World Asteroid Day is marked on June 30 to acknowledge and study the impact of asteroid hits on Earth. The UN website says that we mark “30 June International Asteroid Day in order to \"observe each year at the international level the anniversary of the Tunguska impact over Siberia, Russian Federation, on 30 June 1908, and to raise public awareness about the asteroid impact hazard.\" Asteroids are defined as small, rocky objects that orbit the Sun. Although asteroids orbit the Sun like planets, they are much smaller than planets. Most of them are located in the main asteroid belt—a region between the orbits of Mars and Jupiter. And hence while they revolve around the Sun, they sometimes get pulled into the Earth’s orbit and pose a danger. This day is hence observed with a view to educate the common public about the risks of asteroids and the opportunities in the field.
