The most accurate map for August 21’s total solar eclipse | Hacker News Reader

The most accurate map for August 21’s total solar eclipse

nasaviz.gsfc.nasa.gov

311 pointscyanbane170 comments

Best advice I've accumulated so far:

1. Don't plan to drive anywhere on eclipse day (90% of the US lives within an 8hr drive of totality, so traffic will be horrible)

2. A 600-800mm lens is optimal for photography. Anything short of 200mm is useless.

3. Don't make any solid plans until 3-4 days before. Most places only have about 40% chance of it being clear.

4. If you're photographing the partial phases. Stop and check everything (batteries, memory card, focus, etc) about 5 min before totality.

5. If you have any technological issues during totality, just sit back and enjoy watching it.

6. On eclipse day, if you're in a place that has 2 min or more of totality, just stay there. There's not a lot to be gained by risking moving.

7. All across the US, the sun will be high in the sky, good horizons aren't necessary.

  90% of the US lives within an 8hr drive of totality, so traffic will be horrible

Oh, come on. Less than 5% of America actually cares enough about astronomical events to drive 30 minutes to see something. Much less book a hotel stay.

August 21st is a Monday afternoon, so how many employed Americans are going to ask for the day off, to drive 8 hours, with a 200mm telephoto lens or telescope?

If totality is the size of several counties, and lasts even ten minutes, how many people will be on the road within an hour of the event? Lunchtime (or even all day long) traffic is probably nothing even terrible in 40 out of 50 states. In totality states, traffic won't even compare to a sporting event.

The Willamette valley South of Portland is expecting over 1 million people. The hospital in Lincoln City (where it starts) had been stockpiling and planning for 3 years now. A friend in the event planning business said all portable toilets in the state have been rented, and they are bringing them in from out of state, at 6 times the normal rate. This is going to be a huge event, and gridlock on the freeway that Monday.

2016 article:

http://www.oregonlive.com/travel/index.ssf/2016/08/7_things_...

Hotels across Oregon are already booked solid. Court Priday, manager of the Inn at Cross Keys Station in Madras, said rooms have been gone for a long, long time. "We've been getting phone calls like crazy," he said. "We've been sold out for about three years."

Totality lasts ~2 minutes

You are correct, sir. And thinking about OP's statement a little more, maybe staying off the road is a good idea in the sense that a two minute eclipse can distract drivers on the road.

But in general, unless you happen to glance at the sun in your field of view during the eclipse, it's all the darkness of passing clouds for most of the country.

Are traffic accidents statistically affected by proximity to a total eclipse of the sun?

> Don't plan to drive anywhere on eclipse day

This.

I watched a total eclipse in England in 1999 parked up on the side of the road with other cars doing likewise as far as the eye could see in both directions. Traffic was at a standstill all morning.

Get to where you want to be the day before, and stay there.

My coolest memory of a total eclipse was standing high on a cliff edge over looking the sea. As the sun went totally dark I the moon's shadow move quickly along the beach covering everything in darkness.

Really good points that you made, but I personally think it's good to find a high location with a view so you can take in more than just the sun/moon.

Interesting. The internet says the shadow of the moon during an eclipse has a speed between 500m - 1500m per second. So from a high point you really can see the shadow racing across earth.

I'll strongly second point 5. I saw the 2002 Eclipse from central Australia and it was kinda primal, I regret the time I spent getting a few crappy photos and wish I'd just soaked in the experience without doing that. Other people took and shared _way_ better photos than mine. I won't make that error again. (I don't think I'll make it to the US for this one, but if I do I wont waste time with a camera...)

> Other people took and shared _way_ better photos than mine.

Since the dawn of photo sites on the web, I've completely stopped taking photos of anything except family and friends. What's the point when a thousand photos exist of everything, from every conceivable angle, within 5 seconds of googling.

Even if you manage to get an incredibly cool picture, then what? Nobody pays for photos anymore. Your closest friends will give you a "like" and move on to a million other cool photos. Chances are that even you will never look at your photos again having amassed tens of thousands of them.

It's going to get much worse within a few years. With continuous surveillance cameras everywhere and "life recorders" capturing in high resolution and 360 degrees there won't be an event witnessed by human eyes that hasn't already been photographed or videoed.

Photography as a creative endeavor is dead but people don't know it yet.

> Don't plan to drive anywhere on eclipse day (90% of the US lives within an 8hr drive of totality, so traffic will be horrible).

Speaking of driving, anyone from the Seattle area have any thoughts on the best approach?

The first one that comes to mind is to take 5 down to the path of totality.

The second thing that comes to mind is heading east toward Spokane, and turn south at Yakima and head on down 84 to somewhere in totality.

I've driven the 5 route a few times going between Seattle and California, so I know the roads are reasonable. The big unknown will be traffic. It will have a lot of people from Washington heading down plus the Portland crowd.

I've never headed east from Seattle past, I think, North Bend, so nearly everything on the second route is completely unknown to me.

My bet is that you'll get as far as Portland and then be stuck. I-5 through PDX can be a mess on a regular Monday. Get south of Portland on Sunday and you might be ok.

The Spokane option might work but the unknown there is that most of the roads in Oregon will be one lane each direction with hundreds of thousands of visitors expected in that area.

