/ 21 November 2014

Philae probe ‘sniffs’ organic molecules

Philae Probe 'sniffs' Organic Molecules

The Philae spacecraft managed to beam back evidence of carbon- and hydrogen–containing chemicals shortly before it entered hibernation mode to conserve falling power supplies.

Although scientists are still to reveal what kinds of molecules have been found on comet 67P/Churyumov-Gerasimenko, the discovery could provide new clues about how the early chemical ingredients that led to life on Earth arrived on the planet.

Many scientists believe they may have been carried here on an asteroid or comet that collided with the Earth during its early history.

The DLR German Aerospace Centre, which built the Cosac instrument, confirmed it had found organic molecules.

It said in a statement: “Cosac was able to ‘sniff’ the atmosphere and detect the first organic molecules after landing. Analysis of the spectra and the identification of the molecules are continuing.”

The compounds were picked up by the instrument, which is designed to “sniff” the comet’s thin atmosphere, shortly before the lander was powered down.

It is believed that attempts to analyse soil drilled from the comet’s surface with Cosac were not successful.

Philae was able to work for more than 60 hours on the comet, which is more than 800-million kilometres from Earth, before entering hibernation.

“We currently have no information on the quantity and weight of the soil sample,” said Fred Goesmann, principal investigator on the Cosac instrument at the Max Planck Institute for Solar System Research.

Goesmann said his team was still trying to interpret the results, which would hopefully reveal whether the molecules contain other chemical elements deemed important for life.

Professor John Zarnecki, a space scientist at the Open University who was the deputy principal investigator on another of Philae’s instruments, described the discovery as fascinating.

Complex compounds
“There has long been indirect evidence of organic molecules on comets as carbon, hydrogen and oxygen atoms have been found in comet dust,” Zarnecki said. “It has not been possible to see if these are forming complex compounds before and if this is what has been found then it is a tremendous discovery.”

Organic molecules, which are chemical compounds that contain carbon and hydrogen, form the basic building blocks of all living organisms on Earth. They can take many forms from simple small molecules such as methane gas to complex amino acids that make up proteins.

Philae landed on comet 67P/Churyumov–Gerasimenko after a 10-year journey through space aboard the Rosetta space probe. Philae’s initial attempts to touch down on the comet’s surface were unsuccessful when it failed to anchor itself properly, causing it to bounce back into space twice before finally coming to rest.

It meant the lander’s final resting place was about a kilometre from the initial landing site and left Philae lying at an angle and its solar panels partially obscured.

In a desperate attempt to get as much science from the lander as possible before its battery reserves ran out, scientists deployed a drill to bore down into the comet’s surface.

It is thought, however, that the drilling was unsuccessful because the drill failed to make contact with the comet.

But other findings from instruments on the lander, which were beamed back shortly before it powered down into hibernation mode, suggest that the comet is largely composed of water ice that is covered in a thin layer of dust. – © Guardian News & Media 2014