The Tunguska event that shook Siberia one century ago, on June 30, 1908, prompted a lot of questions on the elements that produced it. This is believed to have been the largest impact event in the recent history of our planet.

The effects of what is now believed to have been a meteorite were felt on an area of 830 square miles, knocking down approximately 80 million trees and sending a strong shockwave miles away from the epicenter of the explosion.

The massive blast wasn’t in fact caused directly by a meteorite, some scientists argue, but by an air burst provoked by a meteorite exploding in mid air. Witnesses at the time described people and houses being thrown in the air, and some even bursting into flames.

The description of the event was less visual, and more connected to a series of sounds, which have been compared to artillery fire.

Researchers have calculated that the meteorite was approximately 100 feet wide, weighted around 617,000 tons and traveled at 21,000 miles per hour. It has been assumed that the meteorite exploded four to six miles above Earth’s surface.

Initial assessments of the damages estimated that the blast was between 10 and 15 megatons (beating the Hiroshima atomic bomb by 1,000 times), but the latest estimations have situated it somewhere between 3 and 5 megatons.

Unfortunately, it wasn’t until 1927 that scientists were able to investigate the area. Traces of nickel and iridium found at the scene come to support the meteorite theory, while the fact that no signs of extraterrestrial materials have been found suggest that the explosion took place somewhere above the Earth’s surface.

The event that marked the beginning of the 20th century goes to show how vulnerable we are to such hazardous events. Moreover, the chances for another meteorite to reach or dangerously approach Earth’s surface remain real, and scientists are currently working on methods to alter the course of all dangerous objects from outer space threatening our planet.