North America to See An Eclipse of the Blue Moon January 31

On Wednesday morning, January 31, residents of North America (and particularly those on the west coast) will experience a rare triple event:

* The full moon will enter the Earth’s shadow and show a total eclipse (turning the full moon into a dark reddish disk)

* This will be the second full moon in the same month – something we call a blue moon

* And it will be a “supermoon,” where the Moon is full just as it’s closest to our planet Earth (this last thing by itself is not especially rare; in fact it will be third “supermoon” in a row).

Having all three together is unusual. The last time we had a blue moon totally eclipsed in the U.S. was more than 150 years ago.

Here are the times of the eclipse of the Moon on the morning of January 31 in different U.S. time zones:

Eclipse Circumstance                  Pacific Mountain Central Eastern

Partial eclipse begins                 3:48 am 4:48 am 5:48 am 6:48 am
Total eclipse begins                   4:52 am 5:52 am 6:52 am ---
Total eclipse ends                      6:08 am 7:08 am ---         ---
Partial eclipse ends                    7:11 am ---         ---         ---

--- means that Moon has already set (is below the horizon)

You can see that in the eastern half of the U.S., the full Moon sets before the total eclipse or just as the eclipse is getting good, but in the western half of the U.S., some or all of the eclipse will be ready to delight those who can get up early (before the Sun does) that morning.

If you are planning to get up to see the last part of the total eclipse, there is one other factor to keep in mind. The eclipsed Moon is setting in the west as the Sun is rising in the east. That means you have to have a clear sight-line toward the western horizon for the eclipse. If buildings or trees block your view in that direction, you could miss the event. So scout out the location where you plan to be in advance. (Maps and charts can be seen at: http://www.skyandtelescope.com/obser…/january-lunar-eclipse/ )

Note: Only the total eclipse turns the Moon an eerie dark red (because of the bending of red light in the Earth’s atmosphere.) Once the total eclipse is over, the reddish effect that eclipse fans like (and the media call a "blood moon") will be gone.

Our remarkable photo, by Elias Politis, shows a 2011 lunar eclipse sequence over the Acropolis in Greece. Click on the image to see it larger.

Enjoy Sunday and Monday's "Supermoon" But Don't Fall for the Hype!

You may read stories in the media about Sunday evening’s or Monday morning’s full moon being a “supermoon.” And it is true that – by a slight amount – the full moon just before Monday’s sunrise will be the closest, brightest, and largest-looking full moon since 1948.

But the average person won’t notice much difference between this “supermoon” and an ordinary full moon. Clouds, smog, and human lights turn out to have a much greater effect on how bright a full moon looks to us. Still, if you look carefully under dark skies, you might convince yourself that the full Moon Sunday night and Monday before dawn looks a bit bigger and brighter than usual.

“Supermoon” is not an astronomical term. It was suggested by an astrologer and suddenly became popular in the media (who always favor superlatives) in 2011. We astronomers have been stuck with it ever since.

Why are some full moons bigger and brighter than others? It’s because the Moon’s orbit around us is not a perfect circle, but on oval shape called an ellipse. That means sometimes the Moon is a bit closer to us and sometimes it’s a bit further away. If a full moon happens just when the Moon is closer, we get a bigger and brighter looking full moon. The more precisely the closest moon and the full moon coincide, the better the super effect. Nov. 14th, the moon is full at 5:52 am Pacific time, while the moon is closest at 3:23 am. That’s a pretty close coincidence.

Does the “supermoon” have any significant effect on planet Earth. You may read predictions that there will be much greater tides or even earthquakes Monday morning. Don’t believe it! We have slightly stronger tides every time the Sun, Earth and Moon are lined up (which they are at every full moon). But the only time the supermoon will show itself in a significantly stronger effect on the shore is if we happen to be in the middle of a huge storm. And the Sun and Moon have no effect on earthquakes, which happen deep inside the Earth.

So if you happen to glance at the full Moon Sunday evening or Monday morning, enjoy the knowledge that the Moon is a bit closer to you. You may even howl at the Moon if the candidate of your choice didn’t get chosen in our recent elections. But don’t add the “supermoon” to your list of things worth worrying about.

