I was really hoping that Curiosity would scoop up some bacteria and they would announce it and peace on earth would result. Oh well, we are still in suspense…
SAN FRANCISCO — The Curiosity Mars rover has discovered something interesting in a scoop of ruddy sand, but NASA scientists say they’re not quite sure what it means.
Sand that was shake-and-baked inside the car-size rover’s chemistry kit bubbled off traces of organic compounds, mission scientists said at a news briefing Monday at the annual meeting of the American Geophysical Union.
Such compounds, made of carbon and chlorine, are of the type that, in some cases, indicate microbes in the soil.
But such compounds also could be contamination from the rover itself — or they may have rained onto the surface inside meteorites, said Paul Mahaffy, a mission scientist from NASA’s Goddard Space Flight Center in Greenbelt.
“It’s unclear if the carbon is Martian or terrestrial,” Mahaffy said.
As the great philosopher Lazlo Toth said after an earlier Mars mission in 1976, “of course you didn’t find life on Mars, you just killed it.”
Words to reflect on.
Kmareka.com 
That letter from Lazlo Toth is hysterical!
Sounds like a mini-short story by Frederic Brown from his collection “Nightmares and Geezenstacks”which was written in I’d say the late 40’s or early 50’s.
Actually-1961-47 short,short fantasy,sf,and horror stories-really amazingly original and good.
The Toth comment is on target in the sense of we may not be able to realize what living things are evolving in alien environments. More likely, however, is that Mars has never had anything that qualifies as being “alive.” The only place that we actually have a sample of life is right here on Earth, and the first evidence of anything alive are fossils in rocks about 3/5 billion years old. It seems likely that the evolution of living systems on Earth must then have been initiated earlier than that date, and since the planet is “only” 4.5 billion years old, about the same age as out Sun, living things must have gotten going here not that long after the planet formed. perhaps 3.8-4 billion years ago. In point of fact, the only sample of life anywhere is right here, and new work recently published seems to indicate that life is an exception rather than a common phenomenon–it is just very difficult to make something alive from something that is not. Sadly, very little money is available to spend on the study of the origin of life on Earth, and more money has been spent on just one of the Mars shots, and has so far has demonstrated that water runs downhill on Mars, that wind blows, and other “significant” work, that is spent by all the research on the evolution of living things by all the institutions in the world over the last 200 years.