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Radio Telescopes on Moon to Study Cosmic Dark Ages

Soulskill posted more than 6 years ago | from the ye-olde-moone dept.

NASA 118

The Narrative Fallacy brings news that NASA has awarded a $500,000 grant to develop plans for an array of radio telescopes to be located on the moon. The telescopes would be used to gather data from the earliest stars and galaxies, observations of which are difficult from Earth due to the ionosphere and terrestrial broadcasts. The grant was part of NASA's sponsoring of 19 "Next Generation Astronomy Missions." Quoting: "The Lunar Array for Radio Cosmology (LARC) project ... is planned as a huge array of hundreds of telescope modules designed to pick up very-low-frequency radio emissions. The array will cover an area of up to two square kilometers; the modules would be moved into place on the lunar surface by automated vehicles. The new lunar telescopes would add greatly to the capabilities of a low-frequency radio telescope array now under construction in Western Australia, one of the most radio-quiet areas on Earth."

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Outstanding (4, Interesting)

Protonk (599901) | more than 6 years ago | (#22509196)

The moon makes for an excellent platform for automated telescopes. People are going to bring up the tired "appolo for diamonds" argument but it doesn't have any bearing on this. The moon has no atmosphere to speak of, little radio interference from the earth and ample room to set up a large array.

This requires less investment than manned missions (which dictate a return and have a HUGE space/safety cost). It will allow us to see other things than what is suggested in the grant--Changra, hubble and the like all have been used for things that were not conceived of during the design phase.

Re:Outstanding (1)

CRCulver (715279) | more than 6 years ago | (#22509236)

Once we start putting radio telescopes, human colonies, and massive solar arrays up there, that little rock is going to be covered pretty fast.

Re:Outstanding (1)

Protonk (599901) | more than 6 years ago | (#22509256)

Not really. 3.793 × 10^7 sq. km is a lot of space. And if it is covered, so what? All the better.

Re:Outstanding (0)

Anonymous Coward | more than 6 years ago | (#22509320)

It'll be fine until one of the nations decides they own it or part of it. The moon belongs to nobody & to everybody.

Re:Outstanding (1)

Protonk (599901) | more than 6 years ago | (#22509356)

THat's a great position to be in. It will work just like international fisheries. We see how those are shepherded well. Property rights will be fine for the moon. Someone has to own it.

Re:Outstanding (1, Flamebait)

Mesa MIke (1193721) | more than 6 years ago | (#22509360)

My guess is it'll be owned by whoever occupies it, which will be fine until the environmentalist fringe starts complaining about how the Moon is being trashed by humans...

Re:Outstanding (4, Funny)

fred fleenblat (463628) | more than 6 years ago | (#22509426)

(a) the cost of transit to/from the moon per pound is so high that only the lightest, skinniest people like paris hilton will be allowed in space. in fact they should be required to be sent into space.

(b) the moon has no oceans, therefore 100% of land area is available for condominiums, hotels, highrises, and shopping districts. Unlike the earth which of which only 20% or so is habitable land. Ideally we would launch the most habitable parts, like Washington DC, to the moon in their entirety to take full advantage of the economy of scale, then convert what was underneath Washington DC into higher value land, like a swamp.

(c) as you could see from last wednesdays lunar eclipse, the educational value of viewing the lunar eclipse from the moon would have been greater than viewing it from earth. No child left behind and all that.

What was the question?

Re:Outstanding (3, Informative)

fred fleenblat (463628) | more than 6 years ago | (#22509254)

>> little radio interference from the earth

Further, I suspect if you set it up on the far side of the moon, you'll get zero interference from earth at all. Maybe some 60 hz hum...but kilohertz and above should be clean.

Re:Outstanding (1)

Protonk (599901) | more than 6 years ago | (#22509280)

right. It is just easier to say "very little" than it is to say "none" and have to explain that I mean "practically none".

Re:Outstanding (1)

sholden (12227) | more than 6 years ago | (#22509578)

But that's where the alien moon base is...

Re:Outstanding (1, Funny)

Anonymous Coward | more than 6 years ago | (#22509638)

if we land on the moon, aren't we the aliens?

Nope (1)

Nazlfrag (1035012) | more than 6 years ago | (#22510224)

Under the terms of the Galactic Confederacy, all these worlds are ours except Europa. Attempt no landing there.

Re:Outstanding (2, Funny)

gardyloo (512791) | more than 6 years ago | (#22509686)

Not true! The only thing there is a "sound"stage where the aliens faked their Earth landing.

Re:Outstanding (1)

secondhand_Buddah (906643) | more than 6 years ago | (#22512214)

You may only be joking, but Buzz Aldrin, an astronaut on the Apollo [first moon landing] mission has clearly stated in an interview that they were approached and observed by at least one Unidentified Flying Object on their historical moon mission, while on the way to the moon.... Here's the interview on YouTube [youtube.com]

Re:Outstanding (0)

Anonymous Coward | more than 6 years ago | (#22513944)

The aliens didn't make contact though because they didn't detect a warp signature from the apollo spacecraft.

