Meteoroid
Meteoroids are small rocky fragments whose size ranges from dust grains to small asteroids. They’re commonly known as “space rocks”. Most of them are made of silicates-minerals that contain silicon and oxygen, and also heavy metals like nickel and iron. Meteoroids that are mostly made of iron and nickel-iron meteoroids are far massive and dense compared to stony meteoroids which are lighter and fragile.
When a meteoroid survives a trip through the atmosphere and hits the ground, it is now called a meteorite.
Where do meteoroids originate?
Scientists believes that most meteoroids are formed from the collision of asteroids that orbit around the sun in a region known as the asteroid belt, which is located between in the paths of Mars and Jupiter. When these asteroids hit each other, they produce crumbly debris-meteoroids. Such fragments will orbit around the sun for millions of years before being captured by Earth’s gravity. When dust particles which are made from asteroid and comets enter the Earth with a high speed, meteor shower occurs. They rub against air particles and create friction when they hit the atmosphere, which also cause the meteors to burn up. The heat now vaporizes the meteors, creating what we commonly say shooting stars. But, do you actually know what happens when a meteoroid enter the Earth’s atmosphere? Meteoroids heat up as they enter the layer of the upper earth’s atmosphere. This causes the meteoroid to glow luminously, causing humans to witness meteoroids in visible manner with their naked eyes. Because of the bright tail they have, many people often referred them as shooting stars or falling stars. Most of them occur in the mesosphere, which is about 50-80 kilometres above the Earth’s surface.
The amount of speed and light that the meteoroids contain affects their travel time and the longer of time they glow. Most meteors that have a larger size and higher speed also have the brighter light and longer of time they glow. Larger meteors shine for about 10 minutes, while the smaller ones can only last in seconds. Unfair isn’t it? That’s why you must not miss the moment.
Meteors appear in different colours
“Different chemicals in the meteors produce different colours as they burn up while entering the Earth's atmosphere,” Samuel said. The atoms in the meteoroid emit light because they are heated up by entering the Earth’s atmosphere, which burns them and so thus they produce different wavelengths of light. For instance Iron, which is one of the most common elements found in meteors, glows yellow. A red glow indicates the presence of element silicon. And lastly, the visible green glow in the trail of shooting star is caused by burning copper.
Types of Meteors
Meteors are known by their size, brightness, and proximity from Earth, according to the National Geographic article. Earth grazers are meteors that are known for having a long and bright tails. They streak close to the horizon. They’re the type of meteors that skim at the top layer of the Earth’s atmosphere or simply bounces back to the outer surface when they’re about to hit the Earth. Some of them streak through the sky as falling stars. The most common earth grazer meteor is known as the “1972 Great Daylight Fireball”, which alarms the whole nation of U.S state of Utah, and causes most the countrymen to feel such enthusiasm in witnessing its journey into the sky. Fireballs are the most common type of meteor, whose sizes range from a basketball to a small car. They also have brighter and longer-lasting light than earth grazers. The International Astronomical Union describes a fireball as a “meteor brighter than any of the planets.” If fireballs are large meteors, bolides are far larger than them. They are brighter and massive compared to the fireballs and earth grazers. They often explode in the atmosphere, and when they do it produces a thunderous sound that can felt on Earth’s surface. The most common hazardous and dangerous bolides are known as super bolides. These type of bolides can endanger species and cause harm to the entire surface of Earth. These can takedown people, environment, animals, and even infrastructures! One example is the super bolide meteor that passed over Chelyabinsk, Russia, in the year 2013. It exploded with a rate of 500 kilotons of TNT that destroys countless of apartments and injured more than 1200 people. Many have said that the Chelyabinsk meteor is 30 times brighter than the sun- the brightest object that it caused people to burn their skins!
Written by Sarah Jane Sederiosa