Valetudo might be the last fragment of a larger moon that was destroyed by the retrograde moons, and its path means it too might eventually get demolished. And these new moons point to a violent and destructive past. His team at Carnegie, along with collaborators at the University of Hawaii and Northern Arizona University, was hunting for objects far beyond Pluto. "This is an unstable situation", continued Sheppard.
But cosmic serendipity placed the moons in front of their telescope. And he realized that Jupiter was right near the part of the sky he wanted to search. While the scientists' planet hunt has so far come up dry, the team, using the recently upgraded Blanco 4-meter telescope at the Cerro Tololo Inter-American Observatory in Chile, also had Jupiter in view, leading to the discovery. This proved to be quite helpful, as the unknown moons around Jupiter are small and dim.
"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".
Jupiter, the largest planet in the solar system, was hardly short of moons before the latest findings. That's bigger than the planet Mercury. More specifically, this moon presents a prograde orbit around Jupiter at a distance where other four moons have retrograde orbits.
Each of the moons is tiny, no more than a mile or two across.
View Slideshow The planet Jupiter now has a total of 79 identified moons. QAI Publishing UIG via Getty Images
For example, a large amount of gas and dust would push very small moons (moons between 1 and 3 kilometers (.6 and 1.9 miles) in diameter) toward their planet.
"We just haven't observed them enough", said Williams, who helped confirm the moons' orbits. The first is that it's small in size, with a diameter that totals only about a kilometer. The center used the Carnegie insitute's observations to calculate the orbits of the newly found moons.
Another two moons rest in an inner section of moons that orbit in prograde. Of Jupiter's 79 moons, 26 remain unnamed, including nine of the 10 new ones.
Nine of them are in previously discovered clusters of moons that are in what astronomers call a retrograde orbit. Sheppard's team speculates Valetudo could be a remnant of a collision between one or more moons. Sheppard says more searching should turn up more moons - maybe a hundred or more of the really small ones.
Valetudo is something of an oddball. Two of them go round in a prograde motion, in the same direction to Jupiter's spin. What's more, those orbits intersect. What's truly freakish is that this set up prone to four moon-to-moon collisions. "It probably has collided with them over time", Sheppard said. Saturn is next with 61. This matter became part of the planets themselves. Sheppard, who is broadly interested in the formation of solar systems and has been involved in the discovery of 48 of Jupiter's known moons, realized this was the flawless opportunity to advance two separate research goals with the same telescope data.
It's possible the various orbital moon groupings we see today were formed in the distant past through this exact mechanism.