Here are the absolute basics for viewing the eclipse safely, and getting the most out of your viewing experience.
Remember NEVER to look directly at the sun while any part of its bright disk is visible (not TOTALLY eclipsed). If there is ANY bright part of the sun showing, you CANNOT look at it without eye protection. When the eclipse is TOTAL, that is, when ALL of it is COMPLETELY covered by the moon, you can then look at it directly without eye protection. In fact, during those few brief minutes and seconds of totality, you MUST look at it without protection to see anything at all. During totality, the eclipsed sun is no brighter than the full moon, and it is an experience you simply will not believe. But please, do NOT look at the sun when ANY PART of it is still bright (not covered by the moon). Eclipse2017.org has eclipse glasses available for sale at a VERY low cost -- and if we're lucky, we might even be able to get the local newspapers to include safe solar filters in their editions published during eclipse weekend. Please do NOT look at the sun with your eyes unprotected when any part of its bright disk is visible!
You want the even shorter version? Here it is:
1) Get in the path of totality armed with your eclipse glasses.
2) Look at the sun ONLY through the eclipse glasses while the eclipse is partial (crescent sun).
3) When the eclipse is total, you can look right at it WITHOUT the glasses - the moon is covering it!
3a) Do NOT try to look through the eclipse glasses at the totally eclipsed sun! You won't see anything!
4) When totality ends, put the glasses back on!
What follows will tell you what you're going to see. To find out when
you're going to see it, click down to this link.
One more time: Please look at the maps, and find a spot IN THE PATH where the weather is going to be clear. And no, we won't know where it will be clear until a couple of DAYS beforehand, so you must be prepared to travel. Sorry, but that's how it is. This is a sight that people travel to the remotest corners of the earth for, and to a veteran eclipse chaser, a change of plans from North Carolina to Nebraska is a big fat "who cares"! You'll know why after you see totality!!! If you're not going to get yourself into the path, then you may as well not read any further, because you will not get the show, and you'll wonder why in the heck we made such a big deal out of nothing. Well, that "nothing" is all you'll get if you're not IN THE PATH!!! So trust us, and get into the path!
Next, find the time that totality will occur there,
IN THE PATH, where you are. In general, these are in the narrative account
of the path, but you can also look at the Google Map that's shown on the maps page.
OK, so now you're in the path, the weather is clear, and you're waiting for the show. If the local government has done its job well, you'll be surrounded by a few thousand new friends who are taking it all in with you. Make sure you have proper protection for your eyes in the form of viewing glasses, and make sure that everyone with you (especially the young ones) have their own pair and UNDERSTAND COMPLETELY that they MUST have them on whenever they look at the bright (uneclipsed) sun. These glasses are NOT regular sunglasses - they are made of a very special material that is SAFE to look at the sun directly through, but monitor them and make sure they don't cheat! We don't want ANYONE to come away from this experience blind! Make sure you use your viewing glasses!!!
About an hour and a half before totality, you will be able to see (through your eclipse viewing glasses ONLY) the first "bite" taken out of the sun. Over the next hour, that bite will grow bigger as the moon eats more and more of the sun's disk. You won't notice anything much (except for all the picture-taking people fussing over their equipment). If you see anyone who has lots of expensive-looking equipment, you may ask to look through it - but be respectful of their setup, and ensure that you don't touch or do anything that they don't specifically let you do! This means kids as well...and leave the pets at home! The eclipse will only scare the bejeezus out of them, and their presence will lessen the effect of totality for you.
As the eclipse progresses, you will see the moon take more and more of a "bite" out of the sun. What you will see (through your eclipse filters, of course!) is a shape that looks like a crescent moon. Of course, it's the sun being covered by the moon, and if you use your imagination you can almost see the moon in front of it, encroaching on it, covering more and more of it as time goes on. What you're seeing, of course, is NOT the motion of the moon due to the rotation of the earth, but the actual movement of the moon in its orbit around the earth! It takes the moon approximately 28 days to travel the 360 degrees all the way around the sky, so if you figure that out (and if you know that the moon's apparent diameter is about a half a degree), then you can calculate that the moon moves its own diameter along its orbit in a little under an hour! So what you'll see in the course of a couple of hours is: (1) the moon will first touch the edge of the sun, (2) the moon will travel all the way across the face of the sun (eclipsing it), and (3) the moon will continue on, eventually leaving the face of the sun.
