Johnny Arnold, age 9, of Darlington, South Carolina, for his question:
Do they know why Saturn has rings?
Our eyes cannot behold the beauty of Saturn's rings without a magnifier. The first person who saw them was the great Italian astronomer, Galileo. He used a home made beginner type telescope. This was more than 360 years ago. Many astronomers have tried to figure how those bright golden rings were formed. They made several good suggestions but nobody knew for sure. Now someone has put forth a surprising, brand new suggestion.
Someday soon, a Mariner type spacecraft will survey faraway. Saturn and relay close up information back to curious minded people on the earth. This just might solve the mystery of how the razzle dazzle rings were formed. While we wait, a clever radar system has solved a few mysteries about the material from which the rings are made.
At present, astronomers cannot prove how Saturn got its golden halo. Until recently, the most popular theory suggested they were formed by an accident. As we know, our golden moon is held in a captive orbit. It is held there by the mighty pull of the earth's gravity. The same holds true for the moons of Saturn. We know that the big planet holds ten orbiting satellite moons. Powerful telescopes were needed to detect the small ones and there may be others.
Many astronomers suspected that long ago a satellite came too close to its giant parent planet. And the gravity of mighty Saturn shattered it to pieces. It was thought that the rings were formed by the fragments, still orbiting around, above the planet's wide equator. Someone deduced that the fragments must be finer than fine particles, possibly dust and icy crystals of frozen gases.
But recently radar detectors have revealed that at least some of the ring particles are sizeable chunks, perhaps like stones and boulders. And right after this, a Russian astronomer suggested that the rings may not be an accidentally shattered moon at all. They just might have been created by shattering accidents that happened on the surface of Saturn.
The idea arose from an unusual comet that appeared in 1969. Astronomers had thought that all comets are old timers, older than the planets. A comet called 1969 proved to be a youngster. It seems logical to suppose that it may have been created from material that exploded out into space by a volcanic eruption. The new theory suggests that a super volcano on Saturn may have erupted the ring material far above the surface. This new idea is an interesting one, but so far nobody can prove it.
We still have volcanic outbursts on the earth. So do Mars and other planets. We had a whopper in the 1880s that blew the top off a mountain. There is evidence that the earth had even bigger ones in the dim distant past. So did Mars. Ages ago, gigantic eruptions on the giant planets might have exploded lots of material out into space. Some may have taken off and become moons. Some may, dust may, have stayed fairly close to home and formed the golden rings around Saturn.
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