Friday, September 22, 2006

Autumnal Equinox

Here's something fun for today. I went looking for it after noticing, at around noon a few days ago, the striking appearance of the day-night boundary on the Seismic Monitor that Kate has displayed in her sidebar. I wondered if I could find a similar display without the earthquake data. I haven't found one to use as a constantly-updated sidebar icon, but I did find a page where you can look at Earth's areas of daylight and darkness, for any date and time you choose between 1700 and 2030.

Try looking at the light map for today's date, and then switching the month to June, and then to December.

A curious note from the text:
Because our atmosphere bends sunlight about a half-degree (60 km) into the area of the Earth that would otherwise be dark, the sunlit part of the Earth is slightly more than half of the entire surface (there is actually more than 12 hours of daylight at the equinoxes).

2 comments:

Wayne said...

What fun! And I'm so glad someone else chose to note the autumnal equinox. The navy.mil pics are great, especially today. There's the sun, right on the equator.

I was a day ahead, but I wanted everyone to have an opportunity to do their shopping and prepare for the big celebration.

Laura said...

Oh, yes, I was supposed to be celebrating! Well, we did buy a car today. (More about that later.) But buying a big thing doesn't feel like a celebration. Maybe since I talked myself out of taking myself out for supper, I could use the last few minutes of equinoctial daylight to bike up to the Co-op and buy some little munchie thing to nibble while I finish tomorrow's sermon...

Say, did you notice the coincidence of the new moon and the equinox? Maybe that has something to do with this left-right sideways-pulling noncommittal feeling that's utterly not conducive to writing something authoritative...

Hmmm. I seem to be writing lots here. Could I be avoiding something???