persephone8
Chrono Cadet
Hi all,
Awhile back, Rainman Time was explaining to me why there were no stars in the backgrounds of pictures taken of the astronauts on the moon. This is what he said:
<font color="blue">No stars in the pictures? The first thing we need to understand is the "state of the art" in video recording devices of today are WAY WAY WAY more sensitive to light than what we had back in the 1960s. When you don't have a high gain (sensitivity) in the camera electronics, you have problems with noise (and those videos from the Moon are clearly noisy). To prevent the noise levels of outer space from saturating the picture, thereby making it useless, they set the "noise floor" of the video devices fairly high. That means faint/dim objects (especially those in a continuous field of black) would not show up on the final video output. But that is not the only piece of science to explain lack of stars in the pictures...there is another piece. We know that we have an atmosphere here on earth, where there is none on the Moon. And we know that our atmosphere has refractive properties, such that it alters light that passes through it. In actuality, it MAGNIFIES objects that pass through it. This is why the moon looks so much bigger on the horizon than it does straight overhead: That light is passing through a larger length of atmosphere when you are viewing it on the horizon. Our atmosphere makes it easier to see stars and planets that are closer to us (but it also distorts them somewhat). Now go to the Moon. No atmosphere means no refractive properties that could potentially enlarge the view of stars. Add them together... a reasonable scientific explanation for no stars in the pictures.
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His explanation seemed reasonable to me.
But then I thought, what about the Hubble telescope. It is able to see farther and clearer because it is farther up in our atmosphere?
Is it because Hubble is not an optic telescope? Is it a radar telescope? Does that exlain that?
The Appropriateness of Chance is Astounding
Persephone
"There are great ideas undiscovered, breakthroughs available to those who can remove one of truth's protective layers" by Neil Armstrong
Awhile back, Rainman Time was explaining to me why there were no stars in the backgrounds of pictures taken of the astronauts on the moon. This is what he said:
<font color="blue">No stars in the pictures? The first thing we need to understand is the "state of the art" in video recording devices of today are WAY WAY WAY more sensitive to light than what we had back in the 1960s. When you don't have a high gain (sensitivity) in the camera electronics, you have problems with noise (and those videos from the Moon are clearly noisy). To prevent the noise levels of outer space from saturating the picture, thereby making it useless, they set the "noise floor" of the video devices fairly high. That means faint/dim objects (especially those in a continuous field of black) would not show up on the final video output. But that is not the only piece of science to explain lack of stars in the pictures...there is another piece. We know that we have an atmosphere here on earth, where there is none on the Moon. And we know that our atmosphere has refractive properties, such that it alters light that passes through it. In actuality, it MAGNIFIES objects that pass through it. This is why the moon looks so much bigger on the horizon than it does straight overhead: That light is passing through a larger length of atmosphere when you are viewing it on the horizon. Our atmosphere makes it easier to see stars and planets that are closer to us (but it also distorts them somewhat). Now go to the Moon. No atmosphere means no refractive properties that could potentially enlarge the view of stars. Add them together... a reasonable scientific explanation for no stars in the pictures.
[/COLOR]
His explanation seemed reasonable to me.
But then I thought, what about the Hubble telescope. It is able to see farther and clearer because it is farther up in our atmosphere?
Is it because Hubble is not an optic telescope? Is it a radar telescope? Does that exlain that?
The Appropriateness of Chance is Astounding
Persephone
"There are great ideas undiscovered, breakthroughs available to those who can remove one of truth's protective layers" by Neil Armstrong
