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 ...

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 ...

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 ...

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 ...

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 ...

Sedna is drifting into a part of its path where human technology can finally contemplate catching up, and that window will not reopen for roughly the span of recorded civilization. Its 11,400 year ...

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 most distant known object in the solar system, appears to rotate about every 20 days, so slowly that scientists thought it had to have a moon, but a month of searching since its discovery ...

Sedna is a solar system body that is one of the most distant bodies found in our solar system. The object's closest approach to the sun is far greater than Pluto's distance away from Earth — at a spot ...

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 ...