by Staff Writers
Copenhagen, Denmark (SPX) Mar 28, 2014
Until now, rings of material in a disc have only been observed around giant planets like Jupiter, Uranus, Neptune and especially Saturn, which is known for its spectacular rings. Now astronomers from the Niels Bohr Institute, among others, have observed the first miniature planet with two rings of ice and pebbles. It is a smaller celestial body, called Chariklo, located two billion kilometers out in the solar system between Saturn and Uranus. The results are published in the prestigious scientific journal, Nature.
Chariklo was located in the Kuiper Belt, a collection of thousands of dwarf planets and comets in orbit beyond Neptune on the edge of our solar system. But at some point it was thrown out of this belt and is now between Saturn and Uranus, where there is a collection of small objects, called Centaur.
Chariklo is the largest of these objects with a diameter of 250 km. This comet like object has been known for many years, but despite careful study, its rings have never been observed before now. This has happened because a new camera is now being used on the Danish telescope at ESO's La Silla Observatory in Chile.
Surprising discovery of rings
He explains that when an object passes in front of a star there is a small dip in the star's brightness and they could see that there was also a dip in the brightness outside the object. This showed that there was a ring of material in a disc around the little object, Chariklo.
"We were not even looking for rings, because they had never been observed around small objects like Chariklo, so it is a totally surprising discovery. The entire passage only lasted 5 seconds, but we could even determine incredible details about the rings. There are two separate thin rings, which are comprised of ice particles and pebbles.
The two rings are only 3 and 7 km wide and no more than a few hundred meters thick. There are 14 km between the centers of the two rings and there is a 9 km wide gap between them. They have been measured at a distance of two billion kilometers with an accuracy of plus/minus a few hundred meters. It is really impressive," says Uffe Grae Jorgensen.
Perhaps formed by collision
"What we are witnessing is perhaps the unveiling of an object that is in the middle of the same stage of development as the Earth and the Moon 4.5 billion years ago, when there was a giant collision between Earth and another planet.
"In the collision, material hurled out in all directions, forming a circular disc around the Earth, which gradually condensed and formed the Moon. Similarly, we believe that another celestial body crashed into Chariklo and a good deal of material was cast out and formed rings. If the two discs around Chariklo gathers and forms a moon, it will be approximately 2 km in diameter," explains Uffe Grae.
In addition to the observations with the Danish telescope at La Silla Observatory in Chile, Chariklo was also followed in lower time resolution from six other observatories in South America, which together made it possible to determine Chariklo's shape and size. There were only a few minutes of observations in total, but the result was the breakthrough revelation of the comet like miniature planet Chariklo with the two rings.
University of Copenhagen - Niels Bohr Institute
Asteroid and Comet Mission News, Science and Technology
|The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.|