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Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Fri Aug 07, 2015 1:53 pm
by henrystar
woody pope wrote:This is a fake. If the earth is lit like it is then the back side of the moon would be as well because the sun is shining on both.
The Moon is lit, but the albedo (reflectivity) of the rocks on the Moon is very low - almost black. No, this is for real.

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Fri Aug 07, 2015 4:00 pm
by bystander

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Fri Aug 07, 2015 4:49 pm
by Lasher
An incredible photo! Could someone fill me in on a couple of features I'm seeing on the earth that I can't figure out. First, just to the right of the moon (being overlapped by the moon in its 1:00 to 3:00 o'clock position is what looks to me like another continent. It's got a similar gray color to N. America and even a fairly sharp focus on what looks like a large lake right at the edge of the moon's overlap. This can't be Australia, unless the Pacific is only about 2,000 miles wide.
Second, I wonder about the curious looking cloud pattern in the Pacific above the moon image. I've been looking at satellite photos for decades and never saw a cloud opening so well formed out with rectangles. Is this some sort of altering of the photo?

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Fri Aug 07, 2015 5:05 pm
by Mulutunnel
An absolutely astonishing picture! Just when I thought all the spectacular near earth views had already been shown us. I wonder if someone could explain a couple of features on it that puzzle me. First, there is what looks like a continent partially covered by the moon at its 1:00 to 3:00 o’clock position. It’s about the same color as N. America and even has what looks like a fairly well focused lake, which is partially obscured by the moon. It can’t be Australia unless the Pacific is only 2,000 miles wide.
Second, I wonder about that curious break in the cloud pattern in the Pacific positioned above the moon. I’ve been looking at satellite photos for decades and I don’t think I’ve ever seen a cloud break that was so artificial looking, made up of right angles and rectangles. Was it necessary to make some sort of alteration to the photo?

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Fri Aug 07, 2015 5:11 pm
by APODFORIST
woody pope wrote:This is a fake. If the earth is lit like it is then the back side of the moon would be as well because the sun is shining on both.
If you compare the surface of the dark side of the moon and the landmass of North America you can see almost the same color and brightness. Bright are the clouds and a bit bright the oceans.

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Fri Aug 07, 2015 5:50 pm
by Chris Peterson
APODFORIST wrote:If you compare the surface of the dark side of the moon and the landmass of North America you can see almost the same color and brightness. Bright are the clouds and a bit bright the oceans.
Here's an albedo map. We're just looking at the brightness, mapped to color (which our eyes are more sensitive to). If we ignore clouds and snow, the Moon and Earth aren't all that different photometrically.
albedo.jpg

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Fri Aug 07, 2015 7:27 pm
by BMAONE23
woody pope wrote:This is a fake. If the earth is lit like it is then the back side of the moon would be as well because the sun is shining on both.
Actually this is a real image rather than a Fake. The Moon is just as brightly lit as the Earth. The WHITE clouds give your eyes the appearance that the Earth is more brightly lit. Consider that the majority of the Lunar Surface is about the color of Fresh Asphalt paving
Like is depicted In this prior APOD about Apollo 17 and Shorty Crater
Click to view full size image
Note the relative darkness of the regolith compared to the White Space Suit

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Fri Aug 07, 2015 7:45 pm
by Ann
Mulutunnel wrote:An absolutely astonishing picture! Just when I thought all the spectacular near earth views had already been shown us. I wonder if someone could explain a couple of features on it that puzzle me. First, there is what looks like a continent partially covered by the moon at its 1:00 to 3:00 o’clock position. It’s about the same color as N. America and even has what looks like a fairly well focused lake, which is partially obscured by the moon. It can’t be Australia unless the Pacific is only 2,000 miles wide.
That is sunlight being reflected by the choppy waves of the Pacific. The Sun is directly above this grayish, non-blue fuzzy patch.

Ann

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Fri Aug 07, 2015 9:08 pm
by geckzilla
It's funny how the things most familiar and closest to us are the things most swiftly declared fake. We've never seen images like this before and yet here we have people telling us how fake it looks. I guess they sit at L1 all day and peer at Earth through their telescope so they should know.

