From the Desk of the Xenobiolgist

     Most people easily know what a biologist does for a living. But ask them what a Xenobiologist does and you'll probably get quite a few "huh?" and "what did you say?" responses. Someone who knows their root words might know that xeno means roughly "stranger". A Xenobiologist studies the biology of strangers, i.e. non-Terran species. Terran means things on Earth, in case I haven't covered that.
     So what might a Xenobiologist do? Well, one of their jobs would be to map out possible evolutionary lines that could emerge on foreign planets. I'll walk you through an example, something a bit more familiar than say Kepler 22b, we'll use good old Jupiter.
     Lifeforms residing on Jupiter would be called Jovians. Now as you may know, Jupiter doesn't have a surface. Then how could something live there you ask? Balloons. Really, big, balloons. Balloons stay aloft by using differences in pressure, you fill it with Helium, a gas lighter than air, it will float. You can do the same thing with living things to, it turns out. A Jovian might process compounds in the atmosphere for nutrients and break it down to lighter gases, using those to float. These things, call them Scoopers, would be big, absolutely huge. Imagine whale shaped creatures, floating around Jupiter's atmosphere, scopping up organic compounds as it lumbers around. It would spend its entire life at the mercy of the air currents, and probably never develop any level of Sapience because it would likely evolve in a low-intelligence herd line.
     Another theoretical creature, we'll call this one an Aeroraptor (it's not real, so we can have cool names), might be capable of powered flight. Technically speaking, Jupiter's atmosphere is filled with combustibles. It sounds silly, but in an environment like this it would be completely possible for a creature to evolve an organic type of jet engine. Like the Scoopers it would collect compounds as it moves, but it would use them to zip quickly around. This type of adaption would likely only evolve on carnivorous creatures, who need speed to ambush their prey in the big open skys. If an Aeroraptor evolved to be big, it would hunt by itself, and if it was small, it would likely hunt in packs.
     Of course these are only a few possible creatures, an environment as big as Jupiter with so many varying layers would have a very complex biosphere. It's fun to think of all the different creatures that could evolve in these environments, and thats a draw most Xenobiologists understand. There are billions of other planets, billions of other systems where unique and interesting species could evolve.