Another day, another confusing scientific discovery.
Despite how knowledgeable we are about the formation of our solar system and how life may have originated on earth, discoveries like these remind us that everything we know are still very much theories. Remember the probe we landed on a comet back in 2014? Well, the probe Philae, and its space craft Rosetta, have now discovered oxygen on the 67P-Churyumov/Gerasimenko comet. And in case you have no idea why that’s important, let us tell you.
Prior to this discovery, the common wisdom was that asteroids, not comets, were responsible for providing Earth’s water in the early years of our solar system. And as you may know, liquid water=potential for life. So scientists also suggested that the comet may host alien life forms. Like, little bacteria guys, not sentient beings with big heads and bug eyes.
To say the least, the discovery of oxygen on the comet came as a bit of a shock to scientists. Kathrin Altwegg, one of the co-authors of the paper, said in a press conference Tuesday:
“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.
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. 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.”
So how did the oxygen survive and not react with the plentiful hydrogen?
There are two theories: that the gaseous oxygen went through a “shock freeze,” which preserved it, or else that oxygen was built onto the icy grains. Scientists think the former is unlikely because gaseous oxygen is so rare outside of our solar system. But the second theory holds…water?
André Bieler, another co-author on the study, explained:
“If you freeze it out very slow in the grains it will react with hydrogen and transform into water ice. The other way to build up O2 is on these grains. We came up with the idea that it could happen through radiolysis, a common effect that is known in the solar system on other icy bodies and in the rings of Saturn.”
This would also mean that the comet was “a very pristine object” i.e. an object that hasn’t changed much since its primordial birthday. That’s why it’s so interesting and important to study, because it leads to startling revelations about the origin of our solar system and how earth came to support such wide and varied life forms (like us!).
This new discovery, scientists say, “suggests that our current models [of the solar system] most probably are not right.”
We recently told you about the comet up in space that’s holding a hell of a lot of alcohol, and now, it looks like there’s so much more we don’t know about even our own solar system.