2024 Eclipse

[MrKawfey]

Is it too early to start a discussion about the eclipse next year?
Here is a link to one of the better maps I have seen:

https://www.timeanddate.com/eclipse/map/2024-april-8

It will give you specific details about any location you pick.
If you have other links, please share them.

Another consideration for observing would be sun's altitude and azimuth on April 8th.
It would be cool if we could list some locations that give you a view in that direction.
Obviously, an open field will give you the best view, but I'm sure some people will want to get to a summit to be "closer" to the sun. 😉

[TCD]

This page:

https://www.sunearthtools.com/dp/tools/pos_sun.php?lang=en

gives this result:

alt: 40.84° az: 232.61°

So, southwest, mid height. Lots of Adirondack viewpoints are open on the south side, so there should be a lot of viewing opportunities!

Much discussion here also:

https://www.vftt.org/threads/total-s...-8-2024.62219/

[Wldrns]

Obviously, an open field will give you the best view, but I'm sure some people will want to get to a summit to be "closer" to the sun. 😉

Not obviously best on a flat field. I have seen several eclipses. The best total eclipse view I had was from a slightly elevated location, a hill overlooking a long stretch of open water in the direction the shadow was coming from. I could see the dark shadow of the moon racing toward me at 1000 mph on the surface of the water. I almost ducked as it approached me. Seemed like I should have heard the sound of a great heavy door closing in the darkness, but of course it was completely silent (except for the cheers of my spectating buddies with me).

In 2004 I plan to be at my brother's cottage on the shore of Lake Ontario on the centerline of totality, again overlooking the approaching shadow over water.

I had a telescope for a direct view. Of course you can look at the TOTALLY eclipsed sun safely with naked eye or through a telescope, but you have to know the exact time when it is safe to begin and then when to look away before the first sliver of the sun's bright surface disk becomes visible. During the 2017 eclipse I had an active app running that, based on my exact geolocation and the time, it gave a countdown of when it was safe to first look and then a few seconds before the end of totality when you must terminate your direct view.

[MrKawfey]

Wldrns, that's a great point about the shadow!
Any idea what that app was?

I just looked at a list of past eclipses and despite having a vivid memory of the '84 and '17 eclipses, I saw the '94 eclipse on the list and I seem to have absolutely NO memory of it.

[Wldrns]

Wldrns, that's a great point about the shadow!
Any idea what that app was?

I just looked at a list of past eclipses and despite having a vivid memory of the '84 and '17 eclipses, I saw the '94 eclipse on the list and I seem to have absolutely NO memory of it.

I don't remember the name of the exact app, but I am sure that if is not already up, it or something similar will be available as the time approaches. it is too valuable not to have. Sorry I deleted it after 2017, but it would have been specific to the ephemeris of that particular eclipse.

The 1994 eclipse was annular only, which is probably why you do not remember. It passed directly over central NY and I was set up to veiw it from where I worked with my colleagues at the AF Research Lab in Rome. Not being a total eclipse, I could only view using tescope projection, not naked eye directly by visual viewing.

There was also a 2000 partial eclipse visible on Christmas day. I remember it was a nice day without much snow on the ground and my in-laws got to see the projection of the very first eclipse they ever saw in any detail from my dining room window.

[MrKawfey]

Yeah, not sure what was going on in 1994 that I would have ignored the whole thing. Considering I wasn't doing anything but delivering pizzas for a living at the time, I would have thought it would stick out in my memory a bit more. Oh well.

For this eclipse, looking at the sunerthtools link that TDC posted, is it correct to assume that the path of the moons shadow will follow a line between the sun icon and wherever I put my cursor on the map? (assuming I put the right date and time in and ignoring the slight curve that it will make due to the fact that the relative angle between me and the sun changes over time)

If so, that's super handy to be able to pick a spot with the satellite view and see what kind of obstructions are in between the location and the shadow path.

[TCD]

I don't know. I only referenced that site for the sun position at the time of the eclipse.

[MrKawfey]

Ok, so I thought this through last night and...I think I have it right:

Technically, the shadow of the moon isn't really moving (at least not much). We're moving with the Earth's surface as it rotates us under the shadow.

The moon is just another thing (a really big thing) sitting between us and the sun, just like a tree or rock. But those things are moving with us on the surface and their shadows rotate around them as they pass under the sun.

The moon essentially stays in the same place and casts a fixed shadow located on a line drawn from the sun, through the moon, onto the surface of the earth. We, at a given spot on the surface, whip through the shadow at 1000mph.

So...a certain competent of it's motion is due to the moon's motion, but on the scale of 4 minutes, the largest component would be the rotation of the earth.

That suggests it would be mostly a West to East motion? Sounds right?

[Wldrns]

Technically correct, yes. Relative to a fixed earth observer, the shadow is "moving" from west to east, with the exact path direction due to the combination of earth rotation and the 5 degree (relative to the equator) of orbital inclination of the moon's orbit. True enough, earth rotation (at the equator) is roughly 1000mph. Away from the equator the surface rotation velocity is reduced by the cosine factor of your latitude.

it is easy to find the contribution of the moon's orbital velocity:

Along its inclined path, the moon's mean orbital velocity is 1.022 Km/s

which is its contribution to the motion of moon shadow over the surface of the earth.
By the way, 1000mph = 0.447km/s
1.022 km/s = 2286 mph

[MrKawfey]

So, if I did the math right:
Secret spot I'm thinking of is in Saranac Lake(ish) at roughly 44 degrees of latitude.

Which makes the surface speed about 720mph.
Looking at a topo map I estimate a 3-4 mile view to the W-SW. This means the moon's shadow should take 15-20 seconds to cover that distance once it comes over the hilltop in the distance.

Unfortunately, I don't think there's a very good view of the hillside below. So it would dive into the valley, then nothing for a few seconds, then zoom over us.

[Wldrns]

Download and practice with the Solar Eclipse Timer on your phone/ipad. You have to pay $1.99 for the 2024 version. I used it in 2017 and it works great for giving you audio cues of what to doexactly when for viewing and safety during all phases of the eclipse, as it is automatically set to your exact GPS location (can be manually loaded if you device is not GPS capable). Be sure to run through the practice video session and it will give you an idea of what it does for you with alerts and warnings.