Good news, bad news on eclipse
Thursday, December 8, 2011
The big astronomical news this week is the total lunar eclipse which will occur on Saturday, Dec. 10.
A total lunar eclipse occurs when Earth's shadow crosses the face of the moon. Such events only happen when the moon is full.
That is the good news, now for the bad news, we won't be able to see much of it from here in Southwest Nebraska.
From our point of view the total portion of the eclipse starts at about 6 a.m. MST. That is when the moon will enter the darkest part of Earth's shadow called the umbra.
At that point a noticeable shadow will start to cross the lunar face. From that point it usually takes about an hour for the shadow to completely cover the moon. That point is called totality.
The bad part for us is, that is when the moon will set, just as totality begins.
So, you early risers find yourself a good, clear, uncluttered view of the western horizon, grab a cup of coffee, or other suitable warm beverage of choice, and watch as the shadow covers the face of the moon then disappears below the horizon.
Now, more good news. If you live in Alaska or Hawaii you will be able to watch all of the eclipse, from the beginning of totality to the end. I know there are readers of the Post in both places.
From Alaska totality will begin at about 4 a.m. local time and end a couple of hours later. From Hawaii be out looking at about 3 a.m. local time.
As for our planetary parade, Venus is that bright thing you have been seeing in the west after sunset these evenings. Keep an eye on Venus for the next several months into June of next year.
Our sister planet will have several conjunctions with the moon and a couple of other planets. There will be a great conjunction of a very slender crescent moon and Venus on Monday, December 26.
Jupiter is coming on strong as an evening object. It is that bright thing you have been wondering about in the eastern skies just after sunset.
Mars is making a return to our skies. It rises in the east at about 12:30 a.m. local time and is due south at about 5:30 am. Mars is another object to keep an eye on for the next few months.
Saturn is another morning object. It is visible almost due south about an hour before sunrise located close to the bright star Spica.
Finally, tiny Mercury has returned to the morning skies visible about a half-hour before sunrise.
Mercury never gets too far above whatever horizon it is over west or east so some kind of optical aid, binoculars or a telescope is often helpful. Look in the southeast.
The fleet-footed planetary speedster will rise higher each day until December 16 when it will head back for the horizon.
SKY WATCH: Full moon and total lunar eclipse Dec. 10. Geminid meteor shower Dec. 13. Usually a good shower to watch, but this year the close proximity of the just-past full moon will spoil any viewing.
NEXT WEEK: Astronomical gift suggestions and more astronomical blathering.