Published: Thu, July 19, 2018
Research | By Jennifer Evans

The Hunt for 'Planet Nine' Discovers 12 New Moons Around Jupiter

The Hunt for 'Planet Nine' Discovers 12 New Moons Around Jupiter

They are about one to two kilometers (miles) across, said astronomer Gareth Williams of the International Astronomical Union's Minor Planet Center.

If these raw materials had still been present when Jupiter's first moons collided to form its current clusters, the drag exerted on the smaller ones would have made them spiral inwards.

The orbits of the 9 newly discovered retrograde moons of Jupiter are shown here. Already, he and his team have discovered evidence of a potential planet beyond Pluto called Planet Nine. Sheppard's discovery brought the total number of objects orbiting Jupiter to 79 - but he said one discovery stood out in particular. Telescopes in Chile, Hawaii and Arizona were used for the discovery and confirmation. "We could choose our field of observation to be very close to Jupiter, so we could look for things moving at Jupiter's rate-foreground objects, moving quite fast", while still on the hunt for relatively slower-moving objects in the fringes of the solar system, Sheppard says. "So, the whole process took a year".

Valetudo, as spotted through the Magellan telescope in May 2018.

But what's particularly wild about these newly discovered moons is that researchers weren't even looking for them.

"Valetudo is like driving down the highway on the wrong side of the road", Sheppard wrote in an email to Fast Company. The other three are prograde, which orbit in the same direction.

Astronomers have found 12 previously unknown moons circling Jupiter, including one "oddball" whose days are numbered, due to its highly unusual orbit. They exist in retrograde - going the opposite direction of Jupiter's spin rotation. One of the moons, Valetudo (between orange markers), can be seen in these images. These all travel in retrograde, or the opposite of Jupiter's rotation, while two more, also though to be moon remnants, travel in prograde.

Jupiter just got a little more crowded.

Nine of the new moons are part of a distant outer swarm of moons that orbit in the opposite direction of Jupiter's spin. They are thought to be the remnants of larger parent bodies that were broken apart in collisions with asteroids, comets and other moons. As such, the orbit crosses those of the more distant retrograde moons, raising the possibility of a possible head-on collision at some point in the future.

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.

Most of the prograde moons orbit much closer to the planet than the retrograde moons do.

Finding lots of these small moons also tells us about conditions in the early solar system. Whether that be an exoplanet orbiting a distant star or perhaps a still-unseen planet lurking at the edge of the Solar System, it's a challenging endeavor.

Jupiter's moons are arranged in a specific pattern that the giant planet has worked out over time.

There are almost 200 moons in our solar system.

Sheppard and his colleagues speculate that Valetudo was probably once much larger, but was ground down, over the course of billions of years, as a result of collisions. But then there was one more, a moon the researchers term the "oddball" of the bunch.

Like this: