Happy Equinox!

We’re now in Autumn (in the Northern Hemisphere), the time when the length of day and night are roughly the same. And from here on out, the nights will be getting longer and the days shorter. It’s often difficult to explain to people how the Earth’s tilt defines how much sunlight we get every day, and how it causes the changing seasons. Here’s the easy thing to do. Show this amazing video to anyone, and they’ll totally get it. It’s a full year’s snapshots of Earth taken by NASA’s Meteosat satellite.

The Bad Astronomer, Phil Plait, has a great explainer on the Equinox, and details what you’re seeing in this video. Check it out.

5 Replies to “Happy Equinox!”

  1. Neptune was also discovered 165 years ago today on September 23, 1846. Johann Gottfried identified it visually by telescope though Galileo may have viewed it in 1612-13 and assumed it was an ordinary star……. Moral: know your planetary Equniox or pay the price.

  2. Ptolemy still rules: it is the source of illumination–the Sun which changes position in the video not the Earth’s axis orientation to it. Did Copernicus write De revolutionibus in vain?

  3. Nice video and I see NASA compiled it, but the Meteosat series of weather satellites are ESA’s – just for the record!

  4. The nights have been getting longer since the sumer solstice, not since the equinox. The post is a little ambiguous and could be misread. Nights will just be longer than the daylight for the next six months.

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