Illustration of the exoplanet 55 Cancri e, a rocky planet almost twice the diameter of Earth that orbits only 0.015 astronomical units of its Sun-like star. Due to its narrow orbit, the planet is extremely hot, with daytime temperatures reaching 4,400 degrees Fahrenheit (about 2,400 degrees Celsius). Credits: NASA, ESA, CSA, Dani Player (STScI)