<p>The full moon will get a tiny bite taken out of it tomorrow as it undergoes one of the shallowest and shortest partial eclipses of this century. (See lunar eclipse pictures.)</p><p>Here's what you need to know about the rare lunar event.</p><p>What is a lunar eclipse?</p><p>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 redonly a portion of its disk appears to go dim. (Read about a total lunar eclipse in 2011.)</p><p><a href="http://news.nationalgeographic.com/news/2013/04/130424-partial-lunar-eclipse-moon-slooh-space-science/">Keep reading...</a></p><p>Read also:</p><p><a href="http://www.space.com/20815-lunar-eclipse-full-moon-webcasts.html">Partial Lunar Eclipse Occurs Thursday: Watch It Live Online</a> (Space.com)</p><p><a href="http://www.arabnews.com/news/449312">Kingdom to witness rare lunar eclipse tonight</a> (Arab News)</p><p><a href="http://www.baltimoresun.com/news/weather/weather-blog/bal-wx-full-pink-moon-to-be-marked-with-eastern-hemisphere-eclipse-thursday-20130424,0,2963279.story">&#039;Full Pink Moon&#039; to be marked with eastern hemisphere eclipse Thursday</a> (Baltimore Sun (blog))</p><p>Explore: <a href="http://news.google.com/news/more?ncl=ddVx-49BxR6Cc7Mp_2WuXUGEylX6M&ned=us">48 additional articles.</a></p>