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

[SetepenSeth]

The good news for me is that I´ll be out on vacations from college on this date, the bad news, I don´t think I can afford a trip to the US, being a broken college student in Mexico City does not allow much of my budget for traveling (shame, shame). Still here will be visible as a partial eclipse, so I got that going for me, which is fine.

 

[OmCheeto]

The good news for me is that I´ll be out on vacations from college on this date, the bad news, I don´t think I can afford a trip to the US, being a broken college student in Mexico City does not allow much of my budget for traveling (shame, shame). Still here will be visible as a partial eclipse, so I got that going for me, which is fine.

There will be one in your area in about 7 years. Start saving your money, and bookmark this thread.

I'm 58 years old, and this will be the first one I've had an opportunity to see.
I just checked my military records, and discovered I was in Florida the last time an eclipse was in the area.
It's kind of funny, as just two months later I was transferred to Idaho, very near the path.
But not too funny.

 

[Stavros Kiri]

Assuming the moon is moving outwards (away from earth) at a [current] rate of about 4cm a year (1m in 25ys; 100,000km in 2.5 bill. ys), can someone give a rough estimate of when will be the last total eclipse?

 

[mfb]

~600 million years

 

[Janus]

Assuming the moon is moving outwards (away from earth) at a [current] rate of about 4cm a year (1m in 25ys; 100,000km in 2.5 bill. ys), can someone give a rough estimate of when will be the last total eclipse?

I get roughly 787 million years. This is assuming the last possible total eclipse will occur when the Earth is at aphelion while the Moon is at perigee. This does not however take into account any change in the Earth/Sun distance during that time period.

 

[Stavros Kiri]

~600 million years

Sounds reasonable, and thanks for the source (I saw the earth-solar system etc. timeline table ... - other useful deadlines/timelines on your source too).
But I mostly meant with a rough calculation, assuming noticable changes on the moon phenomenal diameter, assuming at first stage that the Earth is not moving away from the Sun ... (but it does! ...).

I get roughly 787 million years. This is assuming the last possible total eclipse will occur when the Earth is at aphelion while the Moon is at perigee. This does not however take into account any change in the Earth/Sun distance during that time period.

Sounds reasonable too, and it's about of the same order of magnitude as mfb's.

This does not however take into account any change in the Earth/Sun distance during that time period.

I agree.

 

[Janus]

Sounds reasonable, and thanks for the source (I saw the earth-solar system etc. timeline table ... - other useful deadlines/timelines on your source too).
But I mostly meant with a rough calculation, assuming noticable changes on the moon phenomenal diameter, assuming at first stage that the Earth is not moving away from the Sun ... (but it does! ...).

Sounds reasonable too, and it's about of the same order of magnitude as mfb's.

I agree.

It also doesn't take into account other factors, such as continental drift, which by changing the arrangement of the continents, alters the value of the tidal drag and thus the recession rate of the Moon.

 

[anorlunda]

It also doesn't take into account other factors, such as continental drift, which by changing the arrangement of the continents, alters the value of the tidal drag and thus the recession rate of the Moon.

Wow, I think that's pretty amazing that the models are so refined as to make effects that small significant. How big is that effect. $10^{-1}$? $10^{-3}$? $10^{-5}$?

 

[mfb]

It should be quite significant, as water tides are an important part of the process. Unfortunately it is hard to model that.

The size of Sun increases over time, this is relevant as well.

 

[Stavros Kiri]

Furthermore, both moon's recession rate as well as Earth's rotation seem to be slowing down over time (with a connection between the two effects).
E.g. see:
http://rationalwiki.org/wiki/Recession_of_the_Moon

Note: precise current moon retreat rate: (3.82±0.07) cm/yr

 

[Stavros Kiri]

looks interesting,i am looking forward for watch them

Let's enjoy the total solar eclipses for the next ~600 million years, starting with the one coming up ...
Yeah, we got time!

 

[MalcolmB]

I traveled to Penzance in the UK for the August 11 1999 eclipse and it rained!

I had better luck for the March 29 2006 one in Side,Turkey. We were right on the eclipse track and the BBC team were in the next hotel. Unfortunately dear old Patrick Moore was too ill to attend. I got some great video and stills of the event. I still had time to see it in all its glory despite fiddling with cameras!

Truly awesome is the only way to describe a total solar eclipse.

 

[Battlemage!]

This one will pass right over me. I'll be out there watching, probably in Gallatin Tennessee, or wherever in the state the best weather is.

