Our favorite pieces of space rock are very old. What is interesting is that they are maybe even old as the universe – most of them were formed during the creation of the planets.
If you are interested in piecing out the story behind meteoroids and wish to find out what are the meteors, you have come to the right place. We will investigate the origin of asteroids and meteoroids. Also, we are interested in their chemical composition because it provides priceless information about the place it originates from.
What Are Meteors?
Meteors are flashes of light that accompany an extraterrestrial object that speeds through Earth’s atmosphere. The correct technical term is light phenomena that enter the Earth’s atmosphere and vaporize in the air.
They can completely disappear in the air before they hit the ground. However, it is not rare to witness an object fall and leave a crater of some sort.
Meteors are essentially debris from asteroids. They can stem from planets or similar extraterrestrial bodies that shed remnants that circle in space. Also, they have several categories. They can be either classified based on their chemical composition or size.
A standard meteor has two parts – a coma and a tail. The coma is the field of luminosity that surrounds the body – the center of the rock – and a tail that is recognizable by a bright white to yellow shine that follows the body.
The tail is responsible for the term “shooting star”, although they have nothing to do with stars.
How Are Meteors Formed?
Meteoroids burst into our atmosphere virtually all the time. The moment they pierce the layer of air, they begin to vaporize. The molecules of gas in the atmosphere begin to heat the meteor’s surface. That and the high speed of the meteor’s motion combine and create conditions for the vaporization. The vaporization causes the “fusion crust”, which means the rock will have a glazed and shiny surface. This happens because the meteorite has been burned while the object was passing the atmosphere. This usually happens high in the sky – in the mesosphere – hence most meteors never actually reach the ground.
In terms of size, meteors are usually very small. The large objects that enter the atmosphere disintegrate in the air due to the pressure. As NASA explains, typically less than 5% of the original object reaches the surface of the Earth. The ones that do, have a wide array of sizes – from mere grains to the size of a fist.
Nevertheless, there have been records of massive meteorites that made quite an impact on our planet. Arizona Crater is a consequence of the fall of a 160-feet (50 meters) space rock. Large objects that shine very bright in the sky are called bolides. The 2013 Chelyabinsk fireball was a superbolide.
What Are Meteors Made of?
Meteors refer only to the light phenomenon of the entire event. In terms of composition, the nucleus – the rocky body of the meteor – burns bright and leaves a trail in its wake. The trail, known as ionization trail, is the most recognizable thing about “shooting stars” for amateurs.
Each meteor shines bright, and the colors can sometimes differ. You might spot red, orange, or even green hues high above, and that is not a coincidence. The difference between the colors depends on the chemical compositions and velocities of the object. While it goes through the atmosphere, different chemical compositions and velocities will have different reactions to the Earth’s atmosphere. Furthermore, as most meteors are layered, as each layer burns off, another one is revealed underneath. In turn, the new layer will also trigger different reactions with the air molecules in the atmosphere. Orange and yellow hues signal a presence of sodium in the nucleus of the meteor. Yellow can also be a sign of iron. Blue and green trailing light is a typical representative of magnesium, while violet is a signal for calcium. If you spot a meteor with a red trail, you know that its body is composed of atmospheric nitrogen and oxygen.
What Is the Difference Between a Meteor and a Meteorite?
These two notions refer to the same thing. Essentially, the main difference between these two concepts lies in the location. Meteoroids are cosmic debris, i.e. rocks that circle in space. The moment they enter our atmosphere, they become meteors – the flash of light in the sky. While they are traveling towards the ground, they vaporize. Sometimes they disappear completely, and sometimes they hit the ground. The moment they hit the ground, they become meteorites.
So, you see, the entire confusion about the names is very simple. Meteors and meteorites (and meteoroids) are all the same, but we differentiate them based on their location at the time of observation.
How to Spot a Meteor
The best time to observe the sky in hopes of spotting a meteor (or two) is during the night. The dark is better for catching the fainter flashes of light which are difficult to discern during daylight. The optimal conditions for meteor observing are a clear, moonless night. You should find a place from which you can see a large portion of the sky. Most meteors can be seen after midnight until the break of dawn. However, they can happen any time, there are no rules. The best opportunity for meteor observing is a meteor shower. There are several meteor showers happening each year, and they are all a marvelous event.
You can use a telescope, or you can go without it – meteors are visible with the naked eye.
What Are Meteorites Made Of?
The chemical composition of meteorites is one of the most important parts of meteoroid explorations. Because they are high up in the sky, meteoroids and asteroids are virtually unattainable to us. However, once they fall to Earth’s surface, they become useful sources of information.
There are three main types of meteorites: iron meteorites, stony meteorites, and stony-iron meteorites. Most meteorites belong to the stony meteorites class (94%), while the stony-iron group makes 1% of all meteorites found so far.
Each category has additional subcategories and branches. They serve to precisely categorize the objects based on their chemical composition, size, and mineralogy.
Thanks to the chemical analysis, we can now pinpoint where do most meteorites come from. That includes both the location (Asteroid Belt or Kuiper Belt) and parent bodies (comets and asteroids). Furthermore, we have discovered many Lunar and Martian rocks that have fallen to the Earth’s surface.