The celestial body's unusual orbit “implies that something extraordinary occurred" in the early days of the solar system—and ...

Is there a massive undiscovered planet on the outer reaches of the solar system? The idea has been around since before the ...

"It is possible that a planet once existed in the solar system but was later ejected, causing the unusual orbits we see today ...

An oddly tilted object beyond Neptune moves in perfect sync, one orbit for every ten of Neptune’s, and scientists are ...

In a groundbreaking discoverypublished in The Planetary Science Journal, a team of astronomers led by the Center for ...

Astronomers spotted 139 new objects in our solar system in orbit beyond Neptune. Many of these new trans-Neptunian objects reside in the same area of our system that Pluto does, but some are much ...

Researchers participating in the Discovering the Surface Compositions of Trans-Neptunian Objects program, led by the University of Central Florida (UCF), recently studied these dim objects using ...

A new study reveals the binary nature of a trans-Neptunian object (TNO). A new study authored by Southwest Research Institute scientists Rodrigo Leiva and Marc Buie reveals the binary nature of a ...

The trans-Neptunian object Arrokoth, also known as Ultima Thule, which NASA's space probe New Horizons passed on New Year's Day 2019, may have changed its shape significantly in the first 100 ...

Of the 461 objects described for the first time in the new paper, a few stand out. Nine are known as extreme trans-Neptunian objects, which have orbits that swing out at least 150 AUs from the sun.