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One question: In this picture, the Moon is between Earth and Sun. The camera is between Moon and Sun. Now, the Sun is illuminating both Moon and Earth. Should not the Moon be seen brighter than Earth; the Moon is closer to the Sun, and hence more brightly illuminated. However, the Moon is seen as dull, and the Earth as bright.
Can this apparent brightness of Earth be attributed to the blue water all around? Whereas Moon is without water, and may be absorbing more light than it reflects?
Is something not correct in the above argument?
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Avijnata wrote: Can this apparent brightness of Earth be attributed to the blue water all around? Whereas Moon is without water, and may be absorbing more light than it reflects?
The reflectiveness of a planet or moon is called its Albedo. If it reflected nothing, it would have an albedo of 0; if it reflected everything, it would have an albedo of 1. The Earth has an albedo of 0.37 whereas the full moon has an albedo of 0.12. So, the Earth reflects about 3 times as much of the light as the moon does. That is why it is brighter in the picture. Your guess that it is the water (but includes clouds as well as oceans) that are the main reflecting agents is correct; on the moon you only have the surface dust etc (called the regolith).
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Very nicely explained. Thanks.
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Quote: The reflectiveness of a planet or moon is called its Albedo
"planets or moon" only? No, sorry, Albedo is much more General
modified 19-Jan-21 21:04pm.
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Well, yeah.
But it's really difficult to measure the albedo of a star or black hole...
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
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Of a star not really, of a black hole yes...very difficult where limes likes to go
modified 19-Jan-21 21:04pm.
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It's probably the other way round: Albedo of a black hole[^]
But a star? The light emitted is so huge that it's going to be really difficult to spot the reflection, even if the star emitting it is pretty close!
That's my guess, anyway.
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
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Yes I agree. But fact is Albedo of stars are Facts, Albedo of black hole are theory, at this time. Also looking Forward to really prove the later ones
Not really the final explanation, but also not the worst one, for an overview good enough:
https://en.wikipedia.org/wiki/Albedo[^]
modified 19-Jan-21 21:04pm.
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Very good answer, the only thing is that clouds typically have a far greater albedo than the oceans.
Cheers,
विक्रम
"We have already been through this, I am not going to repeat myself." - fat_boy, in a global warming thread
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So does the Moon absorb more energy than the Earth. We know it doesn't so what happens?
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I think if remember the moons actual colour is a sort of dirty grey rather than the yellow commonly associated with it. I seem to remember there was a Mythbusters episode devoted to it. the reoglith does reflect at an angle to seem bright or something!
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glennPattonBackInThePUB wrote: the moons actual colour is a sort of dirty grey
Yes, we saw that in the moon landing video. Everythnig's grey up there.
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Yup, but as I recall the 'video' cameras were black & white
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That's all they had to be.
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Point, mind you a neighbour of my parents bought a colour TV to see it!
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Maybe to see Louis Armstrong?
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I also think you are imagining the Sun as being much closer to us than it is.
The Moon is a bit more than a light second away from us.
The distance to the Sun is eight light MINUTES, or 500 times as great.
So the Moon was one fifth of a percent, a factor of 0.002, closer to the Sun when the image was taken than Earth was. I think you'd be hard pressed to notice the effect of this difference even if the two bodies had exactly the same albedo.
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Yes, you're right. Agree.
But, does the position of the camera also count, in whatever small way? The camera is closer to the Moon than to the Earth. My answer would be: Keeping a much brighter object farther away from the camera would register more on camera film than a dull object kept closer.
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Well, I'm not exactly building a model car, but I need some parts which can most probably be obtained from a model car.
This[^] is a replica of the helicopter which picked up the astronauts after the Apollo missions 8, 10, 11, 12 and 13. Our Member Coder (Hired) was so friendly to make a ton of pictures of the helicopter in San Diego for me.
It's not going to be a model that collects dust on a shelf. In the last months spent some time on building the mechanical part, based on the frame of a T-Rex 450 eith a raised tail, the tail rotor on the left side and a five blade rotor head. The tail rotor itself will not be accurate, as there are none available for a helicopter of this size. Here is a picture[^]. It still sits on normal landing skids for its first flights, still without the model body.
The parts of the body are made of vacuum formed plastic and show no detail at all. Stuff like antennae, petot tubes, turbine intakes and exhausts, hatches or windows I will have to model myself or get from other models.
Now what could I possibly need parts of a model car for? Please look at this picture.[^] It was taken after the recovery of the Apollo 11 astronauts and you can clearly see that the helicopter has windscreen wipers and rear view mirrors very much like a truck. The scale of the model will be 1:24, wich is very common for model cars.
Does aybody know how to locate similar looking parts, preferrably without having to buy a model of a Peterbilt and throwing everything else away?
The language is JavaScript. that of Mordor, which I will not utter here
This is Javascript. If you put big wheels and a racing stripe on a golf cart, it's still a f***ing golf cart.
"I don't know, extraterrestrial?"
"You mean like from space?"
"No, from Canada."
If software development were a circus, we would all be the clowns.
modified 8-Aug-15 4:48am.
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A rare guest here nowadays, let's hope he reads this.
The language is JavaScript. that of Mordor, which I will not utter here
This is Javascript. If you put big wheels and a racing stripe on a golf cart, it's still a f***ing golf cart.
"I don't know, extraterrestrial?"
"You mean like from space?"
"No, from Canada."
If software development were a circus, we would all be the clowns.
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You can try to catch his attention using the "@" + "John-Simmons-outlaw-programmer" as it is said in his profile.
That will give him a notification like "your name was used in a conversation" or "you were mentioned in a conversation"
Example: @CDP1802
M.D.V.
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpful answers is nice, but saying thanks can be even nicer.
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Ahh, great! Thanks, let's try that.
@John-Simmons-outlaw-programmer
Please take a look at my post at the beginning of the thred and let me know if you have any idea whwere I can look for 1:24 scale parts.
And now I'm going to grab a bag full of charged batteries and the T-Rex 550 and head out to the airfield.
The language is JavaScript. that of Mordor, which I will not utter here
This is Javascript. If you put big wheels and a racing stripe on a golf cart, it's still a f***ing golf cart.
"I don't know, extraterrestrial?"
"You mean like from space?"
"No, from Canada."
If software development were a circus, we would all be the clowns.
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You are welcome, but don't abuse the "@"... he is also known to be a big friend of weapons
M.D.V.
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpful answers is nice, but saying thanks can be even nicer.
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