The distance that separates the Sun from the Earth is an average of 150 million km. This distance is used as a reference to measure distances in the solar system: the average distance from the Sun to the Earth corresponds to 1 AU.
The Earth, like the other celestial bodies in the solar system, orbits around the Sun, but it does not follow a circular orbit but rather describes an elliptical path, the Sun being one of the foci of the ellipse.
Earth is the third planet in order of distance from the Sun; both by mass and diameter it is the largest among the terrestrial planets (that is, among the planets composed of rock and metals) in the solar system.
The Sun is the king star of the solar system around which the bodies of the planetary system gravitate, which also includes the Earth. Its mass represents 99.9% of the mass of the entire solar system.
In the rotation of the Earth around the Sun we highlight two singular points:
- Perihelion is the closest point to the orbit of the Sun described by Earth.
- The aphelion is the farthest point from the Sun in the Earth's orbit.
Since the Earth describes an elliptical orbit, the exact distance between the Earth and the Sun is constantly changing. However, it is possible to define the minimum distance, the maximum distance and the average distance.
Measuring the distance between the centers of the Sun and the Earth we have to:
- The minimum distance from the Sun to the Earth is 147,098,074 km.
- The maximum distance from the Sun to the Earth is approximately 152 million kilometers, specifically 152,097,701 km.
- The average distance from the Sun to the Earth is 149,600,000 km.
What Is an Astronomical Unit (AU)?
The so-called astronomical unit corresponds to the average distance from the Sun, about 150 million kilometers.
At the general assembly of the International Astronomical Union that took place in Beijing in 2012, it was decided to give the astronomical unit the current value of 149 597 870 700 meters.
Examples of Solar System Distances Measured in Astronomical Units
- The radius of the Sun is 0.0047 AU, that is, 700,000 km. By comparison, the volume of the Earth, on the other hand, is one millionth of the Sun.
- Jupiter, the largest planet, is located 5.2 astronomical units from the Sun, 780,000,000 km, and its radius is 71,000 km.
- Neptune, the most distant planet, is 30 astronomical units, 4.5 × 10 9 km.
- The Oort cloud is almost a light-year from the center of the Sun. It is believed that in astronomical units it is believed to be located from 2000 AU or 5000 AU to 50,000 AU from the Sun.
- The closest star to Earth other than the Sun (Proxima Centauri) is 4.2 light-years away.
With some exceptions, the further from the Sun, the greater the distance from its orbit to the orbit of the next object. For example, Venus is 0.33 AU further from the Sun than Mercury, and Saturn is 4.3 AU further than Jupiter; Neptune is 10.5 AU further than Uranus.
If the distance between the Sun and Neptune were the length of a soccer field, the Sun would be 3 centimeters in diameter (two-thirds of a golf ball), the giant planets would be 3 millimeters in size, and the diameter of Earth. and other inner planets would be the size of a flea (0.3 mm).