Einstein Observatory , The first fully imaging x-ray telescope in space, launched by NASA in 1978. Also see HEAO . Used mostly to describe the content of a massive star that is propelled outward in a supernova explosion . The full range of frequencies, from radio waves to gamma-rays, that characterizes light. Another term for light.
Light waves are fluctuations of electric and magnetic fields in space.
The electron has only 0.0005 the mass of the proton . An MeV is equal to one million electron volts. The fundamental kinds of atoms that make up the building blocks of matter, which are each shown on the periodic table of the elements. The most abundant elements in the universe are hydrogen and helium. Despite comprising only a very small fraction the universe, the remaining heavy elements can greatly influence astronomical phenomena.