Friday, February 22, 2008

Eclipses

On Tuesday much of the United States and parts of the Western Hemisphere got to view a full lunar eclipse. I hope my readers had the oppurtunity to witness such an event.

Encarta has a wonderful interactive explanation of both solar and lunar eclipses. Solar eclipses occur when the moon gets in between the Sun and the Earth. Areas under the umbra, the darkest part of the shadow, have a total eclipse while areas in the preumbra have a partial eclipse. A lunar eclipse occurs when the Earth gets between the Sun and Moon. The red seen on the moon during the lunar eclipse is due to the Sun's light having to pass through the Earth's atmosphere first. Shorter light wavelengths get scrambled and therefore usually red's wavelength dominates.

Astronomers fortunately have well documented eclipses on the internet. Hermit Eclipse has a complete eclipse library from 2000 BC to AD 3000. NASA features tables, Google Maps, atlases, and North American eclipse maps. Finally there is a world atlas of eclipse paths on Google Maps for 1960 to 2100 and the sister site of Google Maps eclipse paths from 2000 BC to AD 3000.

1 comment:

Goethe said...

We saw the eclipse here in Manhattan at 10 p.m. In Central Park there is a guy who is often out at night with his binoculars focused on the heavens. Thanks for the links. I am looking forward to 2019 for that total eclipse of the sun!