Oxygen discovered on Rosetta comet, stunning scientists

By Michael Casey Published October 28, 2015 FoxNews.com Facebook1240 Twitter500 livefyre526 Email Print Artist impression of ESA’s Rosetta approaching comet 67P/Churyumov-Gerasimenko. The comet image was taken on 2 August 2014 by the spacecraft’s navigation camera at a distance of about 500 km. The spacecraft and comet are not to scale. (ESA/ATG medialab; Comet image: ESA/Rosetta/NAVCAM) Scientists have for the first time detected oxygen on a comet, a finding that could upend theories about how the solar system was formed. Reporting their findings in the journal Nature on Wednesday, an international team said that they detected “a lot” of molecular oxygen in the cloud of gas, or coma, surrounding the nucleus of comet 67P/Churyumov–Gerasimenko. While molecular oxygen has been found in Jupiter and Saturn, it’s never been found on a comet. The neutral gas comas of most comets are composed largely of water, carbon monoxide and carbon dioxide. Related: Philae’s comet may host alien life, scientists say “It is the most surprising discovery we have made so far in 67P because oxygen was not among the molecules suspected in a cometary comas,” Kathrin Altwegg, one of the co-authors on the paper from the University of Bern, told reporters during a press conference Tuesday. “The first time we saw it I think we all went a little bit into denial because it was not expected to be found in a comet,” she said. “Molecular oxygen is very reactive. There was a lot of hydrogen around when the solar system was formed. Everybody and all models showed that molecular oxygen would react with the hydrogen and would no longer be present as molecular oxygen.” Once they detected the oxygen, the researchers studied the comet for several months and concluded it was present “ in the whole body,” according to University of Michigan’s André Bieler, another co-author on the study. Related: Rosetta discovers that ice on comet disappears in regular cycle Related Image Expand / Contract This single frame Rosetta navigation camera image of Comet 67P/Churyumov-Gerasimenko was taken on 7 July 2015 from a distance of 154 km from the comet centre. The image has a resolution of 13.1 m/pixel and measures 13.4 km across.(ESA/Rosetta/NAVCAM) “The fact that it’s in the whole body led us to the idea that it was primordial so the O2 must have been present at the formation of the comet,” Bieler said. But how did it form and manage to stick around for billions of years? Bieler said the international team considered two theories – either the oxygen was in the gaseous phase and endured a “shock freeze” or the oxygen was built onto the icy grains. The researchers said the first theory was probably unlikely because “gaseous...