Circle Monday, April 14 on your calendars

Circle Monday, April 14, on your calendar. No, not just because it is the day before your income tax is due, that is the date for a total lunar eclipse.

This will be an eclipse that is not for the faint of heart as it will begin late in the evening of March 14, and end in the very early hours of Tuesday, April 15.

A total lunar eclipse--or eclipse of the moon--can only happen when the moon is full, which it will be on April 15, at 1:52 a.m. MDT during the eclipse.

A lunar eclipse is when the moon passes through Earth's shadow cones, meaning Earth is between the moon and the Sun. The shadow cones are in two parts. The outer penumbra which is a dimmer shadow, and an inner much darker umbra.

It is the umbra which causes the moon to have such a dark, reddish hue. It is light from all of Earth's sunrises and sunsets cast out into space and coloring the moon.

The moon will enter the outer edge of the penumbra at about 10:58 p.m. MDT on Monday, April 14. These times are approximate and geared for residents in Southwest Nebraska. It will take the moon almost an hour to cross the dimmer penumbra entering the umbra just past midnight.

During the penumbra stage there will be almost no perceptible change in the coloration of the lunar surface except for perhaps a slight dimming of brightness to those who have a keen eye.

However, when the moon starts to enter the umbra there will be a very noticeable "bite" taken out of the moon's edge. This "shadow bite" will continue to grow larger until the entire lunar face is covered and the coloration will turn a noticeable dark, or even reddish hue.

The darkened umbral stage lasts until about 2:25 a.m. MDT when another "bite" starts on the opposite edge of the moon only this time the brightness of the full moon starts to return and gradually grows until about 3:32 a.m. MDT when the moon is completely out of the umbra and totality is over.

The moon is back into the penumbra perhaps looking a little dimmer than a bright, full moon should, and will be there until about 4:37 a.m. MDT when the moon leaves the shadow cones behind.

There will be a couple of nice telescopic goodies for observers during the eclipse. First, the very bright star Spica will be about one degree to the lower right of the eclipsed moon, and the brightening planet Mars will be about nine degrees to the upper right.

If you would like an observational challenge, try to find the small asteroid Ceres about 15 degrees almost straight up and a little to the left of the moon. At seventh magnitude it should be within reach of even a 10X50 pair of binoculars.

Place the eclipsed moon at the bottom of your binocular field of view and go up three fields of view, Ceres should be near the center with slightly brighter fourth magnitude asteroid Vesta to its lower right.

Look left of the darkened lunar disk for a slightly yellow dot of light that is the planet Saturn. Only a telescope will show its magnificent rings.

SKYWATCH: Third-quarter moon Sunday, March 23 which will be visible even at sunrise in the south. On Thursday, March 27, about an hour before local sunrise a very nice super-slender crescent moon will be very close to a very bright planet Venus, and if you have a very unobstructed, uncluttered western horizon try to find the outer planet Neptune near an even more slender crescent moon the next morning, March 28. If you put the moon out of view at about the 10 o'clock position in the field of view, Neptune will be near the center of the field.

NEXT WEEK: More astronomical blathering.