Rosetta detects O2 molecules, probably from solar system’s birth, on 67P
A comet is leaking oxygen molecules that have been buried since the beginning of the solar system.
The Rosetta spacecraft detected O2 around comet 67P/Churyumov-Gerasimenko, the first time these molecules have been seen around a comet. The oxygen is probably primordial, trapped in water ice as the comet was assembled roughly 4.6 billion years ago, researchers report in the Oct. 29 Nature. Andre Bieler, a planetary scientist at the University of Michigan in Ann Arbor, and colleagues detected the oxygen using a mass spectrometer on board Rosetta, which has been orbiting comet 67P since August 2014.
“This is the most surprising discovery we have made so far,” study coauthor Kathrin Altwegg said at an October 27 news briefing. Researchers did not expect to find oxygen in the fog of gas surrounding a comet. Oxygen is highly reactive, and theories about the formation of the solar system