Total Lunar Eclipse of March 03

A unique total lunar eclipse, that it is partly visible from every continent around the world.

Next Saturday the March 3rd Poya day Night (Sunday Early Morning), there will be a Total Eclipse of the Moon which is visible to us. The total phase lasts 73 minutes. The Penumbral stage which begins at 1:48AM there is only a dimming of the brightness of the Moon which is not easy to notice. But after 3:00AM the Moon will start moving into the shadow cast of the Earth by the Sun. From 4:14AM to 5:27AM the Moon is totally eclipsed illuminated only by Earth light. Though depending on Atmospheric conditions it may be seen glowing red in color. The Partial Eclipse ends after sunrise around 6:15 AM on the East coast and 6:22 AM in Colombo and moonset at 6:29 AM


Lunar Eclipses

An eclipse of the Moon (or lunar eclipse) can only occur at Full Moon, and only if the Moon passes through some portion of the Earth's shadow. The shadow is actually composed of two cone-shaped components, one nested inside the other. The outer or penumbral shadow is a zone where the Earth blocks part but not all of the Sun's rays from reaching the Moon. In contrast, the inner or umbra shadow is a region where the Earth blocks all direct sunlight from reaching the Moon. 

 
Geometry of the Sun, Earth and Moon during a Lunar Eclipse. 
Earth's two shadows are the penumbra and the umbra. 

Three basic types of lunar eclipses:

1. Penumbral Lunar Eclipse - The Moon passes through Earth's penumbral shadow. 

2. Partial Lunar Eclipse - A portion of the Moon passes through Earth's umbra shadow. 

3. Total Lunar Eclipse - The entire Moon passes through Earth's umbra shadow. 

Moon's orbit around Earth is actually tipped about 5 degrees to Earth's orbit around the Sun, means that the Moon spends most of the time either above or below the plane of Earth's orbit. And the plane of Earth's orbit around the Sun is important because Earth's shadows lie exactly in the same plane. During Full Moon, our natural satellite usually passes above or below Earth's shadows and misses them entirely and no eclipse takes place. But two to four times each year, the Moon passes through some portion of the Earth's penumbral or umbra shadows and one of the above three types of eclipses occurs. 

During a total lunar eclipse, the Earth blocks the Sun's light from reaching the Moon. While the Moon remains completely within Earth's umbra shadow, indirect sunlight still manages to reach and illuminate it. However, this sunlight must first pass deep through the Earth's atmosphere which filters out most of the blue colored light. The remaining light is a deep red or orange in color and is much dimmer than pure white sunlight. Earth's atmosphere also bends or refracts some of this light so that a small fraction of it can reach and illuminate the Moon. 

Observing Lunar Eclipses

Not as solar eclipses, lunar eclipses are completely safe and easy to watch. You don't need any kind of protective filters. And most of all you don’t need a telescope. You can watch the lunar eclipse with nothing more than your own two eyes. If you have a pair of binoculars, they will help magnify the view and will make the red coloration brighter and easier to see. 
Of course, an eclipse of the Moon also presents a tempting target to photograph. So if you have any digital or SLR camera, try doing some photography. But remember to dress warmly and take time to enjoy the spectacle! 

Thilina Heenatigala  
General Secretary 
Astronomical Association of Lanka