WASHINGTON, June 15 (UPI) -- U.S. scientists say they've discovered three new objects -- called "Trojan" asteroids -- locked into roughly the same orbit as Neptune.
The discovery was reported Thursday by researchers at the Carnegie Institution of Washington's Department of Terrestrial Magnetism and the Gemini Observatory in Hilo, Hawaii.
Astronomers say the observation offers evidence Neptune, much like Jupiter, hosts thick clouds of Trojans in its orbit, and those asteroids probably share a common source. It also brings the total of known Neptune Trojans to four.
"It is exciting to have quadrupled the known population of Neptune Trojans," said Carnegie Hubble Fellow Scott Sheppard, lead author of the study. "In the process, we have learned a lot both about how these asteroids become locked into their stable orbits, as well as what they might be made of, which makes the discovery especially rewarding."
The recently discovered Neptune Trojans are only the fourth stable group of asteroids observed around the sun. The others are the Kuiper Belt just beyond Neptune, the Jupiter Trojans, and the main asteroid belt between Mars and Jupiter.
The discovery is detailed in the online issue of Science Express.