A newly discovered warp in the outer Solar System may have been created by a small, rocky world, much closer to the Sun than ...

A new study has proposed the existence of Planet Y, an alternative Planet Nine candidate that is smaller and closer to Earth ...

Pluto is no longer a planet. The world’s top group of astronomers, the International Astronomical Union, has stripped Pluto of the status it has held since its discovery 76 years ago. The body decided ...

When NASA released images of Pluto in 2015 taken by the New Horizons spacecraft, many were captivated by the dwarf planet’s heart-shaped feature, now called Tombaugh Regio. And now the mystery of how ...

Astronomers using the Hubble Space Telescope have uncovered the remains of a frozen, Pluto-like world being devoured by a distant white dwarf star.

Astronomers have discovered three small, icy worlds orbiting the sun near Pluto, on the outer reaches of the solar system. The three newfound bodies are likely big enough to be rounded by their own ...

The Hubble Space Telescope may be getting old, but it still has excellent spotting power — witness its discovery of a fourth moon of Pluto, which is between 8 miles and 21 miles in diameter. Says ...

Scientists tracked the dwarf planet Eris as it passed in front of a star, finding that it's probably about the same size as Pluto. "Whether or not you agree with the IAU's 2006 resolution on the ...

PASADENA, Calif.–To paraphrase a certain young lady from literature, the tenth planet Xena is getting curiouser and curiouser. Data released today by the Space Telescope Science Institute reveals that ...

When you buy through links on our articles, Future and its syndication partners may earn a commission. Pluto's equator is partially covered in ridge-like ice spires known as "bladed terrain." A new ...

The origin of the interstellar object 1I/’Oumuamua has defied explanation. We perform calculations of the non-gravitational acceleration that would be experienced by bodies composed of a range of ...