Why does the meteor rain have radiation points?Astmented by astronomers, it feels wonderful

Every year, the meteor in the meteor shower has a radiation point, that is, a point in the sky. All meteors seem to be radiated from this point. In this picture of Wiki -shared resources, it is marked with O.

Meteor Shower has a radiation point

Most of the time, when the earth passes through the track of the comet, we will see a light flashing in the dark night sky: Meteor Shower! Meteor is a comet fragmented -the cold dust particles are called meteor bodies -evaporating in the atmosphere of the earth on the earth. Usually, you will hear the radiation point of astronomers talking about meteor shower. Many people ask how to find a raindrops in the night sky.

Or what is radiation point? Do you really have to find it so that you can enjoy meteor shower?

Wading meteor

Let's start from knowing what it is. Another thing to remember is that the meteor shower occurs when the earth moves in space, whenever we pass through the track time period of comet. Comet is a cold dust object. They threw garbage on the track. The comet particles in space are called meteor flow.

So crossing the meteor flow is like the rapid flow of water flowing through the earth. Water (or comet dust) is by your side. You are immersed in water (or dust), but it only hit you on one side of your body, and the other side is facing the flow of water. jump! The water coming on the face may feel like a big hand trying to push you down. Once you continue to move in the stream, the direction and speed of force will be changed according to the speed and direction of the stream and your speed and direction.

Similarly, when the earth is involved in the meteor group in space, a small amount of comet dust is around us. But they only attack the Earth's side, which is determined by the speed and direction of the meteor group and the speed and direction of the earth. Most streaming rain appeared after the rotation of the earth at midnight. The movement of the earth plus the meteor movement has formed some very fast meteors. However, some meteor shower, like the annual Tianlong Meteor Shower, "Wuxian T" meteor shower, approaching the earth from our night sky. Then the meteor had to catch up with us, resulting in a slow meteor.

Therefore, when you watch the meteor shower, you are watching the dust on the parallel path on the parallel path, as shown in the figure below

When the earth moves through the ocean flow of the comet fragments, the comet dust will enter the atmosphere of the earth on the parallel path. The schematic diagram is from cosmos.

Second analog

Now imagine that you are on the earth and look up at meteors. You cannot ensure that the radiation point is located there by a meteor, but to determine the location of the radiation point by observing a group of meteors to your parallel path.

The radiation point of meteor shower is roughly the same as the illusion of the railway that seems to be gathered in the distance.

Of course, the meteor has nothing to do with the railway. Meteor burning about 60 miles (100 kilometers) on the earth. The rails are on the earth. Note: Don't hover near the rails and think that they will bring you more meteors. They are not.

When you stand on the rails, you will see the illusion of the car rail together in the distance. Similarly, the meteor trajectory in a single meteor shower seems to be at a point -the radiation point on the sky is gathered. As a portrait of shutterstock.

Hey! Who moved my rail?

The radiation point of meteor shower is fixed. Prepare to be shocked. Okay, are you ready?

Radiation points will move.

This is a little -known fact. It is surprising because we often see images about the location of this or that constellation radiation point. But these pictures are set up at the night of meteor shower.

You may ask: Why did anyone tell me before? We don't know! Many long -term meteor observers were surprised to hear this sentence. It happens like the earth turns around the sun. The radiation point of a meteor shower generally moves east of about 1 degree every day, which is roughly parallel to the zodiac. The figure below is displayed

Move the radiation point of the meteor shower of the bottle Δ meteor shower.

From July 20th to August 9th, the movement of the ravage spots of the Bottle Bottle Δ meteor shower. Draw by Don Machholz.

Tip: Don't just stare at near the radiation point

The people always want to know how they can find meteor shower radiation points in the night sky. But when you watch meteor shower, you should not keep staring at the radiation point. Most stars can be seen until there is a distance from the radiation point. So when you watch the meteor shower, try to look at the side of the radiation point -about 45 degrees angle -all directions of the sky.

Tip: Understand your radiation point to rise time

There are some important things about meteor shower radiation points. When the radiation point rises into your sky, you will start to see more meteors. Most (but not all) Meteor Shower is the best viewing after midnight. Because their radiation points will rise at midnight or after. The rare meteor you may see before the radiation point rises will be the meteor, it will start under your field of vision, and then the trajectory of the chief of your sky.

When the radiation point reaches the highest position in your sky, you will also see the most meteor. This is why the Yingxian Meteor Shower is only best to watch before dawn. The radiation point of the Yingxian Meteor Shower rises at midnight for everyone around the world. And for all of us, the radiation point of Yingxian's meteor shower is the highest before dawn. Then the meteor fell from the highest point of the sky. Surprisingly!

So, if you want to watch meteor shower, find out the time when the meteor rain radiation point appears. Then you will see more meteors. Tracing the meteor to find the radiation point. This photo was taken within 3 hours of overlooking the wetland of Dashanbao Wetland, central China on December 14, 2012. Jupiter is on the left and the Orion is near the middle. This shows that Gemini meteors are visible in mid -December each year. The radiation point is just above the picture. The photo was taken by Jeff Dia. Astronomical map on December 13, 2013.

Tip: Carefully observe the long meteor far away from the radiation point

there's one more thing. The meteor trajectory is generally longer than you see from the radiation point. This is very obvious in the image below. The shorter path is close to the radiation point. If you see a short flash in a meteor shower, it is just a meteor flying in your direction. But don't worry, comets will not fall to the ground. The Yingxian Meteor Shower and its radiation point are close to the center of this photo. The fairy star clouds are near the bottom of the image. The picture comes from NASA.

The name of radiation point and meteor shower

By the way, the meteor rain radiation point is important for another reason. Meteor shower is generally named from the constellation of radiation points during its peak. When several meteor showers share a constellation, then the nearest star.

Dragon Steel Meteor Shower, Tianqin Seat Meteor Shower, Treasure Based, Meteor Shower and Treasure Bottle Meteor Shower, British Fairy Meteor Shower, Leo Meteor Shower, Gemini Meteor Shower ... You understand!

Conclusion: Meteor enters the earth at the parallel track. So when you are just standing on the rails, you can see that the trajectory gathers in the distance -you will see that the meteor seems to come from a point in the sky: radiation point!

By: Don Machholz and Deborah byrd and Marcy Curran

FY: Astronomical Volunteer Team

If there is related content infringement, please contact the author to delete after the work is released

Reprinted, please obtain authorization, and pay attention to maintaining integrity and indicating the source

- END -