[Science] NASA confirm: Water ice found on Mars

[poprock]

Two amazing things.

First, there’s ice on Mars. Which means water. Wow.

Second, NASA announced this discovery via Twitter. And said “W00t”.

Proper NASA news release here

Twitter announcement here

Here’s the Twitter feed from the Mars Phoenix robot

Basically, the lander’s camera managed to catch some white patches on the ground disappearing—meaning that it must be ice which melted. I think.

[LesMTS]

Did they not recently come to the conclusion that if Mars had liquid water it would be much too salty for life?

[poprock]

Dunno. They did say that they thought these white patches on the ground were salt, until they started to melt.

[Hammer]

I might be being really dense here, but does Mars not have an ice cap? So surely they knew fine there was ice already?

[LesMTS]

Originally Posted by poprock

Dunno. They did say that they thought these white patches on the ground were salt, until they started to melt.

Ahhhh, I was a bit off the mark, not salty enough to exclude the possibility of life (there are organisms on Earth that can handle the same kinds of extreme salinity) but definitely incredibly harsh.

Originally Posted by Hammer

I might be being really dense here, but does Mars not have an ice cap? So surely they knew fine there was ice already?

Aye, but they get to study it now.

[djtoast]

Originally Posted by LesMTS

Did they not recently come to the conclusion that if Mars had liquid water it would be much too salty for life?

I've always been a little curious about how valid it is to say that for life to exist there must be certain conditions quite like out own.

Why couldn't there be creatures that work in entirely different way to what we see here? Obviously all life on this planet works in broadly similar ways because all life here has broadly similar resources (air, water, other living stuff...) but it seems arrogant to assume our way is the only possible way.

[endless psych]

Originally Posted by djtoast

I've always been a little curious about how valid it is to say that for life to exist there must be certain conditions quite like out own.

Its the old computer model thing that if you move an Earth like planet to an orbit more akin to Mars it becomes like Mars innit. (I.E. using only the information we have avaliable etc) Thing is on Earth there is a huuge range of things we classify as live and a huge range of conditions in which life has been found to develop/flourish. Given we probably don't even understand all these yet its perhaps understandable we use reductionist criteria when trying to look for other life.

If only to find something we might be able to talk to or pet.

On an almost completely unrelated tangent I wish I knew more about how the planet detector things work because I keep wondering if all this detecting of super sized Earths is really detecting whole solar systems and the maths has just gone a bit skew whiff.

[LesMTS]

Originally Posted by djtoast

I've always been a little curious about how valid it is to say that for life to exist there must be certain conditions quite like out own.

Why couldn't there be creatures that work in entirely different way to what we see here? Obviously all life on this planet works in broadly similar ways because all life here has broadly similar resources (air, water, other living stuff...) but it seems arrogant to assume our way is the only possible way.

There are certain criteria that must be met before something can be called "life" and most (all?) of these depend on a certain level of chemical complexity (even if they work in completely different ways), we understand enough to know that there are conditions where this level of complexity cannot arise due to limitations put in place by the chemical properties of the elements.
You can always say "well, we don't know everything", but this is a similar kind of reasoning that is used to validate ghosts or psychic powers or homeopathy.

[endless psych]

Or theres not much point wondering such things because then we could just call anything life?

[LesMTS]

Originally Posted by endless psych

On an almost completely unrelated tangent I wish I knew more about how the planet detector things work because I keep wondering if all this detecting of super sized Earths is really detecting whole solar systems and the maths has just gone a bit skew whiff.

They work by detecting the influence of these objects on other, more visible objects I think. For example, they'll look at the unusual movement of some object and say "well that would make perfect sense if there was a large object kinda the same distance from star X as Earth is from the sun." I believe.

[endless psych]

Originally Posted by LesMTS

They work by detecting the influence of these objects on other, more visible objects I think. For example, they'll look at the unusual movement of some object and say "well that would make perfect sense if there was a large object kinda the same distance from star X as Earth is from the sun." I believe.

Have they tested the equations with our own sun? Or is there not much point given they can't detect less then a certain mass?

[LesMTS]

Originally Posted by endless psych

Or theres not much point wondering such things because then we could just call anything life?

Some still argue that viruses are life. And some utter extremists would argue that self replicating molecules are a kind of life. But most agree on a broad range of criteria including things like ability to respond to stimuli, ability to replicate independently (unlike viruses) etc etc. I can't remember them all, I think there are seven major criteria. I'll look them up.

Originally Posted by endless psych

Have they tested the equations with our own sun? Or is there not much point given they can't detect less then a certain mass?

What do you mean? Also, my physics is shoddy.

[endless psych]

Originally Posted by LesMTS

What do you mean? Also, my physics is shoddy.

Well if they applied the equations on observed gravitational wobbles from our Sun (which presumably someone has done to validate the theory - unless there is some obscure reason not to related to the closeness of the Sun or something) then would they produce a model of our solar system. Also would this model just be minus a few smaller planets or would the larger planets become slightly larger as the method incorporated the smaller planets masses into them?

Kinda like if you had two stones, one huuuge and one small, chucked into some water the ripples would be affected by both but mathematically the easiest thing would be to deduce a slighly more huuuge stone had been chucked in? (If the mechanics of that holds up)

[LesMTS]

Originally Posted by endless psych

Well if they applied the equations on observed gravitational wobbles from our Sun (which presumably someone has done to validate the theory - unless there is some obscure reason not to related to the closeness of the Sun or something) then would they produce a model of our solar system. Also would this model just be minus a few smaller planets or would the larger planets become slightly larger as the method incorporated the smaller planets masses into them?

Kinda like if you had two stones, one huuuge and one small, chucked into some water the ripples would be affected by both but mathematically the easiest thing would be to deduce a slighly more huuuge stone had been chucked in? (If the mechanics of that holds up)

I understand now, but I really don't know how they validate it.
My friend did a PhD in solar theory. He might know. I'll ask him how it all works next time I see him.

[The Continental]

Originally Posted by poprock

First, there’s ice on Mars. Which means water.

Which means it's Martian Mojito O'Clock.