Life-enabling moons can probably only form around small planets, study finds

Earth’s moon is large for the planet’s size, and many astronomers have long believed that this fact has helped make Earth a habitable world. And a new study has now found that our planet was just the right size to form such a large, life-enabling moon. 

The study, by researchers from the University of Rochester in New York, found that rocky planets with a diameter more than 1.6 times that of Earth and icy planets with a diameter more than 1.3 times that of Earth likely can’t create moons that would have those life-enabling effects on them.