standard in, say, ten years of ice mining? Not much, really. And if the NeoMartians don't do then the colony fails do to lack of will.

Quote from: Gawdzilla Sama on August 06, 2018, 06:44:23 AM
Maintaining the atmosphere would be minor compared to establishing it.

For a SWAG let's say 0.01% of the atmosphere is lost every hundred years. How hard would it be to bring that back up to standard in, say, ten years of ice mining? Not much, really. And if the NeoMartians don't do then the colony fails do to lack of will.

Will?  Triumph of the Will?  Nazis on Mars (how appropriate) rather than Nazis on the Moon?  Iron Sky indeed.

Quote from: trdsf on August 06, 2018, 01:18:27 AM
Since Mars is geologically inert -- no apparent continental drift of any sort anymore -- and has a minimal magnetic field, it hasn't a way to both retain and regenerate its atmosphere.  Now, there's a speculative plan that an artificial magnetic shield at Mars' L1 point with the Sun would both provide the necessary magnetic shielding to prevent the atmosphere being stripped by the solar wind, but also allow the planet to warm enough to release the CO₂ at the poles, which would then allow it to warm enough to melt the remaining water (https://www.popularmechanics.com/space/moon-mars/a25493/magnetic-shield-mars-atmosphere/).

The problem then becomes one of Martian gravity -- it can hold a nitrogen-oxygen atmosphere (barely), but it can't retain water (https://en.wikipedia.org/wiki/Atmospheric_escape), even if the surface temperature and pressure are raised to something approximating that of Earth.  So there would probably be atmospheric resupply missions every few centuries, capturing a comet or some such and bringing it in very carefully or in small chunks.

That might be prohibitively expensive and time intensive. It could maybe work if there was sufficient motivation, though.

QuoteAlternately, adding mass to the planet so the escape velocity rises would turn the trick, or some combination of the two.

I wonder how much mass could be added to Mars without disrupting it's orbital motion?

Quote from: Gawdzilla Sama on August 06, 2018, 06:44:23 AM
Maintaining the atmosphere would be minor compared to establishing it.

For a SWAG let's say 0.01% of the atmosphere is lost every hundred years. How hard would it be to bring that back up to standard in, say, ten years of ice mining? Not much, really. And if the NeoMartians don't do then the colony fails do to lack of will.

That's actually not a bad guess â€" you're within a few orders of magnitude, and it would be a sensible safety margin with regard to planning atmospheric maintenance.  When Mars' magnetic field collapsed and the solar wind was able to reach the Martian atmosphere, it still took millions of years to blow it away, and that was about 3.7 billion years ago when the sun was much younger and more active.  It's currently losing its atmosphere at the rate of 100 g/s... but it has 2.5x10¹⁹ g of atmosphere left, even at its low pressure, so it's not like it's wisping away at an alarming rate.

Quote from: trdsf on August 06, 2018, 01:18:27 AM
Since Mars is geologically inert -- no apparent continental drift of any sort anymore -- and has a minimal magnetic field, it hasn't a way to both retain and regenerate its atmosphere.  Now, there's a speculative plan that an artificial magnetic shield at Mars' L1 point with the Sun would both provide the necessary magnetic shielding to prevent the atmosphere being stripped by the solar wind, but also allow the planet to warm enough to release the CO₂ at the poles, which would then allow it to warm enough to melt the remaining water (https://www.popularmechanics.com/space/moon-mars/a25493/magnetic-shield-mars-atmosphere/).

The problem then becomes one of Martian gravity -- it can hold a nitrogen-oxygen atmosphere (barely), but it can't retain water (https://en.wikipedia.org/wiki/Atmospheric_escape), even if the surface temperature and pressure are raised to something approximating that of Earth.  So there would probably be atmospheric resupply missions every few centuries, capturing a comet or some such and bringing it in very carefully or in small chunks.  Alternately, adding mass to the planet so the escape velocity rises would turn the trick, or some combination of the two.

Mars needs a larger iron core and more mass.

Quote from: Cavebear on August 09, 2018, 07:15:07 AM
Mars needs a larger iron core and more mass.

Pretty much.  A project for the next few millennia just might be not only adding a few nickel-iron asteroids to Mars' core, but melting it and starting up the planetary dynamo again.

And then we get to watch what happens when plate tectonics re-start!

Quote from: trdsf on August 06, 2018, 01:36:39 PM
That's actually not a bad guess â€" you're within a few orders of magnitude, and it would be a sensible safety margin with regard to planning atmospheric maintenance.  When Mars' magnetic field collapsed and the solar wind was able to reach the Martian atmosphere, it still took millions of years to blow it away, and that was about 3.7 billion years ago when the sun was much younger and more active.  It's currently losing its atmosphere at the rate of 100 g/s... but it has 2.5x10¹⁹ g of atmosphere left, even at its low pressure, so it's not like it's wisping away at an alarming rate.

Send the robots out every century or so to wrangle small chunks of air-bearing rock. Just do the math to keep ahead of the loss. OR park some big ones around Mars and "siphon" them.

Quote from: Gawdzilla Sama on August 09, 2018, 10:11:25 AM
Send the robots out every century or so to wrangle small chunks of air-bearing rock. Just do the math to keep ahead of the loss. OR park some big ones around Mars and "siphon" them.

Exactly that.  Once an atmosphere is in place, it becomes a matter of maintenance, and only periodic maintenance at that.

Well, "only" in the sense that comets need to be coaxed out of their orbits and brought to Mars and then melted, filtered, and installed into the ocean(s).  Probably going to need to leave some extra at the poles for functioning ice caps.  Anything left over can be hydrolyzed into oxygen and fusion fuel.  This is a project for the end of this millennium, not the end of this century.

Quote from: Unbeliever on August 06, 2018, 01:29:17 PM
I wonder how much mass could be added to Mars without disrupting it's orbital motion?

I missed this question earlier, but it's a good one.  The answer is: lots.  Its orbital period would speed up a little, but only to the extent of making the year a few seconds shorter.  That's because the difference between the mass of the orbiting object (Mars) and the mass of the orbited object (the Sun) is so vast.  The Sun's mass completely dominates the interaction.

Quote from: trdsf on August 09, 2018, 10:29:57 AM
Exactly that.  Once an atmosphere is in place, it becomes a matter of maintenance, and only periodic maintenance at that.

Well, "only" in the sense that comets need to be coaxed out of their orbits and brought to Mars and then melted, filtered, and installed into the ocean(s).  Probably going to need to leave some extra at the poles for functioning ice caps.  Anything left over can be hydrolyzed into oxygen and fusion fuel.  This is a project for the end of this millennium, not the end of this century.

One method of diverting a threatening asteroid would be the gravity tractor, a small mass parked near a large one in such a position to cause the asteroid to change directions. A small tug very far away would do. One the target item is on the right path the "tug" moves to the next one on the list. The variables would be known with practice and a single tug would be constantly sending rocks to Mars. We might choose to have them impact in such a way as to heat the atmosphere a bit with every impact. And it might not be a bad idea to make the impacts happen on the other side of the planet from the initial settlements. Half a planet is a lot of room.

Quote from: Cavebear on August 09, 2018, 07:15:07 AM
Mars needs a larger iron core and more mass.

Nobody needs more Catholicism ;-)

Quote from: Gawdzilla Sama on August 09, 2018, 11:21:18 AM
One method of diverting a threatening asteroid would be the gravity tractor, a small mass parked near a large one in such a position to cause the asteroid to change directions. A small tug very far away would do. One the target item is on the right path the "tug" moves to the next one on the list. The variables would be known with practice and a single tug would be constantly sending rocks to Mars. We might choose to have them impact in such a way as to heat the atmosphere a bit with every impact. And it might not be a bad idea to make the impacts happen on the other side of the planet from the initial settlements. Half a planet is a lot of room.

I'm not sure that impacting on the surface of a much smaller planet than the Earth with an artificially maintained environment (or, more fragile, one being constructed) is a good idea.  I'd much rather see them just diverted into safer orbits.  Now, a water-bearing comet or centaur or plutino, sure, I can see landing that, but I'd like to see the delta-v relative to the surface reduced to damn near zero before letting it fall in, and dropped from as low an altitude as possible.

I am also irresistibly reminded of Mitchell Burnside Clapp's song about orbital mechanics and asteroid shuffling (http://www.ovff.org/pegasus/songs/falling-down-on-new-jersey.html)...

I used to preface my speculative comments with "assume all parties involved are competent."  Nobody ever read that bit, I think.

Quote from: Gawdzilla Sama on August 09, 2018, 04:45:34 PM
I used to preface my speculative comments with "assume all parties involved are competent."  Nobody ever read that bit, I think.

Even with competence assumed, I can't say I'm a big fan of dropping rocks on planetary surfaces, even for the best of reasons.

Quote from: trdsf on August 09, 2018, 05:03:39 PM
Even with competence assumed, I can't say I'm a big fan of dropping rocks on planetary surfaces, even for the best of reasons.

What problems do you have with that I proposed?

Quote from: trdsf on August 09, 2018, 05:03:39 PM
Even with competence assumed, I can't say I'm a big fan of dropping rocks on planetary surfaces, even for the best of reasons.

