Hi Keira;

I think extrasolar planets are great! we call them planets because they are orbiting a star, but are too small to become a star at themselves. Some are "gas giants" similar to our Jupiter, often even bigger. We are just now beginning to detect smaller, rocky planets that are more similar in character to our earth. Up until recently, we could not see most of these planets directly, but rather could tell that something was orbiting a star by the fact that it periodically got in front of the star and blocked some of the light. Only very recently, are we starting to be able to take pictures of extrasolar planets directly, but again, only the very largest ones can be seen in this way. As with a lot of astronomy, much of what we do is detective work.