World Asteroid Day 2023: When Siberia shook with a mega explosion equal to 15 megatons of TNT
On June 30, 1908, it was a normal day on Earth when a mega-explosion equivalent to 12 to 15 megatons of TNT occurred in the air over Siberia.
World Asteroid Day 2023: Asteroids are rocky fragments left over from the formation of the solar system about 4.6 billion years ago. (Representative Image/Getty)
An asteroid is classified as a near-Earth object
The cause of the Tunguska explosion is still not fully understood
The Tunguska event marked a turning point in asteroid exploration
World Asteroid Day 2023: Earth is surrounded by giant rocks that occasionally pass by the planet. Sometimes, these rocks, pulled by the Sun in their orbit, are on a direct collision course. Over a century ago, in 1908, one such piece struck Earth.
On June 30, 1908, it was a normal day on Earth when a mega explosion equivalent to 12 to 15 megatons of TNT occurred over Siberia. It was one of the most powerful explosions ever recorded, flattening an area of about 2,150 square kilometers, including local forests, and causing the loss of at least three lives.
This was not an ordinary explosion; a large asteroid had entered Earth’s atmosphere and exploded in the air before hitting the ground.
Asteroids are rocky fragments left over from the formation of the solar system about 4.6 billion years ago. An asteroid is classified as a near-Earth object when its distance from our planet is less than 1.3 times the distance from Earth to the Sun (the Earth-Sun distance is about 93 million miles), according to NASA’s Jet Propulsion Laboratory (JPL).
What Happened on June 30, 1908?
On the morning of June 30, 1908, a bright light appeared in the sky over Siberia. The light was followed by a loud explosion that shook the ground and knocked people off their feet.
The cause of the Tunguska explosion is still not fully understood. The most likely explanation is that it was caused by the impact of a large asteroid or comet. However, no impact crater has ever been found, leading to speculation that the object may have exploded in the air before reaching the ground.
The Tunguska event marked a turning point in our understanding of asteroid impacts and sparked efforts to prepare for future encounters.
Dealing with Asteroids
Scientists have made significant progress in understanding asteroids and comets. We now have a much better idea of how often these objects impact Earth, and we have developed technologies that can detect and track them. We are also developing technologies that could be used to deflect asteroids away from Earth if necessary.
NASA tracks and catalogs these rogue rocks in space and maintains their orbit to predict their movement in advance. We have now developed a global early warning system that allows us to quickly detect and track asteroids that pose a threat to Earth. If an asteroid is on a collision course with Earth, deflection technologies have also been tested in space.
NASA recently successfully demonstrated kinetic impact technology with DART. This technology could hit an asteroid to slightly nudge its velocity and change its orbit if it is on a collision course.
The Tunguska explosion was a wake-up call that Earth is not immune to asteroid impacts