The Earliest Sunset is Now…

Once again that time of the year…for the earliest Northern Hemisphere sunset (and earliest Southern Hemisphere sunrise)–both of which occur not on the solstice but now, in early December. Here was a discussion from last year…

The Grumpy Geophysicist

We are so disconnected from the reality of the heavens that most people don’t know the moon’s phase (many don’t know you can see the moon in daylight). So the really subtle stuff gets overlooked.  But folks who rise with the sun probably notice that sunrise keeps getting later after the solstice on the 21st of December. And, conversely, the earliest sunset is about now, in early December (a point in time GG really notices–it is nice to have it start to be light later as we approach New Years).

How can that be?

If you know a little astronomy, it is straightforward, and the cool thing is that it is a direct demonstration of the ellipticity of Earth’s orbit.  In northern hemisphere winter, we are near perihelion (closest point to the Sun). And so by Kepler’s Laws, it mess we are traveling faster around the Sun than other times…

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