Rings make ripple crashing comets

Schwankens in the rings of Saturn and Jupiter receive a record of the last impact.Comet impact the rings of Saturn enter distinctive corrugated pattern that can be used to this day if the Comet struck.NASA/JPL/Space Science Institute

The rings of Saturn and Jupiter contain waves of comets, which beat them decades ago caused. Monitoring such as rings wobble was able to demonstrate how common Comet are impact - and can also help, astronomers map the planet cores.

Matthew Hedman, an astronomer at Cornell University in Ithaca, New York, and his colleagues discovered that ripple by the spacecraft Cassini in 2009 in one of Saturn's rings in images. The rings edge on sunlight striking revealed previously unseen light and dark bands in the planet C ring, which is located between about 74,600 and 92,000 km away from the planet. "It's the same thing you see when sunlight race over a corrugated Tin Roof," Hedman says.

The waves appear as particles in the rings above and below, like people in a Mexican wave move. The ripple made as part of the ring joints was run over. The time passed these tilt, become an increasingly stricter spiral, which means that the shorter the waviness wavelength, the more founded before it in was.

Using this relationship, calculated Hedman and his colleagues, that the ripple in the year began in 1983 and founded, that it was caused by invisible comet impact. They argue as the Comet broke kg - make bashed in the ring particles to tilt the ring its cloud of debris - with a total weight from 1011 to 1013 and eggs. Earlier Cassini images also a wave in the adjacent D-ring, probably caused, during the same strike, showed Hedman says.

The more time that has elapsed since the impact the closer that ripple in the rings.Courtesy of Science/AAAS

Jupiter provides more evidence, the comets rings ripple make. A team led by Mark r. Showalter of the SETI Institute in mountain view, California, two sets of waves in images of Jupiter's rings found taken by the Galileo probe in 1996 and 2000 and by the new horizons space probe in 2007.

The team calculated that dirt from two comets Jupiter's rings, the first between January and June 1990 and the second between July and October 1994 had taken. The latter date corresponds to Comet Shoemaker-Levy jump in Jupiter in July 1994.

"It only too well, a match for a chance, his seemed like" says Hedman, who worked on both types of calculations. The Saturn and Jupiter seem results in science today1, 2.

It is noteworthy that ring systems comet impact can a record stretching back decades maintained an astronomer at Queen Mary University of London, United Kingdom says Carl Murray,. "In essence, they have developed an entirely new way of dating comet impact," he says.

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Hedman to examine plans for future higher-resolution and all future missions to come from Cassini images of the rings for signs of past collisions. "We poke are to see if we are a picture of how frequent collision events," he says.

Murray notes, the monitoring of the ripples astronomers help you discover the offal - such as the size and form more over the planet their cores, the may not perfectly spherical. The waves are controlled slowly ever-increasing distance of the planet in direction at a rate by the gravity, which in turn is dependent on internal structure on the planet.

"It much of this structure is for astronomers learn hard otherwise, but these particles all kinds of new information could reveal," Murray says.

Hedman M. M., et al. science advance online publication doi:10.1126/science.1202238 (2011).Showalter, M. R., Hedman, M. M. & Burns, j. A. science advance online publication doi:10.1126/science.1202241 (2011).If you something offensive or inappropriate or that otherwise are not met our conditions or Community guidelines, select you the appropriate "this comment report" Link.Kommentare on this thread are marked according to the time of booking.

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