Re:Outstanding (0)

Anonymous Coward | more than 6 years ago | (#22510490)

The tricky part will be running the fiber optics or aligning regular optics such that the array doesn't make too much radio noise itself. Either that or give up the ability to gather good data when relaying data that's been collected.

Re:Outstanding (1)

mikael (484) | more than 6 years ago | (#22510764)

Only yesterday, they were proposing to send some telecommunications satellites to orbit the Moon so that there would be all-over lunar coverage for astronauts with satellite phones.

Re:Outstanding (1)

cnettel (836611) | more than 6 years ago | (#22513078)

I wonder what the low-frequency observators will make of the fact that the emissions from a body orbiting Sol has remarkable signals in the 50-60 Hz range, and that the linear components of the two distinctive signals changes distinctively with a 24-hour period. (or: not all countries use 60 Hz, you insensitive clod! Try growing up with 50 Hz PAL CRTs and you would also be touchy about it!)

Re:Outstanding (0)

anastasd (849943) | more than 6 years ago | (#22509374)

OK, but why radio-telescopes and not simply optical? If NASA does not need true-color images it is not needed to send any telescope in space, unless it is bigger than Arecibo. Or may be they plan to make simultaneous observations from Earth and Moon? I guess NASA is again short in money and needs some PR to get bigger budget.

Re:Outstanding (1)

susano_otter (123650) | more than 6 years ago | (#22509604)

Radio telescopes receive other wavelengths that are at least as interesting to astronomers and astrophysicists as optical telescopes.

And--if you'd bothered to read the article--the effectiveness of Earth-bound radio telescopes is limited by the RF properties of the ionosphere and the background noise from Earth-bound radio broadcasts.

Re:Outstanding (1)

anastasd (849943) | more than 6 years ago | (#22509988)

Yes, I bothered to read the article and wrote that the only reasonable radio telescope in space is the big one. If you put your satellite dish on Moon it would not get better results than in an average school lab telescope, no matter that it will face no ionosphere. The only profit from small telescopes in space is that they can make better-quality optical images. This cannot be improved by larger size of the ground based ones.
Another useful application of small radio telescopes is for simultaneous observations from Earth and from somewhere-in-space. This greatly increases the speed of data collection and the precision of results. As I know ground radio telescopes are already connected in a network for this purpose, but if we have even your satellite dish 200 000 miles away from Earth, wow, we might see the curvature of the Universe :))

Re:Outstanding (2, Interesting)

Protonk (599901) | more than 6 years ago | (#22509714)

How does a payment of 500,000 dollars for a researh grant to send unmanned radio telescopes to the moon in order to study something obscure generate a bigger budget?

Do you just let stuff spill out of your ears when you make comments on this sort of stuff?

First, the array would be bigger than Arecibo, which is already smaller (by virtue of not being an array) than others on earth right now. The limit to accuracy for those arrays is RF interference and the ionosphere.

Second, NASA is ALWAYS short money and long on projects because they are tasked with building fault proof projects for present needs (as elected officials don't care about space exploration 25 years from now) under constant cuts (because cutting funds for nasa doesn't anger hawks and doesn't seem as bad as cutting funds for school lunches) and with dubious management (political appointees over engineers).

Third, wh-----wait a fucking minute, who modded you "interesting"? fuck.

Re:Outstanding (1)

anastasd (849943) | more than 6 years ago | (#22510252)

Gosh, what an alpha male reaction!

Yes, 500k dollars are not enough for a space mission but are a reasonable amount to spend for better PR of your projects. As far as I know NASA has plans to put telescopes on Moon from 1997, and if it had the money for that, I guess it wouldn't need that much public attention. As for telescope arrays, wait a minute .. I think I said the same thing. Do not make me argue with myself. :)

Re:Outstanding (2, Funny)

Protonk (599901) | more than 6 years ago | (#22510284)

?? Alpha male?

I mean, 500k is a fair amount of money to spend on PR (Far, FAR less than the 2b we spend on recruiting/bonuses for the american military), but my point was that it wasn't spend on PR. I just wasn't. It is beyond disingenuous to claim that this is a PR stunt. It is a research grant. Spending it on PR would be something like this:

"NASA spent 500,000 dollars today to secure the passage of three adult entertainment stars on the space shuttle today, hoping to determine the impact of space on threesomes."

That's PR. This is a research grant for a radio telescope array.

Re:Outstanding (0)

Anonymous Coward | more than 6 years ago | (#22509400)

People are going to bring up the tired "appolo for diamonds" argument but it doesn't have any bearing on this. The moon has no atmosphere to speak of, little radio interference from the earth and ample room to set up a large array.
Can someone explain what is meant by "appolo for diamonds"?

