June 30 is marked every year as International Asteroid Day. Its objective is to create awareness about the dangers posed by asteroids.
International Asteroid Day came into existence in 2016 with the United Nations passing a resolution to mark the anniversary of the Tunguska impact -- the Earth's largest ever asteroid impact -- over Siberia on 30 June 1908.
Tunguska impact was caused by the explosion of a huge asteroid, about 120 feet across, in the atmosphere of Siberia.
According to NASA, pressure and heat led to the asteroid destroying itself and producing energy equaling about 185 Hiroshima bombs.
At least three people had been killed in the explosion and 80 million trees flattened.
After the Tunguska incident, the largest recorded asteroid impact took place in Chelyabinsk in Russia in 2013. Its impact was equal to 440 kilotons of Trinitrotoluene, or TNT, explosives.
The UN says that Near-Earth objects (NEO) -- asteroids or comets -- are "potentially catastrophic threats" to Earth. So far, 16,000 asteroids alone have been discovered.
According to the UN's Office for Outer Space Affairs, asteroid impact is a global issue that requires response on an international level.
"Addressing such a hazard, including the identification of those objects that pose a threat of impact and planning a corresponding mitigation campaign, requires cooperative action in the interest of public safety on the part of the global community," it said.
In line with this objective, two organisations were set up in 2013 and 2014 -- the International Asteroid Warning Network (IAWN) and the Space Mission Planning Advisory Group (SMPAG).
The International Asteroid Warning Network helps countries gauge possible consequences of an asteroid impact and plan mitigation responses.
The Space Mission Planning Advisory Group (SMPAG), meanwhile, helps with the identification of technologies needed for the deflection pf Near-Earth object deflection. Its goal is to create consensus on planetary defense measures.