A dozen new moons have been discovered orbiting Jupiter

This proved to be quite helpful, as the unknown moons around Jupiter are small and dim.

But Sheppard suspects these moons could be holdouts, the "last remnants" of early solar system objects. "Magnificent desolation", Sheppard says, is the ideal.

Scientists were looking for objects on the fringes of the solar system past year when they pointed their telescopes close to Jupiter's backyard, according to Scott Sheppard of the Carnegie Institute for Science in Washington. "Jupiter just happened to be in the sky near the search fields where we were looking for extremely distant Solar System objects, so we were serendipitously able to look for new moons around Jupiter while at the same time looking for planets at the fringes of our Solar System", said Scott S. Sheppard, the team leader, in a release.

Jupiter has dozens of moons, including the large Galilean satellites, including Io and Europa, in this composite image.

These new moons probably formed in a place in our solar system known as the giant planet region, which is between the asteroid belt, dominated by rocky asteroids, and the Kuiper belt, dominated by icy comets. Sheppard realized previous year that the team's search zone for a ninth planet overlapped with Jupiter's orbit.

Jupiter's orbital family has just rapidly expanded, with scientists today announcing the discovery of 10 new miniature moons around the gas giant.

The newly discovered Jupiter moons, with diameters of one to three kilometres (0.62 to 1.9 miles), required multiple observations to verify.

It doesn't behave like the other moons, which tend to fall into a few categories.

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.

The orbits of the 9 newly discovered retrograde moons of Jupiter are shown here. These outer moons take roughly two years to circle Jupiter.

It's further away than the prograde moons, taking around one and a half years to orbit around the planet. Bob Jacobson and Marina Brozovic at NASA's Jet Propulsion Laboratory confirmed the calculated orbit of the unusual oddball moon in 2017 in order to double check its location prediction during the 2018 recovery observations in order to make sure the new interesting moon was not lost. The orbits of the new moons are marked with thicker curves. Maybe 100 or more of the really small ones. "Cars are coming right at you, and it's very likely you're going to have some head-on collision".

Gareth Williams, an astronomer at the Harvard-Smithsonian Center for Astrophysics and director at the International Astronomical Union's Minor Planet Center, predicted that "there aren't any bigger objects undiscovered out there" around Jupiter. "It probably has collided with them over time", Sheppard said. Over the course of a billion years, it may even cease to exist.

The view from the Chilean mountaintop taught researchers a lot, but there's more to learn.

The astronomers were not intentionally searching for new Jovian moons when they began observing. "We think these moons are an intermediate type of object, half-rock and half-ice".

Sheppard, Chad Trujillo of Northern Arizona University and David Tholen of the University of Hawaii are on a quest to find as many faint, distant objects on the edge of the solar system as they can. It's not clear when Valetudo will get a close-up, but it ought to be before anything goes splat.

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