An international group of scientists from the United States, Canada and the UK came up with a way to calculate the number of asteroids falling to Earth from lunar data.
Specialists studied lunar craters with a diameter of more than 10 kilometers and less than a billion years old.
Scientists explained that it is extremely difficult to figure out the damage to the earth's surface, since the movement of lithospheric plates, water, movement of soil and wind erase these traces over time.
Therefore, to find a pristine ancient crater on Earth is not an easy task. The only exceptions are the largest structures, such as Chicxulub Crater on the Yucatan Peninsula.
The authors of the new study suggested that the past could be found out about our planet using a satellite, the Moon, since, thanks to its conditions, the craters remain unchanged forever.
The Earth and the Moon are, by cosmic standards, very close and, if we consider the fall of large meteorites as related events, their frequency should be the same there and there. The task is complicated by the fact that moon craters are difficult to date, - the researchers said.
To date craters on Earth, it is enough to study sedimentary rocks, while on the Moon it is impossible to do this. But the authors of the new work came up with an ingenious solution.
The lunar surface is covered with a layer of regolith - stone dust, formed when the surface is bombarded by space particles of small size. The older the surface, the more regolith on it.
It is known that this dust is less heated under the influence of sunlight, and it gives out heat worse than bedrock. And this difference is easy to notice in the infrared - the younger the surface, the brighter it glows.
To test their theory, scientists analyzed information collected by the Lunar Reconnaissance Orbiter satellite, which has a DLRE instrument that measures the thermal radiation of the lunar surface and its changes during the lunar day.
Experts studied data on lunar craters with a diameter of more than 10 kilometers and less than a billion years old. It turned out that the intensity of the fall of large asteroids and meteorites increased markedly towards the end of the Paleozoic (about 290 million years ago).
This is probably due to some cosmic changes that led to the emergence of new asteroids, or - to a change in the orbits of the old, - concluded the scientists.
A similar picture could be on Earth at this time, the authors of the study are sure.