Oxygen on Rhea and NASA's Big Astrobiological Revelation

The Cassini probe was recently sent to analyze the atmosphere of Saturn's second largest moon Rhea, revealing the planet to be covered in a thin veil of oxygen (70%) and carbon dioxide (30%). This finding represents the first ever confirmation of the existence of oxygen in the atmosphere of any world other than our own.But it's the presence of carbon dioxide that peaked most peoples interest in this story as one of the possible causes for the gas is of course, alien biology.

Though Rhea's low surface temperature -ranging from -281 f to -364 f- the exceedingly thin nature of it's atmosphere, and the subsequent lack of liquid water, make it an unlikely home for any form of life as we know it. But Cassini's find does place the planet's name on an ever growing list of recent discoveries which show that elements essential for life as we understand it actually exist in often surprising quantities and concentrations on planets throughout our solar system.

In fact, the discovery of elements and conditions potentially conducive to life on our neighboring bodies has become so common place, that I have actually stopped writing about many of them. Not because they're not intriguing scientific discoveries, but because the story pretty much always goes the same: I tell you planet X displays a chemical or environmental anomaly which COULD -after years worth of additional analysis- prove to be signs of life on another world. But until that analysis is done, we'll all just have to go with the odds and assume that it isn't. I say, wouldn't it be cool if it was, make a logical argument for why it could be and we all move on to something else.

Well, according to NASA, by this time tomorrow there just might be something new to say about the potential for life on other worlds, as earlier this week the space agency announced it's plans to hold a conference tomorrow at 2:00PM ET, during which it promises to: "discuss an astrobiology finding that will impact the search for evidence of extraterrestrial life."

Pretty much since the moment the press conference was announced the speculations have been flying, the most popular and outrageous of which being that the agency plans to admit some previously withheld knowledge about contact with little gray men. But being the logical creature that I am, I'm going to follow Phil Plait's lead and side with Kottke.org in guessing that the people scheduled to be involved in tomorrows press conference make it likely it will have something to do with previous discoveries on Titan, at least in part anyway.

But who knows, maybe they have somehow confirmed the existence of some sort of extraterrestrial microbes thriving on arsenic on the surface of mars or some alien fungus living off acetylene in Titan's lakes of methane. But while Id be lying if I said I wasn't waiting eagerly to hear just what this new discovery is, if you're holding out for the big "We come in peace moment" in tomorrows press conference, I would say you should prepare yourself for disappointment.

-CAINE-

Source: New Scientist, Bad Astronomy

Image credit: NASA, Voyager, Copyright Calvin J. Hamilton