Ultimate WMD.  Asteroid pool.  Human colony ... in the side pocket.

Quote from: Gawdzilla Sama on August 09, 2018, 06:10:19 PM
What problems do you have with that I proposed?

I don't see the point of deliberately driving it into Mars' surface, especially if there's a colony there.  If you want it for the resources, just tug it into orbit and mine it from there.  If you want to alter its orbit to prevent it from being an impact risk, send it into Jupiter or the Sun.  If you want ices, you want a comet, centaur or plutino, not an asteroid.

Quote from: trdsf on August 10, 2018, 12:48:06 AM
I don't see the point of deliberately driving it into Mars' surface, especially if there's a colony there.  If you want it for the resources, just tug it into orbit and mine it from there.  If you want to alter its orbit to prevent it from being an impact risk, send it into Jupiter or the Sun.  If you want ices, you want a comet, centaur or plutino, not an asteroid.

As pointed out earlier in this thread, the incoming would be aimed at the uninhabited side of Mars, probably opposite Valles Marineris. The impact not only releases the water, it also adds a bit of heat to the atmosphere. I'm not suggesting willy-nilly bombardment of the planet, not with people on it.

Quote from: Gawdzilla Sama on August 10, 2018, 05:04:38 AM
As pointed out earlier in this thread, the incoming would be aimed at the uninhabited side of Mars, probably opposite Valles Marineris. The impact not only releases the water, it also adds a bit of heat to the atmosphere. I'm not suggesting willy-nilly bombardment of the planet, not with people on it.

Ah, okay, I was confused by your use of 'asteroid'.  To the best of current knowledge, they haven't useful water content -- although it does appear Ceres has ice.  That one's too big to manage, though; comets remain our best resource.  That's not without its own problems: comets move really fast, even by planetary dynamics standards.  Centaurs are the next best bet, but they're way out hanging around Uranus and Neptune.  Plutinos  and other Kuiper Belt icy bodies are even further â€" it took nine years for New Horizons to get from here to Pluto, and that's the near one.  Speaking of, New Horizon's flyby of 2014 MU₆₉ is coming up fast -- Jan 1, 2019.

If our understanding of asteroid composition changes and most of them are icy, that's different, of course.  :)

It's worth adding that there's reason to think that Mars still has some of its original ocean (https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2000JE001478), frozen solid across a stretch of the northern hemisphere.  And the Phoenix lander provided evidence for Martian permafrost.  It's hard to say how much water is already there, but there may be quite a bit.

Sorry, just a lump term. Anything beyond Mars that could be useful.

And comets might have the most ice, but as you say, it's currently out of reach. The pushers I spoke of could be guided by a cell phone.

ETA: Remember that the rings of Saturn are made of mostly ice. Enough to make a planet the size of Mars, I think.

Quote from: Gawdzilla Sama on August 10, 2018, 01:21:56 PM
Sorry, just a lump term. Anything beyond Mars that could be useful.

And comets might have the most ice, but as you say, it's currently out of reach. The pushers I spoke of could be guided by a cell phone.

ETA: Remember that the rings of Saturn are made of mostly ice. Enough to make a planet the size of Mars, I think.

But comets don't stay out of reach, unlike centaurs and plutinos/KBOs.  They're on highly elliptical orbits that bring them in close periodically.  The problem with them is not the distance, it's the speeds they attain as they fall in.  The other problem is social: I strongly suspect that absent an actual existential threat to the survival of the human species, very few people will be on board with the idea of harvesting Halley, Encke, Tempel-Swift, or any of the other major short-period comets.

The rings of Saturn are a good solution -- they're also likely to be small enough to be easily manageable.  I don't think you can make a Mars out of the rings, but you could certainly water the existing Mars with them.

Quote from: trdsf on August 10, 2018, 04:00:27 PM
The rings of Saturn are a good solution -- they're also likely to be small enough to be easily manageable.  I don't think you can make a Mars out of the rings, but you could certainly water the existing Mars with them.

That's an idea I hadn't considered, and it seems like a good one, since they have a lot of water ice in them. They'd be a hell of a lot easier to deal with than comets or other debris.

Quote from: trdsf on August 10, 2018, 04:00:27 PM
But comets don't stay out of reach, unlike centaurs and plutinos/KBOs.  They're on highly elliptical orbits that bring them in close periodically.  The problem with them is not the distance, it's the speeds they attain as they fall in.  The other problem is social: I strongly suspect that absent an actual existential threat to the survival of the human species, very few people will be on board with the idea of harvesting Halley, Encke, Tempel-Swift, or any of the other major short-period comets.

That's why I didn't suggest comets. Add to that the fact that they're rather larger than we want for this job.

QuoteThe rings of Saturn are a good solution -- they're also likely to be small enough to be easily manageable.  I don't think you can make a Mars out of the rings, but you could certainly water the existing Mars with them.

I was suggesting that the volume of the rings is about that of Mars, not that we'd make a Mars out of the rings.

Ice bombardment adds heat, oxygen, and water. Sounds like a plan to me.

Quote from: trdsf on August 09, 2018, 10:05:45 AM
Pretty much.  A project for the next few millennia just might be not only adding a few nickel-iron asteroids to Mars' core, but melting it and starting up the planetary dynamo again.

And then we get to watch what happens when plate tectonics re-start!

That would take a LOT and LOT of asteroids to bulk up Mars to where it could hold a human-tolerable atmosphere.  Never mind the time it would take for the iron/nickle to get to the core.  And wouldn't all that splashdown launch enough debris to affect Earth?

Quote from: Cavebear on August 12, 2018, 04:26:28 AM
That would take a LOT and LOT of asteroids to bulk up Mars to where it could hold a human-tolerable atmosphere.  Never mind the time it would take for the iron/nickle to get to the core.  And wouldn't all that splashdown launch enough debris to affect Earth?

Ice, not nickle-iron rocks. From elsewhere:

A "mother ship" in orbit around Saturn sends out "pushers" to find chunks of ice in the rings of the right size. ("right size" to be determined, but not huge.) When one is found the pusher starts it on its way to Mars. The pushers get data from the mothership regarding thrust duration, etc., based on a preliminary push that "weighs" the berg based on delta vee from a standard impulse of the engines. This allows the pushers to be controlled by computers about as small as a cell phone. The berg heads off to Mars, and impacts on the side of the planet opposite Valles Marineris. VM is one of the "low spots" on Mars and would be one of the first places the atmosphere will start to collect an get denser. The impacts are arranged so that the colonists are well away from the hit. The benefit of the impact includes free oxygen, water and a little more heat in the atmosphere.

If conditions at Saturn are favorable a hundred pushers could send 100 bergs to Mars at a time. The amount of time needed to find the next candidate berg could be shortened by having "finders" who located candidate bergs and plant a signaling device on them.

One hundred bergs would be a minimum for a "day's work" for the pushers, but we might be able to get them up to six a day each. That would be 219,000 bergs a year, or 21,900,000 bergs in a century. I won't speculate on the amount of ice that would be.

Quote from: Gawdzilla Sama on August 12, 2018, 05:10:11 AM
Ice, not nickle-iron rocks. From elsewhere:

A "mother ship" in orbit around Saturn sends out "pushers" to find chunks of ice in the rings of the right size. ("right size" to be determined, but not huge.) When one is found the pusher starts it on its way to Mars. The pushers get data from the mothership regarding thrust duration, etc., based on a preliminary push that "weighs" the berg based on delta vee from a standard impulse of the engines. This allows the pushers to be controlled by computers about as small as a cell phone. The berg heads off to Mars, and impacts on the side of the planet opposite Valles Marineris. VM is one of the "low spots" on Mars and would be one of the first places the atmosphere will start to collect an get denser. The impacts are arranged so that the colonists are well away from the hit. The benefit of the impact includes free oxygen, water and a little more heat in the atmosphere.

If conditions at Saturn are favorable a hundred pushers could send 100 bergs to Mars at a time. The amount of time needed to find the next candidate berg could be shortened by having "finders" who located candidate bergs and plant a signaling device on them.

One hundred bergs would be a minimum for a "day's work" for the pushers, but we might be able to get them up to six a day each. That would be 219,000 bergs a year, or 21,900,000 bergs in a century. I won't speculate on the amount of ice that would be.

Mars needs mass to hold an atmosphere.  Ice (water) won't do it, sorry.  Mars needs matter that won't evaporate away like it's possible ancient atmosphere did.  Rocks, metals...

Quote from: Cavebear on August 12, 2018, 05:13:15 AM
Mars needs mass to hold an atmosphere.  Ice (water) won't do it, sorry.  Mars needs matter that won't evaporate away like it's possible ancient atmosphere did.  Rocks, metals...

I have to repeat some things a lot.

It took millions of years, if not a billion, for Mars to lose its atmosphere. The loss was due to FRICTION between solar particles and gases. That's not a speedy process. The process suggested could HELP produce a breathable atmosphere in less than a thousand years, I suspect.

I haven't actually created an atmosphere on Mars, I'm speculating on one possible means. It may be that a combination of methods is used in the end. But it won't be as ephemeral as people seem to think.

