NASA Curiosity rover hits organic pay dirt on Mars

Rodiano Bonacci
Giugno 8, 2018

And NASA didn't launch another mission to Mars for over a decade.

The space agency announced Thursday that its Curiosity rover had uncovered "tough" organic molecules preserved in three-billion-year-old rocks in the planet's Gale Crater, which is believed to have once contained a shallow lake.

In a separate finding, Curiosity also detected that the small amount of methane present in the Martian atmosphere varies with the seasons.

"Both these findings are breakthroughs in astrobiology", wrote Inge Loes ten Kate, of the University of Tübingen in Germany, in an accompanying commentary in Science. And life as we know it requires organic molecules to exist. While organics were discovered by the rover earlier, the age and variety of the newly analyzed samples strengthen the case for a habitable environment in the past.

The samples were found to contain thiophene, 2- and 3-methylthiophenes, methanethiol, and dimethylsulfide.

It's impossible to say whether ancient life explains the Martian organics, however.

Scientists realized that they had to take a step back and try a more cautious, methodical approach. Spikes of methane (CH4) were first noticed in the Red Planet's atmosphere several years ago, drawing intense debate over the hydrocarbon's possible source.

A self-portrait of NASA's Curiosity Mars rover. "We thought Mars was dead internally", Harrison said. Methane is quickly broken down by radiation, so it must be replenished by some source on the planet.

A new analysis of data gathered by Curiosity has confirmed a long-term pattern of methane highs and lows, varying between 0.24 to 0.65 parts per billion. During the summer months, levels of the gas detected by Curiosity rose to about 0.7 parts per billion; in winter, they fell to roughly half that.

"This is the first time we've seen something repeatable in the methane story, so it offers us a handle in understanding it", said lead author of the second paper Chris Webster of NASA's Jet Propulsion Laboratory (JPL).

"[Curiosity's] molecular observations do not clearly reveal the source of the organic matter in [Gale Crater]". "Short of taking a picture of a fossil in a rock on Mars, [finding life there] is extremely hard to do scientifically", says Chris Webster, a chemist at the Jet Propulsion Laboratory and lead author of the methane study.

The term "organic" means something different to a chemist than it does to a produce manager at a grocery store. Such incremental progress is the whole point of NASA's Mars exploration program, Freissinet notes.

A potential explanation for the seasonal Martian methane. Here it is retained by the soil until the temperature increases sufficiently to release the gas.

A crystalline water structure called a clathrate provides a flawless explanation. They therefore suggest that methane could be trapped at depth, gradually seeping to the surface.

He and his colleagues think the methane is coming from underground. "It's on the table with all the other ones", Dr. Eigenbrode said.

Now, the rover has seemingly made a new discovery which will be revealed this Thursday, according to the space agency.

"Although the surface of Mars is inhospitable today, there is clear evidence that in the distant past, the Martian climate allowed liquid water - an essential ingredient for life as we know it - to pool at the surface", NASA reports. "And then we went, 'oops, not only did we not find it, but we don't really know what we're looking for if it's not exactly like Earth.' And maybe that was not the best way to go about it".

Altre relazioniGrafFiotech

Discuti questo articolo

Segui i nostri GIORNALE