Enlarge / “Backlit” picture of Saturn and its rings, taken by the Cassini spacecraft in 2006. (credit score: NASA/Public area)
Astronomers had lengthy assumed that Saturn’s distinctive rings fashioned across the identical time because the planet some 4.5 billion years in the past within the earliest days of our Photo voltaic System. That assumption obtained a critical problem from a 2019 evaluation of knowledge collected by NASA’s Cassini spacecraft, suggesting that the rings have been simply 10 million to 100 million years in the past—a mere blink of an eye fixed on cosmic time scales. Now, a contemporary evaluation of knowledge on how a lot mud has accrued on the rings confirms that controversial discovering, in keeping with a brand new paper printed within the journal Science Advances.
“In a approach, we’ve gotten closure on a query that began with James Clerk Maxwell,” mentioned co-author Sascha Kempf, an astronomer on the College of Colorado, Boulder. In 1610, Galileo Galilei was the primary to look at the rings, although his telescope was too crude to establish them as precise rings. He described them as “Saturn’s ears” since they regarded like two smaller planets on both facet of Saturn. Galileo was bemused when the “ears” vanished in 1612 because the Earth handed via the ring aircraft, much more so after they grew to become seen once more the next 12 months.
Christopher Wren suspected that Saturn had a hoop in 1657, although Christiaan Huygens beat him to publication, suggesting the ring was indifferent from the planet in his 1659 treatise System Saturnium, which additionally famous his discovery of Saturn’s moon, Titan. Robert Hooke observed shadows on the rings. By 1675, Giovanni Cassini had found out that the ring was a collection of smaller rings with gaps between them. Over a century later, Pierre-Simon Laplace would mathematically show that any stable ring can be unstable. Maxwell decided that the “ring” needed to be made up of plenty of small particles, all independently orbiting Saturn, confirmed by observations in 1859. We now know these particles are virtually totally made up of water ice.
Learn 10 remaining paragraphs | Feedback
