View of the solar system. The Pluto Railway is marked in green, Sedna in red, and the newly discovered comet 2006 SQ372 can be seen in blue. Picture: Nathan Kaib
Read aloud Near the orbit of the planet Neptune, astronomers have spotted an object that is extremely far from the sun on its journey through space. The distance between the star and the ice lump 2006 SQ372 is in extreme cases 1600 times as large as the sun-earth distance, researchers said around Andrew Becker of the University of Washington at a symposium in Chicago. The researchers discovered in 2006 SQ372, a 50 to 100 kilometer comet, as part of the Sloan Digital Sky Survey, a large-scale project to capture all possible celestial bodies. Using a special search algorithm, computer programs regularly scanned images of a larger sky sector for supernova explosions. Near a supernova, a paler point was also noticed whose position shifted quickly. "The only objects whose position in the sky changes visibly within one night lie in our own solar system, " explains Lynne Jones, who also participated in the study.

According to the group's calculations, 2006 SQ372 moves on an extremely elongated ellipse that is four times as long as it is wide. The comet needs about 22, 500 years to complete one revolution. Thus he moves away from the sun much more than Sedna, a small planet discovered in 2003, which was previously considered the farthest member of the solar system. Sedna's orbit ranges from 76 to 900 astronomical units, with one astronomical unit equaling 150 million kilometers, the distance between Earth and Sun.

Like Sedna, so in 2006 SQ372 is probably a member of the so-called Oort cloud? a spherical cometary cloud, which probably surrounds the solar system at intervals of 300 to 100, 000 astronomical units. Astronomers assume that from time to time, some chunks of ice from this reservoir are disturbed by the gravity of passing stars and go on a journey into the inner solar system. As they reach Jupiter's orbit, they begin to evaporate and glow brightly in the sky as comets.

2006 SQ372, however, is permanently outside the orbit of the planet Neptune and therefore can hardly be seen on the pictures of the Sloan Digital Sky Survey. Even at its furthest turning point, however, it is still much closer to the sun than the supposed center of gravity of the Oort cloud. "The existence of an" inner Oort cloud "has been postulated for years, " says team member Nathan Kaib. "2006 SQ372 and perhaps Sedna are the first objects that may have come from there. It's very exciting that we can now verify the predictions. "Ad

The discovery of the relatively small ice lump was only possible because he is just at the sunniest point of his orbit. The research team expects that many more celestial bodies will move on similar orbits in the outskirts of the solar system.

Message from the Sloan Digital Sky Survey Ute Kehse

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