Stargazing U.S. Solar Eclipse of Aug. 21, 2017

AI Thread Summary
The U.S. solar eclipse on August 21, 2017, presents a rare opportunity for viewers across the country, with the path of totality spanning from coast to coast. Many participants are planning to travel to optimal viewing locations, particularly in states like Kentucky and Illinois, to ensure clear skies. Essential equipment for viewing includes eclipse glasses, cameras with telephoto lenses, and possibly telescopes, although some participants express concerns about traffic congestion and weather unpredictability. Past experiences with eclipses highlight the importance of mobility to avoid cloud cover and maximize viewing chances. Overall, the excitement surrounding this event emphasizes its significance for both seasoned eclipse watchers and newcomers alike.
  • #201
For each person in North America who sees the total eclipse, there will be 10 who only see the partial eclipse.

If you are supervising a herd of kids, trying to tell them don't look, I offer this suggestion. Adults can see that all small heads are safely in a box. Kids can make their own box as a craft project.
pinholeprojection.jpg
 
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  • #202
anorlunda said:
If you are supervising a herd of kids, trying to tell them don't look, I offer this suggestion. Adults can see that all small heads are safely in a box. Kids can make their own box as a craft project.
Great advice (and the price is right), I bought a pack of 25 viewing glasses off of Amazon a couple weeks ago and just received a letter from them saying they couldn't source the supplier so they were refunding my money and I shouldn't trust the glasses (which are printed with the correct ISO code).
It seems the market is being flooded with knock-off viewing glasses so I thought I'd post this site for reference. https://eclipse.aas.org/eye-safety/iso-certification
 
  • #203
Thanks Anorlunda i sent it to all my kids. Grandson is in Boy Scouts , hopefully he can show the troop how to make them.

I understand resolution depends on size of pinhole ? So it's a tradeoff between sharpness and brightness. A light blocking cloth around the neck would be a good idea ?

Last one in Florida i held a cheapie 7X35 binocular to project an image onto a sheet of paper for a small crowd, left one lens cap on and it worked pretty well.
Got a nice compliment from our VP's drop-dead-gorgeous Admin Assistant . Just a smile from that lady would have melted the iceberg and saved Titanic.

old jim
 
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  • #204
The pinhole box doesn't have to be high-tech. Even natural small holes, e. g. between leaves in a tree, can show this effect, and then you get lots of crescents.

Tree_shadow_during_an_annular_eclipse.jpg

Source

If you only have a partial eclipse, you can also hope for the right density of clouds. Safe naked eye viewing, and if it is too cloudy: the next partial eclipse won't be too far away.
 

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  • #205
Warning! Expletive post to follow!

2017.08.14.oh.dang.png
 
  • #206
OmCheeto said:
Warning! Expletive post to follow!

View attachment 208987

Ay Ay Ay. I sure hope that forecast is wrong. I'm driving from Vermont to Nebraska to get an optimum viewing chance. I already gave up my plans for Oregon. If it's cloudy, I'll scream. The local forecast in Nebraska for the 21st is partly cloudy.
 
  • #207
Meanwhile in the Sun ... (new active spot region today (Mon. Aug 14, 2017), producing flares ...):
https://www.physicsforums.com/threa...17-nice-spot-group.919696/page-2#post-5821897

+ cool flare video there too! If only the eclipse was today! ...

"
logo.png

New active region producing C-class flares

Monday, 14 August 2017 - 13:21 UTC

293-header.jpg


A new and unnumbered active region is now rotating into the earth-facing solar disk. It is new active region that only started to develop about 24 hours ago based on STEREO Ahead EUVI footage.

This video made using footage from SDO shows very clearly that it only recently started to develop as it rotated onto the earth-facing solar disk."

[Go to this link for the video:
https://www.spaceweatherlive.com/en...14-new-active-region-producing-c-class-flares ]

"As a matter of fact, this newly born sunspot region already produced two C-class solar flares, the strongest of these two flares was a C2.7 solar flare that peaked today at 10:46 UTC. Will this become a sunspot region that has the potential to produce strong solar flares? Time will tell!"
 
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  • #208
anorlunda said:
I'm driving from Vermont to Nebraska to get an optimum viewing chance.
Hey. I'm going to be close by. I'll be at the Rush Airport.
map_kansas_troy.png
 
  • #209
Forecast at my planned location in SC is getting worse - now a 50% chance of precipitation.

From the Washington Post:
eclipse-forecast-08142017.jpg
 
  • #210
anorlunda said:
Ay Ay Ay. I sure hope that forecast is wrong. I'm driving from Vermont to Nebraska to get an optimum viewing chance. I already gave up my plans for Oregon. If it's cloudy, I'll scream. The local forecast in Nebraska for the 21st is partly cloudy.
Most of what I saw yesterday said "low confidence". I was just freaked out when I saw the image and Oregon was the only state covered in black. Now I can't remember where I snagged that image from.
Going now through the cities along the path, the image seems pretty bogus.
 
  • #212
russ_watters said:
If you don't mind me asking, where are you going to be? I'll be north of Charleston.
Waterloo - halfway between Greenville and Columbia. A friend has a cabin about 3000 feet from the centerline.

Now it's at 40% chance of precipitation.
 
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  • #213
Borg said:
Waterloo - halfway between Greenville and Columbia. A friend has a cabin about 3000 feet from the centerline.
Nice. I have a spot picked out at a visitor's center a couple of miles from the center, but it is small, first come first served and opens at 8. I plan to start orbiting around 7.

My main backup is Columbia, but I don't have a specific location set yet.
 
  • #214
Driving from PA overnight?
 
  • #215
Borg said:
Driving from PA overnight?
Renting a house in Isle of Palms for the week; arrive Saturday.
 
  • #216
russ_watters said:
Renting a house in Isle of Palms for the week; arrive Saturday.
I'll be driving from from Richmond Monday around 3 or 4am and hope to be there NLT 9am.
 
  • #217
Borg said:
I'll be driving from from Richmond Monday around 3 or 4am and hope to be there NLT 9am.
Yikes - just don't fall asleep during the eclipse!
 
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  • #218
russ_watters said:
Yikes - just don't fall asleep during the eclipse!
Not a problem. I normally get up at that time. :oldwink:
 
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  • #219
Borg said:
Waterloo - halfway between Greenville and Columbia. A friend has a cabin about 3000 feet from the centerline.

Now it's at 40% chance of precipitation.
Now 30%!

The National Weather Service now has a web page devoted to the eclipse. As far as I can tell, it went active just today.

Borg said:
I'll be driving from from Richmond Monday around 3 or 4am and hope to be there NLT 9am.
Oh, bejezeezits! That was my plan...

Future wiki entry: "Worst traffic jam in America happened at 3 am, on August 21st, 2017."
 
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  • #220
I first planned on Idaho, scrap that.

Next plan was Oregon, scrap that because of the anticipated cruise of people from California.

Third plan was Nebraska, scrap that because of weather.

We just scored a camp site in Land Between The Lakes, Kentucky. We got the last available site.

Local forecast for Monday is sunny. We can see 2:40 of totality right from the camp site.

Smile.
 
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  • #221
Eclipse Popularity

Here is an XKCD comic of the eclipse:
eclipse_searches.png


Here is the map referred to (from this site):
eclipse.png


Here is another interesting map from the same article:
Screen-Shot-2017-08-01-at-10.26.41-AM.jpg
 
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  • #222
I will likely end up near Perryville Missouri. Looks far enough from civilization to be not overrun, but all the motels are booked.
 
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  • #223
BillTre said:
Eclipse Popularity

Here is an XKCD comic of the eclipse:
eclipse_searches.png

...
:oldlaugh:

2017.08.15.pf.bring.water.png


I've been camping, in various forms, since 1979. (Actually, since ≈1962, but other people were in charge back then.)

I just dug out my 3 gallon water jug, that I'm pretty sure I haven't used in 25 years.
It took 20 minutes in the shower, to scrub off all the petrified cobwebs.

ps. Found this list on the internet the other day. I think it is mostly accurate.

