Beyond Pluto lies a collection of frozen worlds that challenge traditional ideas of what planets should be. This episode ...

Scientists have detected methane gas glowing faintly above Makemake, an icy dwarf planet smaller and farther than Pluto in space. Until now, Pluto was the only object that far out in the solar system ...

Add Yahoo as a preferred source to see more of our stories on Google. Digital art of distant planet - Dottedhippo/Getty Images On August 24, 2006, our solar system lost a planet. It wasn't by ...

The system, observed using the European Space Agency's Cheops space telescope, consists of four planets — two rocky and two ...

Astronomers have uncovered a planetary system that challenges conventional theories of planet formation. The system likely includes a rocky planet that formed beyond the orbits of its gaseous ...

Since the 1990s, scientists have discovered approximately 6,100 planets outside our solar system, called exoplanets.

(CNN) — The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have ...

The science community may be ecstatic over the discovery of a ninth planet, but the former planet "Pluto" had a totally different reaction. Hours after scientists announced there's solid evidence of ...

Discover the Kuiper Belt: a frozen ring of dwarf planets and trillions of icy bodies, currently being explored by NASA's New Horizons mission.