The Earth is the third planet from the Sun, and the largest of the terrestrial planets. But how many miles is the Earth from the Sun? The Earth’s average distance from the Sun, which astronomers call the semimajor axis, is 92.96 million miles.
But remember that this is an average number. The Earth actually follows an elliptical path around the Sun. At the closest point of its orbit, called perihelion, the Earth is only 91.40 million miles. And then when it’s out at the most distant point of its orbit, called aphelion, the Earth reaches 94.51 million miles.
Astronomers use the Earth’s average distance from the Sun as a standard yardstick for measuring distances in the Solar System. This Earth Sun distance is called an astronomical unit. So, the average distance from the Earth to the Sun is 1 astronomical unit, or 1 AU; and the distance from Mars to the Sun is 1.524 AU, on average. And the average distance from Pluto to the Sun is 39.48 AU.
We’ve also recorded an episode of Astronomy Cast all about planet Earth. Listen here, Episode 51: Earth.