 

[Borg]

Today's APOD put up a nice video of the path.
75% of totality across nearly the entire continental U.S.
Eclipse Across America: Path Prediction Video

 

[Borg]

NASA's Great American Total Solar Eclipse Preview @ 1 pm ET Today

On Wednesday, June 21 - the summer solstice - NASA will hold two major press conferences to provide an overview of the Aug. 21 total solar eclipse, which will be visible to potentially millions of people as the moon's shadow crosses the continental United States from Oregon to South Carolina. You can watch the briefings here, courtesy of NASA TV, beginning at 1 p.m. EDT (1700 GMT) - See more at: https://www.space.com/17933-nasa-television-webcasts-live-space-tv.html#sthash.HLP2eYtS.dpuf

 

[Stavros Kiri]

1. Science Briefing about the eclipse by NASA (a bit lengthy, but good video):


2. Interesting and short ... :

 

[Stavros Kiri]

New & interesting (excellent videos from NASA):
1. Eclipse Primer on "This Week @NASA" (Today, Fri June 23, 2017):

2. Ways to watch the Eclipse (came out on 6/21/17):

3. Safety Briefing (6/21/17):

 

[stoomart]

Today's APOD put up a nice video of the path.
75% of totality across nearly the entire continental U.S.
Eclipse Across America: Path Prediction Video

This makes me glad to be living in Salem, I just hope the weather doesn't do anything crazy. :)

 

[Borg]

For those who haven't gotten glasses yet (like me), 2 million free eclipse glasses will be available at libraries throughout the US.

An interactive map of libraries participating in the eclipse project across the country can be found online.

 

[Stavros Kiri]

For those who haven't gotten glasses yet (like me), 2 million free eclipse glasses will be available at libraries throughout the US.

I still have my packet of "Science&Telescope" eclipse glasses from the Aug. 11, 1999 eclipse in Europe. Who thinks they are still safe to use them?

Here's also a couple of short videos from back then:

 

[Blank_Stare]

I still have my packet of "Science&Telescope" eclipse glasses from the Aug. 11, 1999 eclipse in Europe. Who thinks they are still safe to use them?

As long as they are not compromised from storage, I would expect them to be just fine.

If they are torn, creased, or otherwise compromised in the lenses, I would dispose of them, even if they are a souvenir, so that no one in the future (little kids) get a hold of them, and try to use them.

However, if you have taken care to make sure they made the 18 year journey unscathed, I would expect them to be just fine. On August 22, mine will go into a hard case, and my sock drawer. The 2024 eclipse is only 6-2/3 years, and 90 minutes from home - if I'm alive, I intend to be there with my kids, and (maybe) grand kids.

If anyone is interested in joining us near Makanda Illinois for an eclipse party, check out the thread at: https://www.physicsforums.com/threads/solar-con-eclipse-road-trip-to-makanda-illinois.914983/

 

[Stavros Kiri]

As long as they are not compromised from storage, I would expect them to be just fine.

If they are torn, creased, or otherwise compromised in the lenses, I would dispose of them, even if they are a souvenir, so that no one in the future (little kids) get a hold of them, and try to use them.

However, if you have taken care to make sure they made the 18 year journey unscathed, I would expect them to be just fine. On August 22, mine will go into a hard case, and my sock drawer. The 2024 eclipse is only 6-2/3 years, and 90 minutes from home - if I'm alive, I intend to be there with my kids, and (maybe) grand kids.

If anyone is interested in joining us near Makanda Illinois for an eclipse party, check out the thread at: https://www.physicsforums.com/threads/solar-con-eclipse-road-trip-to-makanda-illinois.914983/

Thanks! It makes a lot of sense.

 

[Borg]

For those who haven't gotten glasses yet (like me), 2 million free eclipse glasses will be available at libraries throughout the US.

An interactive map of libraries participating in the eclipse project across the country can be found online.

I picked up three pair last week and looked directly at the sun with one yesterday. It appears to work well since I can still see.

 

[Stavros Kiri]

It appears to work well since I can still see.

That's what I always wear everyday ...

 

[Blank_Stare]

That's what I always wear everyday ...

Perhaps that explains those nasty bruises on your forehead?...

 

[Stavros Kiri]

Perhaps that explains those nasty bruises on your forehead?...

Gee thanks! ...

 

[1oldman2]

Cool info and video here.
https://www.universetoday.com/136384/nasa-use-converted-bombers-chase-totality/

 

[mfb]

The Concorde did that for more than an hour in 1973.

An F-22 Raptor could probably stay in the shadow for about an hour as well.
SR-71 Blackbird could have stayed in the shadow as long as it had fuel, but the model is retired.

 

[1oldman2]

The Concorde did that for more than an hour in 1973.

From the U.T. article.

Should throw this in also.
Airborne total solar eclipse chasing goes all the way back to August 19th 1887, when Dmitri Mendeleev (he of the periodic table) observed totality from aloft. There’s a great old video of an effort to chase a 1925 total solar eclipse using the airship the USS Los Angeles:

 

[OmCheeto]

This is an fun video:



I was mostly interested in the "Shadow Bands" discussion.

≈4:20 discussion begins about "Shadow bands"

GMT; "...And if you're really lucky, you'll get to observe shadow bands. The shadow bands don't happen at every eclipse. ..."​

≈5:55

SED; "How long does it last?"
GMT; "For about 20 or 30 seconds."​

how to capture shadow bands:

GMT; "Set up a camera on manual exposure on a king sized white sheet".​

On this last Memorial Day weekend, I went to a garage sale, and purchased TWO king sized white sheets, just for that purpose, for a dollar. (pat on back, pat on back)

SED: Smarter Every Day, webcaster
GMT: Gordon M. Telepun: Plastic Surgeon, Eclipse Fanatic, gives talks about "eclipses" at NASA.

Anyone have any tips on how to capture "low contrast" images with a camera?