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Why Mars Is Not the Best Place To Look For Life
EccentricAnomaly writes "A story over at Science News quotes Alan Stern (former head of NASA Science missions) as saying: 'The three strongest candidates [for extraterrestrial life] are all in the outer solar system.' He's referring to Europa, Titan, and Enceladus. So why is NASA spending $2.5B on the next Mars Rover and planning to spend over $6B more on a Mars sample return when it can't find the money for much cheaper missions to Europa or Enceladus?"
This seems unfair at multiple levels. First, we understand the basic Martian environment a lot better than other environments so sending things there are easier. Second we know from the Viking probes that Mars has weird chemistry going on in its surface. We still don't know what exactly happened there. The basic results of the Viking experiments seemed to be consistent with life but no complex carbon compounds were found. We now know that this may have been due to the presence of perchlorates in the surface material which could have destroyed the organic compounds when the samples were heated. Mars is still one of the most promising locations for life.
That said, there are less good reasons why Mars is a frequent target. Sending things to Mars takes a lot less time than sending things to the outer systems. That means if one is a scientist one would rather work on a project that sends something to Mars than something that goes far away. Second, Mars has a place in the popular mind that these various moons do not.
The real question that should be being asked is not why there's so much funding for Mars compared to other locations but why there's so little funding in general. The repeatedly canceled Europa missions would be in the cost range of a few hundred million dollars. This is a tiny amount when one compares it for example to how much money the US spends on Afghanistan monthly. The US has messed up priorities. That's why even as we speak, the Russians are doing a sample return mission to Phobos which will launch in a few weeks http://en.wikipedia.org/wiki/Fobos-Grunt. If the Russians were still dirty commies the US would be in an absolute panic and we'd have congressional hearings asking why the US isn't doing something similar. I hope that as China becomes more of a boogeyman the US will start taking space seriously again, if not for the good of humanity, at least for old-fashioned xenophobia. And I suppose that in the long-run I really would prefer that functioning democracies explore and colonize space than other countries, but that's so far in the future at the current rate of exploration that it doesn't seem to be immediately relevant. Right now, we need to just get some people substantially interested in exploring beyond our little rock.
No, it sits in vaults doing nothing while most of the human race starve. My favourite rich guy story is this one where he was so rich he didn't even notice for a couple of years that someone had stolen loads of money from him. Trickle-down is bullshit.
Which is something for which we don't know much about the long-term health effects of. It might be no better than microgravity.
It's hardly the only massive canyon in the solar system, however. The Saturnian system has some impressive ones (like Ithaca Chasma), made all the more impressive in comparison to the size of the body they're on.
Sounds more like Earth than Mars. :P
Between the greater distance and the electrostatic dust that clings to everything, not nearly as well as on Earth. At least with most other bodies in the solar system, you don't get dust clinging to all of your sensitive electronic equipment.
Water becomes more abundant the further out in the solar system you go.
Not readily. CO2 is such a sparse gas on Mars, and the process to convert it to methane is not trivial. On the other hand, say, on Titan, you've got an atmosphere already full of methane. LOX can be burned like jet fuel on Titan. Most of the solid bodies from Saturn on out, and to a lesser extent in the Jovian system, are covered with tholins -- all sorts of various complex organic carbon compounds, nearly all of which could be used for hybrid rocket fuel much easier than trying to produce methane on Mars. On any body with ice, you can produce LOX and LH anyway; fuel is not really the issue. At least there's lots of LH engines to choose from; there aren't many methane engines out there.
Only with *extreme* difficulty; Mars's atmosphere is so thin it's almost negligible. It's far much easier on Titan or Venus's habitable cloud layer (there's a layer of atmosphere in Venus with a temperature similar to a hot Phoenix day at a pressure similar to that of La Paz -- and even a normal Earth atmosphere is a lifting gas on Venus, so floating colonies are not out of the question. You could even walk outside in shirtsleeves, although you'd need a mask to provide oxygen and goggles to protect your eyes from long-term exposure to the trace carbon monoxide; the small amounts of sulfur dioxide may also be an irritant).
You can do that anywhere. But it's not nearly as simple of a process to do sustainably as you're imagining.
It's far too simplistic to declare Europa and Enceladus's surfaces as being *all* ice. And it's not like anyone would live on the *surface* of such a world when you could so readily go underground for radiation shielding. And those are but two bodies amount the vast many possibilities in the solar system. And who says that colonization needs to occur *on* a solid body anyway? It could just as well be done in space, with only mining done to solid objects (which might not even be planetoids/moons), so you don't have to have your people locked deep in a gravity well. And if you're going to choose a gravity well, why choose a deep one when it might not actually offer any health benefits?
Anyway, this is a whole red herring, because this was a discussion about exploration and the search for life. Colonization is so far off of a topic it shouldn't even warrant consideration at this point in time.
"It felt almost as good as stealing cars from grandma." -- Margaret Thatcher, probably.
1) The simplest boring device is merely a boring (pardon the pun) RTG or nuclear reactor, melting its way in slowly over the course of years.
2) You don't have to bore to get to the subsurface; ice volcanism brings it up for you. Heck, an Enceladus probe doesn't even have to *land*, thanks to its geysers. BTW, Enceladus isn't the only Saturnian moon with ice geysers -- just the one with the biggest ice geysers.
3) Please propose an alternative Europa hypothesis to a subsurface ocean.
I noticed you didn't discus Titan. Titan should be an incredibly easy body to explore due to its combination of a thick atmosphere and low gravity -- hot air or helium balloons, powered blimps, helicopters, fixed-wing aircraft, variable-pitch wing aircraft, autogyros, etc. While the Delta-V requirements to get there are certainly high, they're tempered somewhat by the very easy aerocapture. It's an ongoing laboratory of organic chemistry due to the photocatalytic chemical reactions in its upper atmosphere (likely creating the tholins found all over the Saturnian system -- which we really know very little about, apart from that they're complex organic chemical compounds). It has seasonal and permanent organic lakes, ice volcanism dredging material up from the warmer subsurface, tectonic activity, and on and on. Honestly, of all the bodies in the solar system, I think Titan calls out the most for exploration.
"It felt almost as good as stealing cars from grandma." -- Margaret Thatcher, probably.
Not nearly as easy as terraforming the Sahara desert, though, so why don't we start there ?