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

[russ_watters]

Forecast at my planned location in SC is getting worse - now a 50% chance of precipitation.

From the Washington Post:
View attachment 209017

If you don't mind me asking, where are you going to be? I'll be north of Charleston.

 

[Borg]

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.

 

[russ_watters]

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.

 

[Borg]

Driving from PA overnight?

 

[russ_watters]

Driving from PA overnight?

Renting a house in Isle of Palms for the week; arrive Saturday.

 

[Borg]

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.

 

[russ_watters]

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!

 

[Borg]

Yikes - just don't fall asleep during the eclipse!

Not a problem. I normally get up at that time.

 

[OmCheeto]

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.

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."

 

[anorlunda]

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.

 

[BillTre]

Eclipse Popularity

Here is an XKCD comic of the eclipse:

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

Here is another interesting map from the same article:

 

[jim hardy]

I will likely end up near Perryville Missouri. Looks far enough from civilization to be not overrun, but all the motels are booked.

 

[OmCheeto]

Eclipse Popularity

Here is an XKCD comic of the eclipse:

...

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!]​

 

[OmCheeto]

ps. They forgot "coffee"

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

Long story.

snip!

 

[tony873004]

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

 

[mfb]

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.

 

[arabianights]

my local weather forecast (Washington DC) says partly sunny on 8/21 eclipses day, will keep finger crossed

 

[OmCheeto]

... 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...

 

[Stavros Kiri]

... 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.

 

[Janus]

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.

 

[Stavros Kiri]

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.

 

[Flatland]

Will direct sun damage camera lenses?

 

[Stavros Kiri]

Will direct sun damage camera lenses?

I think, during totality, no.

 

[Flatland]

I think, during totality, no.

What about before? Especially concerning a GoPro.

 

[Stavros Kiri]

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.]

 

[russ_watters]

What about before? Especially concerning a GoPro.

Yes, it will almost certainly damage the camera without the appropriate filter

 

[russ_watters]

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.

 

[Stavros Kiri]

Yes, it will almost certainly damage the camera without the appropriate filter

Even with short exposure time?

 

[russ_watters]

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.

 

[Stavros Kiri]

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.

 

[scottdave]

Here you can see what the eclipse will look like in your location (and what time it will occur). Just put in your city. https://www.timeanddate.com/eclipse/in/usa/houston

 

[jim hardy]

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:

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 like Serena]

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.

 

[scottdave]

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.

 

[Dr. Courtney]

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.