The full moon will get a tiny bite taken out of today as it undergoes one of the shallowest and shortest partial eclipses of this century. (See lunar eclipse pictures.) Though the celestial phenomenon will be visible only in the Eastern Hemisphere, armchair astronomers can watch a live feed of the eclipse thanks to�SLOOH. The Internet-based space-tracking service is broadcasting the eclipse with its robotic telescopes on the�Canary Islands (map) starting at 3 p.m. ET on April 25. Watch the eclipse live: � Here's what else you need to know about the rare lunar event. What is a lunar eclipse? A lunar eclipse occurs when the sun, Earth, and moon align. During total lunar eclipses, the entire moon is engulfed in Earth's darkest shadow. But during partial eclipses, the moon never completely goes dark or turns red'�only a portion of its disk appears to go dim. (Read about a total lunar eclipse in 2011.) "In this case, the moon only just clips the edge of the deepes...