Pluto's discovery by Clyde Tombaugh, key political changes in Scandinavia and America, plus cultural and scientific milestones.

This is part of a series of articles written by members of the Westfield High School Space and Astronomy Club. Their mission is to share their enthusiasm for space and astronomical events with the ...

On Aug. 24, 2006, the International Astronomical Union voted to strictly define a planet, which ultimately downgraded Pluto from the ninth planet from the sun to a dwarf planet — causing controversy ...

Researchers simulate how an ancient impact left a pear-shaped dent on Pluto. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Breaking space news, ...

When NASA’s New Horizons mission flew past Pluto in 2015, it gave humanity our first glimpse of a colossal depression on the isolated world. It's named Sputnik Planitia. Comparable in size to the ...