"We can't really classify the object yet, as we don't know its orbit," said Scott Sheppard, an astronomer with the Carnegie Institution for Science in Washington, D.C. "We only just found this object a few weeks ago."
Based on its reflectivity, scientists believe the icy body, known as V774101, is between 300 and 600 miles (500 to 1,000 km) in diameter, roughly half the size of Pluto. It is almost 10 billion miles from Earth, or three times farther away than Pluto.
Currently, the most distant planet-like bodies in the solar system are Sedna, discovered in 2003, and VP113, discovered in 2012. At more than 80 times farther from the sun than Earth, the two are still closer than V774101, which is currently 103 times more distant from the sun than Earth.
Sheppard said it will take a year of observations to determine if V774101 travels into Pluto's neighbourhood, a region beyond Neptune known as the Kuiper Belt. This swath of space, which contains thousands of tiny planets, is 40 to 50 times farther away from the sun than Earth.
"If it never gets near Neptune that would make the object very interesting as its orbit would be unperturbed by the giant planets and thus allow us to understand the dynamics of the outer solar system," Sheppard wrote in an email.
Sheppard is part of team that is conducting the most extensive search for distant bodies in the solar system.
"It is very much like looking for a needle in a haystack as the night sky covers a very large area that can only be searched one telescope pointing at a time," Sheppard said.
The discovery was unveiled at an American Astronomical Society planetary sciences meeting in Maryland this week.
© Thomson Reuters 2015