Short for quasi-stellar radio source: A quasar is a compact, starlike celestial body with a power output greater than the entire galaxy.

The quasars are believed to be the oldest and most distant objects ever detected, quasars are billions of light-years from earth and moving away from us at nearly 80 percent of the speed of light.

Quasars appear to be stars, but they have large red shifts in their spectra indicating that they are receding from the earth at great speeds.

The exact nature of quasars is still unknown, but many believe they are the cores of distant galaxies, the most distant objects yet seen.

Quasars were first identified in 1963 by astronomers at the Palomar Observatory in California.