Exomoons can last for billions of years, as long as they have hydrogen atmospheres

This is an artist's rendering of a habitable exomoon orbiting a giant planet. Credit: NASA GSFC/Jay Friedlander and Britt Griswold

Free-Floating Planets (FFP), also known as “Rogue Planets,” were first discovered in 2000 by astronomers searching the Orion Nebula. Since then, hundreds of FFP candidates have been identified, and scientists predict there may be billions across the Milky Way. This means they outnumber stars by 20 to 1, and habitable planets by 25 or more. … Read more