# I’ll see you on the Dark Side of the Moon

Over in Great Debates, a recent Troll spoke about a space station “orbiting the dark side of the moon” or some such nonsense.

On came a discussion about the possibility of such a thing. But many people wisely stay out of troll threads. So I put it to you, the General Questions Brigade:

1. There ought to be a “lunarstationary” orbit, oughtn’t there? At what altitude above the moon’s surface?

2. Could there also be a natural lunar orbit that kept a satellite always out of sight of the earth’s surface?

I would have gotten away with it too, if it weren’t for you meddling kids!

1. Altitude would be irrelevant, because the moon has no atmosphere to slow down the orbiting object. You’d just have to make sure that you’re above any inconvenient lunar mountains.

2. I guess it would be possable, although you might have to adjust the orbit periodically to keep out of sight of the earth.

BTW: could you explain why we’re talking about space stations hiding from the earth? I’m one of those people who tries to avoid trolls.

–It was recently discovered that research causes cancer in rats.

Unfortunately not. The moon only rotates once a month, so a “lunasynchronous” orbit would be one that took an entire month to circle the moon. At that distance, the Earth’s gravity would interfere.

Not quite an orbit as such, but there is a gravitational balance point, the L2 point, which is at a point in space behind the moon directly opposite from Earth. It’s not stable, but by making small trajectory adjustments a satellite or spaceship could remain there out of sight from Earth.

Speaking of the DSOTM, do I understand correctly that the moon rotates so slowly that there is a side that is never visible from Earth? And if it’s rotating so slowly, is there any good explanation of why it would perfectly match its orbit around the Earth?

my understanding is that the Earth’s gravity has “locked” the moon’s rotation so that it exactly matches the time it takes to orbit the Earth (or the centre of gravity of the Earth-Moon system, to be more precise.) That’s why we always see the same side of the moon.

The other side of the moon isn’t really dark; when this side is full, the other side is dark, when this side is dark, the other side is is light.

The other side doesn’t look anything like this side - no “seas” - just lots of craters. It was first photographed by a Soviet lunar orbiter.

and the stars o’erheard were dancing heel and toe

Hello? (Hello, hello) Is there anybody in here? Just nod if you can hear me. Is there anyone home?

Lumpy

L2 is an orbit around the moon. It is the only lunarstationary orbit–any others would be lagrange points.

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Er . . . Wrong album, PunditLisa.

There is talk of an orbiting “luxury cruise ship”.

People would be ferried up via Shuttle (or the soon to be seen in a system near you - “tether catapult”), stay a while and then return.

The rates are projected at 1M or so per passenger - and the numbers look good as far as the billable/deliverable ratio for eventual payoff, as people could be dropped off and picked up almost continually.

No reference on hand but it is some California tech start up that wants to do it within 20 years.

for views of the moon, including the other side and a discussion of tidal lock, see:
Luna

*<font color="#FF7777">PunditLisa: Hello? (Hello, hello) Is there anybody in here? Just nod if you can hear me. Is there anyone home? </font>

<font color="#4444FF">Quixotic: Er . . . Wrong album, PunditLisa. </font>*

“Comfortably Numb” off of The Wall, Disc 2. The topic lyric is from “Brain Damage” off of, of course, “Dark Side of the Moon”

I looked in the mirror today/My eyes just didn’t seem so bright
I’ve lost a few more hairs/I think I’m going bald - Rush

Cecil’s take on why the same side of the moon always faces the earth.

I don’t know about space stations orbiting the dark side of the moon, but I caught a glimpse on one of those “search for ET” type programs. You are all familiar with SETI and all, listening for radio signals and such. It mentioned the optimun place for such a listening dish would be to locate it on the side of the moon that faces away from the earth so as not to have any interference from all that earth noise. Now while I believe in other life somewhere out there, the evidence that they have today on recieved signals is virtually nil, so I cannot see why that idea was even thought of… seems like a waste of a lot of money and time.

“Wow! Spider-Man! Are you really friends with the X-men?”
"Not since Cyclops tried to use my viewmaster."
(Marvel Team Up #1)