Quote from: Gawdzilla Sama on August 12, 2018, 05:50:44 AM
I have to repeat some things a lot.

It took millions of years, if not a billion, for Mars to lose its atmosphere. The loss was due to FRICTION between solar particles and gases. That's not a speedy process. The process suggested could HELP produce a breathable atmosphere in less than a thousand years, I suspect.

I haven't actually created an atmosphere on Mars, I'm speculating on one possible means. It may be that a combination of methods is used in the end. But it won't be as ephemeral as people seem to think.

I like you, but apparently I have to repeat myself a lot too.  You can't create an atmosphere on Mars that will last any length of time unless the core increases in mass and therefore the gravity of the planet to hold any atmosphere we create by any means. 

Every method of creating an atmosphere on Mars amenable to humans would be very temporary unless the mass of the planet can hold what is created.  Surface solutions will all be temporary, if not being lost to space as fast as created. 

You can't get over the problem that Mars just isn't massive enough to hold an atmosphere.  That's why it doesn't have one suitable to humans.

Sorry.

Mars is a very dry version of Antarctica (very cold) ... minus penguins ;-(

Quote from: Cavebear on August 12, 2018, 06:04:30 AM
I like you, but apparently I have to repeat myself a lot too.  You can't create an atmosphere on Mars that will last any length of time unless the core increases in mass and therefore the gravity of the planet to hold any atmosphere we create by any means. 

Every method of creating an atmosphere on Mars amenable to humans would be very temporary unless the mass of the planet can hold what is created.  Surface solutions will all be temporary, if not being lost to space as fast as created. 

You can't get over the problem that Mars just isn't massive enough to hold an atmosphere.  That's why it doesn't have one suitable to humans.

Sorry.

And how long is "temporary"? Would the residents not act to maintain the atmosphere?

Quote from: Gawdzilla Sama on August 12, 2018, 06:09:38 AM
And how long is "temporary"? Would the residents not act to maintain the atmosphere?

Easy if they eat beans ;-))

On 5 November 2015, NASA announced that data from MAVEN shows that the erosion of Mars' atmosphere increases significantly during solar storms. This shift took place between about 4.2 to 3.7 billion years ago, as the shielding effect of the global magnetic field was lost when the planet's internal dynamo cooled.
Atmosphere of Mars - Wikipedia
https://en.wikipedia.org/wiki/Atmosphere_of_Mars

Quote from: Gawdzilla Sama on August 12, 2018, 06:21:49 AM
On 5 November 2015, NASA announced that data from MAVEN shows that the erosion of Mars' atmosphere increases significantly during solar storms. This shift took place between about 4.2 to 3.7 billion years ago, as the shielding effect of the global magnetic field was lost when the planet's internal dynamo cooled.
Atmosphere of Mars - Wikipedia
https://en.wikipedia.org/wiki/Atmosphere_of_Mars

QED

Quote from: Cavebear on August 12, 2018, 06:23:45 AM
QED

A billion years isn't good enough for you? Tell me, please, how long after an atmosphere is established on Mars will it be gone again? Please don't account for people maintaining it, the people who actually breathe it and need an atmosphere. Just the inanimate option, nobody there to tweak it and keep it going. 'Cause that would nullify your objections.

Quote from: Gawdzilla Sama on August 12, 2018, 06:41:01 AM
A billion years isn't good enough for you? Tell me, please, how long after an atmosphere is established on Mars will it be gone again? Please don't account for people maintaining it, the people who actually breathe it and need an atmosphere. Just the inanimate option, nobody there to tweak it and keep it going. 'Cause that would nullify your objections.

An atmosphere WOULDN'T be "established" on Mars without more gravity to hold it there.  I'm not sure what you mean by "the inaminate option".

Quote from: Cavebear on August 12, 2018, 06:53:21 AM
An atmosphere WOULDN'T be "established" on Mars without more gravity to hold it there.  I'm not sure what you mean by "the inaminate option".

You refuse to say how long it would take for the atmosphere to erode. Are you saying that it would erode faster that it could be established? If so, that's just wrong, unless you know of a mechanism I don't.

Quote from: Gawdzilla Sama on August 12, 2018, 06:54:46 AM
You refuse to say how long it would take for the atmosphere to erode. Are you saying that it would erode faster that it could be established? If so, that's just wrong, unless you know of a mechanism I don't.

Yes. yes. yes. yes. yes. yes. yes. yes.  That's what I've been saying.  And I'm saying that because Mars doesn't hold an atmosphere for a reason.  No magnetosphere!

MARS STILL HAS AN ATMOSPHERE!

Quote from: Cavebear on August 12, 2018, 06:57:55 AM
Yes. yes. yes. yes. yes. yes. yes. yes.  That's what I've been saying.  And I'm saying that because Mars doesn't hold an atmosphere for a reason.  No magnetosphere!

So, after a few billion years the atmosphere is completely gone, right?

Quote from: Gawdzilla Sama on August 12, 2018, 07:01:16 AM
So, after a few billion years the atmosphere is completely gone, right?

It is gone as fast as you create it.

Quote from: Cavebear on August 12, 2018, 07:02:28 AM
It is gone as fast as you create it.

Nonsense. If that were true there would be no atmosphere on Mars now. Instead, after billions of years, we still have some atmosphere. NOT INSTANT LOSS. That's absurd.

Quote from: Gawdzilla Sama on August 12, 2018, 07:21:35 AM
Nonsense. If that were true there would be no atmosphere on Mars now. Instead, after billions of years, we still have some atmosphere. NOT INSTANT LOSS. That's absurd.

There is virtually no atmosphere on Mars.  Is that what you have been basing all this discussion on?  The Mars atmosphere is about 0.6% of Earth's mean sea level pressure because that is all the planet's gravity can hold!  Mars can't hold the atmosphere you want to create for even a few years.    Everything I search says it just CAN'T WORK...

Quote from: Cavebear on August 12, 2018, 07:42:08 AM
There is virtually no atmosphere on Mars.  Is that what you have been basing all this discussion on?  The Mars atmosphere is about 0.6% of Earth's mean sea level pressure because that is all the planet's gravity can hold!  Mars can't hold the atmosphere you want to create for even a few years.    Everything I search says it just CAN'T WORK...

It currently has not much atmosphere.

You mention "Mars can't hold the atmosphere you want to create for even a few years." but I don't see a reference.

Quote from: Gawdzilla Sama on August 12, 2018, 07:45:48 AM
It currently has not much atmosphere.

You mention "Mars can't hold the atmosphere you want to create for even a few years." but I don't see a reference.

You made the previous claim it could for billions of years.  I don't have to prove that.

So prove it.

Mars still has an atmosphere. QED

So, if we establish an atmosphere there, what do your sources say will be the lifespan of that? "Instantly" is a non-starter.

BTW, have you met Robert Zubrin? http://www.marssociety.org/home/about/mars-direct/

Quote from: Cavebear on August 12, 2018, 06:04:30 AM
I like you, but apparently I have to repeat myself a lot too.  You can't create an atmosphere on Mars that will last any length of time unless the core increases in mass and therefore the gravity of the planet to hold any atmosphere we create by any means. 

Every method of creating an atmosphere on Mars amenable to humans would be very temporary unless the mass of the planet can hold what is created.  Surface solutions will all be temporary, if not being lost to space as fast as created. 

You can't get over the problem that Mars just isn't massive enough to hold an atmosphere.  That's why it doesn't have one suitable to humans.

The reason it doesn't have a substantial atmosphere is because it doesn't have a magnetic field.

It has sufficient gravity to hold a nitrogen-oxygen atmosphere (http://en.wikipedia.org/wiki/Atmospheric_escape); it can't hold hydrogen, helium, water vapor (although it can have pressure and temperature high enough to retain water).  The following diagram shows the gravity and pressure relationship for maintaining an atmosphere; anything below the world can, absent other factors, be retained.

(https://upload.wikimedia.org/wikipedia/commons/4/4a/Solar_system_escape_velocity_vs_surface_temperature.svg)

This is also why Martian methane is such an interesting find: it really shouldn't have any left by now, which means there's a current source.  Methane is a byproduct of some biological processes; it's also a byproduct of physical ones, but finding it at least leaves Martian life in the 'possible' column.

With regard to the lack of a magnetic field, I posted earlier in this thread about a theoretical way to provide Mars with one (https://www.popularmechanics.com/space/moon-mars/a25493/magnetic-shield-mars-atmosphere/) without re-melting the core.

It's mega-engineering, but it's theoretically possible within this century.

Why even do all that work to terraform a planet when we can just build orbital habitats to suit us? We don't need planets!

The High Frontier: Human Colonies in Space (https://en.wikipedia.org/wiki/The_High_Frontier:_Human_Colonies_in_Space)

Quote from: Unbeliever on August 12, 2018, 05:33:17 PM
Why even do all that work to terraform a planet when we can just build orbital habitats to suit us? We don't need planets!

The High Frontier: Human Colonies in Space (https://en.wikipedia.org/wiki/The_High_Frontier:_Human_Colonies_in_Space)

If they have anti-gravity, sure, that might work. But I think it will be a while before Dr. Sumgui has the bugs out of that system.

