Black holes may sound like science fiction, but there is significant evidence to prove they are real.
Some of Hawking's theories revolutionized the way we view the universe, but others still leave scientists scratching their heads.
A high-altitude balloon mission would investigate a controversial way to reduce global temperatures.
Why is the universe the way it is? Over the years, scientists have explored many ways to explain the cosmos, leading to some crazy-sounding ideas.
The European Space Agency’s Space Situational Awareness program is tackling the problem on three fronts.