When it comes to the laws of physics, there are a strict set of rules that things have to follow to exist, and sometimes, the laws of physics tend to warp and bend on other words that aren’t Earth.
NASA recently published a report about an “impossible” ice cloud on Saturn’s largest moon, which goes by the name Titan. It was originally spotted by the Voyager 1 spacecraft in the 80’s, but has once again been observed with the modern Cassini spacecraft, which has a chemical analysis module on-board for observations like these.
The ice cloud is “impossible” because of the characteristics surrounding its formation, which scientists are saying never should have happened in the first place given the environmental situation.
Here on Earth, we understand how water molecules evaporate and then re-condense in the skies, but on Titan, we see other kinds of chemicals at work instead of water. These clouds are made up of dicyanoacetylene, which is a compound of Carbon and Nitrogen, but they still have to follow similar guidelines to get into Titan’s skies and then condense.
Understanding the characteristics of these chemicals, scientists can estimate the physics behind what’s required to make them condense by using math. On the other hand, something doesn’t add up. What we thought we knew about chemistry on Titan is apparently far from the truth, because it doesn’t match what we’re actually observing.
"The appearance of this ice cloud goes against everything we know about the way clouds form on Titan," said Carrie Anderson, a CIRS co-investigator at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and lead author of the study.
Of course, that’s where scientists are reportedly getting stumped. According to NASA, the cloud, which is located in Titan’s stratosphere, doesn’t have the amount of dicyanoacetylene (C4N2) that would theoretically be required for the cloud to have condensed in the first place, so they’re not exactly sure how it was able to condense.
The only thing the cloud has going for it is that it’s in a region in Titan’s skies where temperature has a big impact on cloud formation, but even with this factor in mind, NASA says there should be at least 100 times more dicyanoacetylene vapor in the skies where Cassini spotted this cloud in order for it to actually exist where it does.
One theory that might shed some light on the cloud's formation is that of something known as solid state chemistry, which is when chemical reactions in the skies work in a certain way to actually produce the C4N2 ice we're seeing in Titan's atmosphere. If this were the case, then perhaps C4N2 isn't condensing in Titan's skies at all, and rather, it's just a byproduct of another chemical reaction.
At this point in time, this remains an untested hypothesis that more digging will have to confirm or deny. In any case, this is one strange ice cloud, and scientists are really stumped by its existence.