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Is the sky is black viewed from the Moon and cislunar space?


spartan45

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Neil Armstrong talks to Patrick Moore on The Sky At Night, BBC 1970 (UTube):

PM  Mr Armstrong I do realize that when you were on the surface of the Moon you had very little time for gazing upwards but could you tell us something about what the sky actually looks like from the Moon – the Sun, the Earth and the stars if any and so on?

NA The sky is deep black when viewed from the Moon as it is when viewed from cisluna space, the space between the Earth and the Moon. The Earth is the only visible object other than the Sun that can be seen although there have been some reports of seeing planets I myself did not see planets from the surface but I suspect they might be visible.

Apollo 14 astronaut Dr Edgar Mitchell is quoted in an interview by Sarah E Truman, Ascent Magazine editor, first Canadian Yoga magazine, copyright 2007 (ref Google) as follows:  

SET  In 1971, as you pulled away from the Moon and made your way back to Earth, what did it feel like to be in the space between worlds?
EM  I’ll have to set up the story for you just a little bit. The spacecraft was oriented perpendicular to the plane that contains the Earth, the Moon and the Sun. Not flying perpendicular to that plane – but moving through it back to Earth. The spacecraft was rotating to maintain the thermal balance of the Sun. What that caused to happen was that every two minutes, with every rotation, we saw the Earth, the Moon and the Sun as they passed by the window. The 360-degree panorama of the heavens was awesome and the stars are ten times as bright and, therefore, ten times as numerous than you could ever see on a high mountaintop on a clear night. It was overwhelmingly magnificent.

 

So there seems to be a conflict about seeing stars in space. What’s more I have recently read that Apollo 11 was also rotated to prevent thermal stress (Google), confirming similar conditions between the Apollo’s. Also stars are used for navigation – see below: 

From 13 things that saved Apollo 13, part 6: Navigating by Earth’s terminator – by Nancy Atkinson April 16, 2010 (Google):If the ship’s guidance computer should fail the astronauts needed to use an on-board sextant to confirm their location by sighting-in the stars, similar to how ancient sailors navigated. “There are thirty-seven stars – and one is the sun,” said Apollo engineer Jerry Woodfill, “that provided an accurate way of aligning the spacecraft’s computer platform to allow the astronauts to steer their way through the heavens.” But the explosion of the tank had enshrouded the Apollo 13 spacecraft with debris. Commander Jim Lovell and his crew couldn’t discern the stars from the particles that glimmered in the sunlight. “The situation was, without the ability to see the stars, you couldn’t navigate,” Woodfill said.
 

Space Sextant - Date manufactured: 1960's, Kollsman Instrument Company (Google) Description: Between December 1968 and December 1972, a total of nine Apollo spacecraft carried human crews away from the Earth to another heavenly body. Primary navigation for these missions was done from the ground. As a backup, and for segments of the mission where ground tracking was not practical, an on-board inertial navigation system was used. Astronauts periodically used a sextant to sight on stars and the horizons of the Earth and Moon to align the inertial system, and to verify the accuracy of the Earth-based tracking data.

Recently I was having a discussion with a retired JPL engineer at a space exhibition about the Sky At Night 1970 interview. It was suggested not seeing stars side stepped any further questions regarding seeing lights outside the window. As we talked an agitated passerby butted in saying “Those lights were caused by cosmic rays generating flashes behind the eyes” The conversation abruptly ended, but my interest in the 1970 interview has been fuelled. 1. Can you see stars from space craft windows as easily as you can see stars when driving a car (even in the presence of approaching headlights)? Or does the Sun’s glare/surface reflection effectively turn the sky deep black. 2. Would viewing through a matt black tube allow seeing stars from the Moon’s surface?

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I suspect that the problem was in fact that they landed on the moon in the lunar day.

They also landed on the near side of the moon.

This will have given them the double whammy of light pollution from both the earth and sun. The lunar surface will have been very bright and they had reflective visors to prevent them going blind.

If you landed on the far side of the moon at night then it would be incredibly dark and allow you to see very faint stars indeed.

The photos wouldn't have come out so well then though ;)

Sent from my iPad using Tapatalk

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Neil Armstrong talks to Patrick Moore on The Sky At Night, BBC 1970 (UTube):

PM  Mr Armstrong I do realize that when you were on the surface of the Moon you had very little time for gazing upwards but could you tell us something about what the sky actually looks like from the Moon – the Sun, the Earth and the stars if any and so on?

NA The sky is deep black when viewed from the Moon as it is when viewed from cisluna space, the space between the Earth and the Moon. The Earth is the only visible object other than the Sun that can be seen although there have been some reports of seeing planets I myself did not see planets from the surface but I suspect they might be visible.

Had he been able to shield himself from all the light around (Sun, Earth and the sunlit moonscape), he would have seen as much in the sky as the astronauts could from the spaceship.

The sky on the Moon is very black indeed and filled with stars, but bright lights make the pupil contract. That makes it hard to see weaker sources like stars or planets. A better time to view the stars would be during the lunar night. A better place to view the stars on the Moon would be on the far side, so you're not bothered by a dazzlingly bright Earth.

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Cameras and eyes simply reduce in aperture when in any well lit condition - dim red torches are used when observing for this reason - the sun light on the moon is not attenuated so will be very intense, you cannot look at the sun when stood on the earth with about 100Km of air reducing the intensity, thye moon has no atmosphere so very intense.

If it were not for scattering in our atmosphere we would likely have a black sky.

I suspect they couldn't use a sextant as they need a fairly wide view, I don't think the Apollo craft were fitted with panoramic windows. Also a classic sextant uses the earths horizon, which they didn't have when half way to the moon.

If you cannot see stars in space then how does Hubble, Chandra, Spitzer, Gaia and the James Webb scopes do anything?

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