E veryone knows Earth has one moon. That big, bright object in the night sky is the Moon with a capital M. But astronomers ...

In August, an amateur French astronomer, Adrien Coffinet, messaged an email list dedicated to asteroid and comet research with an announcement. He’d identified a new quasi-moon: “2025 PN7 seems to be ...

Saturn and Jupiter have been locked in a competition for the planet with the highest number of moons. But as it happens, Jupiter never really stood a chance: Saturn has just won by a huge margin. That ...