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The largest meteor strike to hit Earth in more than a century awakened the quiet Russian city of Chelyabinsk on February 15, 2013, shortly after dawn. As the meteor passed directly above the city and fell through Earth’s atmosphere, several individuals recorded it on film. This provided scientists with crucial information about the meteor’s origin and mode of journey to Earth. The meteor was 30 times brighter than the sun and contained 20–30 times more energy than the atomic bomb unleashed on Hiroshima, according to the residents of Chelyabinsk. The meteor did not strike the ground; instead, it exploded 29.7 kilometers above the surface as a result of its incredible speed, creating a blinding flash, a cloud of hot dust and gas, several smaller meteor fragments, and a strong shock wave. The latter was so powerful that it blasted out the windows of homes, businesses, and industries and knocked many off their feet. Although the collision indirectly injured 1,500 people, things could have been far worse if the meteor had made direct contact with the Earth.

The meteor was a typical rock. Scientists have determined that the meteor came from the asteroid belt between Mars and Jupiter’s orbits after watching videos of its path. It weighed between 12,000 and 13,000 metric tons and had a diameter of 0 meters when it entered the Earth’s atmosphere. It fragmented at an altitude of between 45 and 50 kilometers as it plunged into the upper atmosphere at a speed of about 19 km/s, or 50 times the speed of sound. These occurrences typically occur over oceans or sparsely populated areas every IO years or so. This particular strike was over a large metropolis and was witnessed by plenty of people, serving as a reminder of how frequent such events are.

There are multiple stages to a meteor strike. A meteor’s temperature while in motion might be as low as -100 C. Up until Earth’s gravity accelerates it to 17 kilometes per second, it moves at a speed of about 5 kilometers per second. When it reaches 100 kilometers above the earth, three seconds after it first starts to encounter the atmosphere 140 kilometers above the Earth, there is negligible air resistance. The meteor now glows as the material on its surface melts and the air grows dense. The meteor loses 3 to 6 millimeters of surface mass each second as it heats up to above 1800 C, and the mixture of burning gas and dust produces a fireball. The meteor’s core temperature is still relatively low due to the rapid rate at which material is lost through heat, but a tail of vaporized dust and gas is now visible. These tails are frequently visible for up to 45 minutes, and the meteor’s break-through of the sound barrier may be accompanied by a sonic boom. The meteor slows down by 70% as it approaches the Earth, and it may split and break apart during this time. While some meteors enter dark flight at this stage, when they slow down so far that their burning ends and they fall to the ground as a cold rock, others burst into powerful airbursts.

Only a few sizable fragments of the meteor were remained after the Chelyabinsk airburst: the largest fragment was discovered by divers at the bottom of Lake Chebarkul. One rock was collected close to the village of Timiyazevskiy. Since a meteor burst over a region near the Tunguska River in Siberia in 1808, this one was the biggest to hit Earth. The majority of scientists believe that an asteroid with a diameter of about 36.5 meters and a speed of around 54,000 kilometers per hour entered the atmosphere above Russia, despite the fact that information regarding the occurrence is scant. It detonated in an airburst at a height of 28,000 feet, unleashing energy roughly equivalent to 185 Hiroshima atomic bombs and uprooting trees over an 800 square mile area. On average, airbursts the size of Tunguska are thought to occur every 1,200 years. However, in light of the Chelyabinsk meteor, scientists now believe there may be a tenfold increase in the likelihood of comparable things colliding with our planet.