Future travellers to a comet might not need to pack beer or sweets. Two of our favourite vices – alcohol and sugar – are already present on at least one comet in our neighbourhood.

Comet C/2014 Q2, also called comet Lovejoy, made its closest approach to the sun in January this year, becoming visible to the naked eye and also giving astronomers the chance to study the make-up of its atmosphere.

Nicolas Biver and colleagues at the Paris Observatory used the Institut de Radioastronomie Millimétrique (IRAM) 30-metre radio telescope in Sierra Nevada, Spain, to observe the comet when it was at its brightest.


The telescope picked up the signatures of 21 compounds, including organic molecules such as ethylene glycol, formic acid and acetaldehyde that have been detected before on Hale-Bopp and other comets. It also found ethanol and glycolaldehyde, a simple sugar molecule.

The researchers say it’s the first time these substances have been detected on a comet. But scientists who have studied data from the Rosetta mission, which has been orbiting comet 67P/Churyumov-Gerasimenko for over a year, quibble a bit: they’ve seen it too. Rosetta detected ethanol on comet 67P, although the finding has not yet been published. Glycolaldehyde was detected by the mass spectrometer on board the Philae lander.

Life’s potential pathways

Comets contain samples of some of the oldest material in the solar system, and can therefore tell us about how planets were formed in our sun’s youth.

Comets smashing into Earth early in our planet’s history might even have brought the raw materials for life. The organic compounds we find on comets are a start, but more complex molecules could have been created during impact.

“The detection of these compounds in comets helps to expand our knowledge of… the potential ingredients for life that could have been delivered to the early Earth or other planetary surfaces by comets,” says Jamie Elsila, an astrochemist at NASA. “This knowledge can then help evaluate the likelihood of potential pathways to life.”

In 2009, Elsila and her colleagues found the amino acid glycine in samples from comet Wild 2, gathered and brought back to Earth by NASA’s Stardust mission. Scientists on the Rosetta mission had hoped they would detect vastly more compounds than we’ve found on comets before, but Philae’s crash landing meant that it couldn’t drill into the comet as planned, and had to rely on “sniffing” it instead.

“The evidence from observation indicates that complex organic chemistry is much more universal than previously thought,” says Fred Goesmann from the Max Planck Institute for Solar System Research, who led the analysis of organic compounds on the Rosetta mission. “We are just at the beginning of detecting complicated molecules in space. It could well turn out that such material is nothing special at all.”

Journal reference: Science Advances, DOI: 10.1126/sciadv.1500863

Image credit: Fabrice Noel