Sunday , October 17 2021

Ten times faster than we thought: Saturn losing its rings

If you plan to live for 100 million years, then you will witness Saturn losing its last 22 rings.

The rings are being broken in a storm of ice particles and pulled into the gaseous atmosphere of the planet.

The breakup is driven by the massive gravity of Saturn and under the influence of the planet's magnetic field – but it is happening much faster than previously thought.

In fact, this is occurring at peak pace based on measurements made decades ago by Traveler observations of spacecraft, about 10,000 kilos per second.

We've been known for years.

It was the Traveler expeditions that first indicated that the rings would not have a cosmically long life.

NASA estimates that water products are draining from the rings at a rate that can fill an Olympic pool in half an hour.

"That's why the entire ring system will have disappeared in 300 million years," James O & # 39; Donoghue of NASA's Goddard Space Flight Center said in a prepared statement.

But when scientists added Cassini– Measurements of space material in Saturn's satellite ring have found that the rings are less than 100 million years old.

"This is relatively short compared to Saturn's age of more than 4 billion years," said Dr. O'Donoghue, lead author of a study on the rain of rings of Saturn published this week in the journal. Icaro.

More complex than just water

In 2013, Dr. O & # 39; Donoghue was the lead author of an article published by Nature which showed for the first time that the rain was falling from the rings.

The bad news comes from the data collected during the Cassini the fatal plunging of the space probe into Saturn more than a year ago.

It was already understood that the material of the rings was being pulled into Saturn by gravity under the influence of Saturn's magnetic field.

Cassini showed that the intensity of the innermost ring precipitation was much higher than expected.

According to a study published in October Science, Cassini Saturn's rings are chemically more complex – they include substantial amounts of methane, ammonia, molecular nitrogen, carbon monoxide, carbon dioxide, and impact fragments of organic nanoparticles.

"It turns out that ring rain is more like a ring rain," said lead author of the study, Hunter Waite. CassiniIon and Neutral Mass Spectrometer (INMS), in a statement prepared by the Southwest Research Institute.

"Although the INMS was designed to investigate gases, we were able to measure the ring particles because they reached the spacecraft at speeds so high that they vaporized.

"Water ice, along with newly discovered organic compounds, is falling off the rings much faster than previously thought – up to 10,000 kg of material per second."

Waite's colleague and co-author, Dr. Kelly Miller, said that molecular hydrogen was, as expected, the most abundant atmospheric constituent.

The type of chemicals used in a camping stove

"But the downpour coming from the rings included lots of water as well as molecules like butane and propane – the kind of chemicals you can use for a barbecue or camp stove," Dr. Miller said.

The paper also shows that Saturn's innermost D ring is casting dust grains covered by a chemical cocktail into the planet's upper atmosphere. This is happening at a phenomenally rapid rate that, over time, can change the carbon and oxygen content of the atmosphere.

"This is a new element of how our solar system works," said Thomas Cravens, a professor of physics and astronomy at the University of Kansas, and also co-author of the new article.

A hole in the bucket

"Two things surprised me. One is the chemical complexity of what was coming out of the rings – we thought it would be almost entirely water based on what we've seen in the past, Dr. Cravens said.

"The second thing is the sheer quantity of it – much more than we originally expected."

In a prepared statement from the University of Kansas, Dr. Cravens said, "We know that you are colliding with the ring material at least 10 times faster than we thought. If it is not being replenished, the rings will not last – you have one hole in your bucket. "

He said that Jupiter probably had a ring that evolved into the current thin ring, and could be for similar reasons.

"Rings come and go," he said. "At some point, they gradually drain unless somehow they are receiving new material."

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