More molecules: perchlorates on Mars

Paul Raven @ 07-01-2011

It’s just like buses; you wait for ages, and then two life-molecules-in-space stories come along at once. This one’s a little closer to home than the Saturnian subsystem, though; a discovery by the Phoenix rover in 2008 encouraged scientists to re-evaluate some old Viking data:

Phoenix detected a chlorine-containing chemical called perchlorate at its landing site, near the Martian north pole. The researchers suspected that perchlorate may have produced what Viking found, destroying original soil organics and leaving behind the two chlorinated compounds, chloromethane and dichloromethane.

So the scientists performed a lab experiment. They grabbed some dirt from Chile’s Atacama Desert — widely considered to be a Martian analog environment — and spiked it with perchlorate. Then they heated the mixture up in the lab, just as the Viking landers did on Mars.

Just as with Viking, the researchers found chloromethane and dichloromethane.

“The simplest, most reasonable explanation of the Viking results is that there were organics in the soil, and they were consumed by the perchlorate,” McKay said. “I think it’s pretty convincing.”

Don’t get too excited, though:

The results don’t prove that life exists — or ever existed — on Mars. While organics are associated with life here on Earth, that’s not necessarily the case elsewhere in the solar system, McKay said.

[…]

But the prospect of Martian life may be a bit more likely now, since Viking seemingly found life’s building blocks in the planet’s red dirt more than three decades ago.

Said it before, and I’ll say it again – let’s just go there, properly, and find out for real.


Water on Mars? Yup. Life? Naaaaah… or, well, perhaps.

Paul Raven @ 04-08-2008

NASA's Mars Phoenix Lander - artist's impressionOK, so we’re pretty positive about there being water on Mars now, but if you thought all was certainty in the realms of planetary exploration, you’d be wrong wrong wrong. [image courtesy NASA]

It’s all Aviation Week‘s fault, after they ran a story claiming that the White House had just been…

“… alerted by NASA about plans to make an announcement soon on major new Phoenix lander discoveries concerning the “potential for life” on Mars”.

As delightfully ambiguous as any pre-press-release announcement… and unsurprisingly (perhaps even as planned?) home-brew speculationists have been clogging the intertubes with theories about what NASA is (or was, or wasn’t) planning to announce.

So far, so unsurprising. Until you discover that the Phoenix lander itself* has announced that it definitely hasn’t discovered life and that there has been no such White House briefing. What gives?

Personally I suspect nothing more than the results of old-school media briefings and funky new methods (social-media-ZOMG!) getting a bit out of sync, but why spoil a potentially good conspiracy theory, eh? If you really want to burst that irrational bubble, Karl Schroeder has a pretty plausible explanation of what’s probably going on.

The recent discovery that the soil at the Phoenix lander site could support some earthly plants would appear to contradict the findings of the Viking landers from the 1970s. Those craft deployed sophisticated experiments to determine whether life is present on Mars, yet the instruments returned ambiguous results. There was a strong signal indicating life from some of the instruments, yet no evidence of biological material in the soil. The official interpretation that has become orthodoxy as a result, is that the Martian soil is highly oxidizing, ie. that it contains compounds such as hydrogen peroxide that destroy biological materials.

But if Phoenix has found that you could grow earthly plants in the soil at its site, doesn’t this cast serious doubt on that interpretation?

So, not so much “discovering life” as “possibly refuting a speculative negative interpretation of positive results gathered decades ago in support of the possibility of life”… but it doesn’t take a degree in journalism to see which of those two makes the better headline, AMIRITE?

[ * – Well, someone on the team, but you know what I mean. ]


Mars has component minerals for life

Paul Raven @ 27-06-2008

NASA\'s Mars Phoenix Lander - artist\'s impressionLatest word from the Phoenix Lander suggests that the soil of Mars contains the right sort of minerals to support certain forms of plant life – apparently asparagus would thrive there. I now have visions of an Edgar Rice Burroughs chase scene set in a forest of towering asparagus … [image courtesy NASA]

Of course, if you listen to a certain irritatingly vocal minority of asshats, we shouldn’t be wasting our time and taxes searching for the origin of life on other planets because “[l]ife originated on Earth when God spoke it into existence“. O RLY?

I think I’ve reached a tipping point with creationists; I used to find them infuriating, but recently I’ve found I just pity them. If the glory of God serves only to blind you to the glory of the universe, life must be depressingly short on moments of genuine marvel.