Astronomers See Moons Forming in Disk Around Distant Exoplanet

Scientists have never before gotten such a clear view of moons in the making.

Our solar system is home to a magnificent menagerie of moons, from icy ones filled with turbulent oceans to volcanic ones decorated with pits of raging hellfire. To date, astronomers have discovered 4,438 worlds orbiting other stars, and there is no doubt that diverse moons dance around most of these exoplanets. But stargazers have yet to conclusively find any — these exomoons have proven too small and too far-flung to be spotted. Now, after years of observations of a pair of Jupiter-like exoplanets nearly 400 light-years from Earth, astronomers have found the next best thing: a disk of debris orbiting one of these worlds, a ring of rock and gas gradually coalescing under its own gravity. In other words, astronomers have caught a circumplanetary foundry in the act of making moons. This is the first time such a feature has been unambiguously detected. And unlike many extrasolar discoveries, this object was not found through indirect methods — the subtle wobbling of a star revealing the presence of an orbiting planet, for example. This disk was effectively photographed. This is a real image of a baby planet surrounded by its very own moon-making forge.