81–90 of 122 posts
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There's enough atmosphere for Nasa to seriously consider deploying airplanes: http://en.wikipedia.org/wiki/Mars_aircraft
We've had the discussion: https://news.ycombinator.com/item?id=4261806 A cessna would need wings as large as a 747 and be traveling about mach 1 to take off, iirc.
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Why not literally a plant? Like leafy, relies on water, comes from a small seed, reproduces via pollen/wind, based on a cell structure. We have plants in the desert here on Earth that blossom once every X years or decades. Is there a reason such a "plant" could not have survived the harsh later years of mars post surface water? Bonus idea: if these are plants relying on ground water, their location would give away th…
Because plants, of the leafy green variety, have a complex evolutionary history with lots of side trips (like lichen and mold and algae). Further earth based plants are based on the same basic DNA structure as earth based animals. So while it is not "impossible" that an equivalent to plants evolved into exactly one species or micro-eco-system which exists in this one place on Mars, the chance that this occurred and d…
Earlier quoted context omitted.
There's enough atmosphere for Nasa to seriously consider deploying airplanes: http://en.wikipedia.org/wiki/Mars_aircraft
We've had the discussion: https://news.ycombinator.com/item?id=4261806 A cessna would need wings as large as a 747 and be traveling about mach 1 to take off, iirc.
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Is there any chance they could be plants? relying on underground water reserves and appearing every spring to throw around some pollen before slinking back into the cool darkness.
I'm not a xenobiologist so I couldn't quantify the relative chance of them being 'plants'. But this is the kind of stuff we can speculate on. First, we'll need to be a bit loose with our definitions since 'plant' means a very specific kind of thing. So if we define a 'plant' as a chemical process which creates structure in the presence of certain chemicals such that a transformative chemical reaction is enabled where…
Simplest answer would be some seasonal event (either a CO2 snow or annual dust storm) covers the markings.
Earlier quoted context omitted.
Why not literally a plant? Like leafy, relies on water, comes from a small seed, reproduces via pollen/wind, based on a cell structure. We have plants in the desert here on Earth that blossom once every X years or decades. Is there a reason such a "plant" could not have survived the harsh later years of mars post surface water? Bonus idea: if these are plants relying on ground water, their location would give away th…
Because plants, of the leafy green variety, have a complex evolutionary history with lots of side trips (like lichen and mold and algae). Further earth based plants are based on the same basic DNA structure as earth based animals. So while it is not "impossible" that an equivalent to plants evolved into exactly one species or micro-eco-system which exists in this one place on Mars, the chance that this occurred and d…
This stuff blows me away. I think, holy crap this planet has all sorts of real exo-planet kinds of weirdness. I love the idea of reverse icicles although for the life of me I can't imagine what would hold them up once the CO2 gas has vaporized out. One part of me wants to build another Curiosity style rover and catch the next Earth/Mars orbital cycle and put it down near stuff like this. I can believe folks would fin…
This is awesome! I love that Mars continues to baffle, astound, and fascinate us. Sometimes our 21st century hubris makes us think we are reaching some kind of peak knowledge, but moments like this prove that we yet know so little. In particular, the geology of Mars in an incredibly fascinating topic. If you're looking for a good primer on the subject, I highly recommend Mapping Mars by Oliver Morton. Mapping Mars co…
"Peaks of knowledge" have existed throughout our collective history and the single uniting feature of each is that they are never peaks. Local maxima perhaps, but the upslope of discovery always reasserts itself eventually. Afaik, nothing indicates that the future will differ in this regard.
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I think a latex balloon filled with hydrogen could achieve positive buoyancy. Just bring a little bit of water and you can make your own hydrogen.
I don't know of many latexes that are springy at -100 C.
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Because plants, of the leafy green variety, have a complex evolutionary history with lots of side trips (like lichen and mold and algae). Further earth based plants are based on the same basic DNA structure as earth based animals. So while it is not "impossible" that an equivalent to plants evolved into exactly one species or micro-eco-system which exists in this one place on Mars, the chance that this occurred and d…
They could have come down from an external source.
The panspermia theory [1] is based on the idea that perhaps some forms of life could exist in space as it transits from place to place. One of the things that has always bothered me about that hypothesis is the orbital mechanics. Which is to say if you posit a supernova or other energetic event that accelerated a planet (or fragments of that planet) into space, and somehow the life on those fragments survived both the radiation and the effects of vacuum on volatiles, and then it arrived in our solar system, what would the relative velocities be of that material with respect to our planets? And then when that material impacted a local rocky planet how much energy would be released and how would it survive that?
The 'primordial soup' theories have thus always held more interest for me as being more probable. With papers like this one: http://arstechnica.com/science/2012/10/simple-reaction-makes... lending a bit of narrative around how it might have occurred. But the primordial soup theories also need evolution to get from a happenstance chemical mixture into something like multi-cellular organisms.
So follow your chain of reasoning and see what questions it leads you to:
"down from an external source" ...
From where?
How did the plant get there to come down?
What is needed to survive a fall from space? At what velocities?
Etc.