July is summer in the northern hemisphere and you might think this means we are closer to the Sun. This is a common misconception. Earth is actually farther from the Sun in July and on July 4th it is at its farther distance in orbit around the Sun. We call this aphelion.
Earth’s orbit around the Sun is an ellipse. Its closest approach to the Sun in this orbit is called perihelion and its farthest is called aphelion.
The table below shows the date/time and distances for perihelion and aphelion from 2020 to 2025.
|2021||January 2, 2021 8:50 am||91,399,454 mi||July 5, 2021 6:27 pm||94,510,886 mi|
|2022||January 4, 2022 1:52 am||91,406,842 mi||July 4, 2022 3:10 am||94,509,598 mi|
|2023||January 4, 2023 11:17 am||91,403,034 mi||July 6, 2023 4:06 pm||94,506,364 mi|
|2024||January 2, 2024 7:38 pm||91,404,095 mi||July 5, 2024 1:06 am||94,510,539 mi|
|2025||January 4, 2025 8:28 am||91,405,993 mi||July 3, 2025 3:54 pm||94,502,939 mi|
|* All aphelion/perihelion times are in local Washington, DC EDT time.|
Well yes, they always happen close to one another. Aphelion happens about 2 weeks after the July solstice and perihelion happens about 2 weeks after the December solstice.
One of the crazy things about the extremes in Earth’s orbit around the Sun is the Sun’s apparent size in the sky. During perihelion the Sun is a little closer to us and aphelion it is a little farther from us. So this means that the Sun’s apparent size in the sky changes very slightly, i.e. when it is closer (perihelion) it appears slightly larger and when it is farther (aphelion) it appears slightly smaller.
This is just perspective. These size differences are almost unnoticeable. In fact, you really need a telescope to see this difference.
The composite image below, taken with a special telescope, allows us to see this subtle size difference of the Sun between perihelion and aphelion.