I'm working on a science fiction story set in a radio observatory on the far side of the Moon. What sort of research could be done there better than could be done on Earth? Thanks.
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I'm working on a science fiction story set in a radio observatory on the far side of the Moon. What sort of research could be done there better than could be done on Earth? Thanks.
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Not as much as other types of radiation. Our atmosphere is pretty transparent to that kind of light. Obviously lack of shimmer and radio noise from elsewhere would be good.
What's the setup?
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There are a few things that can be done better from the far side of the moon. (btw: Hi everyone! I've been lurking for months, but finally decided to get an account).
Ultra-long wavelengths are stopped by our ionosphere: anything greater than about 20 meters is blocked. Probably not much interesting in that realm, but that's what they said about X-rays! ;-) The far side of the moon would be perfect for this. Also, since the spectrum on the Earth is quickly filling up, putting something out there would be perfect because you wouldn't have to worry as much about interference. And the low gravity would probably make it easier to put up big dishes (think of a Moon-spanning VLBA with 100m dishes! yummy).
One big problem that I see (you could work this into your story) would be the amount of time between successive observations of one point (half the sky isn't visible for 14 days or so!). Not too much of a problem, but if there is a major event in the wrong direction, you are pretty much screwed as far as immediate observations go. In this regard, just building it in space might be easier.
I think this has been done before (I remember reading a book by Clarke recently along these lines).
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Welcome parejkoj! Hope you find sharing your views even more enjoyable than lurking!
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Do you think if Aliens existed they would all be hiding on the Dark Side of the moon to avoid contact with us? Since no one found any aliens when we landed on the moon in the 60's.
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Big, hairy nitpick:
ToSeek, I know you put "dark side" in quotation marks in the Topic line, but please please please don't conflate "dark side" with "far side", m'kay? Bleah.
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Well, part of the story is that it's the "dark" side of the Moon because it's difficult to communicate with Earth from there. But your point is taken (which is why I put it in quotes).Originally Posted by tracer
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Visual astronomy would be quite spectacular on the far side of the moon...
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I suppose it would make sense to have a visual observatory there, too. I'll have to see if I can work that in.
Everything I need to know I learned through Googling.
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Arthur C. Clarke mentions briefly in Rendezvous With Rama the presence of radio observatories on the far side of th moon-- he mentions that a thousand miles of rock is one heck of a great way to get rid of interference, not only from all the junk we broadcast (do you really want to hear that cell phone conversation?) but from LEO and GEO satellites as well.
Also, you can see a lot of the wavelengths that are blocked by atmosphere, and on top of that -- even though half the sky is not visible for 14 days -- the slow rotation makes long-term tracking easier, becuase you can get two weeks of continuous observation with no breaks (like if the time-share for your telescope time in Japan is nixed because the computer system crashed, or your guy in upstate NY had a blackout :wink: ).
Heck, the 1/6 gee means that, effectively, you could have a 300 meter scope with the same gantries they use on a 50 meter.
No air, no corrosion, no bird poop either. To communicate with Earth (on the days when it is over the horizon) a good ol' fiber-optic cable to a transmitter on the other side -- the cable need not be all that long. Heck, a relay satellite in a trojan orbit in front of the moon and behind it should do the trick. If you really want continuous communication. two satellites- one in lunar synchronous orbit on one side (is that possible?) relays to another.
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The strength of the gantry is not just there to support the scope's weight. It also has to support its mass. While stationary, no problem as its mass is only felt as downward weight. However, start moving the scope around and the gantry has inertia to deal with.
Ooh, I just picked a nit!
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I was thinking tho, while inertia remains the same -- you aren't whipping the thing around. Aside from that, you still use a lot less metal in the supports. A big chunk of it does go to supporting the downward weight -- that's why Arecibo is in a valley and basically unpoint-able. On the moon you could get an Arecibo-size antenna onto a gantry of some kind.
But point taken, numbskull.
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Build a network of big scopes--use craters (like Arecibo)--each one could have a really good resolution on it's own, and could link into a Really Very Large Array...The strength of the gantry is not just there to support the scope's weight. It also has to support its mass. While stationary, no problem as its mass is only felt as downward weight. However, start moving the scope around and the gantry has inertia to deal with.
Ooh, I just picked a nit!
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I gave a paper at an aerospace sciences meeting a few years ago suggesting a very long wavelength radio astronomy telescope be put on the far side of the moon.
Grote Reber made measurements at 144 meters wavelength and at 500 meters wavelength. But he had to do this in Tasmania where the ionosphere became transparent during long winter nights at solar minimum. Tasmania is along the agonic line where this occurs. Reber's maps at these wavelengths are quite remarkable! The night sky radiates very brightly and uniformly at these wavelengths except where massive objects absorb it. He was able to map dim spots along the milky way and at the magellanic clouds. It was especially dim at the center of the galaxy. The temperature of the brightness was several million degrees, much brighter than expected from the CMBR.
A telescope on the far side would confirm Reber's measurements. Reber's telescope covered many acres and is the largest single telescope ever built. It was dismantled a few years ago. He passed away about a year ago.
My paper suggested a multi-vee shaped antenna that would be shot many kilometers long from a lander. Wires would be shot out from a central lander in several different directions. The antenna could be electronically steered by choosing the wires to act as receivers. The data would be relayed back from an orbiter. It was an inexpensive way to do kilometric wavelength astronomy.
