Thursday, March 17

A festival of wet worlds

This year's version of the wonderful annual bazaar of new findings about the planets around us, the Lunar and Planetary Sciences Conference in Houston, has been an even richer banquet than usual. With two rovers and three orbiters having been busy probing the red planet for over a year now, not surprisingly Mars was Topic A at the crowded meeting, with two or three Mars sessions going on at once (out of a total of four parallel tracks) most of the time. But there has also been interesting new information about the Cassini mission's studies of Saturn and its moons (especially Titan), the Genesis mission that crash-landed last October, asteroids, comets, meteorites, and a lot of research on Earth aimed at helping us understand what's out there, and how to study it with future probes and roving robots.
Among the highlights so far:
* Most of the information has already come out a bit at a time, but seeing all the images and data Cassini has taken of Titan all together and in great detail has been quite dazzling. It's a place that, as one scientist said, superficially resembles Earth more than anyplace else we've seen, yet it remains profoundly alien and enigmatic. There are clearly-visible riverbeds, but even those differ in appearance: some may have formed through precipitation, while others may be spring-fed. And a puff of methane detected by the Huygens probe when it landed may mean the soil was saturated, perhaps suggesting there had been a very recent "rain" of liquid methane. While nobody has directly detected liquid there yet, all signs suggest that this may be the only place other than Earth where there are bodies of liquid and a whole precipitation/evaporation cycle.
* Although some people have long claimed that Mars may once have had a huge ocean -- a real one, made of water, not like Titan's petrochemical ones -- the evidence keeps getting better. Tim Parker of JPL gave a good talk on this Wednesday, and I expect I'll have a story with more details on that on a later entry here. I won't mention this then, but just between us, I believe I was the first person to make a case for the existence of such an ocean, including detailed maps (which hold up pretty well today) of its exact location and extent, in my 1979 book "Life on Mars". I don't expect any credit -- I'm just an amateur looking in from the sidelines -- but it was very gratifying to discover that at least one scientist who has done serious research on this, John Brandeburg of Florida Space Institute, was inspired by my work.

The rover Zoe, in the Atacama desert
* A lot of fascinating research on how life might be able to survive on Mars even today, and how to search for it if it does. One of the most promising of these is a robot built by engineers at Carnegie Mellen University, and tested in the Atacama desert for the last two years (and again next fall) under the direction of Nathalie Cabrol from NASA-Ames. I met Nathalie and her husband Edmond Grin, also of Ames, down at one of her research sites near the Atacama (at Licancabur, a 20,000-foot volcano on the Chile-Bolivia border), in the fall of '03, and have been following her work with great interest ever since. She was the one mostly responsible for the choice of Gusev Crater as one of the NASA rover landing sites. This new experimental rover, called Zoe, is equipped with a very cleverly designed fluorescent dye system, and succeeded in detecting life in one of the driest, most barren areas of the world's driest desert. My story about that work appeared HERE today.
I'll talk about some of the fascinating ideas about how life might survive under the harsh conditions of Mars today in a later posting.


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