We all know that the Earth and some of the other planets in our solar system have their own satellites or moons orbiting around them. We also know from a recent discovery that an exomoon or extrasolar moon, which is a natural satellite that orbits an exoplanet or other non-stellar extrasolar body, exists. But what has left the scientific community in a tizzy now is the discovery of a planet’s moon having a moon of its own.
The phenomenon has attracted the interest of many astronomers across the globe, who decided to take it upon themselves to find a name for the moon’s moon. Seeing as it is a novel case, one would have thought they would either come up with a scientific or technical name, but it appears they were not at their creative best when they decided to name it Moonmoon.
According to ScienceAlert, in a paper currently up on pre-print resource arXiv, astronomers Juna Kollmeier of the Carnegie Institution for Science and Sean Raymond of the Laboratoire d’Astrophysique de Bordeaux have called them submoons. But other scientists are using the far more delightful term moonmoon.
In the paper, Kollmeier and Raymond describe how they ran simulations to determine whether a moonmoon could exist, after Kollmeier’s son stumped her with the question in 2014, internetnewsblog reports.
There are no known moonmoons in our Solar System, perhaps because the line they need to tread in order to exist is a very fine one. The moonmoon needs to be close enough to the moon to be bound by its gravity, rather than the planet’s; but not so close that it gets torn apart by tidal forces.
That also means there needs to be enough distance between the moon and planet for the moonmoon not to be snared by the planet’s gravity.
Within the Solar System, four moons currently meet that particular requirement: Earth’s Moon, Jovian moon Callisto, and Titus and Iapetus in orbit around Saturn.