As the moon covers up the sun, this crescent is visible to you if you are looking at the sun with your filters. But there's a cool thing that happens, which you may have used back in school to look at an eclipse. Any time the sun's image is projected through a small hole (like a pinhole), you'll see a little crescent projected onto whatever surface you've put up - like the inside of a shoebox or a big piece of poster board, or a wall. Here are some pictures of crescent suns projected through small holes between the leaves in a tree, taken by eclipse chasers the world over:
1994, St. Louis (Sirius Observatory)
courtesy of Jim Rodenstock
2005, courtesy of Glenn Schneider
See if you can see these! Also see if you can make this "sock puppet" effect with your hands:
2005, courtesy of Glenn Schneider
And if you're really good, see if you can create this pinhole effect in a card, and project the images of crescent suns against a wall or other large background:
2005, courtesy of Glenn Schneider
OK, so that's enough fun stuff - time to get serious! About 15 minutes before totality, things start to happen. The sky starts getting noticeably dark, and you notice that the air itself feels "weird". Shadows get weirdly sharp, and the sky takes on a very crystal-clear quality to it. This is only the beginning. As totality approaches, you will be overwhelmed by things to look at, but make sure you at least see these few things:
During totality ONLY, take off your filters and stare at the eclipsed sun. Burn the image into your brain, because you have never seen anything like this, and you never will again (unless you travel to see another eclipse!). This is one of those moments where you have to put your brain on "record" mode, block everything else out, and just store up the sight for the rest of your life. Believe me, ten, twenty, thirty years later, that sight will still be there, and you want to soak up every second now, while you can. Listen to the people around you screaming and yelling like fools, and don't be afraid to offer a few screams of your own - no one will care, and everyone you share this sight with will understand.
The eclipse will progress, and soon you'll see the right side of the eclipsed sun's disk start to brighten. It's going away - get your filters ready, because as soon as the diamond ring shows up again on the other side, you need your filters again! Put them on, say goodbye to the eclipse, think good thoughts about the folks to your east who are now getting the show for themselves, and call your travel agent to get to the next eclipse (which happens to be on 2 July 2019 in the middle of the south pacific - a great excuse for a cruise!!)
When it's all over, make a point to go up to as many people as you can, and thank them for sharing this most special life-experience with you. And don't forget to look in the paper the next day at the pictures that will undoubtedly be there - and laugh at how absolutely impotent they are in capturing the event that you remember from the day before!
Then, come back to eclipse2017.org and leave your thoughts and recollections for us!
Here is how to find out when you'll be seeing all this cool stuff!First, you can download the Eclipse2017.org app! This will tell you EASILY whether you are in the path, and what time the phases of the eclipse will happen for you!
you tell when the eclipse is going to happen where you are? First, go to the Google Interactive Map and zoom in on your
location just like you do with any Google map. On this Interactive
Map, though, whenever you click on a point, you’ll get a popup
window like what you see in the picture below. This has lots of
information about the eclipse’s exact circumstances for the
location you clicked on, which has been calculated for you on the
fly thanks to Xavier Jubier's wonderful 5MCSE eclipse tool. You may not care about
lots of that info, but if you mouse over the picture below, you’ll
see some things highlighted that you definitely do care
about: the times for
the various major events of totality!
course, you should first check to see that you are getting a total
eclipse in your location. If
you’ve selected a place within the dark band, then there should be
no problem, but you’ll see visual confirmation of that in the info
bubble with the picture of the totally eclipsed sun, the fact that
you have times shown for C2, mid-eclipse, and C3, and up there at
the top (just right of center) you'll see the duration of totality
for your location (you want lots of that!). You'll also see that
your "Obscuration" is 100.00% - just what you want!
don’t see all of the above, then you do not have a total eclipse,
and that location you clicked on is NOT where you want to be on
eclipse day! If the
eclipse will not be total for you, then you will not see all the
stupendous, marvelous things that a total eclipse brings, you will
have to use your eclipse viewing glasses for the entire duration
of the eclipse, and you will walk away from the experience
wondering what all the fuss was all about. So don’t miss out – get
into the path of totality and treat yourself to the best show on
The various times listed in the table are all in UT,
or Universal Time. This
is a reference ‘time zone’ used by astronomers, and is basically
just the time in
(If you’re in any other time zone, and the eclipse is total for you,
then you’re in the middle of the ocean!)