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Fri Aug 07, 2015 11:57 pm
by MarkBour
Mulutunnel wrote:An absolutely astonishing picture! Just when I thought all the spectacular near earth views had already been shown us. I wonder if someone could explain a couple of features on it that puzzle me. First, there is what looks like a continent partially covered by the moon at its 1:00 to 3:00 o’clock position. It’s about the same color as N. America and even has what looks like a fairly well focused lake, which is partially obscured by the moon. It can’t be Australia unless the Pacific is only 2,000 miles wide.
Second, I wonder about that curious break in the cloud pattern in the Pacific positioned above the moon. I’ve been looking at satellite photos for decades and I don’t think I’ve ever seen a cloud break that was so artificial looking, made up of right angles and rectangles. Was it necessary to make some sort of alteration to the photo?
I happened to notice both of the features you did and puzzled about them a bit. Without any other reference, that area does indeed look like a land-mass in the one photo. But if you look at the viewtopic link that bystander posted above (http://asterisk.apod.com/viewtopic.php? ... 30#p246630), in that is a video of a sequence of images (posted by neufer). These images bring out answers to both of your questions. (1) As Ann said, this is the reflection of the Sun. Why it looks "brownish gray", I don't know. The things that look like lakes or inlets on this are actually the shadows of clouds, I believe. (2) Odd as that one cloud opening is, in the movie sequence, it appears less surprising somehow, and towards the end, you can see other unexpected odd shapes appear in that same cloud mass, so I think it is just unusual, but random.

The sequence also shows some additional great stuff. Evidently there was no eclipse anywhere on the Earth from this transit, or I think there would have been a visible shadow in one of the images at least. I'm trying to figure out how one can tell exactly where the Moon's shadow would have passed, if one had enough detail. The Sun's central point of reflection on the face of the Earth should be usable to determine where the Sun is in relation to DSCOVR, Earth, and the Moon, but I wonder how accurately. By my crude measurement, the center of the glint is a little left of center on the circular disk of Earth, so the Sun must be slightly to the left of the point straight behind DSCOVRs EPIC camera. So, I'm getting a guess that seems to go along with what Coil_Smoke guessed above, based on a different piece of evidence.

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Sat Aug 08, 2015 12:36 am
by MarkBour
Just the Moon in Blackness
Just the Moon in Blackness
DSCOVRExcerpt50pct20150716.jpg (65.12 KiB) Viewed 23123 times
So, if we remove the Earth from behind the Moon, it looks brighter, and perhaps this is how the Moon "really looks" in the void of space from a spacecraft. But it still doesn't seem nearly bright enough. Why doesn't it look this way to us on Earth? The Moon on a dark night looks quite radiant and white when high in the sky. Is this image at a lower brightness setting than what our eyes would have seen if we were sitting on DSCOVR?

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Sat Aug 08, 2015 12:48 am
by Chris Peterson
MarkBour wrote:So, if we remove the Earth from behind the Moon, it looks brighter, and perhaps this is how the Moon "really looks" in the void of space from a spacecraft. But it still doesn't seem nearly bright enough. Why doesn't it look this way to us on Earth? The Moon on a dark night looks quite radiant and white when high in the sky. Is this image at a lower brightness setting than what our eyes would have seen if we were sitting on DSCOVR?
Our eye/brain system creates its own white and dark levels which are context dependent. Not only brightness, but color adapts. The Moon looks bright white because our brains tell us that's what it is. It only looks less than white if we have a brighter reference object... which is seldom the case.

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Sat Aug 08, 2015 1:18 am
by Remo
Ann wrote:
maurizio52 wrote:This picture looks like an artifact. The moon is defocused while the earth is sharp ( I think that field depth could not be an issue ;-) ) and the right side of the moon shows green halo of unknown origin...
Best regards.
APOD Robot wrote:
Slight color shifts are visible around the lunar edge, an artifact of the Moon's motion through the field caused by combining the camera's separate exposures taken in quick succession through different color filters.
It's probably not just the Moon that is affected by the color shifts. The Moon's left edge is slightly purple, and the same color effect can be seen along the Earth's left edge. The Moon's right edge is green, and the Earth's might be too, but that is hidden one way or another against the blackness of space.

Ann
Almost, but not quite. Indeed, the Moon's right edge is green and the left edge is purple because of the time delay in between camera exposures; however, the Earth's right edge is blue because we are looking at the edge of the atmosphere ( http://www.spaceflight.nasa.gov/gallery ... 20073.html ). The Earth's right side edge would be blue too, except for the fact that it is in darkness.

