Feature Astronomy

Invisible Universe

X-ray astronomy opens a new window on the most energetic cosmic events

By Ron Cowen

- More than 2 years ago

Part one of a two-part series on recent findings in X-ray astronomy and on its future

NASA’s Chandra X-Ray Observatory. CXC
X rays (red dashes) striking Chandra’s four nested, barrel-shaped mirrors that make up its telescope. CXC/D. Barry
The supernova remnant Cassiopeia A. In this image, the intensity of low-, medium-, and high-energy X rays are shown in red, green, and blue, respectively.