APOD: Apollo 16: Driving on the Moon (2013 Jan 29)

[SouthEastAsia]

I realize that the particular exposure setting of this camera apparently was unable to allow recording of background stars, but what did the naked eye see of these astronauts actually see from their perspective? Is the condition from the Moon surface one which makes seeing stars in outer space actually difficult, eg, the Sun's reflective light acting as a giant source of light pollution? Or would humans see a brilliant star-light sky? How about a the naked eye view from the dark side of the Moon? Would there be a dramatic difference in the look of the background sky? Thanks.

[neufer]

Click to play embedded YouTube video.

I realize that the particular exposure setting of this camera apparently was unable to allow recording of background stars, but what did the naked eye see of these astronauts actually see from their perspective? Is the condition from the Moon surface one which makes seeing stars in outer space actually difficult, eg, the Sun's reflective light acting as a giant source of light pollution? Or would humans see a brilliant star-light sky? How about a the naked eye view from the dark side of the Moon? Would there be a dramatic difference in the look of the background sky? Thanks.

[pyrosmile]

why are there no stars in the dark sky?

[Chris Peterson]

How about a the naked eye view from the dark side of the Moon? Would there be a dramatic difference in the look of the background sky? Thanks.

It wouldn't look much different than the sky at a dark location on Earth. At most, you'd see about a magnitude deeper, but you'd also lose some by looking through your helmet.

[neufer]

How about a the naked eye view from the dark side of the Moon? Would there be a dramatic difference in the look of the background sky? Thanks.

It wouldn't look much different than the sky at a dark location on Earth. At most, you'd see about a magnitude deeper, but you'd also lose some by looking through your helmet.

• Ideally one would flip the gold visor up at night.

<<I have donned a shuttle EMU...or at least the upper torso, "Snoopy cap" and helmet assembly. With the gold visor down the view out was akin to wearing silvered sunglasses on a sunny day; no discernible change in colours or hues just darker.>>

During the day, sunshine, earthshine, moonshine and/or LEMshine are almost bound to leak into the large visor and bounce around making for a little night light inside your helmet. One would have to see the stars through the reflection of one's own lit up face.

[owlice]

why are there no stars in the dark sky?

It was daytime on the moon. How many stars do you see in the sky during the day?

[bystander]

How many stars do you see in the sky during the day?

One, if it's not cloudy!

[Chris Peterson]

why are there no stars in the dark sky?

It was daytime on the moon. How many stars do you see in the sky during the day?

Yes, but that's mainly because of the scattered light in the atmosphere. You can see stars quite easily during the lunar daytime. All you need to do is raise your Sun visor, stand in the shade, and avoid having too many bright foreground objects in view.

[neufer]

You can see stars quite easily during the lunar daytime. All you need to do is raise your Sun visor, stand in the shade, and avoid having too many bright foreground objects in view.

With the visor up there is even more opportunity for sunshine, earthshine, moonshine or LEMshine to enter the astronauts helmet un-dilate his eyes and light up his face so as to reflect off of his clear plastic visor. One may or may not figure out how to see stars this way but it sure wouldn't be easy.

[Beyond]

You can see stars quite easily during the lunar daytime. All you need to do is raise your Sun visor, stand in the shade, and avoid having too many bright foreground objects in view.

With the visor up there is even more opportunity for sunshine, earthshine, moonshine or LEMshine to enter the astronauts helmet un-dilate his eyes and light up his face so as to reflect off of his clear plastic visor. One may or may not figure out how to see stars this way but it sure wouldn't be easy.

I should think that one would see lots of stars when doing that. Right before passing out for lack of air

[Chris Peterson]

With the visor up there is even more opportunity for sunshine, earthshine, moonshine or LEMshine to enter the astronauts helmet un-dilate his eyes and light up his face so as to reflect off of his clear plastic visor. One may or may not figure out how to see stars this way but it sure wouldn't be easy.

I'm not so sure about that. FWIW dilation of the pupils only plays a small role in dark adaptation. Most of the effect is retinal.

[DavidLeodis]

It's a fascinating video. Did though whoever wrote the text in the information brought up through the "shows" link in the "second half shows" have to use that f-word derivative. I accept that was not done by the APOD editors (I hope not!) and so could probably not be edited out without permission, but the use of that offensive word (it is to me) was unnecessary.

[BMAONE23]

I realize that the particular exposure setting of this camera apparently was unable to allow recording of background stars, but what did the naked eye see of these astronauts actually see from their perspective? Is the condition from the Moon surface one which makes seeing stars in outer space actually difficult, eg, the Sun's reflective light acting as a giant source of light pollution? Or would humans see a brilliant star-light sky? How about a the naked eye view from the dark side of the Moon? Would there be a dramatic difference in the look of the background sky? Thanks.

