Hot Jupiters are giant exoplanets — even more massive than Jupiter — but they orbit closer to their star than Mercury. When they were first discovered, hot Jupiters were considered oddballs, since we don’t have anything like them in our own Solar System. But they appear to be common in our galaxy. As exoplanets go, they are fairly easy to detect, but because we don’t have an up-close experience with them, there are still many unknowns.
