In the frozen outskirts of the solar system, a reddish dwarf planet orbits in silence. Known as Sedna, it is so distant that one trip around the Sun takes more than 11,000 years. For much of that time ...

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 ...

In 2004, astronomers announced the discovery of a red, frigid planet-like body at the outskirts of our solar system. Michael E. Brown, the Caltech astronomer who spotted the object (and who would ...

James is a published author with multiple pop-history and science books to his name. He specializes in history, space, strange science, and anything out of the ordinary.View full profile James is a ...

While new discoveries about Mars continue to make headlines, another “red planet”—known as Sedna (or 90377 Sedna)—is making its way into the inner solar system. At this moment, the crimson-hued dwarf ...

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 ...

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 ...

In 2003, Caltech astronomer Mike Brown and his team discovered a new addition to the solar system: a small icy world called Sedna. It was a bit of an oddball—taking an extremely elongated orbit that ...

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

The outermost Solar System is a confusing and complicated place. Once you get Neptune, the comets, Kuiper belt objects, and other small icy worlds orbit the Sun in odd patterns. A few of those, ...