Cosmic ray

Cosmic flux versus particle energy at the top of Earth's atmosphere

A block of silica aerogel in a hand.

Temperature map of the cosmic microwave background measured by the Planck spacecraft

01The pigeons roosting inside the horn antenna were trapped and relocated twice before the engineers accepted the hiss was cosmic.
02Penzias and Wilson won the 1978 Nobel Prize in Physics — accidentally, while testing satellite communication equipment.
03Princeton cosmologist Robert Dicke had been building a detector specifically to find this radiation; Penzias called him first, and Dicke told his team: 'We've been scooped.'

In 1991, a single proton hit Earth's atmosphere carrying 3×10^20 eV — the kinetic energy of a baseball thrown at 90 mph. It had no business existing; physics said it couldn't travel that far.