This screenshot from CCTV (China Central Television) shows China’s first moon rover Yutu, or Jade Rabbit, in an image taken by the camera on the Chang’e 3 moon lander, Dec. 15, 2013. China does not ...

A byproduct of aging nuclear weapons stockpiles could help power spacecraft on missions lasting decades. Americium-241, an isotope that can be separated from aged plutonium, is being studied as a ...

One would think that this excellent question would be easy to answer: A bucket full of “deep space” would contain essentially nothing — and, well, there you are! Outer space is, after all, the closest ...