I reserved a campsite at a garden outside of Salem with a friend for Fri-Mon. The Oregon State Parks links to a page with a list of events and venues that are taking reservations.

My plan is to take a long weekend, drive to Idaho (near Boise or Sun Valley). I've been thinking of renting an RV but it may be too late.

Frankly, I find most of the comment by gmiller123456 ridiculous.

There's more to eclipse than looking at the sun. Horizon is also very important, especially the unobtrusive western horizon, where the shadow is coming from, and where you can see dancing light rays from beyond the shadow.

Photography is really not recommended, unless for science, since you have really two minutes of the greatest spectacle of nature, and photography doesn't really do justice to its grandeur.

Drive, and try to get there!

http://www.eclipse2017.org/2017/what_you_see.htm

If you're going to photograph an eclipse, do so with extreme care in your choice of methods and equipment. Don't just aim a camera at the sun and hope for the best! Focusing solar radiation onto a light sensor, be it the one at the back of your camera or the one at the back of your eyeball, is a good way to destroy it.

> 2. A 600-800mm lens is optimal for photography. Anything short of 200mm is useless.

Only if your goal is a closeup shot. I'd be much more interested in a shot with significant context. How easy that is to pull off I don't know, but I'd love to a nature landscape shot @28-35mm (FF) with the eclipse in the sky instead of the sun or moon.

The sun is like 1000x brighter than any object you'd be able to get in the foreground. If you just want a shot during the totality with the corona, it would be possible to get it and expose some other things a little bit (though you will probably need to increase exposure quite a bit...).

But if you want any of the partial phases, you need a solar filter (not just ND filters), and that thing basically blacks out anything that's not the sun.

You could do something with multiple exposures and a filter swap, but you'd need to use care in making the exposure without the solar filter - maybe a handheld card to keep the sun out of the lens. If you've got a drop-in filter holder that can take a solar filter, it'd be a lot easier than using thread-mounted ones.

These are really great tips. I was thinking about driving into the path of totality on the day. After thinking about it more and the hype that is surrounding this thing I am probably not going to. The highways are going to be jam packed (I-95). Reserving a place to stay or something similar in an area is also probably out of the question.

The annular eclipse in California in 2012 really didn't draw much in the way of crowds. Some friends and I drove up to near Mt Lassen and found a field with no real traffic or crowds to contend with. There were others in the field we ended up in, but it was really pretty straightforward.

It seems like there's a lot more hype around this one; I'm not sure why. Maybe 'total' vs 'annular'? Personally, I think they're both pretty spectacular, and annular eclipses have the added benefit of having the awesome ring-of-fire effect.

Have you ever seen a total eclipse? An anular/partial one doesn't even compare to watching the sun during totality with your bare eyes.

Probably more hype because this one covers the entire country in the middle of the day.

#3 is very hard if you are living more than 8 hrs drive from the totality zone. Population-wise way more than 10% of the US lives more than 8 hrs from the totality zone.

> Don't plan to drive anywhere on eclipse day

> Don't make any solid plans until 3-4 days before. Most places only have about 40% chance of it being clear.

If you haven't made plans already, you are probably driving.

Best I could do was get a room in portland the night before. Gonna have to get up stupid early and try to make it. 3-4 days before is gonna be tough.

If you can get east of the Cascades from Portland, that would be your surest bet. Even if the weather is expected to be clear in the Willamette Valley on the 21st, there is a risk that the marine layer could settle in and not clear by the time of the eclipse. The risk is less in August than now, in June, but it could happen.

Can someone explain why the claimed shadow of the moon is vastly more bumpy than it ever appears in the night sky? Or how to square this with the fact that altitude of the highest and lowest points on the Moon differ by less than 20km, or less than 1% of the diameter? The shadow looks like it has bumps of about 5-10% of the diameter.

The diameter of the path of totality is only about 100 miles, because it's only the umbra of the shadow. This is 20x smaller than the moon diameter. But, a 1km moon bump is a 1km bump on the umbra as well, magnifying it's effect by the mentioned 20x and leading to a much different appearance.

I hadn't thought about this effect! You're absolutely right. Thanks very much.

(For others:) A diagram of the umbra makes this clear:

https://c.tadst.com/gfx/750x500/total-solar-eclipse-com.png?...

If you draw a few triangles, you can get an analytic expression.

There are two principal factors at work here.

The first is the eccentricity of the lunar orbit - 0.0549 which means that depending on where in the lunar orbit the eclipse occurs, the moon is closer or further away meaning the apparent size ratio between the Sun and Moon varies. In fact - it's even possible to have an eclipse where the Sun's limb is visible around the edge of the Moon at totality - this is called an annular eclipse. [1]

The second factor is that the Moon is lumpy! The depressions caused by craters and valleys means that totality, as defined as when the Moon completely occults the Sun's disc, varies according to where in the path of totality you are. Parallax effects move the Sun with respect to the observed position of the Moon, so the Sun will peek through the valleys/craters earlier or later depending on your latitude. This lumpiness actually creates one of the most spectacular features of a total solar eclipse, the "diamond ring" effect - I had the rare privilege of seeing this in the 1999 eclipse that crossed south-west England and northern France - a mere teenager but the image is burned into my brain. [2]

Other minor factors come into play which add to why the shape of the polygon changes across the track - the Earth is a spheroid, not a flat plane so the ratio of Sun:Moon coverage varies along the track; also the Moon is still gently turning as it orbits in a manner called libration - while tidally locked to face the Earth, the Moon still rotates marginally faster or slower along its orbit. [3]

The effects of the compensation for totality variation are shown in the second half of the video past ~1:20.

