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]