APOD: 8 Minute and 30 Second Eclipse (2019 Jul 06)

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APOD Robot
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APOD: 8 Minute and 30 Second Eclipse (2019 Jul 06)

Post by APOD Robot » Sat Jul 06, 2019 4:07 am

Image 8 Minute and 30 Second Eclipse

Explanation: The total phase of the July 2nd solar eclipse lasted about 4 minutes and 30 seconds at the point of maximum eclipse. On the surface of planet Earth, that was about 600 nautical miles north of Easter Island in the Southern Pacific Ocean. But from 37,000 feet above, on a charter flight intercepting the Moon's shadow, the Moon could be seen to completely block the Sun for about 8 minutes and 30 seconds. With a tailwind at the mid-eclipse intercept point, the plane was traveling around 488 nautical miles per hour chasing along the Moon's shadow track. From above the clouds this wide-field image of the totally eclipsed Sun and shimmering solar corona over the wing records the spectacular view from a window seat on the sunward side of the aircraft.

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Re: APOD: 8 Minute and 30 Second Eclipse (2019 Jul 06)

Post by orin stepanek » Sat Jul 06, 2019 11:45 am

Orin

Smile today; tomorrow's another day!

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Re: APOD: 8 Minute and 30 Second Eclipse (2019 Jul 06)

Post by neufer » Sat Jul 06, 2019 1:08 pm

APOD Robot wrote:
Sat Jul 06, 2019 4:07 am

The plane was traveling around 488 nautical miles per hour chasing along the Moon's shadow track.
For reference:

The speed of light is 582,750,000 knots or
approximately 100,000 φ nautical miles per second;
(where φ is the golden ratio)
.
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Re: APOD: 8 Minute and 30 Second Eclipse (2019 Jul 06)

Post by Drdf » Sat Jul 06, 2019 6:43 pm

Magnify eclipsed sun in this photo and look at dim object just to the left of sun. Is that Mercury or some other planet?

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Re: APOD: 8 Minute and 30 Second Eclipse (2019 Jul 06)

Post by neufer » Sat Jul 06, 2019 9:28 pm

Drdf wrote:
Sat Jul 06, 2019 6:43 pm

Magnify eclipsed sun in this photo and look at dim object just to the left of sun.
Is that Mercury or some other planet?
  • Venus
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Re: APOD: 8 Minute and 30 Second Eclipse (2019 Jul 06)

Post by BDanielMayfield » Sun Jul 07, 2019 3:07 am

A nice, but not too difficult high school math problem can be drawn from the explanation of today's APOD: At the midpoint of an eclipse the moon's shadow took 4.5 minutes to cross over a point on the earth's surface. An airplane flying at 488 nmph chased this eclipse along the centerline of totality over the midpoint and was able to remain in totality for 8.5 minutes. How fast was the moon's shadow moving with relation to the Earth at the eclipse midpoint?
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Re: APOD: 8 Minute and 30 Second Eclipse (2019 Jul 06)

Post by neufer » Sun Jul 07, 2019 3:48 am

https://en.wikipedia.org/wiki/Solar_eclipse_of_June_30,_1973 wrote:

<<A total solar eclipse occurred on June 30, 1973. This eclipse was observed by a group of scientists, which included Donald Liebenberg, from the Los Alamos National Laboratory. They used two airplanes to extend the apparent time of totality by flying along the eclipse path in the same direction as the Moon's shadow as it passed over Africa. One of the planes was a prototype of what was later to become the Concorde, which has a top speed of almost 1,300 miles per hour (2,100 km/h)(Mach 2). This enabled scientists from Los Alamos, the Paris Observatory, the Kitt Peak National Observatory, Queen Mary University of London, the University of Aberdeen and CNRS to extend totality to more than 74 minutes; nearly 10 times longer than is possible when viewing a total solar eclipse from a stationary location. That Concorde was specially modified with rooftop portholes for the mission, and is currently on display with the Solar Eclipse mission livery at Musée de l’air et de l’espace. The data gathered resulted in three papers published in Nature and a book. A separate observation opportunity was provided on a specialized commercial cruise by the S.S. Canberra, which traveled from New York City to the Canary Islands and Dakar, Senegal, observing close to 8 minutes of totality out in the Atlantic between those two stops in Africa. That cruise's passengers included notables in the scientific community such as Neil Armstrong, Isaac Asimov and the then 15-years old Neil deGrasse Tyson.>>
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Re: APOD: 8 Minute and 30 Second Eclipse (2019 Jul 06)

Post by alter-ego » Sun Jul 07, 2019 4:45 am

BDanielMayfield wrote:
Sun Jul 07, 2019 3:07 am
A nice, but not too difficult high school math problem can be drawn from the explanation of today's APOD: At the midpoint of an eclipse the moon's shadow took 4.5 minutes to cross over a point on the earth's surface. An airplane flying at 488 nmph chased this eclipse along the centerline of totality over the midpoint and was able to remain in totality for 8.5 minutes. How fast was the moon's shadow moving with relation to the Earth at the eclipse midpoint?
chasing along link:

edit:
I left our the answer to your question: 2019km/hr relative to Earth's surface.
Umbral Velocity.PNG
Solar Eclipse Maximum_July 2019.PNG
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Re: APOD: 8 Minute and 30 Second Eclipse (2019 Jul 06)

