Scientists were excited about the possibility of the first rocky exoplanet—but it turns out, they weren’t quite right.
Exoplanet astronomy—the search for planets orbiting other stars—has two major goals. The first is to describe planets in our galaxy in all their weirdness and wonder. The second is to find planets as close as possible to Earth in size, composition, and position in their star system. Where we run into trouble is that the smaller the planet, the harder it is to find—and the more difficult it is to be confident we’ve detected a planet as opposed to something else.