Hundreds of people who love the little planet that was dissed, gather every year in the Arizona town where Pluto was discovered. They celebrate scientific discovery, history and our solar system’s ...

Add Yahoo as a preferred source to see more of our stories on Google. Once the quirky underdog of our solar system, Pluto held planetary status until 2006, when it got a cosmic demotion that still ...

Is Pluto a planet? What's up with the "space jellyfish?" And are aliens real? Astrophysicist, speaker and author Neil deGrasse Tyson, who is stopping in Pittsburgh later this month, answers our ...

Pluto will complete its first orbit since 1930 in 2178, a historic 248-year space journey that spans generations of humans.

Why does Pluto's orbit take so long? Pluto's orbit is not like those of the eight major planets, which are relatively circular. Instead, it is highly elliptical and tilted. At tim ...

On August 24, 2006, our solar system lost a planet. It wasn't by cataclysmic destruction, but rather by the vote of the International Astronomical Union, which declared that Pluto, considered the ...

Astronomers using the Hubble Space Telescope have discovered a fourth moon orbiting Pluto. Pluto - for the record - is still classified as a dwarf planet. Astronomer Larry Wasserman of Lowell ...

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 ...

PRAGUE, Czech Republic — Leading astronomers declared today that Pluto is no longer a planet under historic new guidelines that downsize the solar system from nine planets to eight. After a tumultuous ...