A lunar eclipse is set to welcome Saturday and it's the third in less than a year. While the astronomical event appears to be frequent, enthusiasts had best be ready early as the eclipse will last for only five minutes, the shortest in the century.
On the morning of April 4, the action starts at 3:16 a.m. PDT, with the moon's edge first entering the amber core within the Earth's shadow. It will take another hour and 45 minutes for the Earth's shadow to move across the lunar disk before ultimately enveloping the moon at 4:58 a.m. PDT.
The sunrise will interrupt the lunar eclipse for those watching from east of the Mississippi River. Those on the western end, however, will be able to view the whole event, including totality, the point when the moon is completely inside the shadow of the Earth. For this lunar eclipse, totality will last 4 minutes and 43 seconds, resulting from the fact that, instead of passing through the center of the Earth's shadow, the moon will be skimming the edges.
Lunar eclipses have five stages, each one offering different views to be observed. While the weekend event will be best seen through binoculars or backyard telescopes, it can be enjoyed as well without equipment.
The first stage starts as the leading edge of the moon enters the outer side of the shadow of the earth while the second stage is a partial eclipse. The third stage is totality while the fourth stage begins when the moon starts moving away from the Earth's shadow. By the fifth stage, the moon is almost out of the darkness.
Lunar eclipses appear red because all sunrises and sunsets happening on Earth at the moment of the event produce an incredible amount of light beamed into the planet's shadow. A coppery glow fills the shadow, transforming the moon into a giant red orb as it is observed from Earth. It is also for this reason that lunar eclipses are also called blood moons.
Should the air be clear, the lunar eclipse will also be more brightly seen. If a volcanic eruption, for instance, pollutes the stratosphere and creates haze, the moon will appear a darker red, ashen gray and sometimes even black.
The total lunar eclipse on Saturday is the third of four projected to occur about six months apart. Astronomers call this phenomenon the tetrad and is considered to be generally rare. The next lunar eclipse is set for Sept. 28.
Photo: Bill Young | Flickr
