What happens when a meteorite collides with the Earth?

Scientists examined soil samples in the area of ancient crater fields. It turned out that a significant part of the energy is released in the form of heat, which turns wood into coal. This will make it possible to predict evacuation in case of a threat of collision with a space body.

Burnt wood was found near meteorites with the ground. Source: phys.org

Traces of meteorite impact with the Earth

The absolute majority of space rocks flying into the Earth’s atmosphere never reach the surface of our planet. And most of the meteorites that still flew are too small to form something more than a small hole. Even the Chelyabinsk body with a diameter of about 20 m could not leave any noticeable crater.

The youngest of the craters on Earth was formed in 2007 near a small village in Peru, but this event mostly went unnoticed. At the same time, according to the geological history of our planet, scientists know that when a large body is destroyed in the atmosphere, entire meteorite fields containing dozens of small craters can form. 

However, what exactly happens to the terrain in this case has not yet been investigated. Therefore, people have no idea how terrible the consequences of the collision are in fact. Recently, scientists from Poland and Estonia decided to solve this problem. They explored the Kaali and Kaali Main crater fields in Estonia, Morasco in Poland and Whitecourt in Canada.

Wooden charcoal

The most important thing that researchers paid attention to when studying the soil from meteorite fields were pieces of charcoal. At first they thought that these were the traces of a fire raging in the forest just before the impact of a celestial body. 

Configuration and dimensions of the craters studied. Source: phys.org

However, it is very doubtful that such fires occurred immediately before impact in all four cases, significantly separated by time and space. A detailed study of the samples showed that they do not look at all like those formed during forest fires. It could not have been a fire that arose after the impact.

The tree was burned very evenly, which almost never happens in forest fires. Next to the burnt-out trees there you can always find them almost unharmed. In addition, the coal samples were clearly formed due to the action of a temperature significantly lower than that of ordinary fire. 

So, scientists have come to the conclusion that the trees were fired by a thermal pulse directly from the collision of a meteorite with the Earth. Moreover, they were able to estimate how far from the impact site this pulse propagates. 

Evacuation of the population in case of a meteorite threat

According to scientists, the research will be very useful in case of a threat of a collision with a large meteorite. Bodies which diameter is measured in kilometers crash into our planet once every tens of millions of years.

But objects with a diameter of tens of meters can arrive once a century. And if the place of their fall can be determined at least in a few hours, it allows organizing the evacuation of the population. And a new study suggests which territory will need to be evacuated.

According to phys.org

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