A Show In the Sky All Year Round
Shooting stars can be one of the most entertaining shows possible to see from your backyard. Some people think they are rare but at some periods of the year meteor showers can be very intense, with two hundred shooting stars in one hour. On a perfectly clear, dark sky, you can see different types of them; some move slowly, others fast, some very bright, and some even leave a tale behind them like a plane. In fact, shooting stars are meteoroids, small pieces of rock and ice with the average size of a pea. They enter our atmosphere at high velocity, sometimes thirty kilometers per second, and burn under the friction of the air. When a bigger one enters the atmosphere it gets bright enough to light up the whole sky and last many seconds; in science they are called “bolides.” Meteorites usually disintegrate and never reach the ground, but depending of the angle and speed they enter the atmosphere, some rare big ones strike the surface. Most shooting stars follow the same direction during a “meteor shower” because the Earth is passing through a cloud of meteoroids. A meteor shower can last mere minutes or up to several weeks. But where are shooting stars coming from? The answer is from comets. Comets follow courses that range from the outside edge of the solar system to the hot neighborhood of the sun. These courses sometime cross the orbit of the Earth leaving debris behind. The Earth passes through the same clouds at the same time every year, but the intensity of the showers vary as some comets can take many years to come back to leave more debris. So if comets are crossing the orbit of the Earth why don’t they collide? To make a comparison, if the solar system is represented by the size of Canada, the Earth is the size of a person, and a comet is the size of a mosquito. The chance of getting bitten is nearly zero, even if at some point in their lives the person and the mosquito visit the same campground. The following image shows the phenomenon of comets, and meteorite clouds. I also include a schedule of the most important showers with the peak dates of each one. For this celestial event you don’t need an expensive telescope, all you have to do is lie back on a chair on a clear night and enjoy.