The expected Leonid shower on the nights between Saturday and Sunday and between Sunday and Monday will be less strong than the showers of the past two years, but will be visible to the naked eye
Eran Ofek
Photo: Ofer Gebzo - the Leonid shower in November '98. violent event
On the night between Saturday and Sunday (November 18-17) and on the night between Sunday and Monday (19-18), those who look at the sky after midnight (and until the early hours of the morning) will be able to see the meteor shower called "Leonids".
Most forecasts state that from the Pacific Ocean and East Asia it will be possible to see a very large number of meteors - up to 10,000 meteors per hour. These forecasts state that from Israel it will only be possible to see a slow trickle, of between 20
to 100 meteors per hour.
A meteor is the phenomenon seen when a grain of dust enters the Earth's atmosphere at a speed of several tens of kilometers per second. At such a speed, the dust grain (also called a meteorite) collides with the air molecules, heats up and burns at an altitude of about 100 km. This violent event causes the electrons to be torn from the air molecules, a phenomenon called ionization. The result is that the ionized air emits light in a process similar to that of a fluorescent lamp The emission of light appears to us as a meteor (also called a falling star, but as mentioned it has nothing to do with the stars).
Every night, from dark skies, you can see meteors at a rate of 15-5 meteors per hour. Sometimes, when the Earth passes through a concentrated swarm of dust grains left behind by a comet, a phenomenon called a meteor shower is observed. Since all these dust grains move together in adjacent and parallel paths, the meteors appear as if they are coming from a single point in the sky (this phenomenon is known as the perspective effect. A similar illusion is created when looking along the length of railroad tracks; they appear to come from a single point, when in fact they are parallel).
The meteor shower is usually named after the constellation from which the meteors are seen coming out. Although during the meteor shower you can see meteors anywhere in the sky and not in the area of a specific constellation. But if we follow the paths of these meteors backwards across the dome of the sky we will notice that they converge at one point. The Leonid shower is so called because the meteors look as if they come out of the constellation Leo.
Today, several tens of meteors are known, but in most cases these are weak meters of a few meteors every hour, and only a few are at a reasonable rate of about 100 meteors per hour. The strongest meteor showers are the Chondratids, which reach their peak on January 4th in the morning; the Perseid shower, which peaks on August 12; and the Geminid shower, which reaches its peak on December 14.
Usually the Leonid shower is a medium shower that produces about 20 meteors per hour. But in years when the Earth passes through areas with a large amount of dust grains, we may see rich spectacles (meteor storms) like those seen in 1998 and 1999. In 1998, about 500 extremely bright meteors were observed from Israel every hour, some of which left They are followed by trails that were visible in the sky for about 10 minutes after the meteor disappeared. In 1999, about 5,000 meteors per hour were visible from Israel. Such targets usually occur in the years close to the time when the parent comet, leaving the dust grains in its orbit, passes near the Sun and the Earth. Comet Temple-Tuttle, which is responsible for the Leonid shower, orbits the Sun once every 33 years, and last time it passed near the Sun in February 1998. Therefore, in these years we get stronger than usual Leonid showers.
Predictions of meteor showers are usually based on computer simulations in which dust particles are allowed to eject from the comet and are followed over the years as they orbit the Sun and are affected by the planets' gravity. This year several predictions were prepared by several teams in the world. One of the forecasts predicts that this year's Leonid shower will have two peaks: the first will be visible from the west coast of America on November 18 in the early morning, with a predicted rate of about 2,000 meteors per hour; The second peak will be seen on November 18 in East Asia, also early in the morning, where a rate of about 10,000 meteors per hour is predicted. According to this forecast, the meters at their peak will last over short periods of time - many meteors in a period of only about an hour - and then you know; From Israel we can see a "drip" of about 20 meteors per hour only.
Another forecast, on the other hand, speaks of a meteor shower over the Pacific Ocean, which will last over a longer period of time and will see about 1,000 meteors per hour. According to this forecast from Israel it will be possible to see about 100-50 meteors per hour on the night between Saturday and Sunday morning, and on the night between Sunday and Monday after midnight. It should be noted that these computer simulations only take into account dust and ice particles ejected from the comet in the last 500 years, and are therefore flawed, meaning that additional peaks may appear and surprise.
For those who wish to try and see the meteor, it is recommended to do so in as dark a sky as possible, outside the city.
