Add Yahoo as a preferred source to see more of our stories on Google. This image of Pluto was made after the New Horizons spacecraft flew past the dwarf planet on July 14, 2015, from a distance of ...

Picture a star, about half the sun’s mass shining with a dim red light. Lumbering around it on a 5,000-year orbit is a huge ...

On the 20th anniversary of Pluto’s infamous demotion, Mike “Pluto Killer” Brown explains why any reversal of that decision ...

Add Yahoo as a preferred source to see more of our stories on Google. Earth has a newly-discovered neighbor in the solar system. But the heavenly body – possibly a dwarf planet à la Pluto – isn't a ...

Learn how Pluto nearly kept its planet status in a proposed 12-planet Solar System as its demotion marks its 20th anniversary ...

Unpopular opinion time, Pluto being reclassified as a dwarf planet was a great thing for our understanding of the solar ...

For the first time since its discovery in 1920, Pluto is entering the outer solar system—a journey that’s slowly thinning out its atmosphere.

Twenty years after Pluto lost its planetary status, the debate continues as scientists still disagree over what defines a ...

The discovery of the Kuiper Belt revealed thousands of icy objects near Pluto, challenging its status as a planet. After the ...

Since it was stripped of planetary status, Pluto’s defenders have been fighting the decision – and they’re only getting more passionate ...

Pluto is a bit of a loner. The dwarf planet is no longer considered a regular planet; it does not orbit on the same plane as the solar system's eight planets; and its orbit is both highly elliptical ...