Astronomers have discovered the coldest and most distant object ever found in our Solar System, a dark and frigid world smaller than Pluto and three times further away. The new planetoid, named Sedna ...

Far beyond Pluto lies Sedna, a distant and mysterious world. Its strange orbit and icy surface challenge everything we know.

Caltech astronomers have discovered the most distant known object in the solar system, a frigid, near-planet-sized body of rock and ice that is now three times as far from the sun as Pluto. The ...

Here’s what you’ll learn when you read this story: Roughly three times smaller than our Moon, Sedna has an extremely narrow and elliptical orbit, making its closest approach to the sun (perihelion) at ...

Object 90377 Sedna — a distant trans-Neptunian object known best for its highly elliptical, 11,390-year-long orbit — is currently on its way towards perihelion (its closest approach to the Sun) in ...

Our corner of the galaxy got a little stranger this week with the discovery of Sedna, the most distant object ever spotted in the solar system. Now astronomers are puzzling over how it got there.

The discovery of a nearly Pluto-sized object way out beyond the known worlds could jeopardize the status of Pluto as a planet, adding fresh fuel to an argument among astronomers that is likely to last ...

When the distant planetoid Sedna was discovered on the outer edges of our solar system, it posed a puzzle to scientists. Sedna appeared to be spinning very slowly compared to most solar system objects ...

Recent spectroscopic studies of infrared light reflected from the surface of Sedna reveal that it is probably unlike Pluto and Charon since Sedna’s surface does not display evidence for a large amount ...