Neutrinos are often called ghostly particles. They have almost no mass and no electric charge. They pass through stars, planets and even human bodies without changing. Billions from the sun stream through your hand every second.

Francis Halzen wanted to catch the rarest kind, the high-energy neutrinos that come from deep space. In 1988 he proposed turning the Antarctic ice itself into a detector. Holes were drilled nearly two kilometres down using hot water. Thousands of light sensors were lowered into the clear glacial ice.

The trick uses a simple fact. When a neutrino hits an atomic nucleus, it produces a tiny flash of light. The sensors track that flash. Its path points back to where the neutrino came from in the cosmos.

The project took an international team of more than 450 people from 58 institutions in 14 countries. It worked. IceCube found high-energy neutrinos from beyond our galaxy. That gives scientists information about distant cosmic sources that no telescope can provide.