[1] https://en.wikipedia.org/wiki/Solar_eclipse#/media/File:Annu...

[2] https://youtu.be/WBIyYCdwX1k?t=254

[3] https://en.wikipedia.org/wiki/Libration#Lunar_libration

To anyone who viewed the YouTube link above, reference [2], go back to about 2:45 and watch the start of the diamond ring effect. It's spectacular.

And even better in reality. Everyone science and nature-interested who live near the totality, should seizr the opportunity to go see this.

The shadow is pretty circular near the center of the eclipse. If you look at the map, the bumpiest parts are far from the center where the shadow is elongated due to it hitting more to the side of the Earth's sphere. You'd see an oval if the Earth and moon were perfect spheres. But any irregularity on the moon gets stretched out, and irregularities of the Earth's surface add to it even more.

The effect was probably exaggerated, otherwise you would just see a smooth circle.

If you want to experience the greatest duration plan a trip to Southern Illinois (more info about duration here: https://www.greatamericaneclipse.com/illinois/).

As a bonus a friend of mine's family winery has booked Ozzy to "bark at the moon" during the eclipse: http://loudwire.com/ozzy-osbourne-headlining-moonstock-solar...

Most of the Carbondale area was booked solid months ago. There may be some campsites open but not much else.

I'm staying in St Louis the night before and then picking a direction to drive based on weather. I don't think it's worth all the hassle to get to southern Illinois just to get 3 more seconds of totality.

This map will show you how much totality you can experience, unlike the NASA charts.

http://xjubier.free.fr/en/site_pages/solar_eclipses/TSE_2017...

I'll be in St. Louis for this, too. I'm thinking about viewing it from here:

https://mostateparks.com/event/64121/solar-eclipse-showdown

I've been trying to scout out some open areas away from civilization, mostly to avoid ambient light but also to avoid huge traffic in and out of any park or freeway interchange.

I fully anticipate traffic to be screwed up for hours afterward.

I could be totally wrong, but I just don't see it, at least not down there in Jefferson County. That's not a densely populated area. It's over an hour's drive from Downtown St. Louis. [0]

I have to say, though, I'll probably leave earlier that morning than I'd originally planned, because of the comments in this thread.

[0] https://goo.gl/maps/bJRKJndLnQG2

If you've never seen a total eclipse before and you live in the US, make every effort to see this one! It's not something that you can get the feel of by viewing photos or video. Watching the sun get eaten by a black void activates something deep inside the animal brain. Don't settle for a partial eclipse, do what it takes to get in the path of totality.

If you have seen a total eclipse before, then you don't need any convincing.

I'd recommend finding somewhere near leafy forest if you can. Watching the dappled shade gradually become thousands of tiny crescents is really interesting. I'd never realised that the canopy created multiple pinhole-camera images of the sun until then.

> Watching the sun get eaten by a black void activates something deep inside the animal brain.

I was planning to have my 5 year old son see it. But now I wonder whether it will have any traumatic effect on him.

You would seriously let your son miss this because of some hypothetical traumatic event that might happen? I feel really bad for him if that's the case.

I don't think you worded this very well (which is probably why you're getting down votes), but I agree with your sentiment. This is 100% not something you should shield children from in my opinion - it's a very rare opportunity to see something quite magical - even when you know exactly what's going on.

I was five when I saw my first; only thing traumatic about it was the smell inside the welder's helmet we were passing around to watch it.

Welders helmets are _not_ effective enough to make viewing the sun safe. Don't do that.

Welder here. A welding helmet with a Shade 14 lens should be okay. A lower shade, say Shade 11 or higher, plus dark safety glasses should be okay for short periods of viewing the sun while it is at least partially eclipsed.

1. https://www.space.com/15614-sun-observing-safety-tips-infogr...

Sounds like the kind of thing my father would've said. He was a great one for inflicting trauma as a result of ill-thought-through attempts to prevent it. I really can't recommend him as a role model in that regard or many others.

In any case, I saw my first near-total solar eclipse at about your son's age. I don't recall as it did me any harm - indeed, I thought it was brilliant. The only real cause for trepidation would be looking at it with bare eyes, but there exist any number of expedients there.

It was my 6th birthday when I saw it. I still vividly remember it, in a good way.

Is that the "Black circle"? Or is that the line of the path?

The black circle. The closer you get to the line of the path, the longer the total eclipse lasts.

Is there something special about this total eclipse over others?

It's "relatively" easily accessible for those living in the United States and covers a huge swath of the country.

Many total solar eclipses happen over the middle of the ocean, or at the poles, or in a location that is not as easily accessible.

The next eclipse (after this one) to pass through the United States is in 2024.

For other people's information, it will cut through Mexico, Texas (incl. Dallas), Arkansas, New York (Buffalo), Maine.

