16 tons per year, as many large meteorites falls annually on the Earth’s surface. Such estimates, made by scientists by counting how many meteors falling every year in Antarctica.
What is the number of meteorites annually fall on the Earth in the form of large stones, trying to figure out by British scientists on the basis of studies conducted in the ice of Antarctica.
Their verdict is: if you take into account the meteorites, whose weight exceeds 50 grams, each year, the Earth receives over 16 tons of similar gems.
This estimate does not take into account the smaller stones, and, of course, dust, which is every second bombards our planet. “The vast majority of objects falling to Earth is very small, says Dr. Geoff Evatt, University of Manchester, author of a study published in the journal Geology. – We’re talking about objects hitting the earth’s surface, break up into fragments with a total weight of over fifty ounces. Usually their weight in the amount of up to 50 gram to 10 kg. more Objects that are very, very rare.”
A study appearing in Antarctica meteorites have joined several groups of British scientists – Cambridge, Imperial College London and the British Antarctic service.
One of the most important achievements of their work – the creation of a model that predicts the dependence of the frequency of meteorites falling on the latitude of the place.
Thus, calculations have shown that in polar regions the frequency of meteorites falling is only 60% of the rate of deposition near the equator.
Scientists have long known that Antarctica is the best place to search for meteorites. The reason is simple – the fallen on the ice stones are clearly visible, they are longer present on the surface and therefore more are. For this reason, hunters Antarctic meteorites often go where the movement of glaciers formed the so-called zone of the jam— there is an increased concentration of meteorites.
In his study of Evatt and his colleagues set out to investigate how many meteors fall in a certain area – the chosen ice field near the Shackleton mountains in East Antarctica.
The result exceeded expectations of the hunters in the two systematic searches in 2019 and 2020, they found about 120 meteorites.
After receiving the result in the selected areas, the researchers realized that can conduct assessments of deposition of meteoric matter in the zoom ratio of the entire planet. To do this, they took into account how the Earth attracts the passing of near-earth asteroids, and as the latitude of the place affect the frequency of falling.
According to scientists, the estimates can be independently checked by tracking the fireballs that occur when falling asteroids in the Earth’s atmosphere. This can be done with the help of the satellites in automatic mode which monitors storms in the atmosphere��e planet.
“the Satellites track these explosions in the sky, determining the energy of the event, as well as their longitude and latitude. From this you can assess how they are distributed across the planet depending on latitude,” explained Evatt. According to the authors of the discovery, another important conclusion of the work – overestimation of the probability of the fall of large meteorites in different latitudes, which were previously employed by scientists.
Thus, the updated assessment showed that the probability of such an event in the Equatorial latitudes 12% more and in the polar – 27% less than previously thought.
“I think it’s a fascinating study, and these estimates are similar to the truth. We believe that each year the Land falls about 40 thousand tons of extraterrestrial matter, but a large part – in the form of fine particles,” — said Sara Russell from the natural history Museum of London.
Recently, Russian scientists proposed a new explanation for the phenomenon of the Tunguska catastrophe of concern to researchers for over a century. According to their calculations, significant destruction in the area of Podkamennaya Tunguska are not associated with the space object falling to the Ground, and with shock waves, arising during the passage through the iron of the asteroid through the Earth’s atmosphere.
A mysterious explosion in the area of the river Podkamennaya Tunguska on the morning of 30 June 1908 is the largest fall of a celestial body to Earth in recent history. Based on simulations, the researchers showed that the Tunguska event was caused by an iron asteroid with the most probable size from 100 to 200 meters. This asteroid passed through the Earth’s atmosphere at a minimum altitude of 10-15 kilometers at a speed of about 20 kilometers per second, the angle of entry into the atmosphere had to be less than 1105. However, he fell to the Ground, and continued its movement along the circumsolar orbit, losing about half its initial mass, which could exceed three million tonnes, while maintaining its integrity.
