Eclipse of the Sun Coming in 2 Weeks! And Another in 7 Years!

The path from top left to bottom right is the Aug. 21, 2017 eclipse

The path from bottom left to top right is the Apr. 8, 2014 eclipse

In just two weeks, on August 21, all of North America will experience an eclipse of the Sun. The eclipse will be total on a narrow path going across the U.S. from Oregon to South Carolina. The rest of the continents will see a partial eclipse, with a big bite taken out of the Sun by the disk of the Moon.

If you don't get to see this one, there will be another U.S. total eclipse in only seven years (on April 8, 2024.) If you missed out getting a hotel room or a campground in the zone of totality for August's eclipse, you have no excuse now for 2024! (See the attached map; click on it to see it bigger.)

I've had the opportunity to do quite a bit of media outreach for the eclipse; you can:
1. hear me as part of the eclipse special on the "Big Picture Science" radio show: http://www.bigpicturescience.org/…/eclipsing-all-other-shows
2. see me speaking on the eclipse at the SkeptiCAL convention sponsored by the Bay Area Skeptics: https://www.youtube.com/watch?v=52k9TdQdPNc
3. read my comments as part of legendary science journalist David Perlman's last science article (David, who covered science news at the San Francisco Chronicle, is retiring at the age of 99! May we all have a career as long and respected as his.): http://www.sfchronicle.com/…/Total-solar-eclipse-to-create-…

This week many media and people are waking up to the coming of the eclipse at last. Our free 8-page booklet all about it and how to view it safely can be downloaded from the page: http://nsta.org/solarscience Do read through it to get hints about how best to see and explain this rare sky phenomenon.

A free app, called TOTALITY, can be downloaded from both the Apple and Android app stores, and it will tell you exactly when and how the eclipse will be visible in your location.

If you haven't yet gotten safe eclipse-viewing glasses, your first stop should be your local public library. (Thanks to the Moore Foundation and Google, our project to distribute 2.1 million eclipse glasses has gotten glasses to almost 7,000 public libraries nationwide.)

If your library doesn't have any, here is a page to tell you all the reliable sources of eclipse glasses that are certified to meet the standards for protecting your eyes set by eye-doctors: https://eclipse.aas.org/resources/solar-filters

And for kids, please forgive me if I mention our children's book, "When the Sun Goes Dark," now in its fourth printing. Copies have temporarily run out in some places, but the publisher has it at: http://nsta.org/eclipse

Here is wishing you clear skies for August 21.

Eclipse stamp issued by the US Postal Service

changes the picture you see when you touch it

Happy One Year Pre-Anniversary of the All-American Eclipse of the Sun

August 21 is exactly one year before the 2017 eclipse of the Sun which will sweep across one country and one country only -- the US. On a Monday morning (Aug. 21, 2017) this "All-American" eclipse (as it's being called) will begin on a beach in Oregon and cross the country diagonally to end in the afternoon on a beach in South Carolina.  See the map below.

The eclipse will be total (moon covering the Sun completely) only in a path about 60 miles wide and we expect huge crowds and traffic jams in that zone. The rest of North America (500 million people) will see a partial eclipse, with a big bite taken out of the Sun. Special eclipse glasses or ways of projecting an image of the Sun will be needed to see the partial eclipse safely.

The full story,in everyday language, with a map and times for major cities, and safe viewing guidance, can be found in a free 8-page excerpt from a book, called Solar Science, that Dennis Schatz and I wrote for teachers. It is at: http://bit.ly/2bkGSvA

There is a national committee that I serve on trying to arrange a good experience with the eclipse for as many people as possible. Wish us luck! Dennis and i are also working with science teachers, libraries, and science and nature museums to become centers of eclipse information for their communities.

I'll say more about preparations for the eclipse on this page as the year goes on. But for now, you may want to note the date and if you have friends or relatives in the total eclipse zone, be extra nice to them starting now.

And thanks to Prof. Tyler Nordgren of the University of the Redlands for permission to use his cool poster.

Map of the 2017 Total Eclipse Path

For those of you who are teachers, or who know a teacher, we will be doing a webinar on how to prepare yourself and your students for the eclipse.  For more see:

http://bit.ly/2bbAwfo

Perseid Meteor Shower May Show an Outburst

This Thursday and Friday, there will be one of the best annual meteor showers you and your family can watch -– the Perseids.    And some experts are even predicting that there might be a meteor “outburst” this year –- where the number of shooting stars increases beyond the usual rates.

This is a complicated year for watching the Perseid meteor shower, because the evening sky has a roughly half-lit-up moon in it, making it more difficult to catch the faint “shooting stars.”  So if you can wait until the Moon sets (between midnight and 1 am), you should have better viewing in the pre-dawn darkness.   (That’s great advice for people on camping trip and insomniacs, but probably not useful for those who have to get up for work.)

The best night is the evening of Thursday, Aug. 11 and morning of Friday, Aug. 12^th, although there could be significantly more meteors in the sky on the night before and the night after too.  Meteors or “shooting stars” (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.  These flashes could happen anywhere in the sky, so it’s best to view the shower from a wide-open place.  See the list at the end for viewing suggestions.

The Perseid meteors are cosmic “garbage” 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 or so; it was last here in 1992.  During each pass, it leaves dirt and dust behind and it is this series of long dirt and dust streams that we encounter every August.  Some scientists who study comets and meteors are predicting that 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 super-heated 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 a bit of cosmic material that formed some 5 billion years ago.