They just need to spin, and voila! gravity (sort of).

Quote from: Unbeliever on August 12, 2018, 06:53:40 PM
They just need to spin, and voila! gravity (sort of).

And the dynamic stresses on the outer ring of a wheel-type will be HUGE. You could brace it ten ways from Sunday and I wouldn't get on it. A spinning barrel would require many times the amount of material.

Well, I'm no engineer, so I'll take your word for it.

Quote from: Unbeliever on August 12, 2018, 07:40:54 PM
Well, I'm no engineer, so I'll take your word for it.

I'm not an engineer, but I did hang out with them when I was at Purdue. And I was an engineer in the Navy for twenty years.

Quote from: Unbeliever on August 12, 2018, 06:53:40 PM
They just need to spin, and voila! gravity (sort of).

And one terrorist with a bee-bee gun, and instant people sucked out into space.

https://www.youtube.com/watch?v=2p6D6RjUJEg

"How fast can you run?"

"How scared am I?"

Quote from: Gawdzilla Sama on August 13, 2018, 03:55:13 PM
"How fast can you run?"

"How scared am I?"

Space doesn't literally suck, the air inside the habitat blows.

Quote from: trdsf on August 12, 2018, 02:42:16 PM
With regard to the lack of a magnetic field, I posted earlier in this thread about a theoretical way to provide Mars with one (https://www.popularmechanics.com/space/moon-mars/a25493/magnetic-shield-mars-atmosphere/) without re-melting the core.

It's mega-engineering, but it's theoretically possible within this century.

If a magnetosphere could be provided for Mars, I'll enthusiastically allow for an atmosphere.  I have my doubts though.  But I never claim that problems can't be overcome.  "Someday", we might land on the small liquid metallic surface of Jupiter.  But I want to see HOW first.

I am reminded of a supervisor who used to ask "can a computer do that".  Well probably, eventually.  How much funding and how much time is the question.  Who knows WHAT we can do given money, interest, and time?

Quote from: Cavebear on August 27, 2018, 05:04:51 AM
If a magnetosphere could be provided for Mars, I'll enthusiastically allow for an atmosphere.  I have my doubts though.  But I never claim that problems can't be overcome.  "Someday", we might land on the small liquid metallic surface of Jupiter.  But I want to see HOW first.

I am reminded of a supervisor who used to ask "can a computer do that".  Well probably, eventually.  How much funding and how much time is the question.  Who knows WHAT we can do given money, interest, and time?

That is what all irresponsible governments and plutocrats say.  Money is no object.

Every project manager knows there are 3 parts  to any task (Omnes tres projects habere partes, as Iulius might have not said).   Funding, time and quality.  You can set any 2 but not all 3 at once.  Managers are idiots who think that all 3 can be defined by fiat.

Quote from: Cavebear on August 27, 2018, 04:19:05 PM
Every project manager knows there are 3 parts  to any task (Omnes tres projects habere partes, as Iulius might have not said).   Funding, time and quality.  You can set any 2 but not all 3 at once.  Managers are idiots who think that all 3 can be defined by fiat.

"Do you want it good or do  you want it fast?"

Quote from: Gawdzilla Sama on August 27, 2018, 04:31:19 PM
"Do you want it good or do  you want it fast?"

Sounds like a question in a combined Wendys and McDonalds...

Why terraform another planet when we could just terraform Earth? I think Neil De Grasse Tyson said that.

Quote from: Unbeliever on August 27, 2018, 05:02:28 PM
Why terraform another planet when we could just terraform Earth? I think Neil De Grasse Tyson said that.

We should do both. All our eggs in one basket, a recipe for extinction.

So? Why does anyone care if we go extinct? The universe will be just fine if we're no longer existent.

Quote from: Unbeliever on August 27, 2018, 06:32:55 PM
So? Why does anyone care if we go extinct? The universe will be just fine if we're no longer existent.

We're all the anyones.

We may be the last of the anyones, but I don't seem to be able to work up a sweat over it.

Quote from: Gawdzilla Sama on August 27, 2018, 07:14:59 PM
We're all the anyones.

You can go first ;-)

Quote from: Unbeliever on August 27, 2018, 05:02:28 PM
Why terraform another planet when we could just terraform Earth? I think Neil De Grasse Tyson said that.

We are ... its called Global Warming.

Quote from: Cavebear on August 27, 2018, 04:19:05 PM
Every project manager knows there are 3 parts  to any task (Omnes tres projects habere partes, as Iulius might have not said).   Funding, time and quality.  You can set any 2 but not all 3 at once.  Managers are idiots who think that all 3 can be defined by fiat.

Excellent.

Quote from: Cavebear on August 27, 2018, 04:59:16 PM
Sounds like a question in a combined Wendys and McDonalds...

They mated and produced Burger King ;-)

Quote from: Unbeliever on August 27, 2018, 06:32:55 PM
So? Why does anyone care if we go extinct? The universe will be just fine if we're no longer existent.

The universe doesn't care if we go extinct or not, but I do!  I have show tickets for October!

Quote from: Unbeliever on August 27, 2018, 06:32:55 PM
So? Why does anyone care if we go extinct? The universe will be just fine if we're no longer existent.

It would be very unfortunate for our pets.  :(

Plus, I'm kinda hoping that mankind doesn't rise from the muck merely to argue and war and trash up the place before quickly settling back again in a permanent state of death.  Too much of a downer ending to that tale.

I hope there are enough humans who don't give up easily to save the rest.

Quote from: Gawdzilla Sama on August 28, 2018, 05:48:15 AM
I hope there are enough humans who don't give up easily to save the rest.

Be the change.

Quote from: trdsf on August 27, 2018, 10:34:02 PM
The universe doesn't care if we go extinct or not, but I do!  I have show tickets for October!

Well, I doubt we'll go extinct before October, so you should be good to go. I'd give us at least another year or so.

Quote from: trdsf on July 25, 2018, 03:26:12 PM
It's under the southern polar ice cap (https://www.bbc.com/news/science-environment-44952710).

Ladies and gentlemen, we have a native Martian habitat.  Whether anything's in it remains to be seen, but dayamn.

I dont think any organism will be found on Mars. The works on terraforming mars is on progress.
Maybe ıt has ıts own atmoshfer and the oxygen to be inhaled to be able to promoto life to its habitants: humans!...

I think Mars will need more than just water and an atmosphere for humans to live there, it also needs an intact biosphere, and that will take a lot of time to install. We must have many of the microbes, fungi and such that makes life on Earth possible. Maybe they can be engineered to grow quickly in that environment, though.

Quote from: Unbeliever on August 28, 2018, 03:00:09 PM
I think Mars will need more than just water and an atmosphere for humans to live there, it also needs an intact biosphere, and that will take a lot of time to install. We must have many of the microbes, fungi and such that makes life on Earth possible. Maybe they can be engineered to grow quickly in that environment, though.

Marc Watney got crops going with recycled shit.

Quote from: Unbeliever on August 28, 2018, 03:00:09 PM
I think Mars will need more than just water and an atmosphere for humans to live there, it also needs an intact biosphere, and that will take a lot of time to install. We must have many of the microbes, fungi and such that makes life on Earth possible. Maybe they can be engineered to grow quickly in that environment, though.

I have visited this one ...

http://biosphere2.org

Quote from: Gawdzilla Sama on August 28, 2018, 03:31:09 PM
Marc Watney got crops going with recycled shit.

1.  Yeah, but it was really GOOD SHIT, Man!
2.  You plant potatoes, and all the Irish will leave Earth.
3.  And (see above) what the BBC do for humor?
4.  Blanket Mars with dandelion and crabgrass seeds.  They will grow anywhere.
5.  Send Mercury into Mars.  Great rings for a few hundred years and Mars gets an iron core.  Instant magetosphere.
6.  New TV show.  'ST: Launch Baruch'.  If he finds god, we win.  If not, we win.
7.  Blanket Mars with Water Bears to eat the crabgrass.
8.  Blanket Mars with something that eats Water Bears and excretes oxygen.
9.  Launch Amazon Fullfilment Facility.  "Free shipping on planet".
10. NewNewYork established 2090.

Quote from: Cavebear on September 12, 2018, 06:31:06 AM
1.  Yeah, but it was really GOOD SHIT, Man!
2.  You plant potatoes, and all the Irish will leave Earth.
3.  And (see above) what the BBC do for humor?
4.  Blanket Mars with dandelion and crabgrass seeds.  They will grow anywhere.
5.  Send Mercury into Mars.  Great rings for a few hundred years and Mars gets an iron core.  Instant magetosphere.
6.  New TV show.  'ST: Launch Baruch'.  If he finds god, we win.  If not, we win.
7.  Blanket Mars with Water Bears to eat the crabgrass.
8.  Blanket Mars with something that eats Water Bears and excretes oxygen.
9.  Launch Amazon Fullfilment Facility.  "Free shipping on planet".
10. NewNewYork established 2090.

I found myself yesterday, today and tomorrow.  I found a demi-god (as per ancient definitions).  What do I win?

