It probably doesn’t sound good on a hot summer’s day, but the Earth is actually the farthest it’s been from the Sun all year right now—more than 94 million miles.
The Earth’s orbit around the Sun is slightly tilted. The average distance to the Sun is about 93 million miles. But over the course of the year, the distance varies by about three percent in either direction.
This slight variation is known as the “eccentricity” of the orbit. The orbits of all planets are eccentric, but to varying degrees. The orbit of Venus is the least eccentric at less than one percent. Mercury is the most eccentric – about 20 percent.
In fact, it is almost impossible for one body to have a perfect 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 distorted their orbits.
As Earth’s distance from the Sun changes, so does the amount of energy we receive from the Sun. In our closest period, in January, we get about six percent more total energy than we get now.
Surprisingly, however, it has little effect on Earth’s climate. The atmosphere and oceans store heat and distribute it around the planet. This is why we can have really hot days in the summer here in the Northern Hemisphere, even though the Sun is three million miles further away than in the winter.
Screenplay by Daymond Benningfield
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