16 things to have in your car for a solar eclipse road trip
1. A full tank of gas [Duh!]
2. Extra auto fluids {?]
3. Mobile phone and car charger [Still don't have one.]
4. Maps (the paper kind) [Is GPS supposed to go out? Guessing this is a "I-phone" thing.]
5. Extra cash (the paper kind) [This is a VERY GOOD idea, if going to a 300, about to become 10 million, populated rural area]
6. Extra medication [Goes without saying.]
7. First-aid kit [I was going to ixnay this, until I almost cut the end off my finger yesterday. OUCH! Band Aids!®]
8. Basic toolkit [Still thinking about this. Do I bring all my tools?]
9. Duct tape [I have a full roll, standing by, and ready]
10. Work gloves [Hadn't thought of that]
11. Jumper cables [I'm not bringing mine to jump my vehicle. Solar!]
12. Flashlight with extra batteries ["extra batteries" for your cameras. See my: "My batteries went dead" post]
13. Spare tire or flat kit [Probably a good idea]
14. Emergency flares or reflectors [In standstill traffic?]
15. Water [Non-fluoridated, of course]
16. Food [Canned. ps. don't forget your can opener! And a spoon!]​
 
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  • #224
ps. They forgot "coffee"

Did that one camping trip, many years ago.
Almost got married that day.

Long story.

snip!
 
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  • #225
Here's a simulation that shows how the sizes of the Moon and Sun change over time as viewed from Earth's center

Notice how difficult it is to get a total eclipse in December or January when the Sun is large.

Simulation (runs in your browser): http://orbitsimulator.com/gravitySim...nMoonSize.html
 
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  • #226
In the 21st century, we have 67 total eclipses (list), or 5.6 per calendar month on average.

Jan: 5 <- perihelion Jan 3
Feb: 0
Mar: 6
Apr: 7
May: 7
Jun: 3
Jul: 6 <- aphelion Jul 4
Aug: 12
Sep: 8
Oct: 1
Nov: 3
Dec: 9

The Moon has to cross the ecliptic at the same time as new moon for an eclipse, this leads to about two "eclipse seasons" per year. They shift around over time, however, with a period of 18.6 years, or -20 days shift per year. This year it is in late February/August, next year in early February and July/August, in 2019 in early January/July and then late December, 2020 in June/December and so on. Typically we get one solar eclipse and one or two lunar eclipses per season, in rare cases we get two solar eclipses, but then they are both partial, and only visible from far north/south, respectively.

Overall this leads to a roughly uniform distribution of eclipses, with a small bias towards the summer for total eclipses where the Sun appears smaller today, and a small bias towards the winter for partial eclipses. The position of the perihelion relative to the seasons has a period of ~23,000 years, or just 1.5 days per century, too small to be notable over a human lifetime.

By the way: If you want to be as close to the Sun as possible, 2020 is your opportunity. Kilimanjaro or maybe some place in the Indian ocean, 5th of January around 8 am GMT. The closest perihelion this century.
If you want to be as far away as possible: 4th of July 2019, around 8 am GMT, probably somewhere south-east of Hawaii.
 
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  • #227
my local weather forecast (Washington DC) says partly sunny on 8/21 eclipses day, will keep finger crossed
 
  • #228
OmCheeto said:
... Now I can't remember where I snagged that image from.
...
Duh...

https://www.greatamericaneclipse.com/

Upper right hand image link.
TODAY'S CLOUD COVER PREDICTION FOR AUGUST 21ST COURTESY OF WDTINC.COM, ESRI.COM, AND GREATAMERICANECLIPSE.COM. GET HI-RES FORECAST MAPS AT THIS LOCATION.

hmmmm...


...for the rest of the nation. Lot's more black! Less traffic for me!


Today is the first time in 5 days we have not been overcast in the hours before 1 pm.
(The only time I can do solar PV experiments.)
[expletives deleted] trees...
 
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  • #229
arabianights said:
... partly sunny on 8/21 eclipses day, will keep finger crossed
Relax guys! It will be seen getting dark anyway! ... during the day, which is the amazing part. No clouds can do that.
 
  • #230
Stavros Kiri said:
Relax guys! It will be seen getting dark anyway! ... during the day, which is the amazing part. No clouds can do that.
I've already experienced that once, in '79. This time I hope to actually see more.
 
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  • #231
Janus said:
I've already experienced that once, in '79. This time I hope to actually see more.
I sure hope so too! Seeing the Sun's corona during totality is of course amazing and unique! It's also a big opportunity to study better and more effectively the sun's activity during that time (e.g. flares etc.) ...

But if clouds get on the way ... at least we ought to see the "bright side" of daytime darkness! ... Or a video from high altitude totality, or different location. [Personly, I consider nice videos equally as spectacular! ...]

