It’s Perihelion

It’s as if a big, nerdy weight has been lifted off my shoulders!

I just went online trying to find the date of perihelion this year. I figured it was coming. Wrong. It came at 8:00 PM. Perihelion is Earth’s closest proximity to the Sun.

I like mentioning it (and will tonight on the news) because it’s anti intuitive. Who would expect the Earth and Sun to be closest when we’re our coldest?

Perihelion is part of a small set of facts most people don’t know. Let me help you win your next barroom bet!

The Earth’s orbit isn’t circular. The Earth’s orbit is (close to) an ellipse. We’re 3,000,000 miles closer to the Sun today than in July. As you see that distance is inconsequential in the heating department.

The four seasons are not equal length! Summer plus spring is around a week longer than fall plus winter. Johannes Kepler had this figured out in 1609. Thank heaven for small favors!

spring 92.76 days
summer 93.65 days
fall 89.84 days
winter 88.99 days

The first day of autumn and spring do not have equal day and night! They would if we had no atmosphere and didn’t measure from the moment the Sun breaks the horizon until it falls below it (adding the extra time it takes for the Sun’s diameter to pass the horizon to our day).

It’s as if a big, nerdy weight has been lifted off my shoulders!

5 thoughts on “It’s Perihelion”

  1. I had heard of perihelion and its opposite aphelion but wasn’t sure which was which. Thanks for the explanation and for the interesting seasonal facts!

  2. unless I’m reading this wrong the calculations show that spring and summer are longer not shorter than fall and winter

  3. Although we are closer to the sun during the winter, the northern hemisphere is slanted away, thus giving us winter. During summer we are further away from the sun but the earth’s axis slants us towards the sun, warming us. Guess it all wouldn’t work well if it was the other way around. BTW does anyone know when the magnetic pole swap, (where North will be South and South will be North), is due to occur?.

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