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APOD: Total Solar Eclipse of 1979 (2017 Aug 19)
Posted: Sat Aug 19, 2017 4:07 am
by APOD Robot
Total Solar Eclipse of 1979
Explanation: From cold, clear skies over Riverton, Manitoba, Canada, planet Earth, the solar corona surrounds the silhouette of the New Moon in this telescopic snapshot of the total solar eclipse of February 26, 1979. Thirty eight years ago, it was
the last total solar eclipse visible from the contiguous United States. The narrow path of totality ran through the northwestern states of Washington, Oregon, Idaho, Montana, and North Dakota before crossing into Canadian provinces Saskatchewan, Manitoba, Ontario and Quebec. Following the upcoming
August 21, 2017 total solar eclipse crossing the U.S. from coast to coast, an annular solar eclipse will be seen in the continental United States on October 14, 2023, visible along a route from Northern California to Florida. Then,
the next total solar eclipse to touch the continental U.S. will track across 13 states from from Texas to Maine on April 8, 2024.
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Re: APOD: Total Solar Eclipse of 1979 (2017 Aug 19)
Posted: Sat Aug 19, 2017 11:26 am
by orin stepanek
Three totals for the USA in 7 years; pretty cool!
Re: APOD: Total Solar Eclipse of 1979 (2017 Aug 19)
Posted: Sat Aug 19, 2017 12:19 pm
by heehaw
A Saturn V rocket, ready for launch, weighs 2.8 million kg. In contrast, a Coronal Mass Ejection from the Sun averages 1,600,000,000,000 kg. Such masses are launched successfully from the Sun every few days.
The “surface” of the sun is 5800 K. A typical hydrogen atom in the solar atmosphere moves a factor of 50 slower than escape velocity. Escape velocity from Earth is 11.2 km/s while escape velocity from the Sun is 618 km/s. How the heck does the Sun manage to have such a hugely efficient space program, making NASA look like pikers? Ah, the magnetic field! Yes indeed, somehow, that is the answer, but we don’t know what the “somehow” really is. The Earth’s magnetic field is about half a gauss; but the Sun’s is only about 1 gauss! However, in a solar flare, magnetic field strength is about 1500 gauss. Just above the “surface” of the Sun, the chromosphere has a temperature of 20,000 K and the solar corona (seen in today’s APOD) has a temperature of a few million Kelvin. How come so very hot? Nod slowly, look wise, and intone "the magnetic field."
Maybe we will find the answers when we actually GO there, which we will do about one year from now:
https://en.wikipedia.org/wiki/Parker_Solar_Probe
Re: APOD: Total Solar Eclipse of 1979 (2017 Aug 19)
Posted: Sat Aug 19, 2017 1:06 pm
by neufer
orin stepanek wrote:
Three totals for the USA in 7 years; pretty cool!
Three
Re: APOD: Total Solar Eclipse of 1979 (2017 Aug 19)
Posted: Sat Aug 19, 2017 3:22 pm
by LirrelJohn
neufer wrote:orin stepanek wrote:
Three totals for the USA in 7 years; pretty cool!
Three
"Moonfall", Jack McDevitt. There won't be a 2052 eclipse due to lack of sufficient Moon. There might be lots of transits of Sol
by bits.
It's quite strange how we keep catching up with the "future" as described in various SF movies, novels and TV shows. And how
we still don't have the Moonbases they took for granted so often.
A mere seven years and "Moonfall" will be history, too, just like "Space:1999" and "UFO".
Re: APOD: Total Solar Eclipse of 1979 (2017 Aug 19)
Posted: Sat Aug 19, 2017 3:53 pm
by ta152h0
Are you, the science community, going to do the Einstein experient ?
Re: APOD: Total Solar Eclipse of 1979 (2017 Aug 19)
Posted: Sat Aug 19, 2017 4:19 pm
by James Bailey
Just as I brought up this picture on my screen, Bob McDonald on Quirks and Quarks (
http://www.cbc.ca/radio/quirks)) mentioned having seen this eclipse in Red Lake, ON. He just mentioned it again, saying that it was clouded over, unfortunately.
Re: APOD: Total Solar Eclipse of 1979 (2017 Aug 19)
Posted: Sat Aug 19, 2017 4:34 pm
by neufer
ta152h0 wrote:
Are you, the science community, going to do the Einstein experient ?
Re: APOD: Total Solar Eclipse of 1979 (2017 Aug 19)
Posted: Sun Aug 20, 2017 5:06 am
by BPCooper
There is an error in the description for this APOD. The 2023 annular eclipse path is from Oregon to Texas and down into South America.
It's the 2045 total (the next US one after 2024) that goes from Northern California to Florida. (That's three eclipses in the US in seven years, but two are total and one is annular).