Saturn ‘Burps’ a Giant, Baffling Storm
Photographs of a giant storm on Saturn taken by the Hubble Space Telescope reveal that the storm has grown so much since it was discovered in September by amateur astronomers that it is several times larger than the Earth, scientists announced Tuesday.
“It might just be the largest atmospheric structure right now in the solar system outside of the sun,” said Andrew Ingersoll, a planetary scientist at Caltech. “The last time Saturn did anything of this magnitude was in 1933.” Ingersoll said it is not clear what drives such a massive storm.
“If you like, Saturn burped,” he said.
The storm nearly encircles the giant planet and has ammonia clouds billowing 150 miles high.
Amateur astronomers discovered the white spot in September, when it was the diameter of three Earths, and it has continued to grow. The Hubble Telescope, with its faulty optical system, can still see relatively close objects reasonably well, scientists said during a news conference at the headquarters of the National Aeronautics and Space Administration. The orbiting telescope was trained on Saturn on Nov. 9 and 11 and again last weekend.
By then, the storm clouds ringed the planet with clearly visible swirls and loops in a band 6,000 miles wide. The highest clouds are red; the ones closest to Saturn’s normal atmosphere are blue.
The 400 pictures taken to date will be made into a film, said Charles Pellerin, director of astrophysics at NASA headquarters. “Pretty soon we’ll be able to watch what some people have called the storm of the century evolve in great detail,” he said.
Astronomers do not know what is causing the great storm.
“These planets like Jupiter and Saturn are fluid objects, all the way to the center,” Ingersoll said. “There are no volcanoes erupting, because there are no volcanoes. There is no solid crust. These planets are sort of bubbling caldrons of liquid and gas.”
Ingersoll discounted the possibility that a comet or other celestial object hit Saturn or that the disturbance was formed by the union of smaller storms.
“It has to be some sort of internal intermittent thing on Saturn, like Saturn burped,” Ingersoll said.
Ingersoll said heat is coming out of the deep interior of Saturn and presumably pressures can build up. The planet’s weather is not just driven by sunlight as it is on Earth.
“I don’t really understand it,” he said. “In some mysterious way, which I don’t have a clue about, Saturn burps in the summertime.”
Saturn, the second-largest planet after Jupiter, is the windiest place in the solar system and the storm is being whipped by a west wind of 1,000 m.p.h.
