Astronomers have identified the most distant object ever discovered in our solar system: an object believed to be icy in nature and is located more than 15 billion kilometers (nearly 10 billion miles) from the sun, or three times more distant than Pluto.
According to BBC News, a team led by Scott Sheppard of the Carnegie Institution for Science, and Chad Trujillo of the Gemini Observatory in Hawaii found the object. Using the National Astronomical Observatory of Japan’s Subaru Telescope, it was identified as V774104. They presented their findings this week at the annual meeting of AAS Division for Planetary Sciences.
Early analysis of V774104 suggests that it is 500 to 1,000 km (310 to 620 miles) across and is currently 15.4 billion kilometers or 103 astronomical units (AU) from the sun, Science said on Tuesday. The previously recognized most distant object—the dwarf planet Eris—travels along a path that takes it between 5.7 billion km and 14.6 billion km from the Sun.
Additional research will be needed to discover the shape of the object and the exact path of its orbit through the solar system, but scientists think it may be a new member of an growing class of objects whose unusual orbits suggest they are influenced by nearby stars or other planets.
New object could join an exclusive club
As Science explained, if V774104’s orbit eventually brings it closer to the sun, it would be part of a more common group of icy worlds whose orbits are altered by gravitational interactions with Neptune. If its orbit never gets any closer to the sun, however, it would join dwarf planets Sedna and 2012 VP113 in never coming within 50 AU of the solar system’s central star.
The orbits of their planets are currently closer to the sun than Eris, but will ultimately take them further out into space (66 billion km and 140 billion km, respectively, according to BBC News). Sheppard refers to them as “inner Oort cloud objects,” telling Science that their orbits cannot be explained “from what we know about the solar system.”
Solar system formation models suggest that they were not likely created with these unorthodox orbits. Instead, scientists believe that they might have been perturbed gravitationally and forced out of their previous orbits due to a close encounter with a planet—perhaps one forcibly expelled from the solar system early on during its formation. Another theory is that they were taken from another star that formed in the same stellar nursery as our sun some 4.6 billion years ago.
Regardless of which category it falls into, “the discovery of V774104 is more proof that the solar system is bigger than we thought,” said Joseph Burns, an engineering and astronomy professor at Cornell University, according to the AFP. “We need a little more time to pin down the orbit and determine the object’s exact size, but it must be big to see it at this distance.”
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Feature Image: Artist’s impression: Dwarf planet Sedna’s orbit will take it 140 billion km from the Sun. Credit: NASA/JPL-CALTECH/R.HURT
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