After exoplanets, the next frontier is exomoons around alien planets. And the first one may have been already discovered!
Already more than 1,000 exoplanets have been discovered across the solar system. Now it’s time to find moons orbiting alien planets. And some astronomers say they may have found an oddball system of a planet and a moon floating free in the galaxy rather than orbiting a star. Exciting, no?
The title of their article:
tells everything. Is it a moon or a planetary system lost in our solar system?
The best explanation for the data is a giant planet, about four times the mass of Jupiter, orbited by a moon weighing less than Earth. However, it could also represent a more distant system comprising a small star, around one tenth the mass of the sun, and a planet roughly 18 times as massive as Earth.
Sadly, there is no chance for astronomers to take another peek at the object to confirm their suspicions, because it has moved out of alignment with the background star and now produces no lensing signal.