Saturn hangs on to title as moon king

By Richard Stenger
CNN

(CNN) -- Saturn possesses the most known moons in the solar system, but Jupiter could soon overtake the ringed planet.

Having completed an exhaustive survey of the territory around Saturn, scientists said Wednesday that they had confirmed the existence of 30 satellites around the gas giant.

The tally includes a dozen recent discoveries, all of them small moons traveling in highly eccentric orbits. Moving around their parent planet in several distinct packs, most of the moonlets likely broke apart from larger satellites during violent collisions, astronomers concluded.

The moons, ranging in size from 4 to 19 miles (6 to 30 km), were probably roaming objects ensnared by the gravity of Saturn, the second-largest planet in the solar system, an international research team report in the July 12 edition of the journal Nature.

"We think that most of them are the shattered remnants of originally captured moons. The original moons were captured 4.5 billion years ago, probably by drag friction as they passed (near) the young giant planet," said lead author Brett Gladman, an astronomer at the Observatoire de la Cote d'Azur in Nice, France.

Advanced observation techniques and equipment for ground-based telescopes have hastened an unparalleled flurry of moonlet discoveries. The tally of known moons around giant planets in the solar system has more than doubled in the past two years.

Uranus has 21 known satellites, Neptune eight. Jupiter has 28 identified moons, but the calculation could soon rise, according to Gladman.

"Because Jupiter is closer we can see smaller moons. So I think Jupiter is going to win in sheer number because you can see a lot of little ones that are invisible at Saturn," he said.