A new object has been discovered that orbits the Sun in the most distant trajectory known in our Solar System so far.
Ten years ago an object named Sedna was discovered which stretched our previously defined Solar System boundaries. Sedna was found to be three times further from the Sun than Pluto; at its furthest point in orbit it is 130 billion kilometers away, and at its closest 13 billion kilometers from the Sun. Pluto is found in the Kuiper belt, which is a region filled with tens of thousands of icy bodies; Sedna lives in a region outside of this called the Oort cloud. This is where the new object, named 2012 VP113, was found. The results were published in the journal Nature yesterday.
2012 VP113 is probably a dwarf planet, and was discovered by scientists Chadwick Trujillo and Scott Shepperd whilst searching for distant objects with a Dark Energy Camera. They noticed this object during their first observation, and were able to track it for months until they could decipher its full orbit. Intriguingly, despite Sedna coming in closer proximity to the Sun during certain times of its orbit, 2012 VP113 only reaches 452 astronomical units (AU) at its furthest point from the Sun, whereas Sedna can reach as far as 1,000 AU. One AU is approximately 150 million kilometers, to give you some idea of how far away that is, and is the mean Earth-Sun distance.
2012 VP113 was found to be approximately half the size of Sedna, and is predicted to be predominantly composed of ice. One theory that could explain the locations of these objects within the Solar System is that a large traveling planet knocked out some objects whilst passing through the Kuiper belt.
These discoveries are slowly altering ideas of the birth of our solar system. "It goes to show that there's something we don't know about our Solar System, and it's something important," said astronomer Trujillo. "We're starting to get a taste of what's out beyond what we consider the edge."
It is thought that both Sedna and 2012 VP113 could be members of the Oort cloud; collectively the objects within this region could outnumber all other dynamically stable populations in the Solar System. The scientists are currently following another 6 objects which could also be distant members of our Solar System.