Shedding light on the lunar eclipse

Lots going on this week, let's get to it. First off, the total lunar eclipse on April 14/15. This gets a little confusing because totality -- the darkest part of the eclipse -- begins at about midnight MDT on April 14, when Earth's umbra -- the darkest part of Earth's shadow -- will touch the edge of the moon.

At that point the date becomes April 15.

Totality will continue for about two hours and 23 minutes until 2:23 am MDT when sunlight returns to the left edge of the lunar surface.

The moon will travel through the lower half of the umbral shadow so the lower half of the moon may not be as dark as the upper half.

Remember, there are two parts to Earth's shadow cone that is sent out into space. The dark inner cone called the umbra, and the lighter outer cone called the penumbra. When the moon is in the penumbral shadow the eclipsing effect is not very noticeable.

However, when the moon enters the umbra the eclipse shadow is very noticeable. It will look like a giant cookie monster is taking a bite out of the moon.

This eclipse is the first of four total lunar eclipses without a partial eclipse between them during the next year and a half called a tetrad. The other three will be on Oct. 8, 2014, and April 4, and Sept. 28, 1015.

If the sky is cloudy on that date, point your favorite web browser to www.stargazeronline.org for live coverage of the event. If you miss this one just remember, there are three more coming.

Now, what else is going on? April is a good month for planets. Beginning in the western sky about an hour after local sunset look in the west for our old friend Orion, the hourglass-shaped figure of the mighty hunter.

Just above Orion find the very bright planet Jupiter, the largest of all the planets. Binoculars will show the four Galilean moons -- Callisto, Europa, and Io to the upper left and Ganymede to the lower right.

The brightening moon is high in the south. It will have a meeting tomorrow night, Thursday, April 10, with the star Regulus, the brightest star in Leo, the Lion

At about 11:30 pm MDT, look in the southeast for the bright red dot of the planet Mars. Mars is a fine sight right now in even a small telescope as it was at opposition -- opposite the Sun in the sky -- on April 8 and at its closest to Earth for the next two and a half years.

At midnight look a little the to lower left of Mars for just-rising Saturn. The ringed-planet is a very nice sight in a telescope. Right now the rings are very visible. Saturn will be up close and personal with the moon on Thursday, April 17 at about midnight.

For the next planet, Venus, we will have to wait until about an hour before local sunrise. Look just above the eastern horizon. Later this month a very slender crescent moon will pay a visit to our very bright sister planet.

SKYWATCH: Full moon and total lunar eclipse in the early morning hours of Tuesday, April 15.

NEXT WEEK: The moon and Saturn and more astronomical blathering.