Guest Author - Lea Terry

This weekend, even amateur stargazers can get a close-up look at the solar system in action, with a total lunar eclipse on March 3.

It’s been two and a half years since the last total lunar eclipse. The March 3 eclipse, lasting approximately 74 minutes, will be visible in the eastern United States and Canada, as well as Europe and Africa. For residents of the western United States, the eclipse will already be over by the time the moon rises in their part of the country; however, a total lunar eclipse on Aug. 27 will be visible in those locations. Because the upcoming eclipse occurs early in the evening, it will be convenient for most stargazers, unlike many other astronomical events, which peak during late night or early morning hours. The eclipse will be easily observed with the naked eye, but could be even more spectacular with the aid of binoculars or a telescope. Eclipses are also relatively easy to photograph, with the right equipment.

A lunar eclipse is caused by the moon passing through Earth’s shadow, which blocks the sun’s light from reaching the moon. A lunar eclipse can occur only during a full moon. There are two parts to Earth’s shadow, the outer or penumbral shadow, and the inner or umbral shadow. Total lunar eclipses such as the one on March 3 occurs when the moon passes through the umbral shadow, and are striking for the range of colors the moon can exhibit--from a dark gray to bright orange. About 35 percent of lunar eclipses are total eclipses.

There are two other kinds of lunar eclipses: a penumbral lunar eclipse, which occurs when the moon passes through Earth’s penumbral shadow; and a partial lunar eclipse, when a portion of the moon passes through Earth’s umbral shadow. Penumbral lunar eclipses are difficult to observe, even with a telescope, and so are usually not of interest to amateur stargazers. Partial lunar eclipses, however, are easily observable with the naked eye. About 35 percent of lunar eclipses are penumbral, and about 30 percent are partial.

The last total lunar eclipse was Oct. 28, 2004.