But what are the events?
|Before we describe them, let us also once again
reiterate that you MUST USE PROPER
C1 (“First Contact”): The instant that the first very small bite is taken out of the sun’s disk by the moon. Before this time, you can see NOTHING to indicate to you in any way that there’s going to be an eclipse, so don’t try. And at this time, the sun is also blazing away brightly, and you MUST USE PROPER PROTECTION in front of your eyes when looking at it.
C2 (“Second Contact”): This is the most anticipated time – the beginning of totality! In the five minutes preceding this time, a lot of really cool visual stuff happens all around you, and the thin sliver of sun shrinks to nothing as totality approaches. But because there is still this very thin sliver of sun showing, you still CANNOT look at the sun without filters before C2! After the diamond ring blazes for the few seconds that it will be visible, then you can take your filters off and enjoy totality.
AFTER C2, and BEFORE C3, you CAN look right at the totally eclipsed sun without any filters at all. (In fact, you have to, or you won’t see anything!) This period of totality is only a very short time – a couple of minutes, or maybe less depending on where you are. But this is the ONLY time it is safe for you to stare directly at the most beautiful sight in the sky.
Mid-eclipse: The halfway point between C2 and C3. Totality is half over at this time. Enjoy what you have left!
C3 (“Third Contact”): The time we all hate – the end of totality. The moon moves slightly off the face of the sun, and the diamond ring pops back into view as the first rays of the sun poke back through at us from a valley on the moon. When these rays come out, so must your filters. From C3 on, you HAVE TO USE EYE PROTECTION AGAIN to look at the sun, because now it’s not in total eclipse any more.
C4 (“Fourth Contact”): The moon leaves the sun’s disk, and the last bite disappears. Not very many people notice this event, because it is a complete "who cares" after you’ve seen totality.
|One more time: The ONLY time it is safe to look directly at the sun without eye protection is when it is TOTAL eclipse. For this to happen, you must be in a spot where totality is going to happen in the first place, and the sun must actually BE totally eclipsed! This will happen between the times noted above as C2 and C3, but of course, you must use your common sense instead of your watch to tell exactly: If ANY PART of the sun’s disk is out (bright and not eclipsed), you HAVE to use your filters to look.|
about all those other numbers on the display? Here is a recap if
Lat/lon of the selected point is given at the top left.
Umbral depth: Zero at the edge of the path of totality, this increases to 100% at the center line.
Obscuration: How much of the sun’s area is covered at mid-eclipse.
Magnitude: How much of the sun’s diameter is covered at mid-eclipse (this is not the same as the above!).
Size ratio: The moon’s apparent area divided by the sun’s apparent area in the sky.
DeltaT: A very complicated thing to describe; astronomers use it to be able to compensate in their calculations for the fact that the earth’s rotation over time is not perfectly constant or stable. Unimportant to you, as a casual observer.
Alt: How high in the sky the sun is.
Azi: Where the sun is located (North=0, East=90, etc)
P and V: The orientation of the centers of the sun’s and moon’s disks, given in degrees counter-clockwise from the sun’s North point (P) and as an “o’clock” position as seen from the given location (12.0 is at the top of the disk, 6.0 is at the bottom of the disk, etc).
LC: Limb Correction (if available) – a correction factor to the contact times based on the irregularity of the moon’s edge (mountains, craters, etc.). Of interest mainly to eggheads.
Eclipse2017.org is soliciting
assistance from interested individuals who may want to
act as local providers of video feeds, photos,