61–70 of 193 posts
This dose of realism dampens my enthusiasm slightly, but if we can find such clear signs of water via satellite image I think it is a great indication that water is more present at the surface than previously thought.
Earlier quoted context omitted.
And that someone seems to be this lady, with this most BAMF job responsibility ever: “These are ongoing conversations,” said Catharine A. Conley, NASA’s planetary protection officer, who coordinates the efforts to minimize the chances of life inadvertently crossing the solar system.
Isn't this nearly impossible in the long (although here I mean really, really long) term? Think of trying to minimize the chances of some flu strain in one continent from getting to the other. I mean, once humans start going here and there, what do you do, do you keep everything in containment (exhaled gases, excrements, every form of waste)?
Given the latest NASA news about water on Mars, as in, “flowing water on today’s Mars,” I am still trying to figure out how that would work.
If water boils at 79ºF when the atmospheric pressure is lowered to 0.5psi, what would it boil at given Mars’ atmospheric pressure of 0.087psi?
How could Mars, which barely has an atmosphere, support liquid water? Why would not the water basically evaporate quickly if not boil off almost instantly?
> For the water to be liquid, it must be so salty that nothing could live there, he said. “The short answer for habitability is it means nothing,” he said. This dose of realism dampens my enthusiasm slightly , but if we can find such clear signs of water via satellite image I think it is a great indication that water is more present at the surface than previously thought.
>“If it was too salty, they would be flowing year round,” Dr. Stillman said. “We might be in that Goldilocks zone.”
Dumb question probably, but here goes: Given the latest NASA news about water on Mars, as in, “flowing water on today’s Mars,” I am still trying to figure out how that would work. If water boils at 79ºF when the atmospheric pressure is lowered to 0.5psi, what would it boil at given Mars’ atmospheric pressure of 0.087psi? How could Mars, which barely has an atmosphere, support liquid water? Why would not the water bas…
The water on mars is probably "salty" mixture, maybe slush, but we don't really know what it's consisted of unless we have measurements / spectral analysis of the water mixture.
Dumb question probably, but here goes: Given the latest NASA news about water on Mars, as in, “flowing water on today’s Mars,” I am still trying to figure out how that would work. If water boils at 79ºF when the atmospheric pressure is lowered to 0.5psi, what would it boil at given Mars’ atmospheric pressure of 0.087psi? How could Mars, which barely has an atmosphere, support liquid water? Why would not the water bas…
Dumb question probably, but here goes: Given the latest NASA news about water on Mars, as in, “flowing water on today’s Mars,” I am still trying to figure out how that would work. If water boils at 79ºF when the atmospheric pressure is lowered to 0.5psi, what would it boil at given Mars’ atmospheric pressure of 0.087psi? How could Mars, which barely has an atmosphere, support liquid water? Why would not the water bas…
Earlier quoted context omitted.
> I know that without water life would have never begun, but I still don't fully understand why it is necessary. "Life" is a bunch of chemical processes. A necessary prerequisite is therefore a solvent in which those chemical processes can occur, and which can move substances around, whether it's within a cell, an organism, or an environment. Of all the potential solvents, solids can't move stuff around, and in gases…
"Water is the only molecule that fits the bill, and happens to be the second most common molecule in the universe." [citation needed]
As to the first part, there are uncountable examples of water-based life, and zero examples of non-water-based life. That doesn't rule out its existence, but basic chemistry makes it unlikely, and it won't look anything like life as we know it. No other liquid has the properties needed for any kind of life observed.
As to the second: https://www.google.com/search#q=%22second+most+common+molecu...
Dumb question probably, but here goes: Given the latest NASA news about water on Mars, as in, “flowing water on today’s Mars,” I am still trying to figure out how that would work. If water boils at 79ºF when the atmospheric pressure is lowered to 0.5psi, what would it boil at given Mars’ atmospheric pressure of 0.087psi? How could Mars, which barely has an atmosphere, support liquid water? Why would not the water bas…
Those numbers are for pure water. If water is mixed with something, salts (not just sodium salt, but salts of other elements as well), etc, that changes the properties of the resulting mixture. The water on mars is probably "salty" mixture, maybe slush, but we don't really know what it's consisted of unless we have measurements / spectral analysis of the water mixture.
Earlier quoted context omitted.
I am not good at chemistry, but liquid methane–ethane wouldn't fit the profile?
Actually I found comprehensive answer here if anyone is interested: http://www.space.com/13639-alien-life-methane-habitable-zone...
For one why, look up amphoteric and zwitterion. Water has a super convenient pH range where about a ten millionth of pure water self ionizes aka ten to neg seventh or pH of 7, and all kinds of super convenient reactions occur above and below that pH and its really easy to manipulate ionization rates around that level without using too much. You don't need just a liquid but one where you can really screw around with something like amino acids by easily and cheaply changing the ionization rate of the liquid. So there are super convenient chemical reactions that depend on the ionization level of the liquid and its really easy to manipulate water. Conveniently water "just works" without having to add tons of other stuff to it.
Liquid methane isn't polar enough to really be useful when messing with ionic substances (table salt, etc). Whatever you use for a liquid, it needs to be polar so ionic stuff like salts can dissolve. It turns out that interesting chemistry doesn't happen with non-polar substances at normal temps; thats why when you bury stuff for a couple million years the only thing left behind undecayed (more or less) is non-polar hydrocarbons (crude oil). Ammonia is polar but has other issues.
The hydrogen bonds are important. Water should be a gas at room temp. Really, it should, looking at bonds and molecular weight and stuff. Yet the hydrogen bonds that form keep it liquid at room temp. So you get "gas speed" chemical reactions at "high" room temperature, yet its liquid to a ridiculously high temp.
Maybe some custom liquid silicone with some bolted on weirdness could make a useful artificial blood plasma or "stuff" for life to live in. How it would make it without the chemical plant being made first is mysterious.