The thing is that the Moon is moving with respect to the camera, but the Earth is fixed (it does rotate slightly, however). This is because the Deep Space Climate Observatory satellite orbits at the L1 Lagrange Point: Basically a stable orbit directly between the Earth at the sun. Because the camera is fixed with respect to the Earth, you get the same big ball in the same place each time. Thank you (almost) President Al Gore.

As an aside, I find it interesting that the satellite's position on July 16th was not quite in perfect alignment. This is evidence by both the Moon and the Earth having a dark edge on the right side. Also interesting is that only this slight misalignment/dark edge allowed the green edge artifact to show up. The green filter was shot first. By the time the blue and red filters were shot, the Moon had moved towards the right and those images just recorded black thus allowing the green tint image of the earth below to be superimposed on top of the black Moon edge creating the green edge effect.

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Sat Aug 08, 2015 2:19 am
by ErnieM
Art Neuendorffer wrote:
MadMan wrote:
wolfie138 wrote:
the farside is mostly devoid of dark lunar maria that sprawl across the Moon's perpetual Earth-facing hemisphere

why is that?
I was wondering the same thing. Perhaps the Earth suffered a huge impact, and some of the debris from the Earth impacted the Moon, creating the maria?
It's the mass anomaly from the impact that eventually resulted in the dark lunar maria side permanently facing the Earth.
From current arsenal of scientific instruments available, is it possible to date the huge impact craters on the near side of the moon? This will gives us an estimate of when the dark lunar maria side became permanently facing the Earth. What is the chance that these massive lunar impacts coincided with the one that wiped out the dinosaurs?

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Sat Aug 08, 2015 2:47 am
by Chris Peterson
ErnieM wrote:From current arsenal of scientific instruments available, is it possible to date the huge impact craters on the near side of the moon? This will gives us an estimate of when the dark lunar maria side became permanently facing the Earth. What is the chance that these massive lunar impacts coincided with the one that wiped out the dinosaurs?
Not even close. The craters on the Moon were nearly all produced over a fairly short period early in the formation of the Solar System, a period called the Late Heavy Bombardment.

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Sat Aug 08, 2015 6:02 am
by Ann
Chris Peterson wrote:
MarkBour wrote:So, if we remove the Earth from behind the Moon, it looks brighter, and perhaps this is how the Moon "really looks" in the void of space from a spacecraft. But it still doesn't seem nearly bright enough. Why doesn't it look this way to us on Earth? The Moon on a dark night looks quite radiant and white when high in the sky. Is this image at a lower brightness setting than what our eyes would have seen if we were sitting on DSCOVR?
Our eye/brain system creates its own white and dark levels which are context dependent. Not only brightness, but color adapts. The Moon looks bright white because our brains tell us that's what it is. It only looks less than white if we have a brighter reference object... which is seldom the case.
The Moon looks bright white because our brains tell us that it is? That is a strange explanation.

Unlike the Earth, which is multicolored - mostly white, dark blue and grayish-brown - the Moon is grayish-brown all over, about the same hue as dry earth soil. Some parts of the lunar surface are darker and others are brighter, but they are all more or less the same grayish-brown hue. Therefore, when we look at the Moon on a clear night when it is high in the sky, we don't see color. If we were looking at the Earth while standing on the Moon we would see color, because the Earth is multicolored.
Yuri Gagarin, the first person in space, described the Earth like this:

What beauty. I saw clouds and their light shadows on the distant dear earth.... The water looked like darkish, slightly gleaming spots.... When I watched the horizon, I saw the abrupt, contrasting transition from the earth's light-colored surface to the absolutely black sky. I enjoyed the rich color spectrum of the earth. It is surrounded by a light blue aureole that gradually darkens, becoming turquiose, dark blue, violet, and finally coal black.
But because the the monocolored Moon doesn't offer us any color sensations, we can only judge its brightness, not its hue. And the Moon looks overwhelmingly bright against the black night sky. The magnitude of the full Moon is -12.74. No other object in the night sky comes close to being that bright.

I would say that it is the overwhelming contrast between the illuminated lunar surface and the blackness of the space that makes the Moon look white to us. But since the Earth is brighter than the Moon, mostly because of highly reflective white clouds, the Moon would look "a darker shade of bright" and also probably a little reddish if we could see it in front of the bright multicolored and bluish disk of the Earth.

Ann

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Sat Aug 08, 2015 10:05 am
by hoohaw
I dunno, could of sworn this was Mars.....

