Sun Over

Tomorrow is the fall or autumn equinox.

Sun tracks at solstices and equinoxes

There is a lot more about it in the Astronomical Companion and Astronomical Calendar 2015, but this picture tries to give you a brighter idea of how the Sun rolls overhead, at this equinox (the middle track) as compared with its summer solstice track on the left and its winter solstice track on the right.

The Sun is overhead along those latitudes (the Tropic of Cancer, the equator, and the Tropic of Capricorn) but of course is itself at a tremendous distance outward. One way of putting it is that it’s 11,727 times the width of the Earth away.

The toy Sun in the picture is only 1/40 times the width of the Earth away, and a tiny fraction (but I don’t want to calculate any more numbers) of the size of the real Sun. Still it looks as if it could dry up the strait between Florida and Cuba as it screams over at midsummer.

 

4 thoughts on “Sun Over”

  1. oops,,, I messed up really bad this year, tellin folks that today it the last day of summe,,,, yesterday…. I’m looking at too many calendars and almanacs. Shame on me… lower your lawnmower blades now that the sun isn’t so strong… put the clippings in your compost heap or over your garden as mulch. I still got cucumbers oozing out of their vines, and yellow squashes too.. Who’s got broccoli?
    Feel the balance of the earth tip into the darker side. Love it all…

    1. I had cucumbers earlier this year, but they stopped producing in late July and the vines dried up. I had lots of broccoli plants but they didn’t seem to produce any substantial crowns, so I tore them out. We’ve been experiencing a drought here in Virginia since the middle of July. Bad for the garden and the grass but on the flip side I’ve been able to enjoy the clear skies for the last month, looking at double stars and finding asteroids, Neptune, and Uranus.

  2. If the Sun were really that close, most of the surface of the Earth would be north of the Arctic circle or south of the Antarctic circle!

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