Quote from: Baruch on September 12, 2018, 07:10:57 AM
I found myself yesterday, today and tomorrow.  I found a demi-god (as per ancient definitions).  What do I win?

You get a Bugs Bunny comi...............er, bible. 

Quote from: Mike Cl on September 13, 2018, 11:04:16 PM
You get a Bugs Bunny comi...............er, bible.

And your anger tantrums remind me of the Tasmanian Devil (sometimes).

Speaking of habitability elsewhere -- models suggest multiple ways that Proxima Centauri b, even though tidally locked, could be habitable (https://www.realclearscience.com/articles/2018/09/13/the_closest_exoplanet_to_earth_could_be_highly_habitable.html).

Needless to say, they had to assume an atmosphere and an ocean (nearly a given before postulating any sort of life).  What's interesting is that if Proxima Centauri b does have them, there are multiple ways a stable, habitable environment could exist on a tidally locked world with an eleven-day "year", ranging from a ring of habitability between the too-hot area with Proxima perpetually at zenith and the too-cold dark side, to a dynamic water world with sufficient convection to keep at least some of the dark side warm enough for habitability.

Quote from: Baruch on September 14, 2018, 07:20:04 AM
And your anger tantrums remind me of the Tasmanian Devil (sometimes).

You consider that a temper tantrum??  I see, you needed to get Taz in there somehow.  I do like him; have a bobble head Taz by my computer.

Quote from: Mike Cl on September 14, 2018, 12:24:04 PM
You consider that a temper tantrum??  I see, you needed to get Taz in there somehow.  I do like him; have a bobble head Taz by my computer.

That doesn't surprise me in the least.  Then I think of people I know, I see everything I have interacted with them over, integration, not differentiation.

(https://www.smbc-comics.com/comics/1533390851-20180804.png)

Quote from: Baruch on September 14, 2018, 12:46:18 PM
That doesn't surprise me in the least.  Then I think of people I know, I see everything I have interacted with them over, integration, not differentiation.

Um..................okay. 

Quote from: Mike Cl on September 14, 2018, 03:30:39 PM
Um..................okay.

Math joke and liberal joke.

And no, while Gaia is an interesting idea, I am interested in the human infestation primarily.  Certainly ecologically minded neo-pagans should be into the worship of Gaia.

Quote from: Baruch on September 14, 2018, 06:54:39 PM
Math joke and liberal joke.

And no, while Gaia is an interesting idea, I am interested in the human infestation primarily.  Certainly ecologically minded neo-pagans should be into the worship fo Gaia.

Why can't something like Gaia be acknowledged to exist (if it does) without having to be worshipped? Why this emphasis on worship?

Quote from: Unbeliever on September 14, 2018, 07:00:28 PM
Why can't something like Gaia be acknowledged to exist (if it does) without having to be worshipped? Why this emphasis on worship?

If it is bigger than you, you worship it.  Otherwise Bubba gon' smack you around some more!

I worship nothing, since nothing is the only thing worthy of my worship.

Quote from: Unbeliever on September 14, 2018, 07:08:03 PM
I worship nothing, since nothing is the only thing worthy of my worship.

Is nothing sacred?

It's the false vacuum, baby! ;-)

Quote from: trdsf on September 14, 2018, 10:47:14 AM
Speaking of habitability elsewhere -- models suggest multiple ways that Proxima Centauri b, even though tidally locked, could be habitable (https://www.realclearscience.com/articles/2018/09/13/the_closest_exoplanet_to_earth_could_be_highly_habitable.html).

Needless to say, they had to assume an atmosphere and an ocean (nearly a given before postulating any sort of life).  What's interesting is that if Proxima Centauri b does have them, there are multiple ways a stable, habitable environment could exist on a tidally locked world with an eleven-day "year", ranging from a ring of habitability between the too-hot area with Proxima perpetually at zenith and the too-cold dark side, to a dynamic water world with sufficient convection to keep at least some of the dark side warm enough for habitability.

A whole new take on "The Twilight Zone", but one that actually offers possibilities.  The more we learn about possibilities for life, the more likely life exists elsewhere.

I don't necessarily mean intelligent life.  Alien life could well be all microbial pond scum.  The advance to intelligence might well be nearly impossible for all we know. 

But if it gets beyond that, it means conditions allow for evolution and then I suspect it is unstoppable towards intelligence.

Quote from: Unbeliever on September 14, 2018, 07:00:28 PM
Why can't something like Gaia be acknowledged to exist (if it does) without having to be worshipped? Why this emphasis on worship?

I generally accept that some general aspects of the planet are somewhat self-regulating.  But I don't accept any INTENT OR DELIBERATE ACTION in that.

Quote from: Cavebear on September 14, 2018, 11:37:17 PM
I generally accept that some general aspects of the planet are somewhat self-regulating.  But I don't accept any INTENT OR DELIBERATE ACTION in that.

I agree.  But then I don't worship Mother Earth.

Quote from: Unbeliever on September 14, 2018, 07:08:03 PM
I worship nothing, since nothing is the only thing worthy of my worship.

Nothing (vacuum of space) is bigger than anything else ... so you are its bitch.

Quote from: Gawdzilla Sama on September 14, 2018, 08:10:50 PM
Is nothing sacred?

Missed the sarc tag.  Nothing around here is sacred.  We are the gang to TP the universe in juvenile delinquency.

Quote from: Unbeliever on September 14, 2018, 08:19:21 PM
It's the false vacuum, baby! ;-)

See, even nihilism is a damn lie!

Quote from: Cavebear on September 14, 2018, 11:37:17 PM
I generally accept that some general aspects of the planet are somewhat self-regulating.  But I don't accept any INTENT OR DELIBERATE ACTION in that.

Homeostasis is usually a sign of living things.  Humans tend to take self-regulating systems and smash them.  I don't know if our destruction of the environment is intentional or not.  Are monkeys sophisticated enough to have "intention"?

Quote from: Gawdzilla Sama on September 14, 2018, 08:10:50 PM
Is nothing sacred?

Only cows, and they make the best holy hamburgers!

Quote from: Cavebear on September 14, 2018, 11:30:52 PM
A whole new take on "The Twilight Zone", but one that actually offers possibilities.  The more we learn about possibilities for life, the more likely life exists elsewhere.

I don't necessarily mean intelligent life.  Alien life could well be all microbial pond scum.  The advance to intelligence might well be nearly impossible for all we know. 

But if it gets beyond that, it means conditions allow for evolution and then I suspect it is unstoppable towards intelligence.

Mmm, I don't know.  I think it more likely that life is simple and that intelligent life is difficult.  I judge the first part of that on two observations: one, that life arose quite quickly after the Earth cooled enough to have liquid water -- maybe half a billion years -- and two, everywhere we look (on Earth, anyway) that has the barest minimum requirements for life -- an energy source and a solvent -- has something living in it, even in places that barely 20 years ago, most biologists would say no way.

I judge the second part on a few more observations.  One, the only example we know of intelligenceâ€"usâ€"took a hella long time to evolve.  Even though simple life arose quickly, it stayed very simple for a very long time, something like three billion years.  All the big beasties are quite recent, relatively speaking.  And it took almost another half billion years to get to something that was even just on the starting path to intelligence, much less to an advanced technological society.  All human history, culture and advancement isn't even the barest hair's breadth compared to the history of all life on Earth.

Two, to quote Enrico Fermi, "Where is everyone?"  If intelligent life were easy, there should be many intelligent species older than ours just in this galaxy, and if we've gotten as far as we have in around ten thousand years, imagine a civilization that's been at it for fifteen thousand, twenty thousand, a hundred thousand, a million years.  Assuming by the principle of mediocrity that we are much more likely to be average than we are to be especially advanced or especially behind, if there were a lot of intelligences out there, we'd expect many would be ahead of us and a few of them far ahead of us.  One or two of them with a million years head start on us has already had enough time to have explored the entire galaxy certainly both by probe and directly, even sticking to the speed of light.

And three, large brains are biologically expensive.  Evolution is a lazy process -- if there's an easier way to exploit an environmental niche than brute intelligence, we can expect the easier solution to be the one selected simply because it's the one most likely to be stumbled across.

I don't like the word 'lucky', but it may be that intelligence requires a couple "lucky" breaks in order to happen: an environment best mastered through intelligence rather than instinct and a species scratching at the door of sapience but not quite there yet, at the same time.  So I think it much more likely that life is common, but intelligent life is rare and not at all inevitable.

Quote from: trdsf on September 15, 2018, 09:22:37 AM
Mmm, I don't know.  I think it more likely that life is simple and that intelligent life is difficult.  I judge the first part of that on two observations: one, that life arose quite quickly after the Earth cooled enough to have liquid water -- maybe half a billion years -- and two, everywhere we look (on Earth, anyway) that has the barest minimum requirements for life -- an energy source and a solvent -- has something living in it, even in places that barely 20 years ago, most biologists would say no way.

I judge the second part on a few more observations.  One, the only example we know of intelligenceâ€"usâ€"took a hella long time to evolve.  Even though simple life arose quickly, it stayed very simple for a very long time, something like three billion years.  All the big beasties are quite recent, relatively speaking.  And it took almost another half billion years to get to something that was even just on the starting path to intelligence, much less to an advanced technological society.  All human history, culture and advancement isn't even the barest hair's breadth compared to the history of all life on Earth.

