What is a meteor shower and when does it happen? All about meteor showers
The meteor shower delights sky watchers every year. What makes this beautiful night show? In this article, we are going to review the meteor shower, its types and the time of its occurrence. We also review why this beautiful phenomenon repeats every year.
What is a meteor shower?
A meteor shower appears when meteors enter the Earth's atmosphere at a very high speed. Meteors are solid particles of objects such as comets, asteroids, etc., which have been separated from the object and left in space due to reasons such as collisions. During the journey of these objects in the atmosphere, meteorites interact with air particles and are worn; Friction produces heat. This heat can burn the meteor, resulting in bright streaks of light seen in the sky.
Dust and particles are always bombarding the earth from all directions. If the dimensions of these particles are large enough and the light produced by their burning can be observed in the atmosphere, then a meteor can be seen in the sky. In addition, there is also a meteor shower that occurs at a certain time of the regular year. During the rain, scientists can estimate how many meteors burn in the earth's atmosphere and in which area of the sky the most meteors can be seen.
On average, meteors can travel with a speed of approx 48 thousand kilometers per hour move in the earth's atmosphere and burn. When burning, their temperature is up to 1600 degrees Celsius also goes up. Most of the meteors burn at a distance of about 95 km from the earth's surface – the height of the earth's atmosphere. The next time you watch a meteor shower, know that the distance of the meteor burning in the atmosphere is about 96 km from you.
Of course, some larger meteors, which are even much brighter – brighter than the planet Venus – also descend to a distance of 48 km. to this group of meteorsfireballIt is also said.
What is a meteorite?
Most meteors are very small; Even as small as a grain of sand. So we don't see them burning in the atmosphere. Some meteorites can also survive burning in the atmosphere and hit the earth's surface, which is called “Meteorite” Called. Keep in mind that these are very rare. NASA scientists have estimated that about 48.5 tons of meteorites enter the Earth's atmosphere every day, but only a small number become Meteorite be.
When the meteor hits the Earth, its speed is about half the speed it had when it entered the Earth's atmosphere. Most meteorites are impact craters 12 to 20 meters They make it on the ground. Craters on Earth are similar to impact craters on the Moon and other rocky planets. The smaller the meteorite, the more bowl-shaped and hollow its impact crater is. The heavy impact of large meteorites causes a large area to become depressed, but its depth is less.
The largest meteorite discovered on February 18, 1948 was discovered in a wheat field in the United States. According to those present, a giant fireball hit the ground with a terrible sound. This meteorite sank to a height of 3 meters. Scientists weigh it1070 kg have estimated
What is a meteor storm?
In addition to meteors and meteor showers, another related phenomenon called “meteor storm“, which is a very rare and usually short-term event. A meteor storm occurs mainly with rain, during which more than a thousand meteors can be seen in the sky every hour.
Such events may occur when Earth passes through the orbit of a comet or asteroid cluster. In this case, the presence of particles left over from asteroids and comets and their entry into the earth's atmosphere will cause us to witness a meteor storm.
What is the origin of the meteor shower?
A meteor shower is caused by the interaction of a planet like Earth with a debris stream left over from a comet or asteroid. Comets can leave behind a trail of solid and dust-like particles. Comets are actually dirty snowballs made of ice that orbit the Sun. The ice may be water ice, ammonia, other volatiles, or a combination of these. The size of the dust left by the comet may be as large as a grain of sand, pebble or rock. Sand-sized grains are more common, but sometimes the remnants of comets are very large rocks.
Every time the comet rotates around the sun in its orbit, some of its ice evaporates, and as a result of this evaporation, some solid particles, such as rocks and dust, are separated from it. When these objects are free in space,meteorite” called. The presence of these objects together forms a meteor shower that “dust trailare also known. Note that this is quite different from the tail of a comet.
More Meteor What we see on Earth is caused by the passage of the Earth through the orbit of comets, but sometimes this beautiful phenomenon is caused by the passage of the planet through the trail left by the asteroids. Asteroids are large rocks that orbit the Sun but do not have enough mass to be classified as planets. Asteroids, due to the small gravitational force they have compared to planets, can accumulate solid materials of dust particles around them. This is the reason why when the earth passes through the orbit of the asteroid, the solid particles of the orbit enter the earth's atmosphere and the meteor shower occurs.
How many types of meteor showers are there?
Meteors are often seen singly in the sky. But at certain times of the year, dozens and hundreds of meteors can appear in the sky and create a spectacular and stunning shower. These meteors seem to come from one part of the sky and spread in all directions. How does this happen?
The name of any precipitation that occurs in a certain period of the year is derived from the name of the constellation from which the precipitation seems to originate; for example, Meteor The hunter originates from the constellation of Orion.
There are several different showers a year that astronomers and observers look forward to every year. In the following, we will examine the types of precipitation and when we should look to the sky to observe each of them.
Asadi meteor shower
“Asadi meteor shower” Or “LeonidIt is the brightest and most impressive shower, at the peak of which thousands of meteors appear in the sky every minute. In fact, the term meteor shower was coined after astronomers observed the brightest display of the Leonid meteors in 1833.
Asadi meteor shower occurs every year around November. But the most beautiful show of rain happens at intervals of about 33 years. The next bright rain will be in 2028.
Barsavashi meteor shower
“Barsavashi meteor shower” Or “Perseid“, is another rain that is worth staying up at night. Perseid shower related to the cometSwift-Tuttle” Is. This comet orbiting the Sun has such a large orbit that it takes about 133 years to make a complete revolution around the Sun.
