Saturn becomes first planet to have 100+ known moons
As many as 62 new moons have been discovered around Saturn, taking the total count from 83 to a whopping 145. The ringed world now has the most moons in the solar system, a title that was previously held by Jupiter, which has 92 known moons. Saturn is also the only planet in the solar system to have more than 100 known satellites.
Why does this story matter?
Just months after Jupiter emerged as the planet to have the most moons, Saturn has managed to regain its lost title from the gas giant. Earlier this year, 12 new moons were discovered around Jupiter, taking the count of its known moons, from 80 to 92. Now, Saturn has surpassed Jupiter, to become the 'King of Moons,' again.
The moons are irregularly shaped
The newly discovered moons are irregularly shaped, measuring no larger than roughly 1.6km to 3.2km wide. They orbit Saturn from a far distance, between 9.6 million to 28.9 million kilometers. Saturn's larger moons—such as Titan—orbit closer, within a million miles of the planet. Most of the newly discovered moons orbit Saturn in what's called the Inuit, Norse, and Gallic groups.
The moons have elliptical orbits around Saturn
The newly found moons have huge, elliptical orbits around Saturn, which is at an inclined angle respective to the planet's "regular" moons. The majority of the new moons fall under the Norse group, which contains the most number of moons and has the greatest orbital distance of the three groups. Also, its direction of the orbit is opposite to that of Saturn's rotation.
The moons are thought to be remnants of larger moons
Astronomers believe that new moons are remnants of larger moons. They are thought to be evidence of collisions that took place between Saturn's moons, sometime in the planet's recent past.
How were the moons discovered?
Astronomers used a technique called 'shift and stack' to find the new moons. What happens is that a set of sequential images is "shifted" according to the same rate that the moons move across the sky. The images are then stacked, which enhances signals that are too weak to be observed in individual images, making them brighter so scientists can analyze them better.
The newly discovered moons are key to understanding "big questions"
"These moons are pretty key to understanding some of the big questions about the solar system," said Bonnie Buratti of NASA's Jet Propulsion Laboratory in California. "They have the fingerprints of events that took place in the early solar system."