Two, to quote Enrico Fermi, "Where is everyone?"  If intelligent life were easy, there should be many intelligent species older than ours just in this galaxy, and if we've gotten as far as we have in around ten thousand years, imagine a civilization that's been at it for fifteen thousand, twenty thousand, a hundred thousand, a million years.  Assuming by the principle of mediocrity that we are much more likely to be average than we are to be especially advanced or especially behind, if there were a lot of intelligences out there, we'd expect many would be ahead of us and a few of them far ahead of us.  One or two of them with a million years head start on us has already had enough time to have explored the entire galaxy certainly both by probe and directly, even sticking to the speed of light.

And three, large brains are biologically expensive.  Evolution is a lazy process -- if there's an easier way to exploit an environmental niche than brute intelligence, we can expect the easier solution to be the one selected simply because it's the one most likely to be stumbled across.

I don't like the word 'lucky', but it may be that intelligence requires a couple "lucky" breaks in order to happen: an environment best mastered through intelligence rather than instinct and a species scratching at the door of sapience but not quite there yet, at the same time.  So I think it much more likely that life is common, but intelligent life is rare and not at all inevitable.

Well, I agree so much that you could have actually quoted a previous post of mine (don't worry, you didn't).  But I agree that much.   I suspect microbial life is relatively easy but advancement from there is hard.  But when it does take that first step to advancing ...

BOOM!  No stopping it locally.  Oh maybe a bad day with a gamma ray burst or planetoid intersecting you, but that is rare enough generally so most places life starts will continue.   The game is "if and when" competition starts. 

And how often that occurs we simply will not know until we find some planets where life starts and advances or not.

Life is easy, if you don't have to work for a living.

Intelligence is hard, see Atheistforums.com.

"where is everyone"? Maybe billions of light years away, and millions of years in the past or future. Fermi booted that one, he assumed that aliens would be interested in us, could get to us, and would get to us. All assumptions without basis in fact.

Quote from: Gawdzilla Sama on September 15, 2018, 11:30:25 AM
"where is everyone"? Maybe billions of light years away, and millions of years in the past or future. Fermi booted that one, he assumed that aliens would be interested in us, could get to us, and would get to us. All assumptions without basis in fact.

It is entirely possible that there simply is no viable method for traveling interstellar space in the time that the planets will exist.  That might be a good thing.  I'm not sure I would really want beings like us 1,000 years advanced to find us.

Quote from: Cavebear on September 15, 2018, 11:55:07 AM
It is entirely possible that there simply is no viable method for traveling interstellar space in the time that the planets will exist.  That might be a good thing.  I'm not sure I would really want beings like us 1,000 years advanced to find us.

Yerp. They'd squish us and set the dolphins up with robotic arms. (And you read The Dolphins of Pern?)

But realistically, if they checked on Earth every billion years and found cyanobacteria the dominant life form, they'd be back in about 600,000,000 years for another look. Distant descendants of racoons would meet them just outside Neptune's orbit, to explain that they didn't do that.

Quote from: Gawdzilla Sama on September 15, 2018, 12:21:32 PM
Yerp. They'd squish us and set the dolphins up with robotic arms. (And you read The Dolphins of Pern?)

But realistically, if they checked on Earth every billion years and found cyanobacteria the dominant life form, they'd be back in about 600,000,000 years for another look. Distant descendants of racoons would meet them just outside Neptune's orbit, to explain that they didn't do that.

Was that part of the 'Uplift' series?  I have about 60' of paperback sci-fi books (and more in boxes), so it is hard to remember all the titles.

For "after us", I might bet on bears, but raccoons hold promise.  And don't discount octopi if they ever learn there is something above sea level.

'Breed To Come' had good arguments for cats, too.

If we don't last, probably not other primates either.

Don't know "Uplift" or "Breed to Come". My favorite far future story is "Forgetfulness". Octopi mother died protecting their young. If there was a means of "passed knowledge" they'd have a shot. 'Coons have opposable digits. Bears have flat feet and claws. Not a contest there.

Quote from: Gawdzilla Sama on September 15, 2018, 12:44:28 PM
Don't know "Uplift" or "Breed to Come". My favorite far future story is "Forgetfulness". Octopi mother died protecting their young. If there was a means of "passed knowledge" they'd have a shot. 'Coons have opposable digits. Bears have flat feet and claws. Not a contest there.

I looked up "Uplift Wars" by David Brin and guess I had the wrong book in mind.  Sorry.  I'm sure it involved the same idea though.  'Bred To Come' was about cats and dogs left behind after intelligence enhancements just before humans left Earth and then returned centuries later.

Bears can be bidedel, are omnivores, and can eliminate competitors.  I admire coons for the agility; good potential.  IIRC, it was Sagan who said that aliens visiting Earth 6M years ago might not have guessed that a primate would hit intelligence.

Quote from: Cavebear on September 15, 2018, 12:56:20 PM
I looked up "Uplift Wars" by David Brin and guess I had the wrong book in mind.  Sorry.  I'm sure it involved the same idea though.  'Bred To Come' was about cats and dogs left behind after intelligence enhancements just before humans left Earth and then returned centuries later.

Bears can be bidedel, are omnivores, and can eliminate competitors.  I admire coons for the agility; good potential.  IIRC, it was Sagan who said that aliens visiting Earth 6M years ago might not have guessed that a primate would hit intelligence.

And he's still not far off.

Quote from: Gawdzilla Sama on September 15, 2018, 12:57:59 PM
And he's still not far off.

Well, we can debate that because...  well, we can debate that.  Heard any good raccoon debates lately?  And not the Guardian...

Quote from: Cavebear on September 15, 2018, 01:01:21 PM
Well, we can debate that because...  well, we can debate that.  Heard any good raccoon debates lately?  And not the Guardian...

There's a short story where the last man and last woman on Earth are hiding in the bushes at some park, looking at statues of humans, but with mantis heads instead of human ones.

Quote from: Gawdzilla Sama on September 15, 2018, 01:11:40 PM
There's a short story where the last man and last woman on Earth are hiding in the bushes at some park, looking at statues of humans, but with mantis heads instead of human ones.

Was that a Twilight Zone episode? 

But no matter.  Many sci-fi stories shock the thoughts and that is the purpose.  They are "what if"...  And most people don't like to think about those things.

Read 'Ender's Game'?  When did you know the game was real?  More importantly, did all your arm hairs rise when you did?  I met Card once.

Quote from: Cavebear on September 15, 2018, 12:33:50 PM
And don't discount octopi if they ever learn there is something above sea level.

Charles Sheffield's Heritage Universe (https://en.wikipedia.org/wiki/Heritage_Universe) series has something called Zardalu (https://en.wikipedia.org/wiki/Heritage_Universe#Zardalu), which are a land/sea-dwelling squid-like species, and very nasty. They can, though, be tamed a bit, as some of the characters discovered.

Quote from: Unbeliever on September 15, 2018, 01:19:46 PM
Charles Sheffield's Heritage Universe (https://en.wikipedia.org/wiki/Heritage_Universe) series has something called Zardalu (https://en.wikipedia.org/wiki/Heritage_Universe#Zardalu), which are a land/sea-dwelling squid-like species, and very nasty. They can, though, be tamed a bit, as some of the characters discovered.

Anything more lethal than us is impressive.  Which is why 'Alien' was great.

I think that's why humans make up all sorts of horrible monsters, we can't stand being the most evil thing in existence.

But we seem to be.

Quote from: Cavebear on September 15, 2018, 01:19:21 PM
Was that a Twilight Zone episode? 

I read it as a short story. Car/horse crisis there.

Quote

But no matter.  Many sci-fi stories shock the thoughts and that is the purpose.  They are "what if"...  And most people don't like to think about those things.

Scifi is best at explaining science and what-iffing social scenarios.

Quote

Read 'Ender's Game'?  When did you know the game was real?  More importantly, did all your arm hairs rise when you did?  I met Card once.

Being a military man I assumed that it was real from the start. Which was absurd but that's scifi for you.

Quote from: Unbeliever on September 15, 2018, 01:25:48 PM
I think that's why humans make up all sorts of horrible monsters, we can't stand being the most evil thing in existence.

But we seem to be.

Beowulf was created to scare kids after supper.

Quote from: SGOS on July 25, 2018, 03:41:48 PM
Is this mentioned in the Bible?  How can we know it's true then?

Sorry, I'm still reeling from the recent Mouse invasion.

Wait, you mean that idiot Mousetrap?  You've got to be kidding..  Do I really need to pay attention to this person?  I've been mostly ignoring him so far.  Just another cultish theist creationist.

Quote from: Gawdzilla Sama on September 15, 2018, 01:27:15 PM
Beowulf was created to scare kids after supper.

Cavebear definitely descended from Grendel?

In just a few years you'll be able to vacation in space! If, that is, you can pony up 9.5 million dollars:


https://www.curbed.com/2018/7/3/17531322/space-hotel-orion-span-aurora-station


It looks like it would be a lot of fun, but the price tag is a bit out of my range.