I guess we'll find out in a few days.
 
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  • #232
Will direct sun damage camera lenses?
 
  • #233
Flatland said:
Will direct sun damage camera lenses?
I think, during totality, no.
 
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  • #234
Stavros Kiri said:
I think, during totality, no.

What about before? Especially concerning a GoPro.
 
  • #235
Flatland said:
What about before? Especially concerning a GoPro.
I don't think that should be a problem either, as long as you limit appropriately the exposure time (don't keep it too long).
However, let's wait for more responses to your question (from more people), because I am not a cameras expert.
[I recall taking short exposure pictures of direct sun at different times and with different types of cameras (even a video) with no problem at all ... just there's not much to see on a bright sun. But on the eclipse it would still be interesting.]
 
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  • #236
Flatland said:
What about before? Especially concerning a GoPro.
Yes, it will almost certainly damage the camera without the appropriate filter
 
  • #237
Stavros Kiri said:
I don't think that should be a problem either, as long as you limit appropriately the exposure time (don't keep it too long).
However, let's wait for more responses to your question (from more people), because I am not a cameras expert.
A Go-pro, like many modern digital cameras, especially video cameras, doesn't have an active shutter. Exposure is controlled electronically. So this logic will not save the camera.

Also, a go-pro without a giant lens attached is too low of a magnification to see the eclipse anyway.

I expect an awful lot of people are going to destroy their cameras on Monday.

When I was in high school for the 1994 eclipse, I successfully took a photo with a film camera and no filter. The focal length was 900mm and if I remember correctly I traced and cut out a dime on my lens cap, for a focal ratio around 50.
 
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  • #238
russ_watters said:
Yes, it will almost certainly damage the camera without the appropriate filter
Even with short exposure time?
 
  • #239
Stavros Kiri said:
Even with short exposure time?
Not sure if you saw my last post after posting this, but; No shutter = infinite exposure time

[Edit] And even on my SLR, with shutter, I'd be worried about melting the shutter.
 
  • #240
russ_watters said:
Not sure if you saw my last post after posting this, but; No shutter = infinite exposure time
We posted ~simultaneously. Ok I get it now. I think you're right.
 
  • #242
I was in the autoparts store today and noticed welding goggle lenses.

Took a #12 out to parking lot to look at sun and decided a single #12 isn't enough . It was mildly painful, as was a single #10 i tried last week. ...
Got a #5 , it and the #12 together gave a quite comfortable image with no afterglow when i blink.

So i bought two of each. about ten bucks total.

Here's a picture through two #10's that i made last week, just held them over the lens on Fair Anne's Ipad:
sunthrutwo#10lenses.JPG

two #10's is so dark it took the Ipad quite a while to figure out there was an image present.
I don't know if the numbers add like decibels, but two tens was a bit too dark and a single 12 was too bright.

The guys behind the counter got enthused and tried to order a case of #12 lenses for themselves. Their suppliers are all sold out.

old jim
 
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  • #243
What will the weather be like?
I remember going to Paris for the 1999 solar eclipse (on the edge of the millennium), only to find that the complete solar eclipse was obscured by a cloud!
In the end I only experienced a partial solar eclipse.
 
  • #244
jim hardy said:
Took a #12 out to parking lot to look at sun and decided a single #12 isn't enough . It was mildly painful, as was a single #10 i tried last week. ...
Got a #5 , it and the #12 together gave a quite comfortable image with no afterglow when i blink.
two #10's is so dark it took the Ipad quite a while to figure out there was an image present.
I don't know if the numbers add like decibels, but two tens was a bit too dark and a single 12 was too bright.

The guys behind the counter got enthused and tried to order a case of #12 lenses for themselves. Their suppliers are all sold out.

old jim
I found something, then accidentally closed the window. It said that NASA recommends using #12 or higher welding goggles. The article said that many people feel like their eyes hurt with a #12, but #14 seems too dark, so I guess you have something, combining a #5 and #12. It must be some sort of logarithmic adding, like you suggested.
 
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  • #245
A school I'm working with is taking a field trip to Greenville, SC to see it:

http://www.bju.edu/eclipse/

They invited me, but I'm too busy to make a whole day of it. I'll probably step outside and have a peak from wherever I am in the SE on Monday, but frankly I don't get why people make such a big deal out of a shadow.

