National Day

National Near Miss Day

Celebrated on 03/23/2026

Quick Fact

National Near Miss Day commemorates the moment on March 23, 1989, when a massive asteroid—estimated to be about 1,000 feet wide—passed within 400,000 miles of Earth, a cosmic hair's breadth in astronomical terms. If it had hit, the impact would have released energy equivalent to 1,000 atomic bombs, making it one of the closest and most dangerous near-Earth objects ever recorded.

Origins and Establishment of National Near Miss Day

National Near Miss Day was established to raise awareness about the dangers of asteroid impacts and the importance of planetary defense. The holiday was first proposed by the organization 'The Spaceguard Foundation' in the early 1990s, following the close encounter with asteroid 1989 FC (later named 4581 Asclepius) on March 23, 1989. The day was officially recognized by the United Nations in 2016 as part of Asteroid Day activities, though it remains an unofficial observance in many countries.

Evolution and Modern Commemoration

Over the years, National Near Miss Day has evolved from a niche scientific observance to a broader public awareness campaign. Initially marked by academic conferences and astronomy club events, it now includes social media campaigns, museum exhibits, and educational programs about asteroid detection and deflection technologies. Since 2016, it is often celebrated in conjunction with Asteroid Day (June 30), but some organizations continue to observe it on its original date of March 23.

Facts & General Observations

  • The asteroid 4581 Asclepius, which inspired National Near Miss Day, was discovered only 9 days after its closest approach to Earth, highlighting gaps in our asteroid detection systems.
  • NASA's Center for Near Earth Object Studies (CNEOS) currently tracks over 30,000 near-Earth asteroids, of which about 1,000 are classified as potentially hazardous.
  • The energy released by the 1989 near-miss asteroid would have been equivalent to over 1,000 megatons of TNT—roughly 1,000 times the yield of the Hiroshima atomic bomb.

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