I've heard that every few years since the Mercury Project.

Yeah, I'm not holding my breath, either.

Quote from: Cavebear on September 15, 2018, 01:30:07 PM
Wait, you mean that idiot Mousetrap?

Yes.

I thought it was "Mousetripe"?

Quote from: Gawdzilla Sama on September 15, 2018, 11:30:25 AM
"where is everyone"? Maybe billions of light years away, and millions of years in the past or future. Fermi booted that one, he assumed that aliens would be interested in us, could get to us, and would get to us. All assumptions without basis in fact.

Well, and the other problem is that "where is everybody" is a reasonable question only in a steady-state universe (which was still a viable theory of the universe at the time he said it in 1950 (https://en.wikipedia.org/wiki/Fermi_paradox)).  If the universe has a beginning, there are reasons you can't have an arbitrarily old civilization that could have explored the galaxy by now â€" the need for metal-rich¹ interstellar clouds, at a minimum, and that takes two or three generation of heavy stars going supernova to collect.  So it may well take nearly ten billion years for there to be enough stuff that's not primordial hydrogen and helium to make a world that has all the ingredients to make life possible.

I think it's entirely plausible that while we're not necessarily the first, we're among the first wave of intelligences to arise in the universe.  And looking around at this world, I can well believe we're a rough draft.

---

1: 'Metal' in astronomers' usage: any element that isn't hydrogen or helium

That assumes a model for intelligent life that is the same as ours.

Quote from: trdsf on September 16, 2018, 09:32:47 AM

1: 'Metal' in astronomers' usage: any element that isn't hydrogen or helium

That's strange.

Quote from: SGOS on September 16, 2018, 09:38:22 AM
That's strange.

Almost all elements are in stars.  So basically it is plasma, no matter what element you are talking about.  The amount of room temperature elements is tiny, however normative and essential to life.  So what are even regular metals, when they are a conductive gas?  They don't have the usual metallic properties.  Just as hydrogen under high pressure, in the core of Jupiter, exists as a metal (hence the strong magnetic field of Jupiter).

So in nucleo genesis, there are three generations ... Big Bang (Hydrogen + Helium + trace Lithium).  Regular stellar fusion (Lithium up to Iron).  Supernova formation (all elements with heavier nuclei than iron).  The lower elements are exothermic, but above iron they are endothermic.

Quote from: SGOS on September 16, 2018, 09:38:22 AM
That's strange.

Strange, perhaps, but true (https://en.wikipedia.org/wiki/Metallicity).  Since the vast majority of the universe -- by mass or by particle count -- is either hydrogen or helium, astronomers use 'metal' to mean anything heavier.  70.57% of the universe's mass and 91.00% of the universe's atoms is hydrogen alone; helium makes up 27.52% of the mass and 8.87% of the atoms.  Everything else: the carbon we're made of, the oxygen we breathe, the nitrogen that makes up the bulk of our atmosphere and the silicon that makes up over a quarter of our planet, that's in that leftover 1.91% of mass and 0.13% of atoms.  So for astronomers, there is a great convenience in just bundling those leftover crumbs up under the generic term 'metals'.

So when they talk about a metal-rich Population I star (https://en.wikipedia.org/wiki/Stellar_population#Population_I_stars) like our Sun, they don't just mean aluminium and iron, they also mean neon and carbon.

Quote from: trdsf on September 16, 2018, 09:32:47 AM
And looking around at this world, I can well believe we're a rough draft.

It would be nice to be able to think of humanity as a diamond in the rough, that will one day outshine the galaxy.

But that's a bit too optimistic for my taste.

Came across this interesting tid-bit this morning:

Half the universe’s missing matter has just been finally found (https://www.newscientist.com/article/2149742-half-the-universes-missing-matter-has-just-been-finally-found/)

It's not an unexpected finding, but it was apparently pretty hard to pin down. It had to be somewhere, and intergalactic space was about the only place left to look.

Still no God, though...

Quote from: Unbeliever on September 16, 2018, 05:27:30 PM
It would be nice to be able to think of humanity as a diamond in the rough, that will one day outshine the galaxy.

But that's a bit too optimistic for my taste.

Only if you are named Aladdin, and you have a genie working for you.

A partial explanation of missing mass.  Doesn't help with "dark energy" pushing galaxies apart, or "dark matter" controlling part of the rotation of galaxies.  But definitely leading edge science.  This was previously discounted, though I think an upper limit to the amount could have been estimated earlier.

(https://www.smbc-comics.com/comics/1525703927-20180507%20(1).png)

Quote from: Unbeliever on September 15, 2018, 07:17:22 PM
Yeah, I'm not holding my breath, either.

The problem is that you can't really know what is on (or in) Mars until people go there and look. 

I'd volunteer to go in a heartbeat, even if it meant I'd never make it back to Earth.

Quote from: Unbeliever on September 19, 2018, 01:58:36 PM
I'd volunteer to go in a heartbeat, even if it meant I'd never make it back to Earth.

Commercial companies will get experts there.  There might be gold in them thar hills.  Or even, better, water.

Quote from: Unbeliever on September 19, 2018, 01:58:36 PM
I'd volunteer to go in a heartbeat, even if it meant I'd never make it back to Earth.

I'm with you.  I'd go to Mars even if it's a one-way trip.  Every corner you turn, every rock you pick up, every single moment there would be a new discovery for humanity.  The only thing I'd hate to leave behind is my cat.

"Everywhere I go, I'm the first. Shit under this rock, first to do that." Mark Watney's Unpublished Journal.

Quote from: trdsf on September 19, 2018, 03:41:20 PM
I'm with you.  I'd go to Mars even if it's a one-way trip.  Every corner you turn, every rock you pick up, every single moment there would be a new discovery for humanity.  The only thing I'd hate to leave behind is my cat.

"Here Jonesie"...

;)

Quote from: Cavebear on September 19, 2018, 05:10:08 PM
"Here Jonesie"...

;)

Just pictured trdsf in a tank top and bikini panties.

I'll be at a monastery if you need me.

Quote from: Gawdzilla Sama on September 19, 2018, 05:41:54 PM
Just pictured trdsf in a tank top and bikini panties.

I'll be at a monastery if you need me.

Just don't tell Munch, LOL!  He might stop breathing...

Quote from: Gawdzilla Sama on September 19, 2018, 05:41:54 PM
Just pictured trdsf in a tank top and bikini panties.

Damn, now I'm picturing Young Frankenstein in a tank top and bikini panties...ouch!

Quote from: Unbeliever on September 19, 2018, 06:03:28 PM
Damn, now I'm picturing Young Frankenstein in a tank top and bikini panties...ouch!

Well, just don't think of The Blob in a ...  Oh damn, NOW I've done it...

I think this thread got derailed.

Bikini panties do that for me.

Quote from: Cavebear on September 19, 2018, 06:07:37 PM
Well, just don't think of The Blob in a ...  Oh damn, NOW I've done it...

Alas, I'm rationalist enough that I have to admit you're closest to the reality of the matter here...

Quote from: trdsf on September 19, 2018, 10:15:03 PM
Alas, I'm rationalist enough that I have to admit you're closest to the reality of the matter here...

Well, spandex and the Blob don't really go together in MY mind...  But ask Munch.

Quote from: Gawdzilla Sama on September 15, 2018, 12:21:32 PM
Yerp. They'd squish us and set the dolphins up with robotic arms. (And you read The Dolphins of Pern?)

But realistically, if they checked on Earth every billion years and found cyanobacteria the dominant life form, they'd be back in about 600,000,000 years for another look. Distant descendants of racoons would meet them just outside Neptune's orbit, to explain that they didn't do that.

I'm still a newbie here and trying to catch up to some of the forums, but this one killed me.

When interviewed on how they survived and humans faltered, the raccoons said, "Shit, we're raccoons.  We'll eat anything."

Raccoons are very clever, they can use their little hands.  Very Trump.

Quote from: ferdmonger on September 25, 2018, 11:58:30 PM
I'm still a newbie here and trying to catch up to some of the forums, but this one killed me.

When interviewed on how they survived and humans faltered, the raccoons said, "Shit, we're raccoons.  We'll eat anything."

Well, among a few sci-books proposing non-human critters, I always thought both raccoons and bears were overlooked.  Racoons for handiness and bears for bipedal possibilities.  It might be an instructive challenge.  "Breed To Come' suggested cats for curiosity but I think they are too specialized as carnivores.

Quote from: Cavebear on October 01, 2018, 04:25:22 PM
Well, among a few sci-books proposing non-human critters, I always thought both raccoons and bears were overlooked.  Racoons for handiness and bears for bipedal possibilities.  It might be an instructive challenge.  "Breed To Come' suggested cats for curiosity but I think they are too specialized as carnivores.

Cats like to keep their spare food supply close ... that is why they check you out.

We MUST have manned missions to Mars so we can have Trump brand Martian Mineral Waterâ,,¢Â® available in your grocers freezer before the next presidential election!  And don't forget that big beautiful wall around all known water on Mars to keep undesirables from stealing what's rightfully his..

