Like a roving interplanetary cocktail bar, a comet is carting around booze and sugar. The aptly named Comet Lovejoy contains ethanol and the simple sugar glycolaldehyde, researchers report online October 23 in Science Advances. This is the first time these complex organic molecules have been detected on a comet.
Ethanol and glycolaldehyde have been found around young stars where planets are forming (SN: 5/2/15, p. 10). Finding these molecules on a comet — a frozen time capsule from the birth of the solar system — suggests that they are preserved from the sun’s formative years. While comets probably didn’t play a major role in delivering water and organics to the young Earth (SN: 5/16/15, p. 18), they have a lot in common with the icy asteroids that did.
Comet C/2014 Q2 (Lovejoy) is a visitor from the Oort cloud, a shell of frozen debris enveloping the solar system. The comet was visible to the unaided eye during its closest approach to the sun in January 2015; its unusual brightness made it a good hunting ground for molecules. Nicolas Biver, a planetary scientist at the Paris Observatory in Meudon, France, and colleagues used a radio telescope in the Spanish Sierra Nevada to observe Lovejoy. Ethanol and glycolaldehyde are two of 21 molecules detected streaming from the comet. The other molecules, such as carbon monoxide and a host of organics, have been seen previously in other comets.