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

GNOME Development Outline and Google Summer of Code (GSoC) 2022

  • #45 Timeout! · This Week in GNOME

    Update on what happened across the GNOME project in the week from May 20 to May 27.

  • Selected for GSoC'22

    I'm pleased to share that I'm accepted for Google Summer of Code (GSoC) 2022 under GNOME Foundation umbrella on the Pitivi project. This summer I will be updating the project from GTK3 to the latest GTK4 toolkit. To anyone that wants to be a part of GSoC, I have only one piece of advice, just go for it. Don't think if you can do it or not, don't assume failure before attempting, and don't overthink. I always felt that it is for the best of the best, and I won't be able to clear it, all the big organizations on the GSoC page overwhelmed me, but instead of making it a dream, I made it a life goal. And well, now I'm enjoying it.

Top 10 GNOME Themes for Your Ubuntu Desktop

A list of nice and clean GNOME themes with screenshots for your Ubuntu desktop in 2022 which you can download and install. Read more

lavapipe Vulkan 1.2 conformant

The software Vulkan renderer in Mesa, lavapipe, achieved official Vulkan 1.2 conformance. The non obvious entry in the table is here. Thanks to all the Mesa team who helped achieve this, Shout outs to Mike of Zink fame who drove a bunch of pieces over the line, Roland who helped review some of the funkier changes. Read more

3100 Games On The Steam Deck with Strider and Samorost 2 as Verified

While the additions are progressing, it’s been a little slower to reach the new milestone for the Steam Deck. There are now more than 3100 games validated (3120 games to be precise at the time of writing) on the Steam Deck – in two categories as usual... Read more