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Here’s how much smaller the sun looks at aphelion

We passed aphelion, Earth’s farthest point in orbit around the sun, on July 6. The eye can’t detect it, but a camera shows that the sun around now appears at its smallest in our sky.

Composite image showing the size of the sun at aphelion (our farthest point) and perihelion (our closest point). The photos were taken 18 months apart, and a few days from the events due to adverse weather conditions, but they show an unmistakable size difference of the sun as viewed from Earth, across our yearly orbit. Image by Peter Lowenstein.

The sun at aphelion appears smaller in our sky, as shown in this composite image. This image consists of two photos, taken just days away from a perihelion (Earth’s closest point to the sun) in January, 2016, and an aphelion (Earth’s farthest point from the sun) in July, 2017. The gray rim around the sun (actually the perihelion photo) illustrates that, as seen in our sky, the sun is about 3.6 percent bigger at perihelion than aphelion. This difference is, of course, too small to detect with the eye.

Although taken 18 months apart, and a few days from the events due to adverse weather conditions, you can see there is an unmistakable size difference of the sun as viewed from Earth when it is closest at perihelion and furthest away at aphelion.

Read more: Earth farthest from the sun on July 6

By the way, the moon changes its size in our sky, too, as it moves in its elliptical orbit around Earth. Read more: Close and far moons in 2018

Here are the original photos, used in the composite image above, showing the size difference of the sun between Earth’s perihelion (closest point) and aphelion (farthest point). Image by Peter Lowenstein.

Bottom line: Composite image showing the size of the sun at perihelion and aphelion.

Peter Lowenstein

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