The long, puzzling dwarf planet Ceres, in reality the first named asteroid, has surface features that are much more complex ...

Two decades ago, the International Astronomical Union—which defines and names celestial bodies—redefined the criteria for being a planet, putting Pluto into the new category of dwarf planet ...

Somewhere between a star and a planet, brown dwarfs drift through the galaxy too dim to see with the naked eye and too cool ...

New NASA research hints that Ceres — the closest dwarf planet to Earth — may have once had an ancient "power source" that could have sparked the evolution of extraterrestrial life-forms in the tiny ...

A short video released by NASA uses images taken from the Dawn spacecraft to simulate the experience of orbiting the dwarf planet Ceres, the largest known object in the main asteroid belt between Mars ...

NASA chief Jared Isaacman said at a US Senate hearing that he supports restoring Pluto's status as a planet after a controversial 2006 demotion.

NASA Administrator Jared Isaacman wants to put an end to a decades-long debate among scientists. Is Pluto a planet or not? Isaacman says it should be — but it hasn’t been one for 20 years. That’s ...

NASA’s Hubble Space Telescope recently discovered a small moon orbiting an icy dwarf planet in the distant reaches of our solar system. MK 2 is 100 miles in diameter and is at least 13,000 miles from ...

Astronomers have discovered the first evidence that tiny red dwarf stars can devour their own planets.

It's been 20 years since Pluto lost its status as the ninth planet of the solar system, but we still can't seem to let it go.