Almost 10 years ago, a NASA spacecraft was able to take several photos of Pluto, known for decades as a planet before it was ...

A ninth planet, Pluto, had been discovered. One of the most fascinating aspects of Pluto's discovery is that it was, in part, ...

FLAGSTAFF, Az. – Whether Pluto is officially a planet is the least interesting thing about the runt of the solar system, astronomers will tell you 95 years after the discovery of the fascinating ...

For that's the day my father, Clyde Tombaugh, a farmboy-turned-astronomer, discovered Pluto, becoming the first American to find a planet. (Or a dwarf planet, as it's now officially known.) ...

Today, when tens of thousands of minor planets have been discovered (most residing in an "asteroid belt" between Mars and Pluto), not even the meanest of teachers would require students to learn ...

Here are the five most surprising things discovered by the deep-space instrument. After almost a decade in space, the New Horizons probe's close encounter with Pluto lasted just six days as it ...

A number of astronomers dispute whether Pluto, discovered in 1930, should really be classified as a planet, because it is so dissimilar from the other eight planets in our solar system.

Several, including EB173, are much larger. Pluto was discovered by Clyde Tombaugh in 1930. Many astronomers believe it would be classified as a minor planet in the Kuiper Belt if it were found today.

The Sedona Heritage Museum hosted Sedona-based author Diane Phelps Budden and Lowell Observatory historian Kevin Schindler ...

There was Pluto, discovered practically by luck in 1930, and that was it. Astronomers photographed squares of the night sky and compared the images to see if anything was moving, but either their ...