Consider this, regardless of how White the moon appears in the night sky, it is really a dark body. The surface is about the color of a paved parking lot. The next time you go to the store at night (presumably the parking lot is lit), the surface of the lot is similar in color to the surface of the moon. The reflected light will be lesser than the power of the reflected sunlight though. While there, basking in the glow of the reasonably well lit parking lot, look up at the night sky. The night sky is full of stars but how many (10s) do you see?

[neufer]

With the visor up there is even more opportunity for sunshine, earthshine, moonshine or LEMshine to enter the astronauts helmet un-dilate his eyes and light up his face so as to reflect off of his clear plastic visor. One may or may not figure out how to see stars this way but it sure wouldn't be easy.

I'm not so sure about that. FWIW dilation of the pupils only plays a small role in dark adaptation. Most of the effect is retinal.

[b][color=#0000FF]Helmet designed for easily observing stars on the moon.[/color][/b]

---

<<The surface brightness of the lunar surface during lunar day (and the astronauts only landed on sections in the middle of the two-week lunar day) is as bright as that of an area with similar geology (dark rocks) on the Earth. If one is looking across the lunar landscape, a large part of one's field of view is filled with the extremely bright, glare-inducing landscape. The pupil contracts, and more importantly, the light-sensing chemical rhodopsin is bleached to low levels, adjusting the eye's sensitivity to the bright ambient conditions (this latter factor is responsible for the eye's extraordinary dynamic range, far beyond what the pupil alone can accommodate).

Furthermore, even if looking up through a helmeted spacesuit, parts of the interior of the helmet will be illuminated by the bright landscape and/or the Sun itself. Reflections off the interior of the helmet window will add, not to the external sky background, but to the perceived overall visual background.

One would have to find a large shaded area and furthermore shield one's helmet carefully from all external bright landscape to reduce this background light. And even then, to properly appreciate the stars, it would take several minutes for the retina's rods to rebuild their rhodopsin levels to the levels appropriate for night vision. Try walking from a brilliantly lit room (and a brilliantly lit room has nowhere near the brightness of daylight in most cases) directly outdoors at night, and see how many stars you can count. Not many. Perhaps Armstrong experienced something similar.

Theoretically, the stars are there to be seen. Practically, the astronauts were not equipped with external shade, appropriate sun glare shields on their helmets, or the leisure time to sensitize their eyes to faint starlight on those very busy lunar excursions.>>

[Chris Peterson]

Theoretically, the stars are there to be seen. Practically, the astronauts were not equipped with external shade, appropriate sun glare shields on their helmets, or the leisure time to sensitize their eyes to faint starlight on those very busy lunar excursions.>>

That's really the point: the Apollo astronauts were not well equipped for viewing the stars (why would they have been?), and didn't have the time to explore the limits of their vision.

But if we had astronauts more regularly on the Moon, doing more routine work for longer periods (if we had a moon base, for instance), there's no reason at all to think they wouldn't readily see stars during the daytime. Without atmospheric scatter, it's simply a matter of blocking the eyes from direct glare, which is easy. And dark adaptation isn't a problem- even with fully daylight adapted eyes, we can easily see quite a few of the brighter stars.

We should not make the mistake of using the experience of the Apollo astronauts to form our understanding of what is possible or even likely under different circumstances.

[geckzilla]

It's a fascinating video. Did though whoever wrote the text in the information brought up through the "shows" link in the "second half shows" have to use that f-word derivative. I accept that was not done by the APOD editors (I hope not!) and so could probably not be edited out without permission, but the use of that offensive word (it is to me) was unnecessary.

Offensive to you, common language to others. It was not used in a way intended to offend you so you should probably ease up a bit. The f-word is an amazingly diverse word! I used to view it with disdain as well but it's grown on me. It's an utterance of such emotion. Excitement, fear, grief, anger, whatever you feel like... all wrapped in one convenient four-letter, monosyllabic package. It's hard to find a more efficient word.

[DavidLeodis]

It's a fascinating video. Did though whoever wrote the text in the information brought up through the "shows" link in the "second half shows" have to use that f-word derivative. I accept that was not done by the APOD editors (I hope not!) and so could probably not be edited out without permission, but the use of that offensive word (it is to me) was unnecessary.

Offensive to you, common language to others. It was not used in a way intended to offend you so you should probably ease up a bit. The f-word is an amazingly diverse word! I used to view it with disdain as well but it's grown on me. It's an utterance of such emotion. Excitement, fear, grief, anger, whatever you feel like... all wrapped in one convenient four-letter, monosyllabic package. It's hard to find a more efficient word.

I notice concerning the f-word you "used to view it with disdain" but that it has "grown on" you. Fair enough therefore that you now have no bother with f-words, but I do and so I shall not "ease up" and have no intention of gratuitously using them in speech nor print. I accept that in times of such as shock or under stress that the use of f-words can be expected and that then causes me no bother. I certainly did however not expect to see one in a report brought up through a link in an APOD explanation. We clearly differ in our feelings of when it is and is not OK to use f-words.

