Space is an intriguing place. Full of surprises, space can also be super confusing. One of the many confusions that often manage to make the lives of students hell is the concept of Meteorite. From those space debris that fall Earth to those fleeting flashes of lights in night sky – everything is just very confusing. We will clear those confusions in this article on meteorite facts. Stay with us because things can get slightly confusing. We will try to keep things as simple as possible. In order to understand, we need to start from asteroids.
Meteorite Facts: 1-5 | What is a Meteoroid?
1. Meteoroids are rocks from space. They are small in size. They can break apart from asteroids. Compared to asteroids, the meteoroids are very very very small.
2. Now the question is, ‘what are asteroids?’ Well, they are also space rocks. They are very massive. They hang around in universe and they bang with each other and break apart forming smaller rocks that are meteoroids. Asteroids can even hit planets and their satellites.
3. Meteoroids can originate from comets as well. Comets are essentially small celestial objects and usually made of ice and dust. When comets get closer to Sun, they lose some of the gas and dust, which form the meteoroids.
4. Now the question that naturally comes in is, how big are meteoroids? Well, there is no definitive answer to this. Some sources say that meteoroids can be up to 10 meters wide while some other sources say that they any space rock or object which is smaller than 1 kilometer in width is a meteoroid.
5. One thing that everyone unanimously accepts is that meteoroids are usually very small are often only a few millimeters wide or less.
Meteorite Facts: 6-10 | What is a Meteor?
6. In night sky we often see fleeting flashes of lights. They are meteors. But what causes those flashes?
7. They are basically caused by meteoroids. When meteoroids enter into the atmosphere of Earth, they heat up and then burn and vaporize.
8. When the meteoroids burn in our atmosphere, they produce that fleeting flash of light that we so very often call the ‘Shooting Star’ or ‘Falling Star’.
9. Truth is that they are not stars. They are simply the meteoroids that entered Earth’s atmosphere and burned up. The light we see is because of the burning. The trail of light or the flash we see is cause because of the speed with which the meteoroid is traveling.
10. So, when a meteoroid enters into Earth’s atmosphere and burns up, it is known as meteor.
Meteorite Facts: 11-15 | What is a Meteorite?
11. There are some meteoroids that enter into Earth’s atmosphere but do not necessarily burn up and vaporize completely. Some will reach the surface of Earth.
12. Those that fall on the surface of Earth are known as meteorites. So essentially it turns out that meteoroids, meteors and meteorites are all the same thing but different names depending on location. A quick table will help here:
Can be pieces of asteroids or can be gas and dust remnants of comets
Minimum: A few millimeters or smaller (size of sand grain) and are usually referred to as micrometeoroids
Maximum: Up to 10 meters or anything less that a kilometer wide
It is essentially a meteoroid that enters Earth’s atmosphere and burns. Also known by the names ‘Shooting Star’ or ‘Falling Star’
Same as that of a meteoroid but eventually burns up and vaporizes in Earth’s atmosphere
It is essentially a meteoroid that survives the meteor phase and falls on Earth’s surface
Same as that of a meteoroid but becames smaller in size when falls on Earth’s surface because it loses some mass when it burns in atmosphere
13. Meteorites that are essentially meteoroids can also originate from our Moon and are known as Lunar Meteorites.
14. Then again, there are Martian Meteorites as well. They are nothing but meteoroids that originated on Mars – the Red Planet.
15. Meteoroids that originate from comets are way to small to reach Earth’s surface and become meteorites. They will usually burn up in atmosphere. So, they don’t survive the meteor phase. Ones that survive the meteor phase and become meteorites are usually fragments of asteroids or rocks from Mars or Moon.
Meteorite Facts: 16-20 | How Do Meteoroids Become Meteors?
16. Here is something truly interesting. Meteoroids are space rocks or dust and when then get into the gravitational field of our Earth, they are dragged in.
17. When pulled in by gravitational force of Earth, these meteoroids can travel at a very high speed of up to 252,000 kilometers an hour or 156,585 miles an hour.
18. However, when a small meteoroid enters the atmosphere, it will experience immense resistance caused by friction with air. This will do two things. One of the two is that the friction will heat up the meteoroid to such and extent that it will become incandescent and then burn out and disintegrate or vaporize.
19. When this happens, the meteoroid will leave behind a streak or light that will last for only a few seconds or less. This is what we call Shooting Star. The streak of light that we see is not the burning meteoroid but rather the surrounding air that glows because it is heated by friction.
20. The other thing that happens is that when the meteoroid enters Earth’s atmosphere, it will slow down because of the friction.
Meteorite Facts: 21-25 | How Do Meteoroids Become Meteorites?
21. A big meteoroid can also enter into Earth’s atmosphere. Even the big meteoroid goes through the same process of heating up and slowing down.
22. Once it enters Earth’s atmosphere, whether it will burn up and disintegrate or not or whether it will reach the surface of Earth is dependent on a number of factors like chemical make up the rock, the angle at which the rock entered into the atmosphere, the mass of the rock, the shape of the rock etc.
23. In the meteor phase all meteoroids (whether small or big) will heat up because of friction. This is followed by a phase of incandescence and then outer surface of the meteoroids will start melting followed by ablation and then formation of a fusion crust on the exterior.
24. The fusion crust that forms is usually black in color. This explains why the meteorites that fall on the Earth’s surface are usually black.
25. Meteoroids that eventually survive the meteor phase and reach Earth will land somewhere. But where? Well, most of the meteorites actually end up in water bodies like oceans and seas because 71% of Earth’s surface is covered by water. Remaining meteorites manage to fall on surface where they are discovered later.
Meteorite Facts: 26-30 | Types of Meteorites
26. Now meteorites that are collected need to be classified and organized. That classification is done by several methods. One of those methods is classifying the meteorites as Stony, Metallic or Mixture.
27. The Stony meteorites are the ones that will be composed of rocky material. Metallic meteorites are the ones that will be composed primarily of iron. The Mixture category contains meteorites that will have a mixture of rocks and iron.
28. These three categories are further categorized (subcategories) for cataloging specific types of meteorites. For instance, there is something called Pallasite Meteorites. They are basically rocky-iron meteorites with major metallic component being iron and nickel and in rocky part they contain olivine crystals (a type of crystal very abundant on Earth).
29. There are several other methods that are used by scientists and geologists. They may classify meteorites based on the isotopic composition of the rocks (isotopes are variants of the same chemical).
30. Meteorites may also be classified based on the minerals they contain (known as mineralogy) or can be classified based on chemical makeup (chemical composition of the rocks).
Okay, this completes our list of 30 meteorite facts where were discussed primarily about the differences between meteoroids, meteors and meteorites. We didn’t include fun facts. In our next article on meteorites, we intend to do exactly that. Stay tuned.