Wrong meteorite

The Peruvian fireball made it through the earth's atmosphere safe and sound

The rock meteorite that fell in Peru last year did not behave as expected from ordinary fireballs colliding with our planet. Professor of geology Peter Schultz from Brown University (Rhode Island, USA) is sure of this. The expedition that went to the site of the meteorite's fall discovered that this celestial stone resisted the earth's atmosphere to the last and, unlike ordinary fireballs, did not disintegrate into separate pieces.

The incident happened on September 15, 2007, when a mysterious object crashed to the ground with a roar near the village of Carancas near the Peruvian-Bolivian border in a desert area. At the crash site there was a crater about 15 meters in diameter and several meters deep. The first studies showed that a small stone meteorite collided with the Earth near Carancas. This is not particularly sensational, since fireballs of this size pass through the atmosphere of our planet quite regularly. Most often, meteorites do not cause any harm: the likelihood that they will fall in a densely populated area and harm people is extremely small. However, after Schultz’s expedition, it became clear that the Carancas stone was an exception to the general rules of fireball crashes.

It is believed that a meteorite of this type, entering the Earth's atmosphere, quickly begins to heat up due to air resistance and breaks into many small pieces. Most of these fragments simply burn up in the atmosphere before reaching the Earth’s surface, and what does reach leaves not a large crater, but a relatively small dent. However, the crater at Carancas turned out to be surprisingly large. In addition, the study of sand and dust ejected when the meteorite hit the surface revealed traces of specific and very strong deformation. According to Peter Schultz, the car was flying 40-50 times faster than usual - its speed at the surface of the Earth reached 15 thousand miles per hour (over 24 thousand km/h). In addition, the meteorite did not fall in the form of a rain of stone fragments, but in a single piece: contrary to all theoretical expectations, the atmosphere was unable to destroy the cosmic boulder.

According to Schultz, the whole point is the unusually high speed of the Peruvian car. It was rushing through the atmosphere so quickly that the breaking debris could not overcome the “shock wave front” and, instead of moving away from the original trajectory, they were welded together again. At the same time, the meteorite acquired a more aerodynamic shape, which apparently reduced friction. In the end, the car crashed near Carancas, scattering tons of soil around the crater.

If the American geologist is right, then this does not bode well for us. Now the prevailing theory sounds very reassuring to the average person: they say that if a small meteorite enters the atmosphere, then an observer at sea level can stand even directly in its path. This, of course, is some coarsening, but small cosmic rocks successfully burn up while still in the air. But since there are fireballs (and the fastest ones at that) that can change shape, it means that even small meteorites can reach the Earth and potentially lead to serious destruction.

Schultz himself says the following about this: “You will be surprised when you find out how many lakes and ponds are formed by stony meteorites. We just don’t know about it because they turn to dust when they collide.” On the other hand, even if precedents like the Peruvian one occur from time to time, they are still clearly classified as exceptions to the general rule. So it’s hardly worth exaggerating the microscopic risk that a meteorite will fall on your head.

Vladimir DZAGUTO