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Putting An Observatory On The Moon's 'Dark' Side
wytcld writes: "CNN reports astronomers are pushing for a radio telescope on the 'dark side of the moon' (do real astronomers call it the 'dark side,' when it gets plenty of light?). The proposal by Yuki David Takahashi is amazing mostly because a guy just starting work on his Master's is managing major press for it. Still, a nice dream."
Instead of say, the Hubble, they should call it "The Floyd"
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Remember, the money isn't spent in space -- it's spent right here on earth in order to get into space.
"Ain't no right way to do a wrong thing."
The article says this is good because the moon would shield the telescope from your satellite TV and internet access interfering.
Of course, it doesn't mention how exactly they plan on communicating with it! Sure, radio from the earth / reflected off the earth doesn't interfere, but important signals are also blocked.
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In particular, scientists involved in the Search for Extraterrestrial Intelligence (SETI) project like the prospects of a lunar listening post. A major nuisance they face as they eavesdrop on the universe is the constant interference of radio emissions from Earth.
I'm sure it's a major nuisance to the Aliens too: "How can we continue with our search for intelligent life with all this crap coming from those idiots on Earth!?!?"
try { do() || do_not(); } catch (JediException err) { yoda(err); }
A satellite in geostationary orbit still receives a lot of radio noise from Earth. That's sort of the point of GEO, after all. On the far side of the moon, though, there's this big hunk of radio absorbing rock between the antenna and Earth, which would allow the 'scope to pick up much fainter signals.
Oh, go on, check out my job.
New Scientist has more info including a graphic of how the moon shields raido waves
http://www.kubuntu.org/
Bzzzt. But thanks for playing. The Moon rotates at exactly the same rate as it revolves. Thus it always presents the same face to the Earth. That face might be lit (full moon) or might be dark (new moon), but it is the same always. That's why the Soviet pictures (Luna 3 -- see here for one telling) were such a big deal, as they were the first time any human had seen the "dark" (better, far) side.
The Moon is "tidally locked" to the Earth. Tidal forces have adjusted its rotation so that it presents the same face, due to the equality of rotation rates and revolution rates. So something on the Far Side would indeed be shielded from Earth-based transmissions.
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Why not? you just spent ~$60 (15B) to bailout the airlines, and you didn't even notice did you.
- Adam L. Beberg - The Cosm Project - http://www.mithral.com/
The last time I checked, the moon rotated.
Correct. Once per orbit.
If i am incorrect about this, please Xplain why.
Look at it this way -- when was the last time you looked up at the Moon and saw the far side?
-- Alastair
Unfortunately your post is situated between two notable posts of the scholar and poet "Klerck", at least in the view im in, and you're using the Anonymous Coward ID, therefore im afraid very few will notice your post, as they would be distracted by the awesome and stunning magnitude of his thought process.
:P
The space shuttle can only reach a maximum altitude of 600 miles. This is with no additional weight and isnt even close to the clarke/GEO orbit, at 22,500 FT. Anything higher that the shuttle carries has to be launched by the Inertial Upper Stage (IUS) mechanism you often see satellites spinning out of. The external tank and SRB's, at 154 FT and 116 FT respectively, are dwarfed by the 373 FT tall SaturnV stack that was used to get the spacecraft far enough out that the S4-B could begin its translunar injection. The space shuttle's current EFT cannot be refueled.
In short, you'd have to dust off the Saturn-V diagrams. Since the government would be paying more than likely, this step alone could cost millions.
Of course, we would want/need to revise a little. Computer weight, increased efficency in fuel, etc.. Chalk up a couple extra hundred mill..
Providing you successfully launch materials into space and onto the surface of the moon. You still need to get assembly teams up - and staff. You could use the same launch system.. But you'd need a completely different capsule design.
Apollo designs just wouldnt cut it. For one, you need seating for more than 3. Granted the space savings of the computer (which was only 1 SQ FT in the original apollo.. dont ask me about that one.) could assist marginally.. a soft cockpit also.. but this theoretical new launch system would likely have the power to launch human weight simply, if its hauling tons and tons of building materials to the moon.
You can see where this is going, and i would love to continue this discussion, unfortunately, my computer is cursed and won't stay up for more than a few minutes at a time. I've had to write this post in notepad.