[BMAONE23]

We recently rented (on demand) Jake Gyllenhaal's latest movie "End of Watch" where he portrays a cop in West LA.
Watched for about 10 minutes but never finished it... Way to many F-bombs. Probably every 10th word of dialogue was an F-bomb. It is hard to enjoy a story when every sentence contains a word we try to teach our children not to use. To me, they are the words of ignorance.
If an ignorant person cannot impress other people with their witty repartee, they shock them with profanity.

[Chris Peterson]

Offensive to you, common language to others. It was not used in a way intended to offend you so you should probably ease up a bit. The f-word is an amazingly diverse word! I used to view it with disdain as well but it's grown on me. It's an utterance of such emotion. Excitement, fear, grief, anger, whatever you feel like... all wrapped in one convenient four-letter, monosyllabic package. It's hard to find a more efficient word.

I notice concerning the f-word you "used to view it with disdain" but that it has "grown on" you. Fair enough therefore that you now have no bother with f-words, but I do and so I shall not "ease up" and have no intention of gratuitously using them in speech nor print.

I don't believe she said that she has "no bother" with the word, but rather that she sees it as a word which, in the proper context, is acceptable and appropriate to use.

I agree. To eschew a word simply because it exists, without considering context, seems to me rather immature. And let's not forget that ideas about usage are highly regional. That word is not universally considered particularly bad by English speakers. It is not an expletive at all in many subcultures, and even in British English the word is considered only a mild expletive in most cases. Of course, there are also words that are quite offensive to speakers of British English that most Americans wouldn't think twice about.

Analogous to the concept of seven degrees of separation, I doubt that any site on the Internet is more than a few clicks away from the hardest core pornography, let alone from a site with a word some might find offensive. I think it is sufficient that the APOD editors maintain their own site as scrupulously family-friendly (which they do) without overly concerning themselves with minor issues of language choice on linked sites that otherwise are very appropriate in terms of their related content.

[geckzilla]

We recently rented (on demand) Jake Gyllenhaal's latest movie "End of Watch" where he portrays a cop in West LA.
Watched for about 10 minutes but never finished it... Way to many F-bombs. Probably every 10th word of dialogue was an F-bomb. It is hard to enjoy a story when every sentence contains a word we try to teach our children not to use. To me, they are the words of ignorance.
If an ignorant person cannot impress other people with their witty repartee, they shock them with profanity.

But it's not shocking at all to other people, nor is it meant to be shocking, I think. I mean, once upon a time, sure, there was a time when the word wasn't used in movies and I'm sure that first drop was shocking and probably intentionally so but with the internet, globally available media, and general relaxation on the topic I think we're past that. A cop in west LA? Every ten words sound about right. I agree though, I'd rather hear something witty than some visceral street language. But it wouldn't be simply because of the word. They could go without using it and one-dimensional character archetypes still grate on me, particularly if it's supposed to be a thriller or action flick (I've never seen End of Watch, it may or may not warrant this criticism). One can be very witty and still use plenty of profanity. Several British comedies prove that.

My thoughts are harmonious with Chris's on this matter.

[Ann]

I don't appreciate the f-word, and I would never use it myself. I don't think it is allowed to use it here at Starship Asterisk*, for which I'm grateful.

Ann

[geckzilla]

Interestingly, I think the profanity filter has had more false positives than real catches. I've considered removing it but it was here before I became an admin so I just left it. There are private places, like PM's and such where I would happily express myself with profanity at times...

[BMAONE23]

We recently rented (on demand) Jake Gyllenhaal's latest movie "End of Watch" where he portrays a cop in West LA.
Watched for about 10 minutes but never finished it... Way to many F-bombs. Probably every 10th word of dialogue was an F-bomb. It is hard to enjoy a story when every sentence contains a word we try to teach our children not to use. To me, they are the words of ignorance.
If an ignorant person cannot impress other people with their witty repartee, they shock them with profanity.

But it's not shocking at all to other people, nor is it meant to be shocking, I think. I mean, once upon a time, sure, there was a time when the word wasn't used in movies and I'm sure that first drop was shocking and probably intentionally so but with the internet, globally available media, and general relaxation on the topic I think we're past that. A cop in west LA? Every ten words sound about right. I agree though, I'd rather hear something witty than some visceral street language. But it wouldn't be simply because of the word. They could go without using it and one-dimensional character archetypes still grate on me, particularly if it's supposed to be a thriller or action flick (I've never seen End of Watch, it may or may not warrant this criticism). One can be very witty and still use plenty of profanity. Several British comedies prove that.

My thoughts are harmonious with Chris's on this matter.

I can only think of 1 appropriate use of the word and that is in the heat of passion and usually accompanied by the word Me

[geckzilla]

How uncreative.

[neufer]

Click to play embedded YouTube video.