The finding shows that oxygen can be generated in space without the need for life, and could influence how researchers search for signs of life on exoplanets.
In 2015, scientists announced the detection molecular oxygen at Comet 67P/Churyumov-Gerasimenko, which was studied by the Rosetta spacecraft. It was the “biggest surprise of the mission,” they said — a discovery that could change our understanding of how the solar system formed. While molecular oxygen is common on Earth, it is rarely seen elsewhere in the universe. In fact, astronomers have detected molecular oxygen outside the solar system only twice, and never before on a comet. The initial explanation for the oxygen found in the faint envelope of gas that surrounds the comet was that the oxygen was frozen inside the comet since the beginning of our solar system some 4.6 billion years ago. It was believed that the oxygen had thawed as the comet made its way closer to the Sun. But researchers are rethinking that theory, thanks to a chemical engineer from Caltech who usually works on developing microprocessors.