First alien moon possibly spotted 1,800 light years away

Triple star sunset viewed from an exomoon

Exoplanets are seemingly easy to find these days, but their moons have been all too elusive -- at least, until now. Researchers at the University of Notre Dame claim to have spotted what may be the first exomoon. By looking for gravitational effects on starlight, they've found a relatively small, planet-like object orbiting a much larger object that isn't a regular star. Don't be quick to reach any conclusions, however. The two astral bodies are too far away from anything else in space to have an obvious explanation; while we may be looking at an orbitless planet and its moon, both about 1,800 light years away, the pair could also represent a failed star and an ordinary planet. Even if the objects remain mysteries, though, the techniques used in their discovery should help astronomers locating exomoons in the future.

[Image credit: NASA/JPL-Caltech]