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Full Lunar Eclipse Feb 20/21 / Earth picture
Ant103
post Feb 21 2008, 05:29 PM
Post #16


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Larger view to see stellar field :

And labels :
The ending :






A recapitulative board with view center on Earth shadow :


Avec l'ombre de la Terre :


Some humidity this ending night (this is the reflector I used to put my numeric camera in parallel):






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Floyd
post Feb 21 2008, 07:23 PM
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Very nice Ant! Exactly how it looked in Boston.

-Floyd


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djellison
post Feb 21 2008, 08:46 PM
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I wonder how Chang'e and Kaguya came thru it.

Doug
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DDAVIS
post Feb 21 2008, 10:57 PM
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The eclipse began under a rare rainy sky in Palm Springs, Calif., and as totality began I dispaired of seeing the event. The skies then cleared about a third of the way through totality and I set up my 6 inch reflector, binocculars, video camera and drawing stuff. I hastily drew isophotes on a set of printed out full moon images within which color and brightness information could be noted, using the WWV time signal.
I notice again the tendency of even excellent digital camera pictures to shift the color balance toward garish oranges and reds. The reality as seen by at least this pair of eyes is more subtle and varied. I used the video later to help in drawing the tonal values within the shadow.
This eclipse, at least starting at mid totality, appeared fairly muted in the intensity and range of colors within the Earth shadow. The southern portion near the shadow boundary was a light golden yellow, and the eastern part of the disk displayed a nice spectral gradation to muted orange and duller rusty red. The western Moon shadow colors at that time were less saturated, duller, with a sharper gradation to the dark brown shadow core, or umbra region. The brighter western colors faded in the latter part of totality, and a pale gray lighting appeared along the SW limb, displaced N from the closest part of the shadow edge, shortly before totality ended. As the sunlit Moon returned the shadow colors moved off the disk and faded in the brightning sky. (P.S. I'm having trouble uploading an image file-it never stops telling me it's uploading)

Don
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Doc
post Feb 22 2008, 09:37 AM
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Curse the tropical climate mad.gif

The eclipse was scheduled to take place at 4am here in Dar es Salaam.
There was not a single cloud in the sky at midnight so you can imagine my dismay and frustration when a cloud cover developed and did not let up till sunrise!

By then the moon had set...great pictures Ant. how I wish I could have seen it myself.


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DDAVIS
post Feb 23 2008, 12:34 AM
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Attached Image


Ha! used another browser....Here is an attempt at my visual impression of the Lunar eclipse.
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dvandorn
post Feb 23 2008, 06:06 AM
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Yes! Your 3:38 and 3:51 images are *exactly* what I saw with my naked eye. A coppery feel to the whole scene, edging to an ochre-ish gold along the southeast limb.

-the other Doug


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Guest_Sunspot_*
post Feb 23 2008, 08:51 AM
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This was the best I got, quite a lot of high cloud so very hazy, cloud thickened approaching totality didn't see anything there after sad.gif
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Stu
post Feb 23 2008, 08:59 AM
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Eclipse was due between 01.30 and 05.00 here, so I took the next day off work in anticipation of being too tired after watching the eclipse to function... needn't have bothered, because after 2 weeks of almost perfectly clear nighttime skies here in the Lakes the cloud rolled back in Wednesday night like that scene from Independance Day when the alien ship glides over the mountains, and by 2am next morning the sky was just a flat dome of orange. No hope of seeing anything.

Then to rub salt into the wound, I couldn't even enjoy my day off because a workman spent the whole day digging up my living room floor, looking for the water pipe that was leaking into the shop beneath my flat, so I spent the whole day tramping around town keeping out of his way, in the rain, going back every hour to find yet more devastation...

sad.gif


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edstrick
post Feb 23 2008, 11:14 AM
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Great weather tuesday night, good weather thursday night, BLOTTO wednesday night. grrrrrrr.
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JTN
post Aug 21 2008, 11:04 PM
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(Another ancient thread rises from the dead...)
QUOTE (edstrick @ Feb 9 2008, 07:44 AM) *
"Surveyor III was able to get some variously filtered images of an eclipse in 1966. One color-composite version is shown"

A couple years <or decades, it feels like now> I posted here a considerably improved pair of the Surveyor 3 images, reassembled from good quality black and white color separations published in JPL TR series reports on Surveyor.
[snip]
I've tried poking around the archives here and I don't find the post. It's not on my internetting computer at the moment, so I'll have to dig for it.

