Someone has developed a method to detect the presence of moons orbiting extrasolar planets by using the timing of planetary transits across the star. The timing would vary due to the planet orbiting the barycenter between the planet and the moon.
Astronomers Now Looking For Exomoons Around Exoplanets | Universe Today
The paper: [0810.2243] Transit Timing Effects due to an Exomoon
Someday, we could be finding Earth sized moons around Neptune sized planets. We'll see.
Astronomers Now Looking For Exomoons Around Exoplanets | Universe Today
The paper: [0810.2243] Transit Timing Effects due to an Exomoon
Someday, we could be finding Earth sized moons around Neptune sized planets. We'll see.