Are Curiosity and Perseverance, NASA’s two operational rovers on Mars, in a robotic rivalry to be the first to find a confirmed sign of life on the Red Planet? It would seem that way this week as Curiosity’s onboard lab analyzed some soil it had dug up and found it contained an unusual carbon signature that is considered to be one of the signs of life. Not to be outdone, NASA just announced that Perseverance has been finding a purple coating on rocks everywhere it roams and scientists think this could also be a sign of past life – or at least hold clues on what that life might have been. Purple rocks on Mars? Wouldn’t that have made an excellent Bowie/Prince collaboration?
"These particular purple patches we haven't really seen with past rover missions."
At a recent conference of the American Geophysical Union (AGU), Purdue University scientist Bradley Garczynski explained how he’s using the “scientific eyes of the rover” -- a pair of cameras called Mastcam-Z – to study the purple images taken by Perseverance through various filters that can help determine their composition. National Geographic was at the conference and also reports on Ann Ollila, a geochemist at Los Alamos National Laboratory, who is also studying the purple coatings, splotches and blobs in Jezero crater, which was formed by a meteorite impact billions of years ago, once hosted an ancient lake, and is now the home of Perseverance and its little helicopter friend Ingenuity.
Ollila is taking a more weaponized approach – she’s using the rover’s SuperCam to blast the rocks with a laser to vaporize a hole and make a sound that is picked up by microphones and analyzed – the sound tells Ollila how hard the rock is and reveals other properties. The Supercam then compares the inside of the hole to the purple surface – it found the purple layer is softer and contains hydrogen and magnesium. Add that to the discovery by the Mastcam-Z that it also contains iron oxide and you’ve got … what?
"I don't really have a good answer for you."
That’s not what conference attendees and future Mars explorers wanted to hear from Ollila – they want to know if geological processes are similar among the solar system’s planets, what are the differences and how did they happen. And most importantly – what the heck is the purple stuff? If it’s a sign of ancient life, it’s in the wrong place – the spots in Jezero where Perseverance roams are not where there was water but where magma flowed. Also, the pings don’t match and neither do the compositions of the zapped holes and the purple coating around them. That doesn’t mean they aren’t potential signs of Martian life, says Nina Lanza, the team leader for Space and Planetary Exploration at Los Alamos National Laboratory studying the purple.
"Who knows what Martian microbes do?"
(Wouldn't that have made a great opening line to a Bowie song?)
On Earth, a purple coating on a rock might mean microbes hid on it to escape from the sun’s ray, metabolizing metals in the rock or dissolved in water flowing over it. Ultimately, the purple rocks need to be brought back to Earth for intense analysis in a lab.
If the purple surface on these Martian rocks was really once purple Martian microbes in a Martian lake, that means it could have heated up, vaporized into clouds and formed something Prince could sink his musical teeth into.
Purple rain, Martian pain
Purple rain, Martian pain
I didn’t mean to step on you
Thought you were just a stain
OK, maybe David Bowie.
Take a look at the ground, man
Purple rock, I wonder why
Oh man, wonder if we'll ever know
Is it purple Martian pee
Is there life on Mars?
Don’t you miss those guys?