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Sat Aug 08, 2015 12:03 pm
by neufer
Chris Peterson wrote:
ErnieM wrote:
From current arsenal of scientific instruments available, is it possible to date the huge impact craters on the near side of the moon? This will gives us an estimate of when the dark lunar maria side became permanently facing the Earth. What is the chance that these massive lunar impacts coincided with the one that wiped out the dinosaurs?
Not even close. The craters on the Moon were nearly all produced over a fairly short period early in the formation of the Solar System, a period called the Late Heavy Bombardment.
https://en.wikipedia.org/wiki/Schreibersite wrote: <<Schreibersite is generally a rare iron nickel phosphide mineral, (Fe,Ni)3P, though common in iron-nickel meteorites. The only known occurrence of the mineral on Earth is located on Disko Island in Greenland. Its color ranges from bronze to brass yellow to silver white. It was named after the Austrian scientist Carl Franz Anton Ritter von Schreibers (1775–1852), who was one of the first to describe it from iron meteorites.

Schreibersite is reported from the Magura Meteorite, Arva-(present name – Orava), Slovak Republic; the Sikhote-Alin Meteorite in eastern Russia; the São Julião de Moreira Meteorite, Viana do Castelo, Portugal; and numerous other locations including the Moon.

In 2007, researchers reported that schreibersite and other meteoric phosphorus bearing minerals may be the ultimate source for the phosphorus that is so important for life on Earth. In 2013, researchers reported that they had successfully produced pyrophosphite, a possible precursor to pyrophosphate, the molecule associated with ATP, a co-enzyme central to energy metabolism in all life on Earth. Their experiment consisted of subjecting a sample of schreibersite to a warm, acidic environment typically found in association with volcanic activity, activity that was far more common on the primordial Earth. They hypothesized that their experiment might represent what they termed "chemical life", a stage of evolution which may have led to the emergence of fully biological life as exists today.>>

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Sat Aug 08, 2015 2:47 pm
by Chris Peterson
Ann wrote:
Chris Peterson wrote:Our eye/brain system creates its own white and dark levels which are context dependent. Not only brightness, but color adapts. The Moon looks bright white because our brains tell us that's what it is. It only looks less than white if we have a brighter reference object... which is seldom the case.
The Moon looks bright white because our brains tell us that it is? That is a strange explanation.
But it's the case. Color is a physiological property, not a physical one. Color is a combination of both hue and brightness (that is, we see exactly the same hue, presented at two brightness levels, as distinctly different colors). And our perception of color is relative and adaptive. Put on a pair of colored glasses, and within a few minutes you'll be seeing things substantially the same as you did without the glasses.

The Moon is a low saturation object, and we see low saturation objects as neutral hued in the absence of anything to compare them to. And against a dark sky, our brain chooses "white" rather than "gray", because there is nothing to compare it to. This effect commonly disappears in photographs, because we usually see the surrounds of the image, providing a reference for both brightness and hue.

This APOD provides a color reference for the Moon- both hue and intensity- so we get a more accurate representation of its actual nature than we can ever get against the night sky.

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Sat Aug 08, 2015 3:21 pm
by BMAONE23
Take a "White" piece of paper and cut a Dime sized hole in it. Hold it at arms length so that the Moon is in the "Hole" in the paper. Now shine a White Light on the paper and look just how "DARK" the moon really looks

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Sat Aug 08, 2015 3:48 pm
by Eleanor S
Above and to the left of the moon, within the circle of the earth, is a geometric shape. What is it?

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Sat Aug 08, 2015 7:42 pm
by chuckster
keeper of the faith wrote:You can easily see this is not the Moon for yourself. All you need to do is go out and look at the real Moon. Looks nothing like this. :x
Keeper of what faith ?

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Sat Aug 08, 2015 9:09 pm
by jambo
I thought some one would have corrected the discussion by now--it's the repeat of Friday's APOD, rather than Saturday's view of Mars...

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Sat Aug 08, 2015 10:34 pm
by alter-ego
jambo wrote:I thought some one would have corrected the discussion by now--it's the repeat of Friday's APOD, rather than Saturday's view of Mars...
I'm not sure what your saying. Friday's and Saturday's APODs are distinct; Earth and Mars respectively. Having issues with links maybe?

Re: APOD: Full Moon, Full Earth (2015 Aug 07)

Posted: Sat Aug 08, 2015 10:46 pm
by owlice
alter-ego, the "Discuss" link on the APOD page points to the wrong discussion, is all; for today's APOD, it points to yesterday's discussion.