Two kilometres deep in the glacial ice at the South Pole lies what is perhaps the world’s strangest telescope. This is the IceCube Neutrino Observatory: thousands of detectors spaced throughout a cubic kilometre of ice, looking for the light made by subatomic particles that are streaming through the Earth. Neutrinos are unique particles that pass easily through matter, and they can reach us from hidden places like the interiors of stars and from the most powerful particle accelerators in the cosmos. In this talk I will describe how we do neutrino astronomy at the South Pole, and the universe that neutrinos reveal to us.