I know, it may not look like much, but think about what you’re seeing: a sunset on another world. And those images were taken by a robotic probe that took years to design and build, months to travel the hundreds of millions of kilometers to get to Mars, a harrowing few minutes to descend on a breath of fire through the thin air to land on the surface, and then nearly seven years to travel the landscape long, long past its design specifications.
All that, plus all the amazing science, exploration, and discovery done by Opportunity and its sister rover Spirit… and yet, it’s sometimes the stark beauty of simple things like this that remind us that we have, at least by proxy, placed our feet on other worlds.
I know there are worries here on Earth. But when I see something like this, I remember that the good we do, the awe we feel, and the inspiration we can generate are mighty.
Anyway, scientists have revealed they have found large amounts of carbonates (minerals containing CO3 in them) in rocks on Mars. That’s kind of a big deal: it’s been expected that a lot of rocks would have this compound in them, because there’s lots of carbon dioxide afoot there, and plenty of evidence that Mars was once wet. Those two ingredients lead to carbonates. Yet the rocks looked at closely by the rovers have been strangely devoid of them.
For the rover Opportunity it’s not all that strange; the water on that part of Mars was acidic, and that makes carbonates tough to form. But Spirit is on the other side of the planet, and it was expected it would find carbonates all over the place. Well, turns out it finally has. Some rocks it examined back in 2005 are loaded with carbonates, but it took this long to figure that out because dust that got in the instrument on the rover screwed things up. The scientists had to do some heroic work to tease the data out.
At this point we’ve pretty much exhausted my knowledge of this, but happily we have access to Emily Lakdawalla and her blog, where she goes into detail about the rocks, talking to a scientist involved in all this, too. So go over there and get the rest of this interesting story.
And when you’re over there, don’t forget: we’re talking about a whole planet here. A world. And it was once warmer, wetter, with a thicker atmosphere. Sure, it was over a billion years ago, but it’s always a good idea to keep an eye on Mars when thinking about Earth. There but for the grace of random chance go us.
These are beautiful! They almost look sedimentary, which at least makes some sense given that the region Opportunity is roving, Meridiani Planum, was once under water. Closeups of those rocks show they have the famous "blueberries", concretions of jarosite formed by mineral-laden water.
Stuart has lots more pictures he’s fiddled with, too, and it’s well worth your looking around his site. You should also read Emily Lakdawalla’s great description of Concepcion, talking about how we know it’s a fresh crater about 1000 years old. It’s a fascinating read.
Phil Plait, the creator of Bad Astronomy, is an astronomer, lecturer, and author. After ten years working on Hubble Space Telescope and six more working on astronomy education, he struck out on his own as a writer. He's written two books, dozens of magazine articles, and 12 bazillion blog articles. He is a skeptic and fights the abuse of science, but his true love is praising the wonders of real science.
The original BA site (with the Moon Hoax debunking, movie reviews, and all that) can be found here.
Contact me: The Bad Astronomer "at" gmail "dot" com
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