NASA experts have discovered the largest planet in the Solar system 12 new satellites. Saturn is next with 61, followed by Uranus with 27 and Neptune with 14. This brings Jupiter's total number of known moons to a whopping 79-the most of any planet in our Solar System. And one of them has a very unusual trip around the planet, leading it to be dubbed an "oddball". The work was led by Scott Sheppard, a researcher at the Carnegie Institution for Science who studies small bodies in the solar system and the formation of planets and stars.
Recovery image of Valetudo from the Magellan telescope in May 2018; Jupiter is not in the field but off to the upper left.
Why are we just now hearing about it?
"What's really cool for me here is what they're calling their oddball", Horner told ScienceAlert.
"It takes several observations to confirm an object actually orbits around Jupiter".
It has an angled prograde orbit that takes about a year and a half to complete. This proved to be quite helpful, as the unknown moons around Jupiter are small and dim. Those 2017 moons were labeled S/2016 J1 and S/2017 J1.
The announcement of the new moons was published Tuesday in the International Astronomical Union Minor Planet Electronic Circular.
Researchers say the new Jupiter moons weren't seen before because they are tiny - the biggest ones are only about two miles across.
The orbits of the twelve newly discovered moons of Jupiter are shown here in bold.
Astronomers discover 12 new moons orbiting Jupiter - one on collision course with the others
The nine retrograde moons recently found in Jupiter's orbit go around the planet in roughly two years.
They also have a retrograde orbit, or the opposite direction to the spin of Jupiter on its axis.
The IAU requires moons of Jupiter to have names related to the Roman god Jupiter. There is one other moon orbiting Jupiter that has the same rotation, but Valetudo orbits further away from the planet so its unorthodox movement is more baffling. "It's also likely Jupiter's smallest-known moon, being less than 1km (0.6 of a mile) in diameter".
As a result, head on collisions are much more likely to occur between this "oddball" prograde moon and its retrograde cousins moving in opposite directions. "That's a very unstable situation".
"We think there were originally only three retrograde moons and they were each broken apart through collisions with other objects".
"Valetudo is like driving down the highway on the wrong side of the road". The largest among them are the Galilean satellites-Io, Europa, Ganymede, and Callisto-large moons that orbit close to the planet.
The two others are among a closer, inner group that orbit in the prograde, or same direction. As for how many ultimately will be found, no one knows for sure.
Here's a number in the news - 79.
Valetudo is more than just the odd moon out; it's also a serious collision hazard. That's very surprising, because in the long run such an orbit is bad news. Is that properly a moon, or just a bit of debris? At the same time, they watched for Planet Nine or smaller, distant dwarf planets in the background.