Far from the Sun

It probably doesn’t sound right on a hot summer day, but Earth is actually farthest from the Sun for the entire year about now — more than 94 million miles.

Earth’s orbit around the Sun is a bit lopsided. The average distance to the Sun is about 93 million miles. But during the year, the distance varies by about three percent in either direction.

That slight variation is known as the “eccentricity” of the orbit. The orbits of all the planets are eccentric, but by different amounts. Venus’s orbit is the least eccentric — less than one percent. Mercury’s is the most eccentric — about 20 percent.

In fact, it’s almost impossible for one body to have a perfectly circular orbit around another. Earth and the other planets of the solar system, for example, are pushed and pulled by the gravity of all the other planets. And collisions with other bodies have also skewed their orbits.

As Earth’s distance from the Sun changes, so does the amount of energy we receive from the Sun. At our closest, in January, we get about six percent more total energy than we’re getting right now.

Surprisingly, though, there’s little impact on Earth’s climate. The atmosphere and oceans store the heat and distribute it around the planet. That’s why we can have really hot days during summer here in the northern hemisphere, even though the Sun is three million miles farther than during the dead of winter.
 

Script by Damond Benningfield