I think it is no secret to anyone today that our planet - from the very moment of its birth, about 4.5 billion years ago - is constantly being bombarded by real meteorites. Of course, the situation today is fundamentally different from what it was billions of years ago, but meteorites still fall on our planet. So, every day about 100,000 kg of extraterrestrial matter in the form of dust grains falls on the Earth, the size of 99% of which varies around 0.5 millimeters. However, only a few meteorites reach the Earth's surface. But at what speed do meteorites fly and where does the speed of light have to do with it? In this article, you will find out which space objects fly faster than others and where do supernovae have to do with it.
Meteora - fragments of space objects, particles of several centimeters in size, which enter the atmosphere at a speed of tens of kilometers per second and burn up, creating a bright speck - a shooting star.
How do meteorites fall?
To understand all the intricacies of the life of our planet in the vastness of the cosmic ocean, let's remember what meteorites and asteroids are and how they generally get to Earth. It is important to understand that in space, in addition to stars and planets, there are a myriad of celestial objects.
So, asteroids are space bodies, similar to planets, but not so large that it does not prevent some of them from acquiring their own orbits and satellites. There is also cosmic dust - these are tiny particles of matter that are dispersed in outer space. And intermediate objects of medium size - their size, as a rule, varies from 0.1 mm to 10-30 mm - and there are meteorites. True, scientists know about the existence of huge meteorites, the size of which reaches a length of two and a half meters and more.
They can be dispersed in space, can move along arbitrary trajectories, and their orbits can be relatively stable. Sometimes there is a whole cluster of meteorites - the so-called swarm.
Supernova or supernova - a phenomenon during which a star sharply increases its brightness by 4 - 8 orders of magnitude, followed by a relatively slow decay.
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But at what speed do these space wanderers move across the vastness of the infinite universe and what happens when they fall on our planet? The fastest meteorites travel at 42 kilometers per second (km / s). However, the speed of meteorites that manage to penetrate the Earth's atmosphere and reach the planet's surface is much lower, about 12 km / s. Nevertheless, theoretically - so scientists believe - there may be a number of objects that have not yet been detected, the speed of which is much, much higher.
Fastest meteorites
When a space body flies in the direction of our planet, its main task (let's call it that) is to enter the Earth's atmosphere and not disintegrate. As I said, only a few bodies, mostly larger, reach the surface of the Earth.
And yet, many more meteorites - the bombardment of the Earth - are so small that they go unnoticed. According to Muy Interesante, according to a new study by Harvard astronomers Amir Siraj and Professor Abraham Loeb, the Earth's atmosphere is bombarded by space rocks ranging in size from 1 mm to 10 cm, which move at extremely high speeds. These objects, the researchers argue, could have emerged from supernova explosions, which cause particles to accelerate to subrelativistic or even relativistic speeds - several thousand times the speed of sound and up to a fraction of the speed of light.
Note that the work has not yet passed peer review and is currently published on the Airvix preprint server. It is noteworthy that the work is devoted to one of the main mysteries in astrophysics, which is whether the ejection created by a supernova can be accelerated to relativistic speeds and pass through the interstellar medium to reach the Earth's atmosphere.
The earth is under attack all the time.
As the authors of the study told Universe Today, despite the presence of a solid theoretical basis, the question of whether meteorites larger than a grain of dust enter the Earth's atmosphere at subrelativistic or relativistic velocities remains open. So, to confirm that these very fast meteorites are real, you will need instruments that do not yet exist and which, among other things, must include microphones for recording infrasound, as well as infrared instruments for measuring temperature. It is estimated that a global network of about 600 detectors would be required to register these theoretically existing meteorites.
The study authors also note that today scientists have a wonderful opportunity to study a completely new kind of objects that regularly interact with the Earth's atmosphere. Moreover, their study is a new opportunity to study supernovae in more detail. Well, you and I can only hope that sooner or later astronomers will be able to unravel the mysteries of the universe.
Lyubov Sokovikova