Resumen de Rosetta's comet is first with oxygen
The Rosetta spacecraft has discovered oxygen in 67P Churyumov-Gerasimenko's atmosphere--and the team thinks it may date back to the birth of the solar system, when comets and planets first formed. Molecular oxygen has never been seen on a comet before. Oxygen is a volatile chemical that shouldn't stick around for long in space, and the team couldn't be sure that it wasn't coming from the spacecraft itself. But after seven months of observing, they were confident that the oxygen had been buried in the comet since its birth about 4.5 billion years ago.