Post by neufer » Sun Jul 07, 2019 3:03 pm

alter-ego wrote:
Sun Jul 07, 2019 4:45 am
BDanielMayfield wrote:
Sun Jul 07, 2019 3:07 am

A nice, but not too difficult high school math problem can be drawn from the explanation of today's APOD: At the midpoint of an eclipse the moon's shadow took 4.5 minutes to cross over a point on the earth's surface. An airplane flying at 488 nmph chased this eclipse along the centerline of totality over the midpoint and was able to remain in totality for 8.5 minutes. How fast was the moon's shadow moving with relation to the Earth at the eclipse midpoint?
2019km/hr relative to Earth's surface.
Average orbital speed of Moon: 1.022 km/s

Equatorial rotation velocity of Earth: 0.4651 km/s
-------------------------------------------------------------------------------
Relative lunar velocity at Equator = 0.5569‬ km/s = 2005 km/hr

Relative lunar velocity at 30º Latitude = 2,229 km/hr

(Relative lunar velocity at 30º relative Longitude = 2,574 km/hr)
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Re: APOD: 8 Minute and 30 Second Eclipse (2019 Jul 06)

Post by DMurray » Sun Jul 07, 2019 7:47 pm

I like to look at APOD because that photos are beautiful,educational and uplifting. Unfortunately, this picture mostly made me despair about our ability and willingness to address climate change in a meaningful way. I'm sorry, but the whole idea of a charter flight spewing out who knows how many tons of CO2 over the southern Pacific so that a bunch of relatively wealthy people form the northern hemisphere can have an additional 4 minutes of eclipse doesn't seem to me like something that we should be doing if we are serious about stopping climate change. Of course, individual actions aren't going to solve climate change, the system is the problem, yadda, yadda, yadda. Well the system is US and we need to both collectively and individually start making decisions that address climate change rather than just compartmentalizing climate change into something that is a "political" problem. I usually refrain from pointing things like this out because my motivation is not to call out specific individuals for their behavior, but to point out that we need to think about the consequences of our actions and carefully consider what makes sense and what doesn't before we act.

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Re: APOD: 8 Minute and 30 Second Eclipse (2019 Jul 06)

Post by neufer » Sun Jul 07, 2019 8:40 pm

DMurray wrote:
Sun Jul 07, 2019 7:47 pm

I'm sorry, but the whole idea of a charter flight spewing out who knows how many tons of CO2 over the southern Pacific so that a bunch of relatively wealthy people form the northern hemisphere can have an additional 4 minutes of eclipse doesn't seem to me like something that we should be doing if we are serious about stopping climate change.
  • At least the "relatively wealthy people from the northern hemisphere" who do such things have to learn how to share:
https://en.wikipedia.org/wiki/Solar_eclipse_of_June_30,_1973 wrote:
<<The June 30, 1973 eclipse was also observed by a charter flight from Mount San Antonio College in Southern California. The DC-8 with 150 passengers intercepted the eclipse at 35,000 feet just off the east coast of Africa and tracked the eclipse for three minutes. The passengers rotated seats every 20 seconds so that each passenger had three 20 second opportunities at the window to observe and take pictures.>>
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Re: APOD: 8 Minute and 30 Second Eclipse (2019 Jul 06)

Post by DMurray » Mon Jul 08, 2019 4:41 am

Learning how to share is something that we are taught in Kindergarten. Nobody is going to learn how to share on an eclipse excursion. So, well done - you have come up with yet another way to avoid confronting a serious issue!

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Re: APOD: 8 Minute and 30 Second Eclipse (2019 Jul 06)

Post by neufer » Mon Jul 08, 2019 10:58 am

DMurray wrote:
Mon Jul 08, 2019 4:41 am

Learning how to share is something that we are taught in Kindergarten. Nobody is going to learn how to share on an eclipse excursion. So, well done - you have come up with yet another way to avoid confronting a serious issue!
  • What...me worry :?:
https://en.wikipedia.org/wiki/Sarcasm wrote:
<<Sarcasm is "a sharp, bitter, or cutting expression or remark; a bitter gibe or taunt". Sarcasm may employ ambivalence, although sarcasm is not necessarily ironic. Most noticeable in spoken word, sarcasm is mainly distinguished by the inflection with which it is spoken and is largely context-dependent. The word comes from the Greek σαρκασμός (sarkasmós) which is taken from σαρκάζειν (sarkázein) meaning "to tear flesh, bite the lip in rage, sneer". It is first recorded in English in 1579, in an annotation to The Shepheardes Calender by Edmund Spenser: Tom piper, an ironicall Sarcasmus, spoken in derision of these rude wits, whych ...>>
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