NASA held a press conference today and said something that's been rattling around my head all afternoon: the water that used to sit in a Martian riverbed billions of years ago wasn't just present, it was mild enough that you could have scooped it up and had a glass of it.
That's not me paraphrasing loosely for effect. John Grotzinger, the project scientist for the Curiosity mission, said almost exactly that, if you'd been standing there with this water, you could have drunk it. Not acidic, not full of toxic salts, nothing that would kill you. Just water. On Mars. Billions of years ago.
Here's the actual news, stripped of the poetry. Back in February, Curiosity drilled into a flat gray rock in a spot called Yellowknife Bay, inside Gale Crater, and pulled out a sample of gray powder from about 2.5 inches down. They named the rock John Klein, after a mission engineer who died in 2011 before he got to see any of this. The powder went into the rover's onboard chemistry lab, and today JPL announced what they found: sulfur, nitrogen, hydrogen, oxygen, phosphorus, and carbon, several of the key ingredients you'd want if you were building a recipe for microbial life.
I want to be careful here because I know how this kind of story gets flattened by the time it reaches a headline. Nobody found life. Nobody found a fossil or a squirming microbe under a rock. What they found is that the conditions for life, at least the simple kind, could plausibly have existed in that spot. Grotzinger's line about it being a "habitable environment" is doing a lot of work, and it's a real scientific claim, not a NASA marketing flourish, even though it will absolutely get used as one by every outlet running a headline with "Mars" and "life" crammed next to each other by tomorrow morning.
I've been following this rover since before it landed, which if you've read this blog for a while you already know, because I wrote way too many words back in August about staying up until 1:30am to watch the JPL livestream of the landing, the whole seven-minutes-of-terror thing with the sky crane lowering it down on cables like something out of a kid's toy commercial. My neighbor thought I was nuts for caring that much about a robot landing on another planet. I still think about that landing more than I think about most actual news events from last year.
What gets me about today's announcement isn't even the astrobiology, honestly. It's the sample itself, the color of it. Gray powder, not the rusty red-orange you'd expect from every photo of Mars you've ever seen. That reddish color comes from oxidized iron sitting right on the surface, weathered by billions of years of exposure. Drill down a couple inches and you get something totally different, unweathered rock that's basically preserved the chemistry of ancient Mars like a time capsule. There's something almost unfair about how much information is sitting just below the surface of a planet we've only barely scratched.
Anyway. I don't have a science background, I'm a guy who writes about phones and software as a hobby, so take my summary with the appropriate grain of salt and go read the actual JPL release if you want it straight from people with PhDs. But I wanted to get this down while it was fresh, because six months from now when the news cycle has moved on to whatever gadget launches next week, I want to remember that on a Tuesday in March 2013, a nuclear-powered rover the size of a Mini Cooper found out that a crater on Mars used to have water you could have safely had a drink from.
That's a pretty good Tuesday for a robot.