Among the most unusual objects in the universe, quasars (quasi-stellar radio sources) are strong radio sources with unusual properties. In the early 1960s, a number of powerful radio sources were pinpointed in space which did not correspond with the locations of known objects such as galaxies or nebulae. Astronomer Alan Sandage, studying photographs of an area in the sky where one such object seemed to be, could see only a tiny star with an adjoining smudge. Though the star was compact and not fuzzy like a galaxy or nebula, the star's spectrum was unlike any other seen before, revealing none of the elements known to exist in stars.

Maarten Schmidt (1929-), examining a similar object called 3C273 with the Palomar telescope in 1963, realized that its strange spectrum was actually a normal spectrum with a high red shift. This meant that the object was probably not a star at...