Despite a heat wave roasting parts of the United States and forecast high temperatures close to 90 degrees across southwestern Connecticut, our planet is actually at its farthest point from the Sun today. According to the U. S. Naval Observatory, the Earth reached a point in its orbit called "aphelion" at 12 o'clock EDT this morning. The Earth's aphelion is the point where it is the farthest from the Sun than at any time during the year.
The Earth is typically about 93 million miles from the Sun. However, because our planet's orbit is not a perfect circle but an ellipse, it has a farthest point and a closest point to the Sun. In case you're wondering, the Earth's closest approach to the Sun is called perihelion, and that occurs in early January. The Earth is exactly 3,104,641 miles (or 3.28 percent) farther from the Sun than at its closest approach. The Earth actually receives about seven percent less heat at its aphelion than at its closest approach, according to researchers.
Although the date for both will vary from year to year, the Earth will always be closest to the Sun in early January and the farthest away in early July. Not surprisingly, that comes as a surprise to most people. At perihelion, our planet is about 91 million miles from the Sun. It moves outward to about 95 million miles from the Sun at aphelion. Naturally, some people have the mistaken impression that our seasons are caused by the changes in Earth's distance from the Sun, but this is not the case.
The temperatures and the seasons are not affected by the proximity of the Earth to the Sun or even the rotation of the planet on its axis. Rather, it is the tilt of the Earth that determines the climate. When it is at perihelion in January, the Earth is tilted away from the Sun in the Northern Hemisphere, and the sunlight is not "getting a direct hit" on the Earth's atmosphere. However, when it is at aphelion in July, the Earth is tilted toward the Sun.
Officially, at Sikorsky Memorial Airport in Stratford, the high and low temperatures yesterday, Independence Day, were 88 and 72 degrees, respectively, for an average of 80 degrees. That's seven degrees above normal. The record high temperature for today --- when the Earth is farthest from the Sun --- is 100 degrees, established in 1999. The normal high and low temperatures for this date are 82 and 65 degrees, respectively.
So, as you cool off at the pool, beach, or by the air conditioner today, take comfort in the fact that our planet is farther from the Sun today than at any other day of the year. Today will be mostly sunny, hot, and turning less humid with a high temperature of 86 to 91 degrees. Hot weather will continue through the start of the weekend before a cold front arrives Saturday night and early Sunday, bringing more seasonable temperatures and lower humidity for Monday through Wednesday of next week.
Paul