Or is it "Apollo for diamonds"?

Either way, I've never heard of it...

Re:Outstanding (3, Interesting)

Protonk (599901) | more than 6 years ago | (#22509656)

It's apollo. My ability to spell....sucks. Basically, if you took the cost per pound of payload for the apollo moon missions you would come to the conclusion that even if the surface of the moon were made of pure diamond and it was easily mined (read: pick it up off the ground), it would not be worth the trip. There are a number of fallacies invoked when people use it to describe current space travel, but the basic principle (that $/lb of payload is very high) stands.

Re:Outstanding (2, Interesting)

Nazlfrag (1035012) | more than 6 years ago | (#22510298)

No, it's a pity that it's only made of moonrocks, which Sotheby's sold some of back in '93, at a price equivalent to about $2.2 million per gram. Seeing it cost NASA a little over $50,000 per gram to collect, I'd say it's worth the trip. http://www.space.com/missionlaunches/fl_moonrocks_030806.html [space.com]

Re:Outstanding (1)

hcdejong (561314) | more than 6 years ago | (#22512726)

Of course this only works as long as moonrock is exceedingly rare. Once you start bringing tons of the stuff to Earth, prices will plummet.

Re:Outstanding (2, Interesting)

Dr. Eggman (932300) | more than 6 years ago | (#22509508)

Alright, but what happens when something breaks down? With no atmosphere to burn them up, smaller space debris may impact the surface near the telescope (and stirring up the soil) or the device itself. We already have hear of that the extremly abrasive qualities of the lunar soil. That soil that will find its way into the telescope (especially bad for any moving parts.)

I too, however, am optimistic. Not so much about what the telescope will grant us, but rather the challenges to material science. Solutions to those challenges will prove extremly important if we ever want to have a prolonged or perminent presence on the Moon.

Re:Outstanding (1)

susano_otter (123650) | more than 6 years ago | (#22509636)

We already have hear of that the extremly abrasive qualities of the lunar soil. That soil that will find its way into the telescope (especially bad for any moving parts.)

Too bad we don't know how to design and build phased-array radars... oh, wait.

Re:Outstanding (5, Interesting)

CodeBuster (516420) | more than 6 years ago | (#22509800)

We already have hear of that the extremly abrasive qualities of the lunar soil. That soil that will find its way into the telescope (especially bad for any moving parts.)
I was going to mention the exact problem and it does has the potential to be a problem because, as you mention, lunar dust is extremely abbrasive and fine (imagine sub micron rock particulate with razor sharp and hooked edges because it has never been eroded by wind or water) so it tends to damage or compromise any softer materials that it comes into contact with. However, upon further reflection I believe that the problem, in this case, would be manageable for the following reasons:

(a) The telescopes and related equipment, or at least the parts directly in conctact with the lunar surface, will not be moving around after touchdown so the amount of dust that gets disturbed should be minimal and landing air bags (ala the mars missions) should help shield any sensitive parts during the landing cycle. the parts that do move will not disturb the dust because they will not be in direct contact with the lunar surface AND there are no air currents or other atmospheric effects on the moon to whip up dust from parts moving around (even if they are only millimeters above average surface elevation) which are not in direct contact with the lunar surface.

(b) radio telescopes can be made out of metals and durable plastics without the need for sensitive optics such as finely ground glass lenses so the danger from abbrasive lunar dust could be minimized in this regard by judicious use of durable and hardened parts.

The micrometeorites are a more serious issue. There have been subsequent pictures taken by probes of known Apollo landing sites which reveal new small craters (i.e. craters which occurred near the landing sites in between the time when the probes took the pictures and when the Apollo astronauts left the moon on the ascent stages of their landing vehicles). It is possible that many smaller meteorites have struck the Apollo lander descent stages that were left behind on the moon (although nobody can be sure because they are too small to resolve individually on the lunar surface by telescope and nobody has gone back since to check on their condition). However, even with this potential problem the radio telescope offers an interesting solution.

The individual telescope elements of the radio telescope are less important than the network of them which makes up the whole. This why radio telescopes on earth, such as the very long baseline array [wikipedia.org] , with stations on different continents aggregated together into a single "picture", are distributed rather then building one VERY large singular dish (i.e. one half the size of earth). The individual telescope elements on the moon could be replaced with new ones as needed if individual units, for whatever reason, become non-operable.

Re:Outstanding (1)

ceoyoyo (59147) | more than 6 years ago | (#22511978)

Radio telescopes aren't like optical ones - they're mostly wire mesh, or tinfoilish stuff. A few holes in it aren't critical. The sensitive electronic bits don't make up much of the surface area.

The parts of the telescope that will move are unlikely to be either large or anywhere near the surface. If there are any moving parts at all.

Re:Outstanding (0, Troll)

oldhack (1037484) | more than 6 years ago | (#22510018)

Please, one