For the first time ever, molecular oxygen has been found on a comet. Comet 67P/Churyumov-Gerasimenko, currently being orbited by the European Space Agency’s Rosetta spacecraft, is the subject of a study published Wednesday in Nature. According to ESA researchers, the oxygen present in the comet’s surrounding gasses has likely been there since the formation of the comet.
“It is the most surprising discovery we have made so far, because oxygen was not among the molecules expected in a cometary coma,” the University of Bern’s Kathrin Altwegg said at a news conference held by Nature. Altwegg, one of the new study’s authors, is in charge of Rosetta’s instrument that is used to “sniff” out the atmospheric composition of the comet.
About a year ago, she and the rest of the team now report, it sniffed out some O2. The gas enveloping a comet — known as its coma — usually contains carbon monoxide, carbon dioxide and water. Atmospheric atoms of oxygen — the stuff present in our own atmosphere — were unexpected.
