QUASAR

Quasars are among the most mysterious and fascinating celestial objects known. These are very distant galaxies, the farthest known to us, which emit an enormous amount of energy from the nuclear region. They are 13 billion light years away and more! Since the speed of light is finite, this also means that the radiation of the quasars we observe today was emitted billions of years ago: these objects appear to us as they were in the first billions of years of the universe's life. In this sense it is sometimes said that quasars can represent the "infancy" of galaxies.