NASA's Cassini data show Saturn's rings formed after planet

Source: Xinhua| 2019-01-20 03:04:32|Editor: yan
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LOS ANGELES, Jan. 19 (Xinhua) -- Scientists have found out the iconic rings of Saturn may have formed much later than the planet itself.

According to a new analysis of gravity science data from NASA's Cassini spacecraft, Saturn's rings formed between 10 million and 100 million years ago. That time, on Earth, was during the age of dinosaurs.

The conclusions of the research was gleaned from measurements collected during the final, ultra-close orbits Cassini performed in 2017 as the spacecraft neared the end of its mission. The findings were published online on Thursday in Science.

Saturn formed 4.5 billion years ago, in the early years of our solar system. There have been clues that its ring system is a young upstart that attached to Saturn years afterward.

To figure out the age of the rings, scientists had to measure the mass of the rings. Researchers had the remote-sensing measurements from Cassini and both of NASA's Voyager spacecraft in the early 1980s. Then came Cassini's unprecedented, up-close data from its final orbits.

As the spacecraft was running out of fuel, it performed 22 dives between the planet and the rings, which allowed Cassini to act as a probe, falling into Saturn's gravity field, where it could feel the tug of the planet and the rings.

"Only by getting so close to Saturn in Cassini's final orbits were we able to gather the measurements to make the new discoveries," said Cassini radio science team member and lead author Luciano Iess, of Sapienza University of Rome.

"With this work, Cassini fulfills a fundamental goal of its mission: not only to determine the mass of the rings, but to use the information to refine models and determine the age of the rings," he said.