What's the most powerful thing in the universe? A star? A supernova? A black hole? None of those compare to the epic awesomeness that is a blazar. A blazar is the Turducken of awesome space objects: it's a supermassive black hole inside a radioactive accretion disk inside an active galaxy. Oh, and it shoots jets of radiation from either end at close to the speed of light, right in our direction. Let us explain.
Most large galaxies contain supermassive black holes at their centers (even our own Milky Way). Black holes suck the gas, dust, and other debris around them so fast that not everything can keep up. This forms a sort of traffic jam around the black hole known as an accretion disk.
The gravitational pressure exerted by the black hole on this disk is enough to heat it up to millions of degrees, making it emit a massive amount of radiation. The black hole, meanwhile, is spinning rapidly, which forms a magnetic field strong enough to turn the radioactive material into powerful jets that blast out of each end at close to the speed of light for hundreds of thousands of light years.
Technically, we just described three objects. How's that? A black hole that shoots a radioactive jet perpendicular to our vantage point is called a radio galaxy. If that jet is at an angle, it's called a quasar. If the jet is pointed right at us—making it bright enough to be detectable by Earth-based instruments as far as 9 billion light-years away—it's a blazar.