Language Selection

English French German Italian Portuguese Spanish

Has Huygens found life on Titan?

Filed under
Sci/Tech

IF LIFE exists on Titan, Saturn's biggest moon, we could soon know about it - as long as it's the methane-spewing variety. The chemical signature of microbial life could be hidden in readings taken by the European Space Agency's Huygens probe when it landed on Titan in January.

Titan's atmosphere is about 5 per cent methane, and Chris McKay of NASA's Ames Research Center in Moffet Field, California, thinks that some of it could be coming from methanogens, or methane-producing microbes. Now he and Heather Smith of the International Space University in Strasbourg, France, have worked out the likely diet of such organisms on Titan.

They think the microbes would breathe hydrogen rather than oxygen, and eat organic molecules drifting down from the upper atmosphere. They considered three available substances: acetylene, ethane and more complex organic gunk known as tholins. Ethane and tholins turn out to provide little more than the minimum energy requirements of methanogenic bacteria on Earth. The more tempting high-calorie option is acetylene, yielding six times as much energy per mole as either ethane or tholins.

McKay and Smith calculate that if methanogens are thriving on Titan, their breathing would deplete hydrogen levels near the surface to one-thousandth that of the rest of the atmosphere. Detecting this difference would be striking evidence for life, because no known non-biological process on Titan could affect hydrogen concentrations as much.

One hope for testing their idea rests with the data from an instrument on Huygens called the GCMS, which recorded Titan's chemical make-up as the probe descended. It will take time to analyse the raw data, partly because hydrogen's signal will have to be separated from those of other molecules. "Eventually, I hope, we will have numbers for at least upper limits for hydrogen," says Hasso Niemann of Goddard Space Flight Center in Maryland, principal investigator of the GCMS.

Acetylene could be easier to analyse, McKay says, and it too might betray life. "I would guess that there would be a similar fall-off of acetylene if the microbes are eating it." The work is to be published in the journal Icarus.

By Stephen Battersby
NewScientistSpace.com.

More in Tux Machines

Xubuntu 15.10 Beta 1 Drops Gnumeric and Abiword in Favor of LibreOffice Writer and Calc

Canonical has announced the release of the first Beta build for Ubuntu 15.10 (Wily Werewolf) opt-in flavors, which include the well-known Xubuntu distribution built around the lightweight Xfce desktop environment. Read more

Technology, the law and you: Open-source software

But “free as in beer” isn’t really the point – huge numbers of corporate open-source users opt for paid commercial versions of open-source projects, for simplicity and support. And then there are all those various licenses that protect the openness of the software – GPL, Apache, Eclipse. But the good news is that, with very few exceptions, there aren’t many legal issues for the average company to worry about. Read more

Today in Techrights

Windows 10: is it finally time to migrate to Ubuntu?

Ubuntu continues to grow in popularity, not only with mainstream consumers, but also with Fortune 500 companies. Moreover, government and top notch education entities across the globe have realized they can save millions of USD, and invest funds more prudently for social programmes. Read more