Planet Earth reaches its most distant point from the sun for 2014 on July 3, at 7 p.m. Central Daylight Time in the U.S. By Universal Time, Earth is farthest from the sun on July 4, at 0 hours (midnight) UT).
By the way, the above diagram greatly exaggerates the Earth’s eccentric – oblong – orbit for illustrative purposes. Our orbit around the sun is nearly circular.
Astronomers call our farthest point from the sun Earth’s aphelion. Today, we’re about three million miles (five million kilometers) farther from the sun than we will be six months from now. That’s in contrast to our average distance from the sun of about 93 million miles (150 million km). Looking for Earth’s exact distance from the sun at aphelion? It’s 94,506,462 miles (152,093,481 km). Last year, on July 5, 2013, the Earth at aphelion was a tiny bit farther away, at 94,508,959 miles (152,097,427 km).
We’re always farthest from the sun in early July during a Northern Hemisphere summer – and closest in January during a Northern Hemisphere winter – and that’s a good illustration of the fact that it’s not the Earth’s distance from the sun that creates the seasons on our world. Instead, the seasons result from Earth’s tilt on its axis. Right now, it’s summer in the Northern Hemisphere because the northern part of Earth is tilted most toward the sun.
Meanwhile, it’s winter in the Southern Hemisphere because the southern part of Earth is tilted most away from the sun.
So Earth’s varying distance from the sun doesn’t create the seasons. But it does affect the length of the seasons. That’s because, at our farthest from the sun, like now, Earth is traveling most slowly in its orbit. That makes summer the longest season in the Northern Hemisphere and winter the longest season on the southern half of the globe.
Conversely, winter is the shortest season in the Northern Hemisphere and summer is the shortest in the Southern Hemisphere – in each instance, by nearly 5 days.
Bottom line: Earth is farthest from the sun for all of 2014 on July 3 or 4, depending upon your time zone. Astronomers call this yearly point in Earth’s orbit our aphelion.