Star jelly is a white-grey translucent jelly, that supposedly falls during a meteor shower. It is unknown what exactly it's made of, but analysis prove it to be masses of bacteria. This brings me to the next thing I'd like to post about, "atmospheric beasts" which is basically the idea that a whole ecosystem of flying\floating creatures lives in Earth's atmosphere, or more generally speculated, to be living in the atmosphere of a gas giant. Most People who believe is sky beasts, also believe that the "star jelly" is actually the remains of a dead air jellyfish, which is almost believable, considering that the flesh of some sort of jellyfish (especially one lacking a central nervous system), would be quite similar to the star jelly. So just something I wanted to post, I personally don't believe in them, but the idea is very interesting...