Those interested in Reber's work can find a summary here, but the best description is in the Jan 1968 Journal of the Franklin Institute article referenced.
http://personal.nbnet.nb.ca/galaxy/G_Reber.html
http://personal.nbnet.nb.ca/galaxy/G_Reber.html
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Jack Schmidt lobbied for such a system for Apollo 17, so that they could land on the far side of the Moon. It got voted down, obviously, but some searching might bring up some details on his idea. (Didn't he write his autobiography? Might be in there.)
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It strikes me as a good place to base a SETI program.
Untill a few far side colonies and lunar relay satellites get up there,
you could be sure that you were not going to pick up many anthropogenic transmissions.
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You know, all these extra-large radio and visual telescopes sound like a great idea but without an atmosphere you'd be spending an awful lot of money reparing dings, chips, and downright holes from impacts. Sure no bird poop, but a peanut sized rock would do some nice damage to a mirror.
Unless I'm completely wrong on the frequency of impacts (of any size).
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In the Movie 2001: A Space Odyssey Dr Floyd after arriving at the space station meets "Elaina" a Soviet female scientist aquaintance of his who had "just spent 7 months calibrating the new antenna at Chelenka".
Since the Soviets were first to photograph the far side, convention allows them to name the features such as mountains and craters on it. So most of the larger craters on the far side have russian names.*
Since she uses a russan word to specify where she was one can assume that the antenna may have been in a crater on the far side.
*Yet another reason the west still calls the far side "The Dark Side". I guess it just wouldn't do to teach school children of a cold war society as much of the russian names of far side features as we do about near side features.
I bet not many people in the west could name even one major feature on the far side without a web search. Not that there are many large single features on the far side. Certainly not as many or anywhere near as large as are on the near side. It is pretty much a meteorite devestated jumble on that side. Which, by the way, is the largest single feature of the far side.
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Astronomy could truly flourish on the Moon. Since the moon only rotates once every 28 times this gives telescopes 28 times as much time as is available on Earth or 400 times what is available in LEO to collect light from stars. The Moon has no atmosphere and is seismically dead, and so is extremely steady for mounting telescopes. An optical interferometer established across the lunar farside would give us a resolution about a million times better than Hubble, which would allow us to map Earth-sized planets within 100 light-years of Earth. It would also allow us to penetrate deep back into time to the Big Bang era. The lack of an atmosphere also allows us to station large cosmic-ray, gamma-ray, x-ray, and ultraviolet telescopes. Permanently shaded craters provide free cooling for infrared telescopes.
ToSeek's question was specifically about a radio observatory. The Moon's far side is the only place in the solar system free of Earth's radio signals, and Earth's atmosphere still absorbs many radio frequencies. So on the Moon you could get much clearer signals and more of them for radio astronomy, and radio interferometry could be better calibrated because of the Moon's steadiness.
And one nitpick: please change the title of the thread to "far side"! "Dark side" is VERY bad astronomy! [-X
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I think this is a good bet for you. The lack of results of SETI is a good excuse to advance it to a better, less noisy, place. Of course, through in the telescopes for all the rest of the spectrum just for the fun of it.
However, it may not seem too orginal. And, I suppose a monolith there is still a bit too soon to pull off (maybe it would have worked 2 years ago
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You might want to put your station in the very southern region with all that free ice go with that "moonshine". The "in the crater" makes great sense, too. That's where the ice is suppose to be.
This would also be a good place for an alien transmitter as it could stay recessed in the crater and still have directional transceiving.
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With all the advantages over Earth observatories mentioned, what would the advantages of moon based observatories over satellite ones be?
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I was thinking of putting it just over the lunar backside, but if it's anywhere other than the equator, it wouldn't have full-sky coverage.
Everything I need to know I learned through Googling.
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Well, for things like radio based astronomy, the Moon's a great big blanket, wiping out the Earth's radio transmissions. Since we're the brightest radio object in our solar system at the moment, you'd have to send the satellite pretty far away from the Earth to get the same effect.
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It is also possible to collect far more light; as I said, a lunar observatory would have over 400 times as much time to collect light than telescopes in LEO have.Well, for things like radio based astronomy, the Moon's a great big blanket, wiping out the Earth's radio transmissions. Since we're the brightest radio object in our solar system at the moment, you'd have to send the satellite pretty far away from the Earth to get the same effect.
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It is also possible to collect far more light; as I said, a lunar observatory would have over 400 times as much time to collect light than telescopes in LEO have.Well, for things like radio based astronomy, the Moon's a great big blanket, wiping out the Earth's radio transmissions. Since we're the brightest radio object in our solar system at the moment, you'd have to send the satellite pretty far away from the Earth to get the same effect.
And even more (if not unlimited) light collecting time for the more northern and southern regions.
The moon has numerous advantages over satelites, in my view, at least for a fiction book.
> Ice....Drinking water/soft drinks/"moonshine" :roll: , bathing, oxygen for breathing, oxygen/hydrogen for rocket fuel and power supply for your Lunar Hilton and ore factories.
> What rich dude's gonna pay to go to a satellite?
> What fiction reader want's to go to a satellite? Well if it's a Russian nuclear missle launcher in disguise, but, you've already missed your chance, cowboy, on this one.
> It happens to be very contemporary. The Chinese are going there in 2005 trying to beat Inda (see current issue of "Astronomy"). Ice seems very likely in the lunar craters at the poles where no sunlight ever enters. Which we knew that in the early '70's.
> The moon is much safer from CME's and other solar excitements not to mention meteor storms.
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