Err, what will? Partial? Totality cuts from Oregon to South Carolina and gets nowhere near Mexico or Maine.

He's talking about the 2024 eclipse.

Ah! Fair! I hope I get to see it. :)

Here are my viewing tips, based on my experience in the 1979 eclipse in Oregon.

You can photograph the eclipse, but you will have a much grander experience if you don't try. Photography is just a distraction from the awesome spectacle of the eclipse, including the phenomena that happen on the ground.

There will be plenty of other people taking great photos, so enjoy those after the eclipse. A total eclipse, viewed directly with your own eyes, is truly an experience of a lifetime. No photograph comes close.

Contrary to one or two other comments, eye protection is not necessary during totality and will prevent you from seeing the full beauty of the corona. It is perfectly safe to view the total eclipse with the naked eye, or even with binoculars. Only the partial phases need eye protection (and they definitely do). [1] [2] [3]

In fact, on the hillside we ended up at, something interesting happened. Most of the people wore dark sunglasses and faced away from the sun during the first partial phase, in order to get their eyes a bit acclimated to the dark. The partial eclipse isn't very interesting compared to totality, and the fun stuff at that point is happening on the ground: there are ripples of light dancing on the ground like you see on the bottom of a shallow stream. And you may get to see the shadow rushing toward you at 10,000 miles an hour!

The moment it reached totality, there were shouts of "it's total!" up and down the hill. Everyone took off their sunglasses and looked directly at the total eclipse. Many of us brought binoculars and viewed the corona with them.

The danger is that it is tempting to keep looking at the end of totality, when the string of beads starts to appear at the edge of the moon (where the sun is starting to peek through the moon's valleys), and finally the "diamond ring" where a larger part of the sun appears through the deepest valley. If you bring proper eye protection, switch to it the moment the string of beads appear, and definitely before the diamond ring appears! I recommend doing this after totality and not before, so you don't interfere with your eyes' dark adaptation before totality.

[1] https://eclipse.gsfc.nasa.gov/SEhelp/safety.html

[2] https://eclipse.aas.org/resources/telescopes-binoculars

[3] http://www.eclipse2017.org/2017/what_you_see.htm

> Except during totality, when the Sun's bright face is completely blocked by the Moon, it is never safe to look directly at the Sun through a telescope or binoculars. During the partial phases of the eclipse, you must secure a special-purpose solar filter over the front of your optics before aiming at the Sun.

That's a quote from one of the links. Most people will not be in totality. Most people will only be seeing a partial eclipse. The shaded in line from this [1] image is where totality will happen.

Most people watching the eclipse will need some form of eye wear.

[1] - https://nasaviz.gsfc.nasa.gov/vis/a010000/a012400/a012458/us...

Yes, my comment was addressed specifically to those who will be viewing the total eclipse, not the partial eclipse. That's why I emphasized total eclipse and totality.

But thank you for making it more clear that viewing any other kind of eclipse - partial or annular - requires proper eye protection!

This is all the advice I wish I'd had (but to be honest with myself, probably would have ignored) when I saw the 2002 Eclipse from central Australia.

"A total eclipse, viewed directly with your own eyes, is truly an experience of a lifetime. No photograph comes close."

This is _so_ true.

Smarter Every Day just posted a great video related to this:

> HOW TO WATCH THE ECLIPSE (AND SHADOW SNAKES) - Smarter Every Day 171

https://www.youtube.com/watch?v=qc7MfcKF1-s

I'm hoping the masses take to capturing high definition footage of the shadow snakes. Someone, somewhere will be able to get decent footage hopefully.

What about the rest of the world!!

This eclipse will only be visible in totality within the US. Here's a broader-scale map:

http://xjubier.free.fr/en/site_pages/solar_eclipses/TSE_2017...

This map is way more useful than NASA's. Highly recommended.

There's a total solar eclipse somewhere on earth every year or two. See if there's one coming up near you: https://www.timeanddate.com/eclipse/list-total-solar.html

It is an amazing spectacle (provided there are no clouds), and certainly worth some travelling to see it.

Some tips for photographing it: http://www.nikonusa.com/en/learn-and-explore/a/tips-and-tech...

Solar filters: https://www.bhphotovideo.com/c/buy/solar-photography-filters...

Won't it just be.. black?

It will if you don't pop off the solar filter during the totality! I'm planning on practicing with the solar timer app mentioned by Smarter Every Day; I'm not moving anywhere since I'm in the path of totality (for 1:16!), so I want to make sure I have all the timing down for the little transitional bits, so I can gun off a dozen or so pictures at any of those moments.

I'll also have a timelapse camera set up on a wider angle (incorporating my yard, some trees, the sky, etc.) using pi-timelapse[1]

[1] https://github.com/geerlingguy/pi-timelapse

http://cdn-7.nikon-cdn.com/Images/Learn-Explore/Photography-...

See ErrantAstro's excellent post in this thread, the "second factor": https://news.ycombinator.com/item?id=14547178

I heard from a co-worker who plans to travel to Oregon that some of the hotel rooms in the path of the umbra are sometimes > 2-3k USD for the night(s) prior to the eclipse.

OPB says that Oregon expects a million visitors for the eclipse. If you don't already have solid bookings, don't even try.

