International Asteroid Day
June 30
About International Asteroid Day
International Asteroid Day takes place on Tuesday, 30 June 2026. It is a United Nations-sanctioned global day of education that raises public awareness about asteroids, the hazard a major impact could pose to Earth, and the science of planetary defence. The date marks the anniversary of the Tunguska event of 1908, the largest asteroid impact in recorded history.
What is International Asteroid Day?
International Asteroid Day is an annual observance dedicated to informing the public about asteroids: what they are, what we have learned about them, and what humanity can do to protect the planet from a potential collision. It was co-founded in 2014 by a group that included Queen guitarist and astrophysicist Brian May, filmmaker Grigorij Richters, B612 Foundation president Danica Remy, and Apollo 9 astronaut Rusty Schweickart, with backing from the late physicist Stephen Hawking. The day is now coordinated worldwide and recognised by the United Nations, with events ranging from school workshops to major broadcasts hosted by scientists and astronauts.
When is International Asteroid Day?
International Asteroid Day falls on Tuesday, 30 June 2026. The date is fixed and is observed on 30 June every year. It was deliberately chosen to coincide with the anniversary of the Tunguska event, which occurred on 30 June 1908, when an asteroid roughly 50 to 60 metres across exploded over a remote region of Siberia.
Why International Asteroid Day Matters
Asteroids are not a hypothetical threat. The Tunguska blast flattened around 2,000 square kilometres of forest and felled an estimated 80 million trees, releasing energy comparable to many hundreds of Hiroshima-scale explosions. Had it struck a populated area, the loss of life would have been catastrophic. Smaller objects enter the atmosphere far more often, as the 2013 Chelyabinsk meteor demonstrated when it injured around 1,500 people in Russia through shattered glass alone.
The encouraging counterpoint is that an asteroid strike is the only major natural disaster humanity can, in principle, prevent. In September 2022, NASA’s Double Asteroid Redirection Test (DART) deliberately crashed a spacecraft into the small asteroid Dimorphos, shortening its orbit around its companion by 32 minutes. It was the first time humans had measurably changed the motion of a celestial body, proving that a kinetic impactor can nudge an asteroid off course. International Asteroid Day exists to keep this progress, and the work still to be done, in the public eye.
How to Get Involved in International Asteroid Day
There are many ways to take part, whether you are a curious beginner or a committed space enthusiast.
- Watch the official broadcast – Asteroid Day produces live and recorded programming featuring astronauts, astronomers, and mission scientists. Tuning in is the simplest way to learn directly from the experts driving planetary defence.
- Attend a local event – Planetariums, observatories, universities, and science centres around the world host talks, stargazing sessions, and exhibitions. Check what is on near you.
- Visit an observatory or look up – If skies are clear, an evening of stargazing is a fitting way to mark the day. Many amateur astronomy clubs welcome newcomers to public viewing nights.
- Learn about near-Earth objects – Spend time reading about how scientists detect, track, and catalogue the asteroids whose orbits bring them close to Earth. Understanding the monitoring effort is reassuring as well as fascinating.
- Run a classroom or family activity – Teachers and parents can use the day to spark interest in astronomy through impact-crater experiments, scale models of the solar system, or simple research projects.
- Follow the science missions – Keep up with missions such as DART, ESA’s Hera, and NASA’s OSIRIS-REx, which collect data that improves our ability to deflect a threatening object.
- Support science communication – Share trustworthy resources from space agencies and observatories with friends and family to help separate genuine science from sensational headlines.
- Host a watch party – Gather friends to view the broadcast or a space documentary together, turning the day into a social occasion that spreads awareness further.
History of International Asteroid Day
The idea for Asteroid Day grew out of a 2014 declaration signed by scientists, astronauts, and public figures who wanted to accelerate the discovery and tracking of near-Earth asteroids. The campaign was initiated in October 2014 by Brian May, Grigorij Richters, Danica Remy, and Rusty Schweickart, and it was publicly announced that December. Richters had recently directed a film about a fictional asteroid strike, and the project drew on that creative momentum to reach a wide audience.
The first Asteroid Day was held on 30 June 2015 with events in dozens of countries. Its profile grew quickly, and in December 2016 the United Nations General Assembly adopted a resolution proclaiming 30 June as International Asteroid Day, to be observed globally each year. The resolution followed a recommendation from the UN Committee on the Peaceful Uses of Outer Space, lending the day formal international standing.
Since then, the observance has expanded into a year-round educational effort with a major focus on 30 June. The day has become a fixture for the global astronomy community, and its emphasis has shifted in tone over the years from raising the alarm towards celebrating the rapid scientific progress in detecting and, as DART showed, potentially deflecting dangerous objects. If you enjoy days that celebrate scientific achievement, you might also like National Moon Day, which honours the first human steps on the lunar surface.
Noteworthy Facts About International Asteroid Day
- The day commemorates the Tunguska event of 30 June 1908, which flattened roughly 2,000 square kilometres of Siberian forest yet left no impact crater because the asteroid exploded in mid-air.
- Brian May, lead guitarist of Queen, holds a PhD in astrophysics and is one of the day’s most prominent co-founders.
- The United Nations formally recognised International Asteroid Day in December 2016, fixing the global observance on 30 June.
- NASA’s DART mission in 2022 was the first demonstration that a spacecraft can alter an asteroid’s orbit, changing Dimorphos’s orbital period by about 32 minutes.
- The 2013 Chelyabinsk meteor, around 20 metres wide, exploded over Russia and injured roughly 1,500 people, underlining why early detection matters even for relatively small objects.
Frequently Asked Questions
What is International Asteroid Day?
It is a United Nations-recognised global day of education that raises awareness about asteroids, the risk of an impact, and the science of planetary defence. It is co-founded and supported by leading scientists, astronauts, and educators.
When is International Asteroid Day in 2026?
International Asteroid Day is on Tuesday, 30 June 2026. The date is fixed and is the same every year.
Why is International Asteroid Day held on 30 June?
The date marks the anniversary of the Tunguska event of 30 June 1908, the largest asteroid impact in recorded history, which devastated a vast area of Siberian forest.
Spread the Word
Help raise awareness by sharing International Asteroid Day with your friends, family, and followers. Use the hashtags #AsteroidDay and #AsteroidDay2026 on social media. The more people who understand the science of planetary defence, the stronger the public support for the missions that keep watch over our skies.
Related Awareness Days
- National Moon Day & Apollo Moon Landing Anniversary – Celebrates humanity’s first steps on the Moon and our wider exploration of space.
- International Women in Engineering Day – Highlights the engineers behind the spacecraft and instruments that make missions like DART possible.
- National Science Week – A broader celebration of science and discovery for all ages.
Links
- Visit the official International Asteroid Day website
- Explore more awareness days at AwarenessDays.com
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