By David Ward
If you enjoy being out in the winter moonlight, then put the night of Jan. 30-31 on your calendar. First of all, the moon is full, which happens every 29 days or so. Also, it is a blue moon, meaning that it is the second full moon in a calendar month. That does not happen very often, hence the phrase “once in a blue moon.”
Then it is a supermoon, which happens when the full moon is closest to the earth in its orbit. That night the moon will appear somewhat larger in the sky than normal. To top that off, it is the third straight full supermoon in a row. The really cool thing about that night is that we get to see a total eclipse of the moon in addition to everything else.
Before you get too excited, I have a little bit of cold water to throw on your plans. The full moon, blue moon and super moon parts of the program can be seen at any time that night. For the eclipse part, you have to get up early, about 5 a.m. It will be a great way to start your day, however.
If you are wondering about what exactly a total eclipse of the moon might be, remember that beautiful eclipse we had last August? That was an eclipse of the sun and the shadow of the moon fell on the earth. This time, just the opposite is happening. The shadow of the earth will fall on the moon. It only happens when the moon is full, when it is opposite the sun in the sky. Since the orbit of the moon is not exactly lined up with the orbit of the earth, it does not happen every time the moon is full.
If you were fortunate enough to see the total eclipse of the sun last summer, you may remember that the moon only covered the sun completely for a very short time, about two minutes. In fact, one of the most amazing coincidences about our world is that the apparent size of the sun and moon in the sky is exactly the same. We get to see the beautiful sight of the sun’s corona only during a total eclipse of the sun when the rest of the sun is obscured by the moon.
Guess what? The earth is bigger than the moon and so our shadow will be on the moon a lot longer, about an hour and a quarter. If you were standing on the moon watching all this, and I guess you would call it an eclipse of the sun from that perspective, you would not see the sun’s corona. The earth would block it all out.
You would see something just as cool, a ring of fire all around the edges of the darkened earth. That would be the combined sunrises and sunsets all around the earth, and no human eyes have ever witnessed that sight. It will be bright enough to light up the surface of the moon and that is why we see a weirdly tinted reddish moon in the sky during a total lunar eclipse. Be sure to watch for it.
When to see it
So here is the schedule for the eclipse of the moon in the early morning of Wednesday, Jan. 31. First of all you will need to be somewhere you can see fairly low into the west. The show begins at 3:48 a.m. Shortly after that, you will notice a bite is being taken out of the moon by the earth’s shadow. At 4:52 a.m., the moon goes completely into our shadow. Now you will see that deep red color engulfing the moon. As the moon goes further into the shadow that red color will probably darken. The exact tint depends on our atmospheric conditions here on earth. The total phase ends at 6:08 a.m. and for the next hour, the moon goes back to its normal self. Somewhere in here, the moon will set and the sky will become light with the approaching dawn.
While you are out there watching the eclipse, look high in the southeast for a bright, almost yellowish object that is not twinkling. That is the planet Jupiter, and the much dimmer, reddish Mars is nearby. They are the only naked-eye planets visible now. Mercury, Venus and Saturn are lost in the sun’s glare and not easily seen.
Be sure to voice a humble word of thanks to the moon when you are out there because neither you nor I or anyone else would probably be here on this special planet if it were not for our moon. It is the largest moon in the solar system in comparison to the size of the planet which it orbits. Our large-sized moon acts as a gyroscope on the earth, steadying our tilt towards the sun. Computer models show that without the moon, the earth’s tilt would wander all over the place, creating a climate change so drastic that it would be almost impossible for advanced life like us to gain a foothold here on the earth.
Let’s hope the skies are clear and enjoy the full, blue, super, eclipsed moon!