I have to drive about 15 miles south from my house to get deep into the totality, and I know all the back roads, and I still expect epic gridlock.

A high school graduation at the Expo center in Redmond is enough to cause 97 to backup. The eclipse backup will indeed be epic.

Washington or Oregon? Why would you stay in Washington? The roads into the area of totality in Oregon on that day will be horrendous. It would probably be faster to walk. Fortunately our church has a camp almost smack on the totality line so we are staying at a cabin there for a few days around the event to avoid the traffic.

I don't see the point of booking something without knowing the weather unless you don't care about throwing it away and going somewhere else. My initial plan was to book several hotels in different areas, but it seems like every hotel inside the path of totality requires a 2 week notice to cancel (and this was months ago).

Since I'm about 1.5 hours from the path of totality in Georgia, my current plan is to drive out at like 3AM (before the roads have a chance to get packed) and just stay in the area.

If it looks like the weather isn't going to cooperate, I'm going to leave a day earlier. Get a hotel outside of the path of totality, and do the same thing I was planning to do at home (leave at 3AM to drive into it).

I'm in New York. I'm more than 1.5 hours away from the totality, so I'm going to have to head south and hope - although, I'm in the somewhat enviable position of just being able to sleep in a car... as long as someone cracks the window and leaves me a bowl of water.

On the other hand, the totality will pass in the very early afternoon, so I can probably just head back once it's over.

Are you thinking Greenville? Columbia? Somewhere off I-95?

Yeah, I was looking at Georgia and South Carolina - seems like the most reasonable destination.

A train is going to take me 16 hours, minimum - and a car will take 12. I might just go ahead and book a flight, but then I still need a car.

Book it months in advance, and then the price is normal. That's what I did. I'll be in Salem.

Are you sure you still have a reservation???

There were some big news stories here in Oregon about this. People made reservations literally a year in advance, only to have the hotels cancel them once they figured out why people were booking!

The only good news is some hotels may have done people a favor. Those were on the Oregon coast, in the Lincoln City and Newport areas, where, even in the middle of August, there's a good chance of overcast skies (marine air).

That's an excellent point. I'll call them to confirm. Thanks.

I thought of that, but the chances of the hotel canceling at the last minute after someone else throws money at them was just to high.

But you're still out the money in case of heavy cloud cover.

And I don't trust people not to cancel early bookings once they realize what kind of prices they can get.

I am on a project in Bend, OR and the city is booked solid for that week. The camp grounds are booked as well. Your best bet would be to rent an RV and boondock out on the BLM land around town.

Yes the hotel prices are very high, but I hadn't seen any that high.

I actually have an RV and live in Portland. Where do you recommend boondocking close to Portland?

Anywhere along 20 before Millican. Or along SW George Millican HWY which is a connector between 20 and Prineville.

thanks

I'm thinking of driving south from Hood River towards Madras; OR-26 between Government Camp and Madras is probably going to be backed up, though (or so I imagine).

We're some New Hampshire tech bumpkins who got a hotel in Charleston SC for 15% of that. We're going to leave our phones and cameras inside, and just hang out by the pool with some cold beverages and experience the eclipse as it unfurls. Granted, it's not quite in the center, but I think it should be close enough to make the trip worth making. I suppose in a panic, we could drive about 40 miles north. Should we?

At the pool? Go to the beach!

We're travelling all the way from Australia for this (thanks to my epic girlfriend). Got a roadside motel in Pleasant View, ~50 miles from maximum totality (Hopkinsville), for <$200. Only booked it the other week.

Not expecting it to be anything flash, but there's stuff out there. Don't be put off!

Yeah, it's crazy.

I waited too long to plan and we're flying (ourselves) up to Idaho Falls and paying like $700/night. Selection was really bad and virtually every other town I tried had zero availability at any price!

Yeah, I'm from Idaho Falls and know someone that is renting out their house for $8k a night. I tried to convince my parents that they should do the same thing with their house, but they'd rather stay in house and not worry about traffic those days. Most of the town is going to close down for a few days around the eclipse because of all the visitors.

Say, many friends and I are all converging to camp just outside Pocatello with the intention to drive up first thing that morning, either up 15, to 33, or over to Rexburg/Idaho Falls area...

...would you have any advice on where you think we might want to go (assuming we're not fighting clouds)?

We could only get our campground on the night of the 20th, so don't have time to do reconnaissance as we would have wished; the main thing is just to make sure we get somewhere with a view of some kind.

(I lived in Utah as a kid and came up through the area many times but can't correlate my ancient memories with places...)

All ears!

I'm not sure how busy they'll be, but the Menan Butte and the Rexburg Bench could both provide some good views. Of course the Butte is in the desert and will be pretty hot and isolated, but if you bring your own shade and are wary of snakes you should be fine. It'll be right in the center of the path (or as close as you can get eyeballing it) so you'd get about as much time possible. My grandparents live a two minute drive from the base of the Butte, so that's probably where I'll go.

Gimlet's Every Little Thing podcast did a bit on the eclipse a month or two ago — there were towns booked solid then, I imagine it's only tougher now.

I think Oregon is a bad spot to view it. The weather (yes, even in summer) is too unpredictable and it's too close to populated coastal areas.

