Skip to footer

New 'moon king': Saturn passes Jupiter with 20-moon discovery

Scientists have discovered 82 moons are orbiting Saturn, making it the planet with the most known moons. Jupiter previously held the title with 79.

|
NASA/JPL/Space Science Institute/AP
Saturn is seen here July 23, 2008 from the Cassini spacecraft, which orbited Saturn from 2004 until 2017. Twenty new moons have been found around Saturn, giving the planet a total of 82.
  • By Marcia Dunn Associated Press

| Cape Canaveral, Fla.

The solar system has a new winner in the moon department.

Twenty new moons have been found around Saturn, giving the ringed planet a total of 82, scientists said Monday. That beats Jupiter and its 79 moons.

"It was fun to find that Saturn is the true moon king," said astronomer Scott Sheppard of the Carnegie Institution for Science.

If it's any consolation to the Jupiter crowd, our solar system's biggest planet – Jupiter – still has the biggest moon. Jupiter's Ganymede is almost half the size of Earth. By contrast, Saturn's 20 new moons are minuscule, each barely 3 miles in diameter.

Dr. Sheppard and his team used a telescope in Hawaii to spot Saturn's 20 new moons over the summer. About 100 even tinier moons may be orbiting Saturn, still waiting to be found, he said.

Astronomers have pretty much completed the inventory of moons as small as 3 miles around Saturn and 1 mile around Jupiter, according to Dr. Sheppard. Future larger telescopes will be needed to see anything smaller.

It's harder spotting mini moons around Saturn than Jupiter, Dr. Sheppard said, given how much farther Saturn is.

"So seeing that Saturn has more moons even though it is harder to find them, shows just how many moons Saturn has collected over time," he wrote in an email. These baby moons may have come from larger parent moons that broke apart right after Saturn formed.

Seventeen of Saturn's new moons orbit the planet in the opposite, or retrograde, direction. The other three circle in the same direction that Saturn rotates. They're so far from Saturn that it takes two to three years to complete a single orbit.

"These moons are the remnants of the objects that helped form the planets, so by studying them, we are learning about what the planets formed from," Dr. Sheppard wrote.

Just last year, Dr. Sheppard found 12 new moons around Jupiter. The Carnegie Institution had a moon-naming contest for them; another is planned now for Saturn's new moons.

The jury is still out on whether any planets beyond our solar system have even more moons. For now, Saturn has the most known moons.

Monday's announcement came from the International Astronomical Union's Minor Planet Center.

This story was reported by The Associated Press. The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute's Department of Science Education. The AP is solely responsible for all content. 

You've read  of  free articles. Subscribe to continue.
Real news can be honest, hopeful, credible, constructive.
What is the Monitor difference? Tackling the tough headlines – with humanity. Listening to sources – with respect. Seeing the story that others are missing by reporting what so often gets overlooked: the values that connect us. That’s Monitor reporting – news that changes how you see the world.
editor@csmonitor.com
Subscribe
Mark Sappenfield
Editor

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.

Subscribe to insightful journalism

QR Code to New 'moon king': Saturn passes Jupiter with 20-moon discovery
Read this article in
https://www.csmonitor.com/Science/2019/1008/New-moon-king-Saturn-passes-Jupiter-with-20-moon-discovery
QR Code to Subscription page
Start your subscription today
https://www.csmonitor.com/subscribe