Total and Annular Solar Eclipses

Question

Why is it they are almost never visible from the US, but rather more commonly seen in the Southern Hemisphere?

Answer 1

Hi Apricot!

Both southern and northern hemispheres receive equal numbers of solar eclipses.  If, as in this month of August, there's an eclipse primarily in the Northern Hemisphere, there's probably an eclipse in the Southern Hemisphere about six months before or after.  And indeed, February 6, 2008 there was an annular eclipse in Antarctica, while on January 26, 2009 we'll have one primarily over the southern Indian Ocean.

If you'd been watching between 1923 and 1939, you would have been able to see six total and annular eclipses (four total, 2 annular) over US territory.  Although some rules do apply in eclipse prediction, essentially it's entirely a random thing whether a given country gets several eclipses or none at all in a given time.

Answer 2

Over a long period of time, the U.S. is just as likely to see total and annular eclipses as anywhere else. It's just that the U.S. is going through a bleak spell at the moment, with no total eclipses since 1979. However, not to worry because there will be annular eclipses on 20th May 2012 and 14th October 2023 and total eclipses on 21st August 2017 and 8th April 2024.

Incidentally, in the long term, total eclipses are slightly more common in the northern hemisphere because the earth is farthest from the sun in July, so the sun appears smaller and is more likely to be completely covered by the moon at the time when the northern hemisphere is tilted towards the sun. By the same reasoning, annular eclipses are slightly more common in the southern hemisphere.