The light we see today is what the quasar looked like billions of years ago. Some scientists think that when they study quasars they are studying the beginning of the Universe. Quasars give off huge amounts of energy. Astronomers think that quasars are located in galaxies which have black holes at their centers. The black holes may provide quasars with their energy.
Quasars are so bright that they drown out the light from all other stars in the same galaxy.
The word quasar is short for quasi-stellar radio source. Most of them are larger than our solar system. Show me the Level 2 version of this page.