Heads up for a coming lunar eclipse

Consider this your official "heads up."

Mark your calendars for Wednesday, Oct. 8, and Thursday, Oct. 23, as days you will want to be outside and observing.

On Oct. 8, there will be a total lunar eclipse, but you will need to either stay up late or get up early to view it.

Remember, there are two areas of Earth's shadow that extend out into space. The first--and largest--is the penumbra, or the outer shadow cone. The other is the inner, and darker, shadow cone. It is called the penumbra.

Totality can only occur when the moon is within the umbral shadow cone. When the moon is in the penumbra there is only a very slight darkening which is not usually perceptible to the viewer.

Totality will begin at about 3:15 a.m., MDT for viewers southwest Nebraska and into Colorado. For those in the Central Time Zone it will be an hour earlier, 4:15 a.m. CDT. The eclipse will end about an hour before sunrise.

The moon will not move through the exact center of the umbral shadow so the outer edge of the moon may -- or many not -- become totally dark, or in the case of a lunar eclipse, turn reddish.

This lunar eclipse is the second in a series of four consecutive total eclipses called a "Tetrad." The next one will be April 4, and the final one Sept. 28, both in 2015.

More as the dates draw closer.

Otherwise, what else is going on?

Tonight, Wednesday, Sept. 24, is a new moon, and as the saying goes, a new moon is no moon. Since the non-illuminated side of the moon is facing Earth, it will be totally dark (and no, that is not the dark side of the moon).

However, the next night on Thursday, there will be an excruciatingly slender crescent moon just above the southwestern horizon. If you look about a half-hour after local sunset and use your binoculars to look a field-of-view and a half to the left you might be able to see the tiny dot that is the planet Mercury.

If you want to know the times of your local sunrise or sunset, point your favorite browser to www.sunrisesunset.com, enter your location (city and state) and ask for a list of times. A lot more information, which I won't go into here, is available on that calendar also.

Saturday, Sept. 27, will feature a double planetary viewing opportunity, but you will need a very clear, unobstructed, dark, western horizon to do it. Look southwest for a slightly thicker, four-day old lunar crescent. Just to the moon's left will be the dot that is the planet Saturn.

Both of them will be in the same binocular field of view.

The second planetary conjunction is just a bit further left of the Saturn/moon pair, again looking southwest about an hour after local sunset.

SKYWATCH: New moon, Wednesday, Sept. 24. If you have been following Mars, you know by now it is nearing a great meeting with the star Antares in Scorpius, the Scorpion. Keep watching Mars as it moves eastward against the background stars until the evening of Monday, September 29, when the crescent moon will form a straight line with Mars and Antares. It you put some glass on them -- either binoculars or a telescope -- you will notice the similarity in color. That is how Antares -- the "Rival of Mars" -- got its name.

NEXT WEEK: More astronomical blathering.