APOD: Eclipse at 44 000 Feet (2013 Nov 07)

[APOD Robot]

Eclipse at 44 000 Feet

Explanation: Timing was critical to catch this image of November 3rd's solar eclipse. But flying at 44,000 feet, intrepid eclipse chasers on a chartered jet traveling 500 miles per hour managed to intercept the the Moon's shadow. The remarkable flight made a perpendicular crossing of the central shadow track. Darkening the skies beyond the wing tip at that moment, the Moon's shadow was moving at some 8,000 miles per hour across the Atlantic Ocean, 600 miles southeast of Bermuda. After only an instant of totality, this snapshot captured the lunar disk in silhouette. Rays of sunlight shining past peaks and valleys along the lunar limb created the fleeting appearance of a glistening diamond ring.

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[Nitpicker]

Warning: potentially dumb questions to follow ...

Why a perpendicular crossing? For the challenge? To allow you to observe from the side windows? I imagine the timing would have been easier to achieve had a parallel approach been attempted.

[Chris Peterson]

Warning: potentially dumb questions to follow ...

Why a perpendicular crossing? For the challenge? To allow you to observe from the side windows? I imagine the timing would have been easier to achieve had a parallel approach been attempted.

Answered in the caption links...

[Nitpicker]

Damn, so it is (thanks Chris). For side window observation. I did "read" that link, but my skim reading is obviously getting worse. Couldn't everyone have just crammed into the cockpit?

[Markus Schwarz]

Couldn't everyone have just crammed into the cockpit?

The trip was planed with some preparation and is not just a simple snapshot. You probably don't want to setup your camera equipment in the cockpit and interfere with the pilot during the flight. I guess it's easier to mount the camera on a passenger seat than inside the cockpit too.

[Nitpicker]

Couldn't everyone have just crammed into the cockpit?

The trip was planed with some preparation and is not just a simple snapshot. You probably don't want to setup your camera equipment in the cockpit and interfere with the pilot during the flight. I guess it's easier to mount the camera on a passenger seat than inside the cockpit too.

Indeed. I was being facetious.

[Indigo_Sunrise]

Reading Ben Cooper's description of the flight, it was definitely no small feat to acquire those images.
Super-awesome!

[Most hated]

I watched the in cabin video, looks like they blew it by failing to turn off the cabin lights. So they really paid a lot of money to do this, and did not get the full results, also, it looked like an almost last second dash to get the cameras in place and running

[waterfall0007]

I question the statement:
"the Moon's shadow was moving at some 8,000 miles per hour across the Atlantic Ocean"

Looking in some other sources for the speed of an eclipse shadow:

http://apod.nasa.gov/apod/ap040926.html
This shadow moved across the Earth at nearly 2000 kilometers per hour. (1243 mph)

http://sunearthday.nasa.gov/2006/faq.php
Why do eclipse tracks move eastward even though the Earth rotates from west to east?
Because the Moon moves to the east in its orbit at 3,400 km/hour. Earth rotates to the east at 1,670 km/hr at the equator, so the lunar shadow moves to the east at 1,730 km/hr (1,074 mph) near the equator. You cannot keep up with the shadow of the eclipse unless you traveled at Mach 1.5.

http://library.thinkquest.org/C0126702/eclipse.htm
The speed of the shadow at the equator is about 1706 km/hr (about 1060 mph); near the poles, where the speed of rotation is virtually zero, it is about 3380 km/hr (about 2100 mph).

http://en.wikipedia.org/wiki/Solar_eclipse
The total eclipse lasts for only a maximum of a few minutes at any location, because the Moon's umbra moves eastward at over 1700 km/h. (1056 mph)

http://petapixel.com/2013/08/29/eclips- ... rom-space/
The shadow moves across the Earth at about 1,250 miles per hour, and only the people near the center of the shadow see a total eclipse.

[geckzilla]

I watched the in cabin video, looks like they blew it by failing to turn off the cabin lights. So they really paid a lot of money to do this, and did not get the full results, also, it looked like an almost last second dash to get the cameras in place and running

This is a solar eclipse, not a night time scene. The sun is darkened but there is still a lot of light outside. Turning off the lights seems unnecessary. These may be standard running lights and it may be against regulations to turn them off. I'm not a pilot, though, so this is a very big guess. They look like they have their equipment setup just fine at the beginning. I see no last second dash. The moments of the eclipse are certainly rather frantic as they adjust their equipment to deal with the turbulence. You can see on the viewfinder the ring is shaking significantly due to the plane shaking.

[Nitpicker]

I question the statement:
"the Moon's shadow was moving at some 8,000 miles per hour across the Atlantic Ocean"

It was near sunrise for this shot, meaning that sunlight was at a shallow angle to the Earth's surface. This has the effect of increasing the speed of the Moon's shadow on the Earth's surface.

[neufer]

I question the statement:

"the Moon's shadow was moving at some 8,000 miles per hour across the Atlantic Ocean"

The Moon is moving perpendicularly ~2100 mph vis-a-vis the Sun as is its shadow.

But close to sunrise the surface of the Earth is at a steep angle to the perpendicular making for elongated shadows that move much faster.

(Velocities less than 2100 mph are due to the fact that the Moon's shadow is chasing the eastward rotation of the Earth.)

[Boomer12k]

Well...that is one way to see one if there is cloud cover.....AWESOME!

:---[===] *

[carl peters]

44,000 feet? what were you flying in ,an sr 71 ? most jets dont go past about 35,000 ft.
to be honest the shot looks fake to me..

[Chris Peterson]

44,000 feet? what were you flying in ,an sr 71 ? most jets dont go past about 35,000 ft.
to be honest the shot looks fake to me..

Where do you get that? Heavy jets usually have maximum pressure altitudes at around 45,000 feet, and routinely fly at 40,000 feet. Small jets like the one chartered here (such as Gulfstreams) usually have pressure ceilings well over 50,000 feet, and routinely fly at 45,000 feet. There's nothing in the slightest bit unusual about a chartered business jet flying at 44,000 feet.

[Nitpicker]

44,000 feet? what were you flying in ,an sr 71 ? most jets dont go past about 35,000 ft.
to be honest the shot looks fake to me..

Comment of the day, Sir! I didn't think I could be so effortlessly outclassed.

See:
http://en.wikipedia.org/wiki/Dassault_Falcon_900

Service ceiling of 51,000 ft

[BPCooper]

Thanks for the compliments and comments. Yes, where the shadow first touches down, it is moving much much faster than it is when it reaches the center of the path across the globe. Even faster than 8,000mph in the area more to the west of us where it first hit earth (at sunrise).

Yes, this was a first of its kind intercept as we had to do it at 90 degrees to see it (otherwise, near sunrise, only the pilots would see it if we flew with the path). As noted there is a full description on my website link. Even the eclipse veterans are impressed with our feat and only being about a second off. But, viewing from a plane in general is nothing new.