PARIS The European probe Rosetta has discovered oxygen in abundance in the atmosphere of the comet "Tchouri", according to a study published Wednesday in a British magazine.
This discovery is considered by scientists as "a total surprise." They think it might be necessary to review the models on the formation of the solar system.
This molecular oxygen (O2) may be older than the solar system, dating back 4.6 billion years, according to the study.
"This is the most interesting discovery made so far around the comet" 67P / Churyumov-Gerasimenko, Rosetta escorted by fifteen months, said Kathrin Altwegg, University of Bern (Switzerland) l One of the study authors.
This is the first time found that the oxygen - more commonly known as molecular oxygen - in a comet, although it has been detected in other celestial bodies such as the icy moons of Jupiter and Saturn.
"You may need to change our current models on the formation of the solar system, because right now, does not require the presence of molecular oxygen in a comet," said Andre Bieler, University of Michigan (USA), co author of the study.
The spectrometer Rosina, one of the key tools of the Rosetta mission has performed measurements of gas between September 2014 and March 2015, while the comet 67P approached the sun.
Rosina found nearly 4% of molecular oxygen (compared to steam H2O) in the cloud that form the comet's tail, the study found. This rate has remained stable over the months.
This makes the fourth oxygen comet importance after the water vapor (H2O), carbon monoxide and carbon dioxide.