Asteroid Day (also known as International Asteroid Day) is an annual global event which is held on the anniversary of the Siberian Tunguska event that took place on June 30, 1908, the most harmful known asteroid-related event on Earth in recent history.The United Nations has proclaimed it be observed globally on June 30 every year in its resolution. Asteroid Day aims to raise awareness about asteroids and what can be done to protect the Earth, its families, communities, and future generations from a catastrophic event. For example, 2014 HQ124, discovered April 23, 2014, went past 1,250,000 km from Earth the same year, June 8th, only 46 days after discovery, and 2015 TB145, went past at 490,000 km only 21 days after its discovery.
The International Asteroid Day is a global awareness observance that aims to educate and inspire people to know more about asteroids, their part in the formation of the universe, and how they can be useful. The observance was founded by the astrophysicist Dr. Brian May. In 2016, the asteroid day was officially observed by the United Nations. The observance occurs annually on June 30th.