Four new moons spotted around Saturn

The ringed planet boasts 28 moons, a solar system record

By Richard Stenger
CNN.com Writer

(CNN) -- Astronomers have detected four additional moons orbiting Saturn, raising the total number of known satellites around the gas giant to 28, far surpassing any other planet.

The discoveries sustain an unrivaled rush of new satellite sightings. The official tally of known moons around Saturn has increased by ten in less than three months.

The number around all giant planets has more than doubled during the past 18 months, according to the International Astronomical Union, which announced the latest Saturn finds last week.

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"The biggest problem now is coming up with names for all these things," quipped J.J. Kavelaars, who helped track down the 10 most recent Saturn satellites.

The Canadian astronomer and his colleagues detected a flurry of small and eccentric moons in late September using a large telescope atop Mauna Kea, Hawaii.

Since then the international team has steadily confirmed their existence with observations from telescopes in Chile and California.

One of four new moons discovered around Saturn this month

"There is a reason that they are coming out in drips and drabs," Kavelaars said. "We found them all with the telescope in Hawaii. They are very faint so it's taken some time to see them again with other telescopes."

They are quite different than their much larger, better known satellite cousins. Their orbits are highly inclined relative to Saturn's equator and rings. Moreover, some are highly elliptical. Some orbit in the same direction as Saturn spins. Others go around in the opposite direction.

The moons orbit Saturn from a distance between 10 million and 20 million kilometers (6.2 million and 12.4 million miles). Astronomers estimate that they range in diameter from 50 km (31 miles) to only several kilometers.

Their unusual orbits suggest that Saturn captured the satellites after it formed. Some astronomers speculate that they were once Centuaurs, a group of diminutive ice objects that orbit the sun between Saturn and Uranus.

The latter gas planet has the second highest number of satellites in the solar system, 21. Continued observations of Saturn could increase its commanding lead in the satellite deparment, Kavelaars said.

"I wouldn't be surprised if there are a couple more we can pull out in the data set in the not so distant future."

Astronomers discover four new moons orbiting Saturn
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Two planets smaller than Saturn found orbiting distant stars
March 30, 2000

General Information on Saturn
The Irregular Satellites of Saturn
International Astronomical Union

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