International Asteroid Day: Know the Possibility of Collision with Earth and Key Facts
International Asteroid Day is observed every year on 30 June to raise awareness about asteroids and the potential risks they pose to Earth. The United Nations officially recognized this day to educate people about the importance of planetary defense.
If you’re interested in space and celestial objects, then today’s observance holds special importance. Asteroids, which are rocky bodies orbiting the Sun, are remnants from the early formation of the solar system—about 4.6 billion years ago. Unlike planets, they are much smaller in size and mainly exist in the asteroid belt between Mars and Jupiter.
Why June 30?
The date was chosen to mark the anniversary of the Tunguska event, which occurred on June 30, 1908, in Siberia, Russia. It remains the largest recorded asteroid impact on Earth. In memory of this event, the UN declared June 30 as International Asteroid Day in 2016, aiming to promote global awareness and research efforts. The initiative also highlights the work of organizations such as the United Nations Office for Outer Space Affairs (UNOOSA), the Committee on the Peaceful Uses of Outer Space (COPUOS), and the International Asteroid Warning Network.
How Are Asteroids Formed?
During the formation of the solar system, dust particles began clumping together to form larger masses called planetesimals. These attracted more dust and gas due to gravity, eventually forming planets. The leftover fragments that didn’t become planets are what we now call asteroids. Some broke into smaller pieces due to collisions, while others merged into uniquely shaped rocky bodies.
Could an Asteroid Hit Earth?
There is always a possibility of an asteroid colliding with Earth, though major impacts are extremely rare. One example is the Barringer Crater in Arizona, formed around 50,000 years ago by an asteroid about 30 to 50 meters wide.
According to NASA’s Center for Near-Earth Object Studies (CNEOS), the chance of a large asteroid hitting Earth within the next 100 years is very low. Scientists use precise astrometric techniques to track asteroid orbits, helping predict potential threats with high accuracy.