Due to their sizes-one to three kilometers-these moons are more influenced by surrounding gas and dust.
"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", Dr Sheppard added.
Dr Sheppard said: 'This is an unstable situation. "The only thing that we know at the moment are the orbits and the approximate size", International Astronomical Union's Minor Planet Center director Gareth Williams told The Washington Post.
Trying to detect dim space objects and dwarf planets in our solar system with the Blanco telescope, at the Cerro Tololo Inter-American Observatory in Chile, the scientists noticed that Jupiter came in the telescope's field of view. So the researchers had to continue observations.
Diagram of the new moons split into different groups. The moon can be seen moving relative to the background of distant stars.
Two of the newly discovered satellites orbit with a group that are in between the outer group and the Galilean moons. As NPR science correspondent Joe Palca reports, the 12 newest moons were announced today.
So, what of this final "oddball" moon?
In fact, Sheppard and his team at Carnegie think that this moon could be all that's left of a previous collision in orbit around Jupiter. Its powerful gravitational pull allows it to capture large passing objects that then collide with each other, forming dozens of new, smaller moons.
Tholen and Fohring's observations allowed the team to follow the motions of the possible moons and refine the orbits of these satellites. Nine more are part of a distant outer swarm of moons that move in the opposite direction of Jupiter's rotation. But every so often, the planets seem to align (no pun intended) and a new discovery just falls right into their laps.
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. It would be like driving down a highway going the wrong way. "And that's very bad, because head-on collisions are likely to happen". The astronomers are now running computer simulations to determine how the ancient moons fragmented.
"Over a human lifetime, it doesn't happen".
He believes that there may be more astronomical secrets found near the large planet. "These moons are likely half ice and half rock".
"This just shows how chaotic our solar system was in the past". Since they are still around, now, that means they formed after that gas and dust had been swept away by the solar wind.
Scott Sheppard: "It's been about a decade since the last moons around Jupiter were discovered". Sheppard says more searching should turn up more moons - maybe a hundred or more of the really small ones.