Wyoming is the way to go, or western Nebraska. Don't expect to get hotels, but camping on a rancher's land is easy, and the arid climate in the summer minimizes chances of cloud cover.

Errr, east of the Cascades, Oregon is pretty dry and sunny. Look at the satellite today, for instance:

http://weather.cod.edu/satrad/exper/?parms=northwest-02-48-0

Perfect example of the Cascades blocking the crap.

That said, it looks like things are going to be a complete and total mess here in central Oregon with all the people converging on this area.

http://eclipsophile.com/total-solar-eclipses/total-solar-ecl... has weather overviews for various locations and it rates eastern Oregon as possibly the best place as far as weather goes. Once you get east of the mountains there's much less water to cause viewing problems.

>, or western Nebraska.

I'll be in eastern Nebraska (Omaha) and will drive south on I-80 towards the eclipse path and hopefully pull off to the side and park somewhere.

What's hard to plan for is whether too many other Nebraskans will have the exact same idea which means I have to camp out a ridiculous 12 hours before the event to secure a spot -- or give up entirely.

The ideal location is 70 miles wide and 2100 miles long. I don't think viewing space is going to be much of an issue.

PS: Sure, the closer to the center the longer the total eclipse lasts. But, you still end up seeing the same thing.

>The ideal location is 70 miles wide

True but I was trying to minimize the distance from Omaha airport since I have to catch a flight 5 hours later. It will be interesting to see how many of the ~500,000 Omaha residents will be on that stretch of I-80!

I highly recommend rescheduling your flight.. seriously. Right before and right after the eclipse roads will be slammed! One article from Missouri said to expect Florida hurricane evacuation level traffic. If you still want to try to fly, bring LOTS of water in case you are stuck in traffic for hours.

from I-80 (in Lincoln) take highway 77 south towards Beatrice. The closer you get to Beatrice the longer the totality. Lincoln will get about 1 min, Beatrice gets 2:35.

I'm planning to drive up north from Denver, the day of. Kind of concerned about how many people will have the same idea, and how early I should start...

Many people I've talked with are planning to make this event into a long weekend. If you want to avoid traffic... and find parking - I'd recommend at least Thursday.

I'm in Denver area too. The question is this:

How much better is a 100% eclipse vs. a 90% eclipse that we'll get here?

Is it worth the trip to Wyoming? I think so, but not positive.

According to everything I've read, and all pictures I've seen, 99% is one thing, and 100% totally something else.

I'm in Lincoln and I don't think too many people are planning to go far since its in the middle of the day.

Camping on a rancher's land with permission is easy. But given the expected crowds, friends in e.g. Glendo (population ~200) plan to be out enforcing their property rights against the anticipated tens-of-thousands of out-of-towners. So be smart, camp on public land. Otherwise you'll likely get shot.

If you check out things ahead of time, you'll find that many landowners plan on cashing in by allowing paid dry camping.

Why not just get a hotel outside of the path of totality, get up super early and drive to it?

That's what I'm doing but the wildcard is we don't know what a meaningful amount of "super early" would mean since we don't have recent eclipses in the USA to use as past guides about crowd behavior. It's an unprecedented mega event since the last total eclipse to cross the USA-48 was 1918 when the horse & buggy was still prevalent.

I plan to find a spot 6 hours early but my worst fear is that everybody else camped out 12+ hours before I did. Or there is unforseen traffic gridlock towards the path of totality.

That's true, but the path of totality is 70 miles wide. If you make contingency plans, pick an area that isn't too populated but has multiple roads, my guess is that it will be fine.

>everybody else camped out 12+ hours before I did

Basically every spot is a good spot as long as you can get to it. Gridlock starting the day before is the only problem I can foresee that would keep me from actually getting there.

I'll probably pack the bikes in the insane case that I have to leave my car on the side of the road 20 miles outside of the path of totality or something. But the only way I see that happening is if it turns into something like a hurricane evacuation.

Wait a minute:

I thought the last full eclipse to cross the USA was in the late 70's??? Pretty sure it hasn't been since 1918.

Yep, I was right:

https://en.wikipedia.org/wiki/Solar_eclipse_of_February_26,_...

>I thought the last full eclipse to cross the USA was in the late 70's?

Right, but that 1979 one didn't reach the major metro areas across the entire swath of USA-48. That's what people mean by comparing it to 1918[1] in terms of widespread national interest.

The eclipses of 1918, 2017, and 2024 attract extra attention because of the paths crossing numerous population centers.

[1] https://www.greatamericaneclipse.com/20th-century/

What do you think of Grand Teton? I will in Yellowstone that week. I am not sure if we should go do Grand Teton or Nebraska for the eclipse. Ideally I want to hike somewhere for a few miles to avoid the crowds.

The Grand Tetons/Yellowstone are super packed on normal summer days. Jackson Hole is super expensive on normal summer days.

Probably gonna have a hard time.

I have a campsite reserved in Yellowstone and would drive South. I guess a good plan would be to pick a trail and go there at night so you are already on thew trail before the crowds come. Not sure about the weather though.

I scouted the same area. The weather should be perfect by mid-day. Plan to drive v.early-morning a couple of hours East or West (across a mountain range in either direction) depending on a bad weather forecast. You'll know the night before.

