MOSCOW, March 29, Nikolai Guryanov. A meteorite capable of destroying human civilization will fall to Earth earlier than thought. What the new calculations are based on and what the scientific community says about it — in the material.
«Collisions will be»
The death of humanity as a result of an impact from space is one of the most popular doomsday scenarios. And quite possible. According to Igor Mitrofanov, head of the Department of Nuclear Planetology at the Space Research Institute (IKI) of the Russian Academy of Sciences, in the future there will definitely be «collisions with large asteroids that the earth's civilization will not survive.»
Dinosaurs died out 66.5 million years ago, most likely due to a meteorite. He left in Mexico the Chicxulub crater with a diameter of 17-20 kilometers. According to Mitrofanov, such an event is likely to repeat itself over the next 100 million years.
March 7, 08:00
But this is unlikely to happen in the near future. In 2015, the Swedish Global Challenges Foundation, together with the Institute for the Future of Humanity at Oxford University, named the 12 main planetary risks for the next 100 years. The collision of the Earth with a large celestial body took ninth place — after the uprising of artificial intelligence, nuclear war, a pandemic and other threats. The probability of a catastrophic strike from space is one hundredth of a percent.
It looks like these forecasts will have to be revised for the worse.
Ten times stronger than an atomic bomb
To assess the probability of large meteorites falling to Earth, scientists study large impact craters on the planet. The dimensions of the comic object are determined by the diameter of the funnel. Then the frequency of strong impact events is extrapolated.
James Garvin of NASA's Goddard Space Flight Center concluded that the calculations were wrong. In his opinion, four known impact craters in different parts of the planet are actually much larger. Accordingly, the objects that left these traces are also larger. Thus, the risk of disaster is much higher.
Garvin and his colleagues used Planet's catalog of satellite imagery. It is a private organization created by former NASA employees. At its disposal is a fleet of 200 small orbiters, the so-called cubesats. Each with a powerful telescope. The system gives a «picture» with a resolution of three and a half meters.
Based on thousands of overlapping images, scientists created a 3D map of the craters. Added data from two NASA altimeter lasers, one of which «sees» through the forests. Removed from the map everything that is not related to impact events. And they used an algorithm developed by Garvin to search for ring structures on Mars.
Small craters showed no anomalies. And around four large ones about a million years old — Zhamanshin (Kazakhstan), Pantasma (Nicaragua), Bosumtwi (Ghana) and Itturalde (Mexico) — twice as many were revealed by one more ring.
In particular, the Zhamanshin crater is 13 kilometers away. However, Garvin discovered that he had an outer rim with a diameter of 30 kilometers. Pantasma in Nicaragua «grew» from 14.8 to 35.2 kilometers.
The explosions that took place there ranged from 300 to 700 megatons. This is an order of magnitude more than that of the most powerful nuclear weapon in the world — the Soviet Tsar Bomba AN602 (50-60 megatons).
«Enough to throw some of the Earth's atmosphere into space. Although these impacts were not as destructive as the impact of the meteorite that killed the dinosaurs, they could affect the global climate and cause local extinctions,» writes Science.
The stakes are too high
The scientific community treated these results with caution. According to Brandon Johnson, a planetary scientist from Purdue University (USA), the outer rings of craters, if they really exist, could be formed by ejecta after impacts. Garvin counters: it is unlikely that the ridge of rubble would have survived for a million years. He explains the volatility of craters by strong erosion.
According to previous calculations, which, in addition to ground data, also took into account the number of large craters on the Moon and the size of potentially dangerous asteroids in Earth orbit, a meteorite a kilometer or more in size collides with the planet every 600-700 thousand years .html» data->
According to Garvin, in the last million years alone, four such objects crashed into continents (that is, once every 250 thousand years). But two-thirds of the planet is covered with water. This means that many more dangerous meteorites have actually fallen to Earth.
Garvin admits that his team has «proven nothing» so far and field studies are needed to confirm the results. On this, other scientists, including skeptics, agree with him: the stakes are too high to ignore this hypothesis.