Those of you who have seen a meteor shower at some point in your life will agree with me when I say it’s a truly incredible experience. The cosmic fireworks blazing across a dark blue sky are really something to remember. But how and when do meteor showers occur? Well, when dust particles that separated from asteroids or comets enter the Earth’s atmosphere at very high speed, they start to heat up to extremely high temperatures, because of friction with the air. Seeing as there is only vacuum in space, meteors don’t experience air resistance so they are free to roam, but when they rub against the air particles in our atmosphere, friction is created and they start to burn. Most meteors are small enough, sometimes as small as a grain of sand, that they never reach the surface of the Earth, burning out completely while in mid-air, creating a bright flash, which is why we often refer to meteors as “shooting stars”, visible at a height of about 60 miles. If a meteor is large enough to withstand burning out completely, and it happens to reach the Earth, it’s called a meteorite.
Whether a meteor will fall apart or not, is determined by several factors, such as its speed, angle of entry and composition. If a fast meteor enters the Earth’s atmosphere at an oblique angle, it is more likely to burn out. As for composition, meteors that are made up of iron withstand the stress better than those made up of stone, and they have a better chance of crashing down to Earth, but even that is unlikely, as they usually break up at around 5 to 7 miles up, as the atmosphere becomes denser. Large meteors usually explode above the surface, causing massive damage either by impact of the debris or by fire. One such event happened in 1908 Siberia, the famous Tunguska event.
Although meteors are usually seen falling from the sky alone, there are certain situations when dozens or hundreds of meteors per hour can be seen across the night sky. That’s what we call it meteor shower and it occurs when the Earth passes through a trail of debris left by either comets or asteroids. The shower which occurs when the Earth passed through a cloud of debris left by Halley’s comet is called the Orionid meteor shower. Other large meteor showers include: the Leonid, which is the brightest and most intensive of them, and can shower the Earth with thousands of meteors per minute, every 33 years or so; the Perseid, which is associated with the comet Swift-Tuttle, and is the most widely watched meteor shower, peaking at August 12 with more than 60 meteors per minute blazing across the sky; the already mentioned Orionid, which happens every 75 to 76 years, with 50-70 meteors per hour; the Quadrantid and the Geminid, which came from dust particles of an asteroid. Meteor showers are named after the constellations from where the shower appears to be coming from.