An amateur astronomer recently isolated the presence of a previously unknown small moon around Jupiter in data collected by Canada France Hawaii Telescope in February 2003. This object joins the Carmé group, which includes several satellites moving retrograde around the planet.
Four years ago, we thought that Jupiter was surrounded by 67 moons. In 2018, a team of astronomers noted the presence of twelve new satellites around the giant, bringing the number of Jovian moons to 79 . As is the case with the other moons of Jupiter, those which rotate in the same direction as the planet (as is the case here) must have a name ending in the letter "a", while the others have a name ending with the letter "e". All these moons have since been named after descendants of Zeus (Pandia, Ersa, Eiréné, Philophrosyne and Euphémé).
But Jupiter, which offers a strong magnetic field that can capture a lot of space junk in its orbit, could have tens or even hundreds of undiscovered moons orbiting around it. In fact, one of them was recently spotted by an amateur astronomer named Kai Ly. This is the first time that an amateur astronomer has discovered a moon around Jupiter.
This new little moon joins Carmé's group. It is a group of Jovian satellites that share similar orbits and move retrograde on semi-major axes between 22,900,000 and 24,100,000 km. In other words, these small moons move in the opposite direction to the rotation of Jupiter on an extreme inclination with respect to the orbital plane of the planet.
Carmé is the largest satellite in this group, with a diameter of about 46 kilometers. According to the researchers, it would be an asteroid once captured by the gravity of Jupiter. The twenty-two other members of Carmé's group would actually be pieces detached from the asteroid following a collision.
The amateur astronomer made his discovery while analyzing a dataset collected by University of Hawaii researchers using the Canada-France-Hawaii telescope ( CFHT) in 2003. Kai Ly reportedly paid particular attention to the footage collected in February of that year. At the time, Jupiter was in opposition to the Sun with respect to Earth. Our planet was therefore in the middle of a "straight line" between the sun and Jupiter, allowing astronomers to clearly see the Jovian system illuminated by our star.
Ly then relied on follow-up observations from the Subaru Telescope, still in Hawaii, to confirm that the object was indeed bound to Jupiter's gravity. In an introductory article, Ly described his discovery as "a summer hobby before returning to school “.
This rock, the 80th moon of Jupiter , is temporarily designated EJc0061, pending the intervention of the International Astronomical Union. As explained above, it will have a name ending with the letter "e", since it evolves in the opposite direction of the planet.
