While for most people Pluto is the most distant planet in the Solar System, things get a lot more fuzzy once you pass Neptune and enter the realm of trans-Neptunian objects (TNOs). Pluto is probably ...

Sedna is drifting into a part of its path where human technology can finally contemplate catching up, and that window will ...

A rendering of the farthest object in our solar system, Sedna, is seen. Sedna is a mysterious planet-like body three times farther from Earth than Pluto. What’s three times further out than the planet ...

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 ...

Planetary scientists continue to debate what Sedna’s presence says about the history of our solar system. Now, S. Alan Stern of the Southwest Research Institute in Boulder, Colorado, says large bodies ...

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 ...

Sedna was initially observed to possess an unusually slow rotation period of 20 days, leading astronomers to hypothesize the presence of an unseen companion moon responsible for this sluggish rotation ...

Sedna, the Solar System's farthest known object, does not have a moon, puzzled astronomers have revealed. Its slow spin was thought to be due to the gravity of a small, companion body. Researchers ...