International Asteroid Day
June 30 · Level 10 · #70 of 2238
International Asteroid Day explores the small celestial bodies that preserve clues to the Solar System’s history. The UN observance also explains why detecting objects that approach Earth matters, alongside research into planetary defence.
How it is celebrated: scientists and educators host talks, livestreams and planetarium events. Observatories and science centres explain how researchers find asteroids, calculate their orbits and send spacecraft to investigate them.
The date commemorates the Tunguska event of 1908. A cosmic body exploded above Siberia, flattening a vast area of forest without leaving a large impact crater.