Tabetha Boyajian, an astrophysicist at Louisiana State University in Baton Rouge who is not part of the crew, called the verdict of the new moons "cool" in an email. Sheppard describes this as "an unstable situation", noting that collisions between two moons are possible due to the 12th moon's odd orbit. "It's going to slap into something".
Over the lifetime of the solar system, a collision seems inevitable. Other than that, not much is known about it or the other confirmed moons. Because it's like peering around the trees in our own forest and trying to count them all rather than using an overhead drone, Sheppard said. The observatory is nestled high in the desert mountains of the Atacama region. If you said four, you might be Galileo.
Valetudo, as spotted through the Magellan telescope in May 2018.
With 67 other known moons flying around Jupiter, there's already a good amount of traffic around the gas planet, as shown in the illustration above. They then look for objects that shift position between the two images, relative to the background stars.
This isn't likely to be the last new moons that we hear about coming from the gas giant, and astronomers believe there are still plenty smaller satellites that remain undetected. The telescope in Chile, with a powerful digital camera that can shade against glare and scattered light, provided Sheppard and his collaborators with a wider and more detailed view than had been possible before.
Jupiter's neighborhood was always crowded, but the discovery of 12 new moons around the giant planet makes it more intriguing. The newly discovered moons' relatively small size - between 0.6 to 1.8 miles across - is probably why scientists did not know about them before.
For example, the discovery that the smallest moons in Jupiter's various orbital groups are still abundant suggests the collisions that created them occurred after the era of planet formation. Nine others orbit with Jupiter's outer retrograde moons in the opposite direction.
Astronomers describe the twelfth new Jovian moon as an "oddball". In the meantime, they're waiting for the IAU to formally accept "Valetudo" as the name for the oddball moon. On the other hand, among these, there is the smallest moon of Jupiter found to date, Valetudo, named after the daughter of Jupiter and the goddess of hygiene in the Roman mythology. This means, unlike the closer in moons, it crosses the outer retrograde moons.
"Valetudo is like driving down the highway on the wrong side of the road", said Sheppard. "And that's very bad, because head-on collisions are likely to happen".
With current technology, as well as the next generation of telescopes that will have even more capabilities, Sheppard believes that they could definitively say whether Planet Nine exists in the next few years.
The study was published in the International Astronomical Union Minor Planet Electronic Circular. Nine of the new discoveries are found in this group. Which direction the moons swing around the planet depends on how they were first captured by Jupiter's gravitational field.