
Quasars – the brightest and most powerful objects in the Universe – are ignited when galaxies collide, astronomers have said.
These celestial objects can be a trillion times brighter than the Sun, according to Nasa.

Quasars – the brightest and most powerful objects in the Universe – are ignited when galaxies collide, astronomers have said.
These celestial objects can be a trillion times brighter than the Sun, according to Nasa.