Has Huygens found life on Titan?

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.
-
- Login or register to post comments
Printer-friendly version
- 1992 reads
PDF version
More in Tux Machines
- Highlights
- Front Page
- Latest Headlines
- Archive
- Recent comments
- All-Time Popular Stories
- Hot Topics
- New Members
Openwashing Apple and Microsoft Proprietary Frameworks/Services
| Viperr Linux Keeps Crunchbang Alive with a Fedora Flair
Do you remember Crunchbang Linux? Crunchbang (often referred to as #!) was a fan-favorite, Debian-based distribution that focused on using a bare minimum of resources. This was accomplished by discarding the standard desktop environment and using a modified version of the Openbox Window Manager. For some, Crunchbang was a lightweight Linux dream come true. It was lightning fast, easy to use, and hearkened back to the Linux of old.
|
Openwashing Cars
| today's leftovers
|
Recent comments
14 hours 56 min ago
15 hours 23 min ago
1 day 3 hours ago
1 day 4 hours ago
1 day 23 hours ago
1 day 23 hours ago
3 days 3 hours ago
4 days 8 hours ago
5 days 15 hours ago
1 week 22 min ago