Today the Earth reaches its furthest point from the Sun in its annual orbit.  This is Earth’s aphelion, position 1 above.

It’s a source of wonder to me that this happens at our hottest time of year.  Shouldn’t aphelion cool things off?

Apparently not by much.  The orbit determines Earth’s livability but has far less affect on temperature than the composition of our atmosphere and the tilt of the earth’s axis.  Right now the northern hemisphere is tilted toward the sun and we certainly feel it.

If we had the data and computer horsepower we could prove aphelion’s effect on climate because it hasn’t always occurred in July.

According to Wikipedia, “On a very long time scale, the dates of perihelion and aphelion progress through the seasons and make one complete cycle in 22,000 to 26,000 years. There is a corresponding movement of the position of the stars as seen from Earth that is called the apsidal precession.”

So, hey, if you’re around 12,000 years from now, aphelion will happen in December.

It’s something to look forward to.

(drawing of aphelion and perihelion by Peasron Scott Foresman via Wikimedia Commons)