Quasar 3C 273. Radio image showing the core (red, top left) of the quasar 3C 273 and the jet (green- blue) emanating from it. Quasars are amongst the most powerful sources of radiation in the sky, emitting the energy of thousands of normal galaxies. They all show a very large red-shift in their spectral lines which, if the Hubble Law is applied, makes them the farthest objects known in the universe. 3C 273 is the nearest quasar known at a distance of about 2000 million light years from Earth. The jet is mainly formed by fast- moving electrons which emit radiation via the synchrotron process.