Post by Centaur on Dec 21, 2011 3:51:14 GMT -6
A poster on another message board reported that his two planetarium programs predicted a partial solar eclipse on 2011 DEC 24, yet he was puzzled that nowhere has an announcement of the event been published. I’ve calculated that it will not be an eclipse.
The test is whether the angular separation between the centers of the Sun and Moon is less than the sum of their angular semidiameters, as measured from the point on the Earth’s surface where the separation is minimal. In this case the former exceeds the latter by over seven arcminutes, so the test fails.
For observers in northern Canada near the Arctic Circle on December 24, the Sun will barely get above the southern horizon at local noon, while the Moon passes slightly above the Sun with their limbs missing each other by over seven arcminutes.
I’ve created a preview graphic with my self-made software. It shows the conjunction at its tightest as viewed from the ideal location in northern Canada at true local noon on December 24. The Moon would actually be made invisible by the Sun's glare, but I colored it dark to demonstrate its location.
The test is whether the angular separation between the centers of the Sun and Moon is less than the sum of their angular semidiameters, as measured from the point on the Earth’s surface where the separation is minimal. In this case the former exceeds the latter by over seven arcminutes, so the test fails.
For observers in northern Canada near the Arctic Circle on December 24, the Sun will barely get above the southern horizon at local noon, while the Moon passes slightly above the Sun with their limbs missing each other by over seven arcminutes.
I’ve created a preview graphic with my self-made software. It shows the conjunction at its tightest as viewed from the ideal location in northern Canada at true local noon on December 24. The Moon would actually be made invisible by the Sun's glare, but I colored it dark to demonstrate its location.
