Ann, It is due to the eliptical orbit of the moon around the Earth and the Earth around the sun. The distance between the Earth and the Moon varies during its orbit. When eclipse occurs when the moon is nearest to the Earth, a total eclipse will occur. But when the eclipse occurs when the Moon is most distant from the Earth, its relative size in the sky is smaller and it will not quite block out the entire sun, hence an annular eclipse will occur. Thanks Rodger ----- Original Message ----- From: "Ann House" <ann@annhouse.org> To: "Utah Astronomy" <utah-astronomy@mailman.xmission.com> Sent: Monday, February 22, 2010 9:20 PM Subject: Re: [Utah-astronomy] 2012 annular eclipse
Would someone, who is much more knowledgeable than myself, please explain how we have annular solar eclipses. In other words, why is the size of the moon smaller so it doesn't completely shut out the sun, whereas sometimes the moon is large enough to totally eclipse it.
I can't stay up one more night worrying about this. Thanks.
-A _______________________________________________ Utah-Astronomy mailing list Utah-Astronomy@mailman.xmission.com http://mailman.xmission.com/cgi-bin/mailman/listinfo/utah-astronomy Visit the Photo Gallery: http://www.slas.us/gallery2/main.php Visit the Wiki: http://www.utahastronomy.com