Mars has an active volcano ...

https://dailycaller.com/2018/10/26/mars-plume-like-cloud/

It doesn't seem to be an active volcano, but rather left-overs from a recent dust storm. It is near a volcano, however. But I don't think it's active.

Tectonic activity? Don't think so.

No, Mars is geologically inactive, so far as we know.  They're going to be landing an ultrasensitive seismometer there next month on the Mars InSight mission (https://mars.nasa.gov/insight/).  There's no known tectonic activity or active volcanoes, but there may be some geological settling going on; depends on how long ago the core cooled.  There's only a remnant of the original magnetosphere, west of the Tharsis volcano complex and centered over the southern hemisphere, so there's probably only a few hotspots left in the Martian core, no actual liquid flow.  Without a molten core and mobile mantle, there can be no tectonic plate movement.

Anyway, even if most of what InSight is going to sense are meteor impacts, those will help provide infomation on Mars' core.

Quote from: trdsf on October 29, 2018, 12:28:04 AM
No, Mars is geologically inactive, so far as we know.  They're going to be landing an ultrasensitive seismometer there next month on the Mars InSight mission (https://mars.nasa.gov/insight/).  There's no known tectonic activity or active volcanoes, but there may be some geological settling going on; depends on how long ago the core cooled.  There's only a remnant of the original magnetosphere, west of the Tharsis volcano complex and centered over the southern hemisphere, so there's probably only a few hotspots left in the Martian core, no actual liquid flow.  Without a molten core and mobile mantle, there can be no tectonic plate movement.

Anyway, even if most of what InSight is going to sense are meteor impacts, those will help provide infomation on Mars' core.

Then how to explain that ... liquid water?

It's never aliens...unless it's aliens:


Could 'Oumuamua be an extraterrestrial solar sail? (https://phys.org/news/2018-11-oumuamua-extraterrestrial-solar.html)

This is a bit off topic, but I didn't see a better place for it, and didn't think it needed a new thread all its own.

I personally doubt that Oumuamua was an alien solar sail, but I could certainly be wrong.

What do y'all think?

Not enough cross-section to be a sail unless the payload was tiny. Remember Mote in God's Eye? MacArthur's pilot thought they were about to attack a moon. The ship itself, cut free from the sail, fit into Mac's hangar bay neatly. (Impact damage excepted, of course.)

Well, the simple solution is to catch up with it and examine it closely.  We have about ten to twenty thousand years before it leaves the Sun's sphere of gravitational influence...

Quote from: trdsf on November 06, 2018, 11:04:16 PM
Well, the simple solution is to catch up with it and examine it closely.  We have about ten to twenty thousand years before it leaves the Sun's sphere of gravitational influence...

The raccoons can go out and take a look.

Quote from: trdsf on November 06, 2018, 11:04:16 PM
Well, the simple solution is to catch up with it and examine it closely.  We have about ten to twenty thousand years before it leaves the Sun's sphere of gravitational influence...

How fast would a probe have to move to catch up to it?

Quote from: Unbeliever on November 07, 2018, 01:35:39 PM
How fast would a probe have to move to catch up to it?

Greater than 42km/sec from Earth distance to Sun ... is escape velocity from the Solar System.  So assuming the probe is going at least that fast, then the catch up vehicle has to be going even faster.

Quote from: Unbeliever on November 07, 2018, 01:35:39 PM
How fast would a probe have to move to catch up to it?

If it wasn't bound to an elliptical solar orbit, the Parker Solar Probe could do it easily.  It's the fastest space probe ever now, having reached a velocity of 213,500mph (about 60 miles a second) or 95.4 kilometers per second.  'Oumuamua is moving at a relatively stately 26.3 km/s -- which is quite a bit faster than our fastest outward-bound probes, the Voyagers, Pioneers and New Horizons.  Voyager 1, the fastest of them, is moving "only" 17 km/s.

It turns out that it's possible that we could actually get a probe to it in as little as five to ten years (https://en.wikipedia.org/wiki/%C3%8A%C2%BBOumuamua#Hypothetical_space_missions).  It's not as unreachable as we thought.  I think we should drop a probe on it to travel the galaxy with it and at least leave some further notice that we were here.

Quote from: trdsf on November 08, 2018, 07:21:09 PM
If it wasn't bound to an elliptical solar orbit, the Parker Solar Probe could do it easily.  It's the fastest space probe ever now, having reached a velocity of 213,500mph (about 60 miles a second) or 95.4 kilometers per second.  'Oumuamua is moving at a relatively stately 26.3 km/s -- which is quite a bit faster than our fastest outward-bound probes, the Voyagers, Pioneers and New Horizons.  Voyager 1, the fastest of them, is moving "only" 17 km/s.

It turns out that it's possible that we could actually get a probe to it in as little as five to ten years (https://en.wikipedia.org/wiki/%C3%8A%C2%BBOumuamua#Hypothetical_space_missions).  It's not as unreachable as we thought.  I think we should drop a probe on it to travel the galaxy with it and at least leave some further notice that we were here.

Humanity should extinct with embarrassment.

Quote from: Baruch on October 03, 2018, 10:56:33 PM
Cats like to keep their spare food supply close ... that is why they check you out.

I'm hoping to die while my cats are outside in Springtime.  Seriously, I don't want my family to discover they ate me.  I wouldn't care, of course, being dead, but it might have a reduction in finding them new homes...

Quote from: Cavebear on November 09, 2018, 10:58:24 AM
I'm hoping to die while my cats are outside in Springtime.  Seriously, I don't want my family to discover they ate me.  I wouldn't care, of course, being dead, but it might have a reduction in finding them new homes...

Idunno Cave.
Family members would be bringing a little piece of you into their homes as a memento.
Literally as well as figuratively. But still.

Cave, I have a sign over my mailbox.

"If mail is not picked up for three days please ask police to make a health and safety check."

It's "magnetic", so I can take it in if I'm going to be away from home for any time. Pet sitter takes in the mail if I'm on vacation.

I always have food and water out for ~2 weeks.

Quote from: Mr.Obvious on November 12, 2018, 06:07:41 AM
Idunno Cave.
Family members would be bringing a little piece of you into their homes as a memento.
Literally as well as figuratively. But still.

Corpse parts of saints, were considered in early Christianity, to have magical powers.  Matrons would bring them to worship on Sunday.  This bothered the clergy, this is when they insisted putting them in reliquaries under the altar.

Quote from: Mr.Obvious on November 12, 2018, 06:07:41 AM
Idunno Cave.
Family members would be bringing a little piece of you into their homes as a memento.
Literally as well as figuratively. But still.

Well, yeah, but doesn't that make the first litterbox poop a bit weird?  I mean, should it be saved with my ashes or something?  ;)

Quote from: Gawdzilla Sama on November 12, 2018, 06:12:43 AM
Cave, I have a sign over my mailbox.

"If mail is not picked up for three days please ask police to make a health and safety check."

It's "magnetic", so I can take it in if I'm going to be away from home for any time. Pet sitter takes in the mail if I'm on vacation.

I always have food and water out for ~2 weeks.

Outstanding idea!  Though my cats will eat dry food until they throw up.  No self-control whatsoever (my fault, they aren't used to it).  The mailbox message is fantastic...  The mail deliverer would see.  The newspaper deliverer would see.

I'll get right on THAT idea.

Use a metered feeder, they might be skinnier when help comes, but they won't expire.

And I hope you never need any of this. :hugs:

My cats will have to fight with my roaches, for my leavings.

Can you move that along, please. There's a good lad.

Quote from: Gawdzilla Sama on November 16, 2018, 06:45:29 AM
Can you move that along, please. There's a good lad.

Join all the lovely demons in Washington DC why don't you?  Give them your wisdom?

TOUCHDOWN (http://mars.nasa.gov/insight)!!!

HOORAY! We can never have too many landers on Mars!

I just heard (from Veritasium) that the latest Mars lander will be able to detect ground motion smaller than the diameter of a hydrogen atom! WTF?

Finally, we may be able to find out what the interior of Mars is like.

Quote from: Unbeliever on November 26, 2018, 07:15:35 PM
I just heard (from Veritasium) that the latest Mars lander will be able to detect ground motion smaller than the diameter of a hydrogen atom! WTF?

Finally, we may be able to find out what the interior of Mars is like.

Huh. That is rather small.

Quote from: Unbeliever on November 26, 2018, 07:15:35 PM
I just heard (from Veritasium) that the latest Mars lander will be able to detect ground motion smaller than the diameter of a hydrogen atom! WTF?

Finally, we may be able to find out what the interior of Mars is like.

They turned the sensors on during the flight, since they expected no vibrations in space.  They wanted to see what absolute quiet looked like.  Turns out there was a small, steady fluctuation -- the seismometers were picking up their own atomic thermal vibrations.

I mean, dayamn.

Anyway, the seismometers are sensitive enough that they will be able to pick up the surface waves from marsquakes, as well as the P and S waves, and they will be able to use those to pinpoint the epicenter of the quake -- yes, they're going to triangulate from a single point.  That blew my mind as much as the sensitivity of the device.

Quote from: Shiranu on November 26, 2018, 07:24:25 PM
Huh. That is rather small.

The "Tremors" like monsters there will shake things up ;-)