From early childhood, everyone knows that the sun - is a huge ball of glowing, star, located far, far away.But the question of what is the distance from the Earth to the Sun, the answer can not every adult higher education.This article explains how to change the distance from the Earth to the sun throughout the year, as the scientists measured the distance and how much it is in comparison with the remoteness of other space objects.
sun from Earth of about one hundred and fifty million kilometers.Earth's orbit is not a perfect circle, but an ellipse, so the distance between the center of the solar system and the Earth at different times varies.Its minimum value in astronomy is called perihelion, and the maximum - aphelion.Perihelion is equal to one hundred and forty seven million kilometers, and the value of the aphelion is one hundred fifty-two million kilometers.Perihelion is in January and the aphelion - July.
From the Earth to the Sun seems small.In fact its diameter exceeds the diameter of the earth at the equator 109 times.The great distance from the Earth to the Sun - that's the reason that we see in the sky a relatively small circle of red and yellow.The moon is at times closer, but in the night sky looks smaller.The distance from the Earth to its only natural satellite is approximately equal to 384.3 thousand kilometers.This is 390 times smaller than the distance from Earth to the sun.The time during which the sunlight reaches the surface of our planet, still eight minutes and twenty seconds.
How scientists were able to measure the distance from Earth to the Sun?What methods are used?The first attempts in this direction were taken in ancient Greece, but to talk about the real outcome was possible only after the seventeenth century.In the late Middle Ages used the method of parallax.This method consists in the fact that on the basis of data on the Earth's radius, and observations of the Sun from the Earth is determined by the angle at which to being on the horizon, the sun will be visible Earth.The distance from one space to another object is calculated by the parallax displacement.
In the second half of the twentieth century, the technological revolution has brought a new way to measure distances in space.Radar method is as follows: in the direction of the space object is sent to a pulse signal is received from it, and then on the basis of data on the pulse transit time double the distance from the Earth to the object of interest at a certain rate calculated distance.Today, astronomy is a dynamic new way for you to know how many kilometers away from us little-known stars and planets galaxies.This is the Sunyaev-Zeldovich, based on the fixation change of the radio emission of the object in time, gravitational lensing, which is based on the study of the deflection of light rays in the gravitational field of an object, the method of molecular rings, commonly used for the initial evaluation of the distance from the solar system to a galaxy.
How to answer the question about what the distance from the Earth to the Sun?Big or small it?Everything is relative.It is significant in comparison with the distance from the Earth to Mars or to the moon, but it is almost negligible compared to the distance to other stars and galaxies.The closest planet to Earth is Venus, and she removed at 41.4 million kilometers.Between Earth and Mars 78.3 million kilometers, between the Earth and Mercury - 91.6 km.But Jupiter and other giant planets are from the Earth more than the sun.
To measure outer space often used such quantities as parsecs and light years.At a distance of one parsec of space object annual parallax is one second (hence the name "parsec" - the parallax of a second).Light year - it is the distance that light travels in a year.These values are used in the measurements for the study of distant celestial bodies.For example, from the Earth to the star Alpha Centauri light goes four years to Sirius - eight and a half years, while the orange giant Betelgeuse - 650 years!