Can confirm: The company I work for just opened a hotel in Oregon and the nightly rates we are getting that weekend are very high.

That's a lot to bet on good weather.

I don't want to travel to this one if I can avoid it, and there seems to be none in Europe in my life time.

Will the April 2024 one be as good as this one? I suppose one drawback of that one is that april is probably(?) much larger risk of clouds in a lot of the US, than august?

https://www.timeanddate.com/eclipse/list-total-solar.html

If you want a laugh, mute the audio track of the video on that page and play the Game of Thrones Main Title instead.

Hello everyone. I'm currently working with a group who plans to do some experimental sounding of the effects of the eclipse on the ionosphere. If you want to learn more about this project please check out our website http://hamsci.org/. We are pushing a number of fun ways to get involved with collecting very useful data for scientific analysis.

I'd like to ask anyone who lives on the midwest or east coast to consider helping these projects:

1. EclipseMob: http://hamsci.org/node/148

This project will ship you a set of ICs and a breadboard that will make up a VLF receiver. No soldering is required. It's a great kit to put together with children.

After you build up the kit you plug it into your phone's microphone jack and run an app that agregates radio signal information (I/Q data I think) to the EclipseMob organizers. After the eclipse is over you'll still be in possession of a fully capable VLF receiver kit. You can use it to listen to VLF signals that are interesting. This may include human generated traffic or whistlers.

2. Total Eclipse SEQP: http://hamsci.org/seqp

If you have an amateur radio license and want to help participate in a contest you can hop on the air and operate during the eclipse. The more people on the air the better dataset we have.

3. Setup a Reverse Beacon Network receiver.

The main dataset we use is the Reverse Beacon Network. It's a set of automated receivers that listen to short-wave Morse code and RTTY communications. If you have a few bucks burning a hole in your pocket and want to set up a we have a page that talks about how to do this: http://hamsci.org/cw-reverse-beacon-network-how-guide

Using these data sources we would like to generate a very high resolution picture of the effects of a solar eclipse. As it turns out we don't exactly have the best understanding of what goes on during an eclipse.

We have a few other projects in the works that I'm not very familiar with. One idea is recording I/Q data from JT65 bands and building a data set via Zenodo so that everyone who contributes to the data set gets their name as a reference on papers that use it.

If you're interested and want to hear more about this you can reply to this post or send me an email to my "work" email. My email username is jk369 and my university's mail address is njit.edu.

Regarding weather, places that have clouds due to convection have a chance of clearing up during the eclipse. I experienced this in China in 2009 - completely overcast two hours before totality, clearing up just in time due to lower solar insolation and less convection.

You shouldn't count on this, try positioning for good weather in advance regardless, but just keep it in mind so you don't crash your car heading for better weather if things look poor.

My first thought: how will this affect traffic.

I've been in Atlanta too long.

Me too.

We were going to make a weekend trip out of this. But we realized the chances of bad weather are pretty high at our planned viewing site in Western North Carolina and that it would be better to stay in Atlanta closer to an Interstate Highway so we can quickly drive to an alternate site.

It might be difficult to predict a clear sky. Because of hot, summer humidity, The eastern US has a pretty good chance of afternoon thunderstorms during the time of the eclipse.

When was the last time an eclipse like this happened in the US ?

It depends what you mean by "like this."

The last US West Coast to US East Coast eclipse was 1918.

The last time the totality was entirely within the current US borders and never over land elsewhere was 1257.

https://en.wikipedia.org/wiki/Solar_eclipse_of_August_21,_20...

I remember seeing one around 1975 (I was in Kindergarten). Not missing this one!

Question for those who know more than I do about this. According to [0] the sun will be about 97% obscured at my house. Is it worth traveling for that last 3%?

0: http://xjubier.free.fr/en/site_pages/solar_eclipses/TSE_2017...

I'm no expert, but YES!! Drive the miles to get to 100%. There is absolutely no comparison between 99% and 100%. They're just totally different beasts.

What do the black circles mean?

Just wondering, how much is this going to cost into the loss of electricity generation from the Solar plants across US.

You should find this article interesting! https://qz.com/973684/california-will-lose-enough-solar-ener...

Do you get the full eclipse effect anywhere inside of the green line? Is there an advantage to being at the red line?

The closer to the red line the longer you'll get totality. But anywhere in the green lines you'll have some period of totality.

The interactive map: https://eclipse2017.nasa.gov/sites/default/files/interactive...

will tell you exactly when and for how long you'll get totality anywhere along the route.

Thanks! That is a much better map than original article.

So what will be the practical difference between 99.4% (at my home) and 100% about 35 miles away. Is it worth the effort to travel to the true totality zone? I do unfortunately have a commitment that day, that I cannot avoid, about 2 hours before the max obscuration passes by.

The difference between totality and 99 percent is estimated to be brightness of 10000x brighter! In a clear sky, a total eclipse will let you see 4 planets and lots of stars! It's a once in a lifetime event--- at the least an EPIC adventure! Make sure to bring LOTS of water, in case you are stuck in traffic forever. (Before and after the eclipse)

35 miles seems small enough to not worry about it - it's just a half hour drive! It's still months away, I'd hope you could reschedule that conflict.

