Tonight, February 20, 2008, will be your last opportunity to view a total lunar eclipse until December 2010. A lunar eclipse occurs when the Earth lines up directly between the Sun and Moon such that the Earth's shadow completely covers the Moon's surface. Tonight's eclipse will last for about 3.5 hours, 50 minutes of which the Moon will be in totality. During the eclipse the Moon will change color from gray to red. This is due to the glow cast on the Moon from indirect sunlight passing through Earth's atmosphere. The Moon's color during an eclipse varies based on the amounts of dust and clouds in the Earth's atmosphere. The more dust in the Earth's atmosphere, the more red the Moon will appear. The United States will be able to view the majority of the eclipse. Click on the above map above to determine your best viewing times.
To learn more about tonight's eclipse, see the NASA Eclipse Home Page and this NASA feature story. To learn more about eclipse terminology, see the Educator's Guide to Eclipses. Click here for a classroom activity on creating two scale models of the Earth-Moon system that can be used to demonstrate lunar phases and eclipses. Click here for an eclipse viewing activity for students.