How far is the universe from the earth?

Yuri GagarinWas the first human being to fly in space, and compared with more than 50 years ago when the story told that "the sky was very dark, while the earth was bluish," the universe has become familiar for many years now. Newspapers who Japanese astronauts are active at the International Space Station are also frequently reported, but about the question of how many meters high from the ground should be called "universe"Royal Observatory of GreenwichIt is explained in the following movie uploaded.

Where does Space begin? On Vimeo


How much altitude is needed to be called "universe"?


About 12 kilometers from the ground is "TroposphereIt is called. The troposphere spreads to the lowest part of the atmosphere and visible light and radio waves reach.


The tropospheric atmosphere contains a lot of water vapor, clouds are formed, weather is born. Also, the altitude of around 10,000 meters where a large airplane fly is minus 40 to 50 degrees cold.


And further away from the ground, until 50 kilometers "stratosphereThis area is called. Unlike the troposphere, the stratosphere differs from the troposphere in that the higher the altitude, the higher the temperature, the lower the stratosphere the minus 15 degrees to 0 degrees.


The reason is strong ultraviolet rays coming from the sun.


However, by the time we reach the surface where we live, ultraviolet rays are considerably weakened. Because it is in the stratosphereozone layerIt absorbs ultraviolet rays. By the energy of the ultraviolet rays absorbed by the ozone layer, the temperature in the stratosphere is higher than in the troposphere.


Apart from the ground, up to 85 kilometers altitude is "Middle zoneThis area is called.


In the universeMeteoroid substanceThere are countless small dust called. When this chile is pulled by the gravity of the earth and enters the atmosphere, it will fire until it burns out.


A shooting star we see romantically at the coast is a figure in which Chile is burning out in the middle sphere.


To the height of 100 kilometers from the groundCarman LineThere is a boundary line called. However, this boundary line is a virtual one set by humans.


Hungarian aviation engineer also called father of aviation engineeringTheodore Von CarmanThis line named after is set just as "the boundary between the atmosphere and the universe". When space research was popular around the 1950s, when calculating the orbital speed to escape the Earth 's atmosphere, it is the beginning that the sea level altitude 100 kilometers was set as the boundary between the atmosphere and the universe.


Now it is considered for the first time that rockets and humans have crossed this line "arrived at the universe." In other words, the boundary between the Earth and the universe can be said to be 100 kilometers altitude. The distance from Tokyo to Oarai-cho in Ibaraki prefecture is approximately 100 kilometers in straight line distance.


However, strictly speaking, the atmosphere exists higher than this Carman line. Up to 800 kilometers from the groundThermosphereIt is called. Exposed to the energy from the sun, atmospheric molecules in the thermosphere sometimes have a temperature equivalent to 2000 degrees. The temperature mentioned here is not a sensory one, but it means the amount of vibration of the molecule.


When the particles flying from the sun strike the molecules of the atmosphere of the thermosphere, the state of energy changes and light is emitted when trying to return to the original state.


The emission of this particle is the identity of the aurora. The aurora that I am thinking that we are romantic is actually a physical phenomenon caused by particles flying from the sun.


In the thermosphereInternational Space Station(ISS)space shuttle·Hubble Space Telescope, And a lot of other satellites are also flaring.


Outside the thermosphereOutside atmosphereThere is also an area called, but as soon as the altitude rises the atmosphere becomes very thin and the influence of gravity becomes weak, so it can be said that it is almost the same as outer space.


Furthermore, it reaches the moon at about 380,000 kilometers from the ground.


In addition to that far, Mars and Jupiter are turning around the sun.