International Asteroid Day 2025

In 2016, the United Nations proclaimed June 30 as the International Asteroid Day.

Tunguska Impact

June 30 is the anniversary of the Tunguska impact, also known as the Tunguska event. On that day a large explosion occurred in the sky over the Podkamennaya Tunguska River in Siberia, Russia.

It destroyed about 2,000 square kilometers (770 square miles) of the forest in the area, flattening about 80 million trees. The area is sparsely populated, and there were no official reports of human casualties.

It is thought that an asteroid or a comet was responsible for the blast. The Tunguska event is considered to be the largest asteroid impact on Earth in recorded history.

What Is an Asteroid?

Asteroids are rocky leftovers from the formation of the solar system 4.6 billion years ago. They revolve around the Sun and are sometimes called planetoids or minor planets.

Asteroids are mainly composed of minerals and rocks, while comets are made of dust and ice. Meteorites can be dust particles or fragments from a comet or an asteroid.

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