A lunar eclipse is caused by the moon being totally in the shadow of the Earth. It is when the Earth, moon, and sun are in direct alignment with one another. The sun shines on the Earth and casts a cone shaped shadows that is 1.3 million kilometers (800,000mi) long, and the distance of the moon from Earth is only 240, 000mi. Eclipses can only happen when there is a full moon, and when the moon and Earths planes cross.
The moon orbits every 29.5 days, but Earth only once a year, so the eclipse happens when the two planes cross. One of the benefits of the lunar eclipse is that the whole thing can be viewed by the naked eye, unlike solar eclipses. When the moon is eclipsing, it changes colors. This is because of the red and orange light wavelengths (that are more prominent) that leak into the shadows, causing the moon to colors like rusty brown, golden, and burnt toast. This is the most exciting part for astronomers because the color change depends on the clearness and density of clouds in the atmosphere.
The best way to view a lunar eclipse is to use binoculars. Yes, a lunar eclipse is viewable to the naked eye, but to really see the color changes and details of the moon as it eclipses, a pair of binoculars works best. The whole thing usually lasts for about three hours, one hour for entering, one hour for exiting, and about 90 minutes being eclipsed.
Eclipse of the Sun
The eclipse of the sun is a remarkable yet dangerous event. Because it is so incredible, people like to view it, but many view it improperly. Many people get equipment that is not meant for viewing solar eclipses, and they risk permanent eye damage. Just quickly peering into a telescope aimed at the sun is very harmful to the eyes. A total solar eclipse occurs when the moon moves over the solar disk, and casts a shadow that travels on Earth's surface. It will begin to move over the sun about an hour before total eclipse, and as the sunlight decreases, the light of the moon increases. The sun's surface soon becomes a crescent as it is gradually covered up by the moon. Just before total eclipse, streaks of light called Baily's Beads escape. These streaks are caused by light coming through valleys, craters, and irregularities on the moon's surface. Then, total eclipse occurs, an interval known as saros. The maximum time for a solar eclipse is around seven and a half minutes long.