I have several hundred miles if I wanted to go to the totality zone. But I'm still curious what it will look like in the difference of 100% vs 82% at my home.

Well, one difference is that if you go to where there is totality you can look with the naked eye once totality is achieved. If you are in a place where it is only partial, most experts recommend only looking through filters or via pinhole projection.

What affect is this going to have on solar power? California has a load of solar going on, and this may cause a complete collapse in solar output very suddenly (way more suddenly than the evening). Can peaker plants come up quickly enough?

On a hot August summer day, LOTS of power will be lost. It's recommended to turn off your A.C. to help prevent blackouts and the prevent use of more expensive natural gas power.

https://qz.com/973684/california-will-lose-enough-solar-ener...

Pretty cool that it's going to pass directly over Clemson, SC. Literally almost dead center. (2:53 mark of the path video).

Are these safe to view? I thought these would be black. Another link talks about "getting eye protection"?

Eye protection is essential.

There was a total eclipse in Britain when I was a child [1], and everyone bought special protective glasses to wear.

Mine were like the paper red-green "3d" glasses you used to get, but with a black film that was close to opaque. They worked fine.

[1] http://xjubier.free.fr/en/site_pages/solar_eclipses/TSE_1999... ("Britain" is exaggerating, but we were in Cornwall on holiday.)

Before and after the totality, same rules apply as always—if you don't have solar filter glasses (and lens filters on any cameras), don't look at the sun.

But once the totality starts in your location, you can pop off the filters/shades and look with the naked eye. Just be sure to put them back on once totality is just about over!

* The most accurate map for Aug 21, 2017's total solar eclipse for north America (nasa.gov)

Why would they use a tif format for the downloadable map? I haven't seen a tif format in 10 years.

I used to work in the group that produced that animation and I can tell you that the TIFF format is alive and well in the 3D graphics world. It is supported by most high-end graphics software, has an open, extensible spec, and can be losslessly compressed if desired. It's also popular in Earth Sciences work due to the GEOTIFF format that adds georeferencing data tags.

PNG is a reasonable alternative, usually, but TIFF is entrenched. TIFF had legal issues in the past with respect to the LZW compression, which is a shame. PNG might never have been needed if TIFF had been free of patent encumbrances.

lossless format (potentially) that everyone can open?

Nope. This is in fact why TIFF is pretty much dead.

The format is very extensible. It was originally specified to have 5 ways to encode data: uncompressed, LZW, fax, RLE, and JPEG. The use of proprietary encodings is normal however, along with several non-proprietary encodings. Data can be lossless or not. Data can be bitmap or vector. There are even two different ways to store JPEG data, with many tools supporting only the original style and many other tools only supporting the newer style.

Now consider trying to view a TIFF that you have received. You have a several TIFF-capable image viewers. No two of them handle the same set of encodings. The most recently installed viewer is associated with the file extension, and as a normal user you are thus unable to use the other viewers. If you install another TIFF-capable viewer, you gain the ability to view some TIFF images while losing the ability to view some other images.

PNG just works. JFIF and EXIF JPEG do too, because nobody creates 12-bit or arithmetic-encoded files. GIF just works.

After looking at the map, I can't imagine why a lossless format is required. I just exported in as a jpg, and it would take a magnifying glass to see the difference. And the jpg was 16/7% the size (at 90%). Waste of government bandwidth.

I'd imagine NASA's more concerned with pixel perfect reproductions than your average government agency, given the sort of imagery they're often working with.

PNG?

No need for PNG since there is no transparency. JPG uses 24 bit color depth vs 32 on a PNG.

Would love to hear how they generated the shadow contours from the Moon to the Earth's surface!

it's projection geometry. You create a geometry object with the earth's surface shape. Another with the moon's surface shape. Then, a light source that emits from a sun's shape. All objects are placed at the appropriate distances, and made to rotate and translate through space according to normal orbits.

Then, you project the light from the sun onto the earth, with the moon in-between. This creates the 2D shape on the earth's surface corresponding to the shadow.

I've set up something very similar to this in Blender, although its floating point precision was too low, so I had to fudge things a bit.

Thanks dehhn. From the LRO picture in the article, you can see that they're actually taking high-precision elevation maps of both the Moon and Earth into consideration, which sounds like something rather computationally intensive. I might be wrong, but I don't think they used Blender to handle that.

I would be curious to hear what tool they actually use, their pipeline, etc.

To the best of my knowledge, it was animated in Maya and rendered with Pixar's Renderman. When I was in that group, we used IDL to do any elaborate calculations needed, and then imported the data into Maya/Renderman. This is exactly what Hollywood does when they have to render a scene that requires a lot of simulation. I can ask Ernie if he used anything special for this production.

That's amazing, thanks so much. Ernie, if you're reading this, great job :)

Depends how high precision those maps are, but I can't imagine it being a very big deal with the right data pruning(you only need to consider elevations near wear earth intersecting sun rays are close to tangential to the moons surface)

Times in UTC would be more helpful.

Not for an event where the total eclipse will only be visible in the continental US. The map in TFA changes timezones so that local time is always used. It's the same as flight schedules where takeoff and ETA are always represented in local time.

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