Planets with an eggshell
ou open the airlock door. Your first step onto the surface of a new planet! It is hot, but your spacesuit protects you. A thin layer of clouds hides the sun. But something is wrong. You climb down the ladder. What is it? You spin around your axis. Wherever you look, the horizon is the same distance away. This planet has no elevations at all. It is as if you are standing on the outside of an eggshell. Such planets probably really exist. "Eggshell planets," a recent study shows, are to be expected in a solar system under certain…