The expression “shooting star” is misleading. These are not shooting stars but grains of dust penetrating the Earth’s upper atmosphere at speeds of about 30 to 70 km/s. The heating caused by the friction in the air tears electrons from the atoms: this is ionization. It results in a brilliant and very brief trail of light that lightens the sky.
The origin of these particles, many of which are as large as a grain of rice, is mainly cometary. When our planet, on its trajectory around the Sun, crosses the multiple veins of dust that comets have left in their wake, the meteors rain down by the hundreds every hour. This is called a meteor shower, but the term most often used is “shooting star shower.”
Shooting stars showers and storms
These showers are periodic and more or less important from one year to another, depending on the density of the dust stream. The most famous, called the Perseids (named after the constellation where its radiant is located), occurs every year around August 12. Note that it is not the only one to be remarkable. Others, like the Leonids in November, can be very spectacular. In 1833 and 1966, for example, the flow of meteors exceeded, respectively, 150,000 and 200,000 per hour! In these cases, we speak of a shooting star storm.
Notwithstanding the annual swarms, it is possible to observe, on average, according to statistics, a shooting star per hour. Of course, it is advisable to watch for them in an environment where light pollution is very low. The brightest and longest are bolides. The largest of these meteors can reach the ground.