On January 4th, at 9:00 a.m. EST, the Earth will be almost 1.5 million miles closer to the Sun than normal. But don’t worry — this occurs every year at around this time, known as perihelion. The word perihelion is from Greek roots, with peri meaning near, and helios, meaning Sun.
As we all know, the Earth orbits the Sun, a journey that takes 365.2422 days to complete. And that orbit happens to be a near-perfect circle, but not quite. So there is a spot where the Earth swings a bit closer to the Sun (at perihelion, on January 4), and a point where it will be farther away (at aphelion, on July 3) in that orbit.
On average, we are 92,955,807 miles away from the Sun (called an “astronomical unit”). At perihelion, the Earth will be a distance of 91,404,322 miles from it (1,550,885 miles closer than normal); at aphelion, six months later, the distance increases to 94,505,901 miles (1,550,094 miles farther away than normal).
Will we see a difference in the Sun’s size, being so much closer?
Not really. While a 3.1 million-mile change in relative distance between the nearest and farthest points from the Sun may sound like a lot, the truth is that 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. The effect of this slight change on distance throughout the year amounts to just 3.3 percent.
Will we feel a difference in temperature?
It may seem strange to learn that, while the Northern hemisphere is undergoing the coldest temperatures of the year, the Earth is actually closest to the Sun than at any other time during the year. Of course, as most of us learned in school, seasons are controlled by the tilt of the Earth’s axis, rather than by its distance from the Sun. We experience summer or winter conditions based on whether our half of the Earth is pointed toward the Sun, or away from it.