World Asteroid Day 2019: Here's why the day is important for humanity.

Near-Earth objects (NEO) are those which can pose a potential catastrophic impact for Earth and its beings and Asteroids are one of them. As of right now, NASA has 16,000 near-Earth asteroids and the last major impact that an Asteroid had on the planet was on 30 June, 1908 near river Tunguska in Siberia.
It is due to this that in December 2016 the UN decided to observe 30 June as World's Asteroid day.
The Association of Space Explorers wrote the proposal for this and it was endorsed by Committee on the Peaceful Uses of Outer Space (COPUOS).
NEOs are recognised to have a massive global impact and a response has been demanded by the United Nations Office for Outer Space Affairs (UNOOSA). The measures that have been taken to counter the threat include identification of those objects and then planning a corresponding campaign for preventing an event from occurring.
The second biggest impact of an asteroid was not too long ago in 2013 when a large fireball entered the atmosphere and disintegrated in the skies over Chelyabinsk. There were no reported casualties.