EIGHT 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 the shower; this is a show for the 99%!)

6. Dress warm – it can get cooler at night even in August (and don’t forget the insect repellent while you are outside)

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!

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.)

Happy Fall Equinox on Monday and Other Sky Events

Monday morning (Sept. 22) is the "autumnal" or fall equinox for those of us in the Northern Hemisphere. On that day, the length of the day and the night are roughly the same ("equinox" means equal night). We are moving from the summer, when the days were longer, toward the winter when our nights are longer -- and our parts of the planet have fewer hours to heat up from sunlight.

The equinox is sometimes called the official start of fall and throughout history there have been festivals and beginnings celebrated at the time. It so happens that Foothill College, where I teach, starts its fall quarter on the equinox this year, so I will be welcoming several hundred new students to my classes with a happy equinox greeting (and many who don't know the term will be looking at me as if I were a crazy person!)

The fall quarter will bring many interesting events to fans of astronomy. Tonight, Sunday, the MAVEN spacecraft will be inserted into orbit around Mars, so it can begin to study how little Mars, with its lower gravity, lost its atmosphere over the millennia, and how its remaining air layers interact with the radiation and wind from the Sun.

October 8th, we will have a total eclipse of the Moon (these are much more common than total eclipses of the Sun.) Alas, for those of us in North America, this will be a middle of the night eclipse! The full Moon will go dark as the Earth's shadow falls on it, but most of us will be in bed, deeply asleep, when it happens. For example, in San Francisco, the eclipse happens from about 2:30 am to 5:30 am, so only dedicated night owls will be watching it. (If you miss it, don't worry, there will be two lunar eclipses visible in 2015.)

On October 19th, a newly discovered comet will come closer to the planet Mars than any known comet has come to Earth, and so our robot "representatives" around Mars will be keeping their cameras out for that pass.

On October 23rd, in the afternoon, much of North America will witness a partial eclipse of the Sun in the afternoon. Many astronomy organizations will be planning eclipse parties, with safe viewing options. I will do a full post about the eclipse when we get closer to the time.

And, down on Earth, October 25th, the opening day of the 2014 Bay Area Science Festival, I will be giving a free public talk on Mt. Tamalpais about the "Top Tourist Sights of the Solar System: Where Bill Gates' Great-Granddaughter will go for Her Honeymoon." See: http://wonderfest.org/top-tourist-signs-of-the-solar-system/

Comet PanSTARRS: Beware of the Internet Hype, but Check out the Sight

This coming week is perhaps the best time to look for a new comet in our evening skies, as long as your expectations are not set too high by some of the media attention it has received.   The comet – a chunk of ice and dirt from the distant backwaters of the solar system – is falling around the Sun with closest approach to our star on Sunday, March 10^th.  

For the next week, it will be visible very low on the horizon if you look toward the west.  Tuesday and Wednesday it will be near the crescent Moon and may be easier to spot as a result.  But here are the problems beginners will need to keep in mind:

1. It’s so low in the sky you will need to look for it from a location where you have a clear view all the way down to the western horizon -- and no hills, buildings, or trees in the way.  Out by the ocean is really great.

2. Things on the western horizon are SETTING – going quickly below the edge of the sky.  That means there is a very short window to see the comet.  Try too early, and the sky is too bright with sunlight.  Try too late, and the comet is below the horizon.  About 30 - 45 minutes after sunset is what experts are recommending.

3. If there are clouds or fog in the western direction, or you’ve got bright street or car lights in your view, the comet may be too hard to see.  In March, weather is an issue in many locations.

4. And the comet is so far from Earth, it is not spectacularly bright. In general, binoculars may be needed to pick the head of the comet and the faint upward-pointing tail out of the glow of the sunset.

Get the latest observing information at: http://www.skyandtelescope.com/observing/highlights/Spot-Comet-PanSTARRS-in-Twilight-196688441.html

By the way, if you are wondering about the strange name for a comet, it’s taken from the automated survey telescope in Hawaii that discovered it in 2011: the Panoramic Survey Telescope and Rapid Response System. 

Look Up in the Sky Monday Night

As the Sun sets on Monday evening, Jan. 21, and you face South and look up, you should see a pretty sight. The planet Jupiter will be very close to the Moon, almost cheek to cheek with it. Their "closest approach" in the sky will be around 7 pm Pacific time.

The two just happen to look close on the sky -- in reality, Jupiter is 1,700 times further away. Jupiter is the largest planet in our solar system -- eleven Earths could fit side by side into its diameter.

As an extra treat, you get to see the bright star Aldebaran just below the Moon-Jupiter pair. Aldebaran, the reddish eye of the bull figure that gives its name to the constellation of Taurus, is a cool giant star, about 44 times as wide as the Sun. It is about 67 light years away, meaning the light we see tonight took 67 years to get to Earth. If you could see Aldebaran up close, it would shine over 400 times as bright as the Sun. But with all that distance between it and us, it's just a reddish point in our sky.

As you can see in the diagram, the Moon and Jupiter are already close tonight and will still be close on Tuesday night. But Monday is the best time to look up. Take the kids outside in the evening or make a date to be outside with someone with whom you like to spend time in the dark.

(Thanks to Sky & Telescope magazine for the diagram I am showing.)