Add Yahoo as a preferred source to see more of our stories on Google. A new and improved definition for the term 'planet' will soon be proposed that would expand the title beyond the confines of solar ...

The International Astronomical Union defines a planet as a celestial body that orbits the sun, is massive enough that gravity has forced it into a spherical shape, and has cleared away other objects ...

Add Yahoo as a preferred source to see more of our stories on Google. When you buy through links on our articles, Future and its syndication partners may earn a commission. Credit: NASA/Johns Hopkins ...

For many people, the definition of a planet was only made clear in 2006, when the spunky world Pluto was demoted from a planet to a dwarf planet. Now, a team of astronomers is pushing for “planet” ...

Historians and educators have joined astronomers in an effort to break a deadlock on contentious discussions over a definition for the word “planet.” A decision is expected in September, but history ...

As an astronomer, the question I hear the most is why isn’t Pluto a planet anymore? More than 10 years ago, astronomers famously voted to change Pluto’s classification. But the question still comes up ...

The world’s astronomers, under the auspices of the International Astronomical Union (IAU), have concluded two years of work defining the difference between “planets” and the smaller “solar system ...

Hey, remember Pluto? Of course you do! When most of us were brought up in school we learned that there were nine known planets in the Solar System, and Pluto was the one that hung out on the outskirts ...

Scientists have spent 12 years arguing over how to classify Pluto, and a recently published paper offers a new — but surprisingly old — reason for restoring the object's planetary status. The new ...

The International Astronomical Union defines a planet as a celestial body that orbits the sun, is massive enough that gravity has forced it into a spherical shape, and has cleared away other objects ...