National Geographic has a great visualization of what we know about exoplanets and their habitability. This image shows that thus far, we’ve found fifteen planets (including Mars) that are a) the necessary distance from their star to have the right surface temperature, and b) are the right size to be considered “Earth-like”.

The image with more detail shows every suspected exoplanet, it’s size and orbit vis-a-vis its star system’s ‘goldilocks zone.’ We’re finding a lot of planets, and a few candidates.

You can view the image better here.

You know, it’s got to be an exciting time to be an astronomer. Then again has there ever been a boring time to be an astronomer? Why aren’t I an astronomer?