Two Million Free Eclipse Glasses through Libraries (and a Free Booklet)

As you may know, there will be a rare eclipse of the Sun on August 21, 2017, and it will be visible throughout the United States. A spectacular TOTAL eclipse will be seen on a narrow path (about 70 miles wide) from Oregon to South Carolina. The rest of the U.S. and North America will see a PARTIAL eclipse, where only a part (but a substantial part) of the Sun is covered by the Moon. To look at the Sun when part of it is showing, special (but not expensive) glasses are required or you could damage the sensitive tissue in your eyes.

Millions of people will need glasses on August 21, and for the last year I have been grappling with the issue of how to get glasses to as many people as possible. Now, I am delighted to tell you that several astronomy colleagues and I have been able to get funding for glasses to be distributed through public libraries nationwide.

Thanks to the generosity of the Gordon and Betty Moore Foundation near San Francisco and Google, two million safe eclipse glasses will be made available through public libraries. Each library will get a supply of glasses to share free of charge and a booklet all about the eclipse and how to explain it to the public. The booklet, which I wrote with my colleague Dennis Schatz, is now ready and can be downloaded free at:

http://www.starnetlibraries.org/EclipseGuide/

The first part of the booklet explains all about eclipses, the August eclipse and when and how it will be visible in different parts of the country, and how to observe it safely. It's written for beginners in science, so we hope everyone can benefit from it. The second part consists of information to help librarians plan public programs around the eclipse.

You could do your city or town a big favor by taking the booklet or just its web address in to your local library and encouraging them to participate in the eclipse and the glasses giveaway. Libraries can register for the program (through the STARNet Library Network at the Space Science Institute) at the website: http://www.starnetlibraries.org/2017eclipse/

If, for some reason, your library can't participate in the program, there is information in the booklet on how to get eclipse glasses from the companies that manufacture the certified safe glasses that will protect you and your family's eyes. This spring is the time to make plans for where you will be and what you will do when the eclipse arrives on August 21.

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.)

Good Meteor Shower This Wednesday Night

This Wednesday evening and Thursday morning there will be one of the best meteor showers you and your family can see.

This is a great year for the Perseid meteor shower, because it is happening during the phase of the Moon called New Moon (which is when the moon is absent from the sky).  So there will be no moonlight to interfere with seeing the faint “shooting stars” of the meteor shower.

The best night is the evening of Wed, Aug. 12 and morning of Thur., Aug. 13, although there could be significantly more meteors on the night before and the night after too.  Meteors (which have nothing to do with stars) are pieces of cosmic dust and dirt hitting the Earth’s atmosphere at high speed and making a flash of light.

The peak of the shower is predicted to happen around 1 am PDT Aug. 13th, which means that after it gets dark on Aug. 12th, there should already a good number of meteors to watch for.

Here are a few tips for best viewing:

8 HINTS FOR TAKING A METEOR SHOWER

1. Get away from city lights and find a location that’s relatively dark

2. If it’s significantly foggy or cloudy, you’re out of luck

3. Your location should allow you to see as much of the dome of the sky as possible

4. Allow time for your eyes to get adapted to the dark (at least 10 -15 minutes)

5. Don’t use a telescope or binoculars – they restrict your view (so you don’t have to be part of the 1% with fancy equipment to see it; this is a show for the 99%!)

6. Dress warm – it can get cooler at night even in August

7. Be patient (it’s not fireworks): keep looking up & around & you’ll see flashes of light

8. Take someone with you with whom you like to spend time in the dark!

The Perseid meteors are cosmic “garbage” (dust and dirt clumps) left over from a regularly returning comet, called Swift-Tuttle (after the two astronomers who first discovered it).  The comet itself returns to the inner solar system every 130 years; it was last here in 1992.  During each pass it leaves dirt and dust behind and it is this long dirt and dust stream that we encounter every August.  Some experts are predicting we might briefly encounter an especially crowded part of the debris stream this time.

Each flash you see is a bit of material from the comet hitting the Earth’s atmosphere and getting heated up (and heating up the air around it) as it speeds through our thick atmosphere.  Both the superheated dust and dirt and the heated air contribute to the visible light we observe.  Since comets are left-overs from the early days of our solar system, you can tell yourself (or your kids) that each flash of light is the “last gasp” of cosmic material that formed some 5 billion years ago.

[Note: image from Mike Hanley, American Meteor Society]

Apr. 14-15, 2014 Total Eclipse of the Moon Visible Throughout North America

I've put the information about this eclipse in question-and-answer format:

1. What Is Happening?

               Late on Monday evening and early Tuesday morning, Apr. 14-15, a total eclipse of the Moon will be visible from throughout the U.S.  In a lunar eclipse, the full Moon and the Sun are exactly opposite each other in our skies, and the Earth gets between them. This means that the Earth’s shadow falls on the Moon, darkening it.  (See the diagram above.) This will be a nicely democratic event; the eclipsed Moon will be high in the sky and easily visible (provided it’s not cloudy.)

2. When Will the Eclipse Happen?

Event	Pacific	Mountain	Central	Eastern
Partial eclipse starts	10:58 pm	11:58 pm	12:58 am	1:58 am
Total eclipse starts	12:07 am	1:07 am	2:07 am	3:07 am
Total eclipse ends	1:25 am	2:25 am	3:25 am	4:25 am
Partial eclipse ends	2:33 am	3:33 am	4:33 am	5:33 am

As the shadow of the Earth slowly moves across the Moon, we first see only part of the Moon darkening (partial eclipse).  When the Earth’s shadow completely covers the Moon, we see a total eclipse, weather permitting.  

The best times to watch probably start a half hour before total eclipse starts, by which time a substantial part of the Moon is eclipsed.  The whole total phase lasts 78 minutes this time, and it looks pretty much the same the whole time, so only the most dedicate eclipse buffs will stay up for the whole thing.

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.  Light 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 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.

               Also, as the Moon becomes dark, other things in the night sky become easier to see.  As you look toward the southwest, you can see Mars to the right of the Moon, the bright star Spica just below and near it, and Saturn off to the left. Here is a nice diagram from Astronomy magazine (click to make it bigger). 

(Note that this is drawn for 3 am Central Time, which is 1 am Pacific Time.)

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 more dangerous eclipse is the solar one, where it is the Sun that gets covered.) Lunar eclipses don’t require you to have fancy equipment or to go to a dark location.  Bring binoculars, if you have them, to see the Moon larger, but just your eyes are fine.  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 from space.) 

Also, if kids have to miss this eclipse, you can console them by letting them know that there will be another total lunar eclipse on Oct. 8^th, 2014 (and two more in 2015.)