27 March 2008

Spirit's science at Home Plate: SAFE!

Posted by melissa

With the MER budget scare having blown over, now is a perfect time to reflect on the science at Home Plate – and beyond – that Spirit has yet in store.  Rather than vent frustrations about the near-disaster of a 40% funding slash, I’d rather be reminded that we’re lucky – astoundingly lucky – to be operating spacecraft on the surface of another planet.  And for Spirit, I think the best is yet to come.

            Right now, Spirit is tilted towards the Sun on the north edge of Home Plate, where the rover will stay until sometime in October, when spring arrives to the south of Mars.  So – you may say – if Spirit can’t drive for 6 months anyway, why not just hibernate the ol’ girl?  I’ve heard that argument before, and here’s my response: Spirit may be a quadriplegic right now, but she’s not blind.  The MER team has a rigorous winter science campaign planned for Spirit, including the mother-of-all-panoramas: a 360-degree view of the winter scene, from the rover deck to the horizon – that’s over a hundred individual snapshots stitched together, taken in 13 unique filters.  Here’s a sneak preview of what we have so far, pieced together from “blue” filter images: 

It will take months to finish shooting this panorama, called the “Bonestell Pan”.  But when it’s done, it’ll be spectacular.  Last winter, when Spirit was parked at Low Ridge, we collected the equally monstrous McMurdo Pan, which is arguably the most scientifically-rich product that Pancam has acquired. There are plenty of Ph.D. theses in that panorama – including mine.  Over the next few months I’ll be mapping the extent of silica-rich material over the entire 360-degree McMurdo Pan, and when this winter is done, I’ll do the same over the Bonestall Pan.  In the end I’ll be able to say something about how widespread the hydrothermal activity might have been in this area.

Hydrothermal activity?  That’s right – the silica-rich stuff that Spirit has discovered is thought to have formed around hot springs and/or vents.  Think Yellowstone on Mars – without the buffalo.  (Check out this article in Astrobiology Magazine or this Scientific American podcast for more on the silica deposits.) There’s an incredible story emerging about hot springs and explosive volcanism at Gusev Crater, and Spirit is poised to continue putting the pieces together.

When spring comes and Spirit can drive again, we’ll head south to check out two features called “von Braun” and “Goddard,” both of which look similar to Home Plate, and might be the sites of ancient vents.  It’s the geologic “promised land” for Spirit – we may find more silica-rich deposits, layered volcanic sediments, lapilli, sulfur-rich soils, or something entirely new. That’s the best part: we don’t know what we’ll find.  We just know we have to go. 

As Ray Arvidson (the MER deputy principal investigator) said in the MER all-hands meeting on Monday, when Spirit’s future was up in the air, “If we lose the capability to drive spirit to Von Braun and Goddard… that’s beyond bad, that’s beyond very bad – that’s criminal.”

            So after Spirit’s near-death experience this week, I’m breathing a huge sigh of relief that we’re safe to push forward with the great science ahead of us.  Our little rover still has a lot to live for.