Saturday, March 04, 2006

Awfully vast

What was that line from Johnson yesterday? "Awfully vast or elegantly little." Comet Pojmanski is elegantly little. The awfully vast is coming. On March 29, at 10:56:52 AM local time, I will be at longitude 31 degrees 23.1 minutes E, latitude 36 degrees 46.0 minutes N, to watch the Sun go as black as an inkpot for 3 minutes 44.9 seconds. On that day and in that place the Moon will pass directly in front of the Sun, and the apparent disk of the Moon will be 1.0493 times larger than the apparent disk of the Sun. (This ratio varies from about .90 to 1.07, depending on the distances of the Sun and Moon from the Earth.) It is just a coincidence that the apparent sizes of Sun and Moon in the sky are so nearly the same. If the ratio of apparent diameters was always less than 1, we would never have a total solar eclipse, one of nature's most awfully vast events. If the ratio were significantly greater than 1, total eclipses of the Sun would not be so gloriously rare.