http://www.abc.net.au/news/2015-10-29/rosetta-comet-67p-churyumov-gerasimenko-molecular-oxygen/6892708

The Rosetta spacecraft has detected significant levels of molecular oxygen coming from Comet 67P/Churyumov-Gerasimenko in a discovery that has taken astronomers by surprise.

The discovery, reported in the journal Nature, may provide new clues about the conditions and environment where the Earth, Sun and solar system were born 4.6 billion years ago.

“This is the first comet that we’ve found which has molecular oxygen,” said the study’s lead author Dr André Bieler of the University of Michigan.

What’s surprising is that it’s the first.

Water dissolves molecular oxygen as we know (otherwise fish couldn’t breathe) and the colder it is the more oxygen it dissolves. So when it freezes this dissolved oxygen becomes trapped in bubbles. On unfreezing the oxygen molecules are released, so we should be seeing at least some molecular oxygen being released in every comet.

mollwollfumble said:

What’s surprising is that it’s the first.

Water dissolves molecular oxygen as we know (otherwise fish couldn’t breathe) and the colder it is the more oxygen it dissolves. So when it freezes this dissolved oxygen becomes trapped in bubbles. On unfreezing the oxygen molecules are released, so we should be seeing at least some molecular oxygen being released in every comet.

Only if the water had come into contact with gaseous oxygen surley.

Peak Warming Man said:

mollwollfumble said:

What’s surprising is that it’s the first.

Water dissolves molecular oxygen as we know (otherwise fish couldn’t breathe) and the colder it is the more oxygen it dissolves. So when it freezes this dissolved oxygen becomes trapped in bubbles. On unfreezing the oxygen molecules are released, so we should be seeing at least some molecular oxygen being released in every comet.

Only if the water had come into contact with gaseous oxygen surley.

What PWM said. It is unsurprising that earth’s shallow water is oxygenated because there is O2 in the atmosphere, because of abundant photosynthesis.

There is no abundant photosynthesis on a comet. There is no O2 atmosphere.

O2 is rare in space, compared to other small molecules. This is a very surprising result.

http://news.sciencemag.org/chemistry/2015/05/why-there-so-little-breathable-oxygen-space