(Photo of the Lick Observatory with the Moon behind it by Rick Baldridge of the Peninsula Astronomical Society.  This was taken with a special lens to enlarge both the observatory and the Moon.)

A Total Eclipse of the Moon Sunday Evening September 27

I thought you might like advance notice of a very nice upcoming lunar eclipse visible next Sunday evening in North and South America and in the early morning in Europe and parts of Africa and west Asia. Below are the basics in the form of questions and answers.  All you need to enjoy the eclipse is clear skies and (on the American west coast) an unobstructed view toward the East.

Next week you will start reading media reports about this being both a “blood moon” and a “supermoon,” but don’t pay too much attention to that.  The Moon will be a bit closer to the Earth in its orbit than average, making it look a bit bigger, but the difference is not especially significant.  And every lunar eclipse could turn reddish, as explained below.  It’s rarely the color of blood, but the media love anything that can be connected to thoughts of violence.

The Sept. 27, 2015 Total Eclipse of the Moon

1. What Is Happening?

On Sunday evening Sept. 27, a total eclipse of the Moon will be visible from throughout the U.S. (and North and South America.) In a lunar eclipse, the full Moon & the Sun are exactly opposite each other in our sky, and the Earth gets between them. This means the Earth’s shadow falls on the full Moon, darkening it.  It’s a nicely democratic event; no special equipment is needed to see it (provided it’s not cloudy or foggy.) Plus it happens early in the evening; kids can watch & still be awake for school next day.

2. When Will the Eclipse Happen?

The table below is for the U.S. (for other countries and continents, see: http://www.timeanddate.com/eclipse/lunar/2015-september-28  which can be set for your home location.) 

Event	Pacific	Mountain	Central	Eastern
Partial eclipse starts	Moon not up	7:07 pm	8:07 pm	9:07 pm
Total eclipse starts	7:11 pm	8:11 pm	9:11 pm	10:11 pm
Total eclipse ends	8:23 pm	9:23 pm	10:23 pm	11:23 pm
Partial eclipse ends	9:27 pm	10:27 pm	11:27 pm	12:27 am

As Earth’s shadow slowly moves across the Moon, we first see only part of the Moon darkening (partial eclipse).  When our shadow completely covers the Moon, we see a total eclipse. The best time to start watching is about a 20 minutes before total eclipse begins, when much of the Moon is already darkened. 

NOTE: On the west coast, the eclipse will start low in the Eastern sky, so make sure your observing location has an unobstructed view toward the Eastern horizon.

3. What is Visible During a Lunar Eclipse?

As the shadow of the Earth covers the Moon, note that our natural satellite doesn’t become completely dark.  Some sunlight bent through the Earth’s atmosphere still reaches the shadowed Moon and gives it a dull brown or reddish glow.  The exact color of the glow and its darkness depend in part on the “sooty-ness” of our atmosphere – how recently volcanoes have gone off and how much cloud cover, storm activity, and human pollution there is around the globe. 

Once the Moon is totally eclipsed, the stars in the sky should become more easy to see.  What makes this eclipse a little bit unusual is that, by coincidence, it is happening just one hour after the Moon has reached the closest point in its monthly orbit around the Earth.  So the Moon will look a bit larger in the sky than usual.  (The media will be calling it a “supermoon,” but the effect is pretty subtle for the average person.)

4. Is it Safe to Watch, and How do I Watch?

Since the Moon is safe to look at, and eclipses make the Moon darker, there’s no danger in watching the eclipse with your eyes or a telescope.  (The dangerous eclipse is the solar one, where it is the Sun that gets covered.) And lunar eclipses don’t require you to go to a dark location.  Bring binoculars to see the Moon larger, but just your eyes are fine.  Since the total eclipse will last for an hour and 12 minutes, be sure to take someone along with whom you like to spend time in the dark!

5. What Can I Tell My Kids (or Kid Brother or Sister)?

Suggest that they take a careful look at the shadow of the Earth as it moves across the bright face of the Moon.  What shape is it?  The round shape of the Earth's shadow suggested to the ancient Greeks, more than 2000 years ago, that the Earth’s shape must be round too.  Eclipse after eclipse, they saw that the Earth cast a round shadow, and deduced that we lived on a round planet (long before we had pictures of it from space.)