Scientists have learned that the air surrounding Comet 67P where the European Space Agency's probe landed is rich with oxygen.
Rosetta mission scientists have found oxygen in the atmosphere of comet 67P/Churymov-Gerasimenko. This discovery could change the way we understand how the solar system was formed. The molecular oxygen O2 was detected by the ROSINA mass spectrometer, only one of the instruments aboard the Rosetta spacecraft. It has been traveling with the comet since August last year. This discovery was a great shock, however. Kathrin Altwegg of the university of Bern in Switzerland, the project leader of ROSINA, the Rosetta Orbiter Spectrometer for Neutral Analysis, said they were in denial at first, because molecular oxygen was really not expected to be found on a comet.
It may not sound as spectacular, but it is actually the most surprising discovery made so far.
Molecular oxygen is common on Earth but really rare anywhere else in the universe. Astronomers detected molecular oxygen outside the solar system only twice, but never on a comet.
It is highly reactive which means it likes to bond to other kinds of atoms. So, it was previously thought that the oxygen present at the dawn of the solar system would be combined with hydrogen present at the time to form H2O, or water.