Saturn’s rings are one of our solar system’s magnificent sights, but may be a relatively recent addition, according to data obtained from NASA’s Cassini spacecraft before the robotic explorer’s 2017 death plunge into the giant gas planet.
Scientists said on Thursday a calculation of the mass of the rings based on gravitational measurements of the planet collected by Cassini indicated they formed between 100 million and 10 million years ago in roughly the final 2 percent of Saturn’s current age.
On Earth, 100 million years ago was during the dinosaur age.
The findings challenge the notion favored by some astronomers that the rings developed soon after Saturn formed about 4.5 billion years ago along with the other planets including Earth. Others felt the rings were much younger, but lacked crucial data like their mass to estimate their age reliably.
“I like the rings and their fascinating dynamics, whether they are young or old,” said Sapienza University of Rome aerospace engineering professor Luciano Iess, lead author of the study published in the journal Science.
Saturn is the sixth planet from the sun and the solar system’s second-largest, after Jupiter. All of the four gas planets possess rings, though Saturn’s are the biggest and most spectacular, with a diameter of about 175,000 miles (282,000 km). The numerous thin rings are 99 percent ice and 1 percent silicate particles from interplanetary debris.
Their mass turned out to be 45 percent lower than previous estimates based on 1980s data from NASA’s Voyager spacecraft. Lower mass indicates a younger age, the researchers said, adding that the still-bright rings would have been darkened by debris over a longer period.
Scientists suspect the rings formed perhaps when a large icy comet or moon ventured too close to Saturn and was shattered by gravitational forces or moons collided in orbit. Saturn has 62 known moons.
There may not be a more precise answer about the origin and age of Saturn’s rings “until we can get samples of ring material in our labs to examine, and possibly date via radioactive decay,” said Cornell University astronomy professor and study co-author Phil Nicholson.
Data from Cassini’s final orbits, diving between the planet and the rings as fuel ran low, also provided insight into Saturn’s internal structure, including a core estimated at 15 to 18 times Earth’s mass. It also indicated that Saturn’s atmospheric layers start rotating in sync deeper into the planet compared to Jupiter.
Reporting by Will Dunham; Editing by Sandra Maler
Trump picks Antonin Scalia’s son to replace disgraced former Labor Secretary: report
On Thursday, NPR reported that President Donald Trump is naming Eugene Scalia, the son of the late Supreme Court Justice Antonin Scalia, to take over as Secretary of Labor.
Scalia, who served on the court from 1986 to his death in 2016, was known as one of the staunchest conservatives on the bench. His seat was deliberately kept vacant by Republicans for over a year to deny President Barack Obama the ability to make an appointment to it.
The Department of Labor was until this month run by former federal prosecutor Alexander Acosta, who resigned in disgrace amid renewed questions about his role in brokering a potentially illegal sweetheart plea agreement with hedge fund manager and accused child sex trafficker Jeffrey Epstein.
Trump border official melts down on MSNBC after refusing to admit Trump lied about ‘mass raids’
On Thursday's edition of MSNBC's "The Beat," Ari Melber confronted acting Customs and Border Protection Commissioner Mark Morgan about President Donald Trump's empty threat of "mass raids" of communities nationwide by immigration officials — and Morgan was not pleased.
"The president said there would be these mass raids. Described as thousands of arrests," said Melber. "Were there mass raids, yes or no?"
"First of all, I don’t actually call this a raid," said Morgan. "I think words matter."
"Words matter, so I’m going to get to your response," said Melber. "Were there mass raids as promised?"
DOJ policy blocking Trump from being indicted ‘factored into’ the end of the Stormy Daniels case: report
Federal prosecutors decided to close the investigation into the 2016 criminal hush money payment to Stormy Daniels and Karen McDougal that benefitted the Trump campaign because, in part, of the policy that prevents the indictment of a sitting president, according to a new report from USA Today citing an anonymous source.
Michael Cohen has already pleaded guilty to the violation of campaign finance law. He said that he carried out the effort in coordination with and at the direction of then-candidate Donald Trump in order to increase his chances of victory in the 2016 presidential election.