Don't get me wrong. I'm 150% for space exploration. I think the visions of humanity have become severly limited - the age of wonder has gone the way of Camelot. I'd be on the first moonshot, if i could. I guess they need sysadmins on the moon. I just don't think the US, especially under the republicans, is going to do the space thing much. Remember - Republican translates into "Warmonger, rich oil tycoon" in politiceese - Very little room in dubya's brain for science. Its not christian, anyway. The world still rests atop a stack of giant tortoises. err, wait.. thats hindu.
And before anyone decides to begin a diatribe on the instability of windows, its not windows - its my computer itself. 1)
Linux locks, too, 2) The computer HANGS, the OS doesn't crash.
The only problem is, that while an observator on the far/darkside of the moon has a lot of benifits, we can't get there. While NASA could go to the moon in 1969, they don't have a single rocket to do the same now and radio telescopes are huge, less gravity will help, but you still need a huge capture area to hear signals from 100/1000/10000 lightyears away. The moon missions only required the transport of 3 people and life suport (and dune buggy), but the requirements of an serious observatory would be much greater requirements. The article doesn't mention if there is expected to be a support staff or if this would be purely robitic. There is a further problem in that they want it place it on the far/dark side of the moon, to avoid radio interference, (if this was built an optical telescope seems like a simple addition), so how do you get the information back to earth, the cabling required to get the signals back to the near/(bright?) side of the moon would be huge, or maybe you orbit a sattilite for relay purposes, but in anycase this is still a huge undertaking. Don't get me wrong I'd love to see this but this would cost Billions and Billions (said with carl sagan voice) and take 20-30 years, and as the US gov has canned SETI and they were make to look like fools in Contact I can't see them too keen on this.
Uh... this is very wrong, but not obviously so I suppose the moderators can be forgiven. The reason for the cratering difference between the near and far sides of the Moon is ENTIRELY due to the fact that the near side is a slightly younger surface than the far side. You know all those dark "mare" areas you see on the near side? There are essentially none on the far side; what those are are lava flows dating back generally 3+ billion years, filling large basins created by giant impacts that mostly date back 3.9 billion years or more. Those mare lava flows covered over all the old craters, giving a somewhat smoother surface (by the way, if you look through a telescope at the Moon any time, near the terminator, you wouldn't ever again call it "silky smooth", anywhere).
In any case, the Moon does NOT act as a meteor shield for the Earth, in any significant way: the Moon's mass is only a little over 1% of that of Earth, it's cross-sectional area around 10%, and the Earth-Moon distance is so relatively huge that the chance of anything destined to hit the Moon also coming in a direction that it would have hit the Earth if the Moon wasn't there is somewhere around the 0.1% level - i.e. 99.9% of the meteors that hit the Moon wouldn't have gone anywhere near Earth anyway; and generally the Earth will receive about 10 times as many meteor hits as the Moon does, so the Moon shields a miniscule 0.01% or so of the ones that do hit.
Ok, so much for that theory. What about the rest of the post? Half the time the telescope would be unusable? That's sort of typical of telescopes actually - have you ever tried looking at the stars in daytime? In any case, one of the proposals mentioned was actually a polar observatory, in one of the craters that never receives any sunlight in the amazingly deep south pole basin. These are also shielded from Earth, and would be close to ideal 100% of the time - except they can only look south relative to our orbit around the sun, so somewhat over half the sky would be missing...
So it would be much more feasible to "place a radio telescope device with massive rfi shielding from the earth's noise out in deep space"? First consider the proposed size of these telescopes is huge - several km across! How do you propose to launch such a huge structure (the most massive parts of a lunar telescope would be constructed from in situ materials, and thus not require any launch from Earth)? How do you propose to launch the immensely more massive shielding? We're talking billions of tons here, when it costs $10,000 to launch a pound in the US these days?! Why is it that any time someone talks about the Moon these days it's a ridiculous proposal, but then the same people come up with immensely more hare-brained and expensive schemes!!!
"ask everyone to turn off the power for a few hours"!? I'm sure a few hours a year of telescope time (and remember they're dedicating some sort of Arecibo or bigger-size telescope to this) will really satisfy the astronomers... and what sort of totalitarian political system do you think the world would need to actually get a request like that followed?
Oh well, just had to respond to the +5 on the post...
Energy: time to change the picture.