Why Is This The Shortest Day Of The Year?

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By By Steve Pool

SEATTLE - The Earth tilts on an axis as it orbits around the sun. In the Northern Hemisphere, Dec. 21 is the day when we are tilted the furthest away from the sun -- thus the sun appears lowest in the sky (about 19 degrees above the horizon at noon for Seattle). That means the sun spends the least amount of time above the horizon that day.

It's exactly opposite in the Southern Hemisphere, where the Earth is tilted closest to the sun, so for them, today's the first day of summer. So while we're bundling up, Australians hit the beach during the holiday season.

It works the opposite for summer on June 21. That's when we're tilted closest to the sun, and get the longest day of the year.

Your Photos

YouNews Waiting their turn Waiting their turn
A Washington State Ferry waits its turn to dock at the Lopez Island Ferry Terminal as the sun rises over Mount Baker in the background.
YouNews Reflection Reflection
During my time in Seattle, WA, I've had the opportunity to take all sorts of interesting pictures. There is water everywhere here, and in this shot; it provides a perfect mirror to the road above.
YouNews Weekend Sky Objects Weekend Sky Objects
These images were taken Friday and Saturday under with a bright moon. M42 is a 45 minute stack of 122 frames and M15 is a 34 minute stack of 14 frames. A Meade 6-inch refractor
and a Nikon D3100 was used for all the images. Stacking was
done with Deep Sky Stacker (freeware).