This Week: We’re Closest to the Sun
One misconception we often read in letters, emails, and comments from our readers is the idea that it’s cold in the winter time because the Earth is father from the Sun. While this assertion may sound good, unless you live in Australia, or some other location “down under” the Equator, it’s actually just the opposite.
This week, (on January 4, 2012, at 8 p.m., Eastern Time, to be exact) the Earth will reach perihelion, its closest point to the Sun for the year.
Perihelion can fall anywhere between January 2 and January 6 in a given year. At that point in its orbit, the Earth is 91,407,282 miles from the Sun, a difference of about three million miles from its farthest point, or aphelion. Earth will reach aphelion on July 5, 2012, at 4 a.m., Eastern Time, at a distance of 94,509,130 miles from the Sun.
It may seem strange to learn that, while the U.S. and Canada are experiencing their coldest temperatures of the year, the Earth is actually closer to the Sun than at any other time during the year.
Even though most of us learned in school that seasons are controlled by the tilt of the Earth’s axis, rather than by its distance from the Sun, many people forget. We experience summer or winter conditions based on whether our half of the Earth is pointed toward the Sun or away from it. While we’re battling ice and snow in the Northern Hemisphere, our neighbors to the south are enjoying summer, and vice verse.
A three million-mile change in relative distance may sound like a lot, but our overall distance from the Sun is so great that this otherwise large figure amounts to a drop in the vast astronomical bucket of infinite space. This slight change in distance has virtually no effect on our weather throughout the year.
So, while you’re shivering and scraping the ice off of your car’s windshield this winter, try to remember that the Sun is actually three million miles closer than it was in July. Maybe that will help you feel a little warmer.