X-ray astronomy

Detection of X-rays from intensely hot gas in the universe. Such X-rays are prevented from reaching the Earth's surface by the atmosphere, so detectors must be placed in rockets and satellites. The first celestial X-ray source, Scorpius X-1, was discovered by a rocket flight in 1962.

Since 1970, special satellites have been put into orbit to study X-rays from the Sun, stars, and galaxies. These include the Chandra X-Ray Observatory and the Röntgen Satellite. Many X-ray sources are believed to be gas falling into neutron stars and black holes.