Proxima b: Is There Alien Life Just 'Down the Block,' or Even Closer?

Leroy Chiao served as a NASA astronaut from 1990-2005. During his 15-year career, he flew four missions into space, three times on space shuttles and once as the co-pilot of a Russian Soyuz spacecraft to the International Space Station. Chiao has performed six spacewalks, in both U.S. and Russian spacesuits, and has logged nearly 230 days in space. You can read more of Chiao's Expert Voices Op-Eds and film reviews on his Space.com landing page.