I did happen to be in a great location for the eclipse of 1984 (New Orleans). Yep, it's darker. Kinda eerie. Not a big deal.
 
  • #246
I like Serena said:
What will the weather be like?
I remember going to Paris for the 1999 solar eclipse (on the edge of the millennium), only to find that the complete solar eclipse was obscured by a cloud!
In the end I only experienced a partial solar eclipse.
Wasn't Paris in the totality zone in the Aug 11, 1999 Eclipse? I saw it from London. It was my 3rd and Cool! (1st in 1984 - annular, 2nd in 1994, 4th in 2005, - this is my 5th [a man is never happy! ...])
What exactly do you mean by
I like Serena said:
In the end I only experienced a partial solar eclipse.
?
Because of the clouds? What difference does it make? Totality is totality ...

Dr. Courtney said:
but frankly I don't get why people make such a big deal out of a shadow.

I did happen to be in a great location for the eclipse of 1984 (New Orleans). Yep, it's darker. Kinda eerie. Not a big deal.
In a sense, you're right. I agree. But seeing the sun's corona during totality is not just a shadow! It's a unique opportunity.
 
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  • #247
Yes, you can use your phone camera. But don't do long-term exposures (pointless anyway as the sun is so bright), and don't use additional lenses without a proper filter.
Phone cameras don't have a shutter and can have the sun in view during normal use - they are typically built to survive a short (seconds) exposure, otherwise the cameras would break down frequently.
According to this article, Apple confirms that iPhones can survive it, and NASA says that a few seconds with any type of phone should be fine. I didn't find the original statements, but it agrees with what I saw elsewhere as well.

Stavros Kiri said:
What difference does it make? Totality is totality ...
You don't see the corona and the diamond ring effect before/after it with clouds.
You have the darkness, but apart from that it is just like a partial eclipse. Interesting, but not the reason why you go into the region of totality.
 
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  • #248
mfb said:
You don't see the corona and the diamond ring effect before/after it with clouds.
You have the darkness, but apart from that it is just like a partial eclipse. Interesting, but not the reason why you go into the region of totality.
I agree on one part:
Stavros Kiri said:
In a sense, you're right. I agree. But seeing the sun's corona during totality is not just a shadow! It's a unique opportunity.
And you need no clouds to see it properly!

But a clouded total eclipse is totally dark, while a partial one is not!* That's the difference and that's what I meant.

* Unless on extreemly heavy cloudiness
 
  • #249
scottdave said:
The article said that many people feel like their eyes hurt with a #12, but #14 seems too dark,

If you tried the #14 shortly after the #12 i think your eye might still be recovering , like at night when you're driving into bright Xenon headlights.
What i noticed with two #10's is it's so dark that light from alongside and behind floods in and reflections make the image really hard to see.

So i bought an inexpensive welding helmet with a #10 in it and taped the second one over the first. It works fine, blocks side light and will keep me from sunburning my face . I have an assortment of lenses so can find a comfortable combination that day. I will err toward conservative - might have to drive home after dark.


.
upload_2017-8-17_7-50-47.png

Got one for Fair Anne, too.

Home Depot, farm supply stores, and autoparts stores are likely places to find them not yet sold out.
 
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  • #250
Just my luck...

I bought a 10-pack of solar eclipse glasses on Amazon... Apparently Amazon is recalling them, as fakes, or knock-offs. The price should have been my first clue, I suppose...

So, now I am looking for a solution in the 11th hour. Of course, all the welding supply houses are out of the lenses required.

I do have some filter paper and binoculars, as well as an old K-Mart telescope with a solar filter, but sharing them between at least 4 people will be less than ideal, so I was hoping for a solution that scales to the individual.

The guy at the welding supply store claims I can stack lenses, as long as they "add up to 12 or higher".

I didn't find anything about that at the NASA website, so I thought I'd ask here.

Can anyone speak knowledgeably on this subject, please?

Do the shade numbers simply add together to get the right number? Can I really stack a shade #8 and a shade # 5 to get the same as a shade #13 lens?

Thanks.

EDIT: NM, according to http://perkins.owu.edu/solar_viewing_safety.htm , you can not simply stack and add for a total. Thanks
 
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