Did this ever come to light? I'd be interested to see it.

Random Googling found some monochrome images (bottom of page) that look rather more interesting than the referenced one. No idea of provenance (I assume Surveyor 3 data is not available online, in general).
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scalbers
post Dec 12 2015, 10:53 PM
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For fun I can update this 7 year old thread to mention I'm working on a lunar eclipse model. It's possible for me to render images of the moon seen from Earth, and I'm starting to work on the Earth seen from the moon. Here is a work in progress of a view of Earth from the moon just barely inside the umbra. It still has a bit of aliasing to address. Careful inspection will show a white outer ring, a bluish middle region (from ozone) and a darker red inner region (within the troposphere). This run is without clouds, but does have some stratospheric aerosols.

Attached Image


More on the model is here: http://laps.noaa.gov/albers/lunar/lunar.html


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JohnVV
post Dec 13 2015, 05:39 AM
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cool

Celestia gives i interesting view for the April 4 2015 eclipse
-- as seen from the Moon - and like the above image they are dark


now there is limited atmosphere simulation at a distance
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scalbers
post Dec 17 2015, 08:46 PM
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Thanks for the Celestia view. This provides a reminder that it would be nice to add in a representation of the solar corona, as the brightness range of the rendered image allows.

I mentioned this model in passing to Emily at the AGU conference and she posed the question of whether Earth city lights would be visible on the moon during totality. As an example, I found a web site where it states Tokyo would appear +23.7 magnitude from 30AU away. This translates to about magnitude +9.8 as seen from the moon, below naked eye visibility. Additionally I believe there would be significant glare from the ring of light refracting through Earth's atmosphere making this more difficult to see in practice, depending on how deeply immersed the observer is in the umbra. The apparent magnitude of the developing ring is about -20 for an observer on the edge of the umbra and -15 for an observer in the center (about the full moon seen from Earth). The latter value is somewhat tricky to specify due to the deep red color, meaning the apparent magnitude can deviate from the "visual" V-band magnitude.

Here is an image similar to post #27 with some of the antialiasing measures applied:

Attached Image


In this view around the edge of the umbra the brightness is scaled so the unattenuated (and non-limb darkened) sun is white with 255 RGB counts. When we go to the center of the umbra the red ring faintly shows up with 17 counts in the red channel, somewhat more than 100 times surface brightness reduction in the red channel. This looks pretty dim even when I crank up my monitor brightness. So it's barely possible to show the full dynamic range involved. The second image shows this as a blinking comparison between edge of umbra and center of umbra views. This is a good test of one's monitor contrast. It's also possible to scale up the brightness of the image while you're displaying it to see the red ring better.

Attached Image


(UPDATED Jan 3, 2016)


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scalbers
post Dec 23 2015, 03:52 PM
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With several further refinements, here is now an animation of the eclipse seen from the moon:

Attached Image


To deal with the brightness range, during the partial eclipse and shallow total eclipse (as seen from this point on the moon) the brightness is scaled so that 255 is the surface brightness of the center of the sun. When we are more inside the edge of the umbra the brightness is scaled up by a factor of 10.

In reality the red ring would be broken up by clouds so here is a movie that shows this with some idealized cloud locations. The handling of solar limb darkening is also improved. Extra frames are added near the end of the total eclipse.

Attached Image


The solar corona is relatively much dimmer than the rest of the scene being shown. It seems it would barely register more than a count or two unless the brightness scale is cranked up further. Unlike the view of a solar eclipse and diamond ring effect from the Earth, there is less opportunity to view the inner corona from the moon due to the large size of the Earth's silhouette. Thus the diamond ring seen from the moon is essentially the refracted light passing through the thin layer of the Earth's atmosphere.

I like to view these animations full screen with the monitor brightness turned up. The view might resemble wearing sunglasses or a solar filter depending on the stage of the eclipse. Even in deep totality the surface brightness could be fairly bright in spots, kind of like a sunset on Earth. I'm presently assuming clean air so adding tropospheric aerosols may dim things a bit more when we're in deep totality.

(UPDATED Jan 2, 2016)


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