The earth’s atmosphere is a powerful barrier against meteors. Most explosives explode in mid-air before reaching the surface of the earth.
If they are like a grain of sand, we will see a meteor and even make a wish. If its size is larger, we will see a fireball in the sky, and it is likely to disturb us. If it is larger (like a bus) and explodes in the air, then we should pay attention.
In order for a meteor to ignite a fireball, the meteor must be at least the size of an olive or walnut. Similarly, the larger it is, the faster it moves, and the brighter the fireball will be.
Scientists know that meteoroids-objects between 100 microns and 50 meters in diameter-often explode before reaching the surface of the earth, but they don’t know why.
In order to get the answer, a team led by Jay Melosh Analysis of the Chelyabinsk incident.
On February 15, 2013, a meteoroid with a diameter of about 20 meters exploded in Chelyabinsk, Russia.body Released 500 tons of energyThirty times higher than the Hiroshima nuclear bomb, the explosion occurred at a height of 29,000 meters. Although the mass of the object exceeds 10,000 tons, the largest fragment recovered is 650 kg.
Melosh’s team used a specific computer program that can incorporate the solid materials that make up the object and the surrounding fluid into the equation.
“We have been looking for something similar for a long time-Melosh explained A statement -Most of the programs we use to simulate the impact can tolerate multiple materials, but you can take the average. In this case, we can consider all the different materials and perform more efficient calculations on them.”
Thanks to this simulation, the researchers were able to push air into the meteoroid and let it leak out, thereby greatly reducing the strength of the meteoroid. in conclusion, Published on Meteorology and Planetary Science, Is our atmosphere has a better shielding layer than meteoroids, better than researchers thought.
When an object hits the earth, the high-pressure air in front of it will seep into its pores and crevices, causing the body of the meteorite to separate and explode.
Although this mechanism can protect us from small meteoroids, large meteoroids may not be affected. Iron meteorites are denser, and even smaller meteorites tend to reach the surface.
A huge meteorite exploded over Antarctica without leaving a crater