Space.com

What's Hot This Week Dwarf Planet Pluto Holds Big Surprises for Speedy NASA Probe by Charles Q. Choi, SPACE.com Contributor Pluto may be small, but it is proving to be big on surprises. With NASA's New Horizons spacecraft now speeding toward it, our understanding of the dwarf planet should transform even further. A Conversation With Pluto's Killer: Q & A With Astronomer Mike Brown by Mike Wall, SPACE.com Senior Writer Five years ago today (Aug. 24), Pluto was demoted from full-fledged planet to a newly created category, "dwarf planet." The International Astronomical Union made the official call. But if any one person can be held responsible for Pluto's "death," it's probably Caltech planetary scientist Mike Brown. Sponsored by: Pluto's Planet Title Defender: Q & A With Planetary Scientist Alan Stern Five Years Later, Pluto's Planethood Demotion Still Stirs Controversy NASA Teams With Publisher on Sci-Fi Book Series Striking Photo Looks Into the 'Eyes' of Cosmic Virgin 45 Years Ago: How the 1st Photo of Earth From the Moon Happened