Scientists have unraveled the mystery of the disappearance of carbonaceous meteorites during their plunge into the Earth's atmosphere
Kyiv • UNN
Carbonaceous asteroids, rich in organic molecules, rarely reach Earth due to their destruction by the Sun and the atmosphere. The study sheds light on the origin of life.
The Sun and Earth's atmosphere act as a filter for carbon-rich meteorites.
UNN reports with reference to Nature Astronomy.
Carbon-rich asteroids are very common in space, but meteorites of this type account for only 5% of those that fall to Earth. This mystery has puzzled scientists for decades. But a new report by astronomers from Curtin University in Australia, the International Centre for Radio Astronomy (ICRAR, also in Australia) and the Paris Observatory indicates that scientists have managed to understand the reason. Moreover, the discovery sheds new light on the origin of life on Earth.
Context
Carbonaceous asteroids are a key part of the solar system formation puzzle. They contain water and organic molecules, the necessary components of life as we know it. However, such rocks account for less than 5% of meteorites found on Earth.
Solving the mystery of carbonaceous meteorites
The authors of the study comprehensively analyzed almost 8,500 meteoroids and their fall sites. Data from 19 fireball observation networks in 39 countries were used - this is the most detailed and complete study of its kind conducted to date.
According to the findings, asteroids break up as a result of a close collision with planets.
Weak carbon material cannot survive in the atmosphere. The study shows that many of these meteorites do not even reach the atmosphere
Heating an asteroid in 'sunlight'
The Sun emits radiation across the electromagnetic spectrum, which includes, in addition to visible light, ultraviolet and X-rays. This radiation can heat the surface of a meteoroid to extreme temperatures and cause its volatile elements, such as water and organic compounds, to evaporate.
This heating, which is repeated on each orbit, can create thermal stresses in the rock as it alternates between hot and cold, leading to fractures.
High-speed entry of asteroids into the atmosphere creates intense friction. They heat up until they glow. That is, they turn into a "fiery bolide". These are fatal consequences, and most asteroids break up into small fragments or evaporate completely before reaching the Earth's surface.
'Building blocks of life'
The discovery also sheds new light on the origin of life on Earth: in fact, this type of meteorite is particularly important because it contains water and organic molecules, key ingredients for the birth of the first organisms.
Let us remind you
NASA has reduced the probability of asteroid 2024 YR4 colliding with Earth to 0.28%. The space object, measuring 40-100 meters, may approach the planet in December 2032.
