APOD: Moonquakes Surprisingly Common (2010 Oct 10)

[dogcroucher]

This question's intrigued me for some time: why is the flag "flying?" Shouldn't it be hanging languidly on its staff, or sort of flopping downward in the low gravity? Did they starch it to extend outward rigidly? I assume they must have done something to make it "fly" so, for the pictures. Is it some super-thin mirco film that "flies" in the solar wind? There isn't enough atmosphere there to make any other kind of wind, right?

Is there any information on how they anticipated this problem and the solutions they considered?

[Chris Peterson]

This question's intrigued me for some time: why is the flag "flying?" Shouldn't it be hanging languidly on its staff, or sort of flopping downward in the low gravity? Did they starch it to extend outward rigidly? I assume they must have done something to make it "fly" so, for the pictures. Is it some super-thin mirco film that "flies" in the solar wind? ;) There isn't enough atmosphere there to make any other kind of wind, right?

Is there any information on how they anticipated this problem and the solutions they considered?

There is a rod running across the top of the flag, so it stays extended. They did, indeed, anticipate the problem and deal with it (in order to get nice PR photographs, of course- it is important to remember that going to the Moon was only partly about the science). The flags are made of Nylon, and are ordinary, commercially available flags ordered by NASA from a flag company. Nothing special, except for the support system.

There are film segments all over the Web showing these flags being planted, and you can see from the way they move how the flags are actually constructed.

[dogcroucher]

This question's intrigued me for some time: why is the flag "flying?" Shouldn't it be hanging languidly on its staff, or sort of flopping downward in the low gravity? Did they starch it to extend outward rigidly? I assume they must have done something to make it "fly" so, for the pictures. Is it some super-thin mirco film that "flies" in the solar wind? There isn't enough atmosphere there to make any other kind of wind, right?

Is there any information on how they anticipated this problem and the solutions they considered?

[bystander]

I don't think this was staged. http://en.wikipedia.org/wiki/File:NASA- ... thrise.jpg

Obviously photoshopped!

[nz1m]

Just above the lunar seismometer is an angle'd white "box." I'm assuming this is the packet of corner cube retro reflectors deployed about all the landing sites? An earthbound laser would target the retroreflectos for several reasons. First, to time the light's return to accurately measure the moon's max and minimum orbital distance. Next to more precisely map the landing locations.

[orin stepanek]

I don't think this was staged. http://en.wikipedia.org/wiki/File:NASA- ... thrise.jpg

Obviously photoshopped!

I'm not the handiest with photo shop; though my son is. I'd have to ask him. But; lets see. You'd have to paste in the Lunar landscape; paste in the photo of the Earth; but wait;-- you have to be in outer space to get that photo!?!?!?? How do they do that.

[JuanAustin]

thanks chris, so....what you are saying to my original question is that universal time will be the convention used everywhere everywhen, no matter if you're on the earth's moon or jovian moon or all points in between? if so, what time would it be if someone asked you or you were following some protocol somewhere that you needed to measure time/day? would they be Star Trek like or what exactly?

[Chris Peterson]

thanks chris, so....what you are saying to my original question is that universal time will be the convention used everywhere everywhen, no matter if you're on the earth's moon or jovian moon or all points in between? if so, what time would it be if someone asked you or you were following some protocol somewhere that you needed to measure time/day? would they be Star Trek like or what exactly?

Not everywhere. If we had a colony on Mars, I'd expect its time to be based on the Martian day (the sol). That's because Mars rotates once every 24.6 hours, so it makes perfect sense to break the day up into 24 mars-hours, each with 60 mars-minutes of 60 mars-seconds. That's only for civil time, of course, like when people get up, go to work, eat, go to bed. You wouldn't use mars-seconds for anything critical; the standard second would still be used as the basis for any critical timekeeping.

In general, if your environment has a natural diurnal cycle near 24 hours, it makes sense to develop a local time system. Otherwise, you need an artificial system in any case, so you might as well use Earth's, in which case UT probably makes the most sense (although the time zone of the command base on Earth might make sense, too).

[noki]

Where are the stars in the sky? There are NO stars or planets visible in the photo!

I know there is bright sunlight, but there is no atmosphere on the moon... shouldn't you be able to see the stars?

[Ann]

Where are the stars in the sky? There are NO stars or planets visible in the photo!

I know there is bright sunlight, but there is no atmosphere on the moon... shouldn't you be able to see the stars?

No. Absolutely not. If there had been stars visible in the sky, then the picture would definitely have been photoshopped.

It's broad daylight in this picture. Yes, the sky is black as it always is on the Moon, but the contrasts between light and darkness are extremely glaring, almost blinding. It is impossible to see stars under such conditions. The camera can't see stars either, not under the conditions that the photo was acquired. Remember that an astroimages that show stars in the sky have usually been "gathering light" for minutes or longer. The photo of Buzz Aldrin was probably taken in less than a second.

Ann

[mexhunter]

These photos always evoke memories of the event.

Only for those of us old enough to remember the event!

Click to view full size image

It is a cover of collection, in very short time it will have 50 years.
Treat it with care.
Many greetings
César

[bystander]

I'm not the handiest with photo shop; though my son is. I'd have to ask him. But; lets see. You'd have to paste in the Lunar landscape; paste in the photo of the Earth; but wait;-- you have to be in outer space to get that photo!?!?!?? How do they do that.

With that massive rocket you saw.

Click to play embedded YouTube video.

[orin stepanek]

I'm not the handiest with photo shop; though my son is. I'd have to ask him. But; lets see. You'd have to paste in the Lunar landscape; paste in the photo of the Earth; but wait;-- you have to be in outer space to get that photo!?!?!?? How do they do that.

With that massive rocket you saw.

Click to play embedded YouTube video.

Cute! But not built yet.http://www.newscientist.com/article/mg2 ... nal-issues

[emc]

Massive Rocket Project, LA Times article, July 19, 2009

I visited the Huntsville, AL U.S. Space & Rocket Center museum last century. One of the many exhibits that I enjoyed was a section of a Saturn V on display inside the museum. I could track a single wire in the wiring harness (of many wires) around the wall of the rocket… amazing craftsmanship! A beautiful work of art and science!

[emc]

examiner.com article, October 4, 2009

news Buzz last year...

[mpharo]

Moonquakes Surprisingly Common
Oct 10, 2010

I wonder if moonquakes could also be caused by anything that causes earthquakes on earth; volcanic activity below ground. There are probably some pretty strong quakes there on the moon.



Michael Pharo