Methane Dwarf Beacon: Cutoff Frequency Reveals Magnetic Field
Radio astronomy began with the mysterious noise caught by the antenna of Karl Jansky and the rhythmic pulses that Jocelyn Bell Burnell playfully called 'little green men'.
A Lighthouse at the Edge of the Universe
In the first few hundred million years after the Big Bang, the universe was a dark ocean in which the first stars and black holes ignited. Some of those black holes shot out narrow jets of plasma traveling at nearly the speed of light. If such a jet points straight at Earth, we see it as a bright spot: a blazar.