Earth passes through the orbit of this comet every year in August. Passing the orbit of this comet will cause its dust particles to burn in the earth's atmosphere and we will witness heavy rain. Barsaushi shower is not as active as Asadi shower, but it is still one of the most popular astronomical phenomena that can be seen with the naked eye. At the peak of rain, which occurs from August 19 to 22, it is expected to see 60 meteors every minute.
Predator meteor shower
“Predator meteor shower” Or “Orionid“Also from a comet called “HollyIt originates. This comet orbits the sun once every 75 to 76 years. Shichachi rain occurs every year around October and lasts for a week. Observers can see about 50 to 70 bright meteors every hour at the peak of the shower.
Quarterly meteor shower
“Quarterly meteor shower” Or “Quadrantid“From the remnants of an asteroid named “2003 EH1It turns out that some astronomers believe that it was part of a comet and separated from it centuries ago. The solid particles – rock and dust – remaining in the orbit of this asteroid will enter the Earth's atmosphere in late February, early January, and due to its burning, we will witness a meteor shower.
Gemini meteor shower
“Gemini meteor shower” Or “Geminids“Also due to the dust and rock particles of an asteroid called “3200 Phaeton» is created which is close to the ground.
This beautiful phenomenon is mainly caused by particles remaining in the orbit of comets; For this reason, those precipitations caused by asteroids are more special and different from others. Gemini shower occurs every year in Esfand, and it is expected to see about 40 meteors per hour at the peak of its shower.
Meteor shower observation guide
People who live in the Northern Hemisphere are in a better position to observe the meteor shower than those in the Southern Hemisphere. To observe meteors during rain, you must be in a dark place away from light pollution. A bright moon can completely destroy your view of meteors; Because the moonlight prevents you from seeing the glow of the meteor as it burns up in the atmosphere. Light pollution also reduces the darkness of the night sky. When the sky is not completely dark, the brightness of the meteor is not well defined; Therefore, the best place to observe the meteor shower is in a dark space away from the lights of the city or village.
The meteor shower reaches its peak in the hours before sunrise. As we explained above, it is possible to see a meteor in the sky at any time of the year. But Meteor Certain times of the year occur; When the Earth passes through the orbit of an asteroid or comet.
In addition, weather can also affect meteor shower viewing. A clear sky without clouds can create a beautiful night for you; For this reason, the rains that occur in summer, such as the Bersavoshi meteor shower, have more fans than the rains that occur in winter.
Meteor shower photography guide
Photography A meteor shower can be seen as an exercise in patience and perseverance; Because meteors appear quickly and suddenly in the sky. Each night only a certain number of meteors can be seen per hour; Do not expect to record beautiful pictures of meteors every moment. In the following, we review some of the photography needs of this exciting phenomenon.
First you need a tripod. Photographing meteors requires a long exposure, even if you can keep your hand still for a long time, the performance of a tripod is still better; Because your images will be clearer. Heavy tripods help reduce wind shake, but even a simple tripod is fine.
Choose a wide-angle lens to cover a larger area of the sky. In this case, the chances of recording the image of the meteors will be higher.
Use the shutter cable or the camera's built-in timer. A tripod is used to reduce camera shake. But keep in mind that pressing the shutter button can also cause the camera to shake and spoil the image; Therefore, it is better to use the shutter cable or the timer of the camera to record a beautiful picture of the meteor at any moment, without shaking the image.
Focusing is very important in night sky photography, but it is more difficult at night. To be sure of the focus of the camera, first focus on a star and take a picture of it. If the star looks like fuzzy bubbles, change your camera's focus settings. Then record a test image again and check it to be sure of the correct focus result.
Next, you need to point your camera in a certain direction. Even though we don't know when and where exactly the meteors will appear, their possible landing place is known; It is necessary to turn your camera towards the desired precipitation constellation.
As the earth rotates, it looks like the sky and the stars are rotating. If you have chosen the game angle for the camera, you can cover a wide area and easily capture the rotation of the earth in your images. But if you want to photograph a smaller area, use the 500 rule. In this rule, you divide 500 by the size of your lens (say 20mm) and that's the longest exposure time for an area with your 200mm lens.
Conclusion
In this article, we learned about meteor shower and its types. First, we reviewed what a meteor is and when it becomes a meteor shower. We also got acquainted with the concepts of meteorite and meteor storm. Next, we investigated the origin of this rain and found that this phenomenon could be caused by the passage of the planet (Earth) through the tracks of asteroids or comets. After that, we reviewed the types of meteor shower and the time of occurrence of each. Finally, we got acquainted with the photography of this amazing phenomenon and saw that we have to be patient and trial and error to capture it.
Frequently asked questions
When a planet passes through the tracks of asteroids or comets, which are mainly dust and rock particles, these particles enter the Earth's atmosphere and their burning produces a bright light, which is called a meteor shower.
Meteors are objects like dust or rocks that have entered the atmosphere and burn up in the Earth's atmosphere. If the meteorite is so big that it does not burn up completely in the earth's atmosphere and hits the earth's surface, it is called a meteorite.
According to its origin, the meteor shower can be divided into Barsaushi, Asdi, Jozai, etc. In each of these types, the name of the rain comes from the constellation of its origin.
Although it is possible to see meteors in the sky at any time of the year, each precipitation can be seen in different periods of the year and it depends on the position of the earth in its rotation around the sun. In the middle of August, March and November, you can see some of the richest annual rainfall.
To observe this fascinating phenomenon, one should go to dark areas and away from the light pollution of cities and villages. The important thing is that the sky is well open so that there is a possibility of seeing more meteors. Keep in mind that the darker the sky, the more likely you will see a meteor. Moonlight can be considered a major nuisance for you, because lighting up the sky makes it less likely to see a meteor and burn it up in the atmosphere.
