Source: NASA/JPL
The rings of Saturn may be iconic, but there was a time when the majestic gas giant existed without its distinctive halo. In fact, the rings may have formed much later than the planet itself, according to a new analysis of gravity science data from NASA’s Cassini spacecraft.
The findings indicate that Saturn’s rings formed between 10 million and 100 million years ago. From our planet’s perspective, that means Saturn’s rings may have formed during the age of dinosaurs.
The conclusions of the research – gleaned from measurements collected during the final, ultra-close orbits Cassini performed in 2017 as the spacecraft neared the end of its mission – are the best answer yet to a longstanding question in solar system science. The findings were published online Jan. 17 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. But how long afterward?
To figure out the age of the rings, scientists needed to measure something else: the mass of the rings, or how much material they hold. 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.
The dives allowed the spacecraft to act as a probe, falling into Saturn’s gravity field, where it could feel the tug of the planet and the rings. Radio signals sent to Cassini from the antennas of NASA’s Deep Space Network and the European Space Agency relayed the spacecraft’s velocity and acceleration.
Once scientists knew how much gravity was pulling on Cassini, causing it to accelerate – down to a fraction of a millimeter per second – they could determine how massive the planet is and how massive the rings are.
“Only by getting so close to Saturn in Cassini’s final orbits were we…
The post NASA’s Cassini Data Show Saturn’s Rings Relatively New appeared first on FeedBox.