I'm an astrophysicist. My research team published a paper in the Astrophysical Journal describing how and why WASP-69b's tail formed, and what its formation can illuminate about the other types of planets astronomers tend to detect outside of our solar system.

A universe filled with exoplanets

When you look up at the night sky, the stars you see are suns, with distant worlds, known as exoplanets, orbiting them. Over the past 30 years, astronomers have detected over 5,600 exoplanets in our Milky Way galaxy.

It isn't easy to detect a planet light-years away. Planets pale in comparison, in both size and brightness, to the stars that they orbit. But despite these limitations, exoplanet researchers have uncovered an astonishing variety—everything from small rocky worlds barely larger than our own moon to gas giants so colossal that they've been dubbed "super-Jupiters."

However, the most common exoplanets astronomers detect are larger than Earth, smaller than Neptune, and orbit their stars more closely than Mercury orbits our Sun.