Lunar Eclipse Sunday January 20 from Tom B.

Attached is information on the coming Lunar Eclipse. 

I plan to have the telescope on the

field in front of our house that evening, 9:00 p.m. until 11:30 p.m. if

anyone wants to come out to view Moon through the telescope.

Tom Butler

Despite the current weather, I'm going to highlight a few viewing opportunities for January skies.  There are two events happening in the coming two weeks that are fun to watch.  This is a long read, I'm trying to enhance your viewing with some explanation that you won't get from the television news and weather reporters.

First and most dramatic is the total lunar eclipse Sunday night, January 20.  The long-term weather forecast I'm looking at right now indicates a good chance of clear skies Sunday night.  With a solar eclipse (eclipse of our star, Sun), Moon's shadow races across Earth giving a few lucky people in its shadow a few short minutes of totality.  With a lunar eclipse, we are watching the shadow of Earth cast upon Moon as Sun, Earth and Moon line up in a nearly perfect straight line.  Think of a lunar eclipse as being like a drive-in movie.  Anyone remember those?  So, in this analogy, everyone at the movie is able to watch the show at the same time.  In this case that is everyone on the night side of Earth.  This time, we are lucky to be able to see the entire movie. 

The eclipse begins slowly as Moon enters the partial shadow of Earth.  The partial shadow or penumbra is dim and hardly noticeable until just before Moon approaches the darkest part of Earth's shadow.  Next, Moon enters the darkest part of Earth's shadow, the umbra.  This will start with the lower left (eastern most) portion of Moon and progress to cover the entire Moon.  For about an hour Moon will be in the darkest part of the shadow, lit only by the reddish light of the sunset and sunrise glow in Earth's atmosphere.  Then Moon will slowly emerge from the shadow of Earth. 

Here are the times:

Moon enters Earth's umbra:  9:34 p.m.
Total eclipse begins: 10:41 p.m.
Moon deepest in shadow:  11:12 p.m.  This is also the exact moment of the Full Moon, when Sun and Moon are on opposite sides of Earth.  Moon will look full before and after the eclipse.
Total eclipse ends:  11:43 p.m.
Moon leaves Earth's umbra:  12:51 a.m.

The other main event is for early risers.  If you are up before dawn (6:20 a.m. is currently an hour before sunrise and a good time for these observations), you have likely noticed the bright object high in the eastern sky.  That object is Venus, one of two planets with an orbit between Earth and Sun.  Can you name the other?  The word planet means wanderer.  Watching this event will show you why ancient people thought of the planets as wanderers.

As I write this, there is a less bright but still noticeable object just below Venus in the morning sky.  That is Jupiter, the gas giant, largest of the planets in our solar system.  Jupiter has four large moons, Io, Europa, Ganymede and Callisto.  You can see these moons of Jupiter with a pair of binoculars.  They line up in a straight line, sometimes all four on one side of Jupiter or the other.  Sometimes there will be some on one side of Jupiter and others on the opposite side.  Occasionally you may see only 3 or even just two if some of the moons are in front of or behind Jupiter from our viewpoint.  Their positions change rapidly, over a period of an hour or two you may notice the distances between them changing.  Making a drawing can help you track those changes.  From day to day, you will notice large changes.  While you have your binoculars out, look at Venus.  You may be able to see that it is not a fully lit disk.  Venus shows phases similar to the phases of Moon. 

What makes this really interesting is that the distance between Venus and Jupiter is decreasing right now.  This is a slowly progressing event.  From morning to morning, you will notice Jupiter getting closer and closer to Venus.  They will be closest on Tuesday morning, January 22, so most of the approach has been above the recent clouds.  Following Tuesday, the two will separate with Jupiter rising higher into the sky while Venus sinks into the sunrise.  Such an event is called a conjunction (coming together).  Venus and Jupiter only appear to be close together.  In reality, Venus is about 70 million miles from Earth while Jupiter is about 540 million miles from Earth.  Both values for the current time.  So that is about 470 million miles between them, not so close.  In fact, Venus is much closer to Earth than Jupiter which explains why when you look at them, Venus looks nearly the same size as Jupiter.

Now for the really fun part.  Still in the morning sky, you can watch Moon as it nears Jupiter on Wednesday January 30 and is really close to Venus on January 31.  If you look closely on February 1, you might be able to see another planet, Saturn which is very near the horizon.  The distance from Venus to Moon will be about equal to the distance between Moon and Saturn.  You will need a really good eastern horizon to see Saturn.  Nearby trees or houses to your east will block your view.  Saturn is also less bright than Venus or Jupiter which makes it harder to find.  By February 2, Moon is below Saturn.  Venus and Saturn will have a conjunction in February.  Jupiter and Saturn will also have a conjunction in December of 2020.  The conjunction of Jupiter and Saturn is a really slow event but again, notice the distance separating the two and check them from time to time to see the change that is occurring.

By summer, Jupiter and Saturn will be high in the sky at midnight.  Venus slowly sinks into the sunrise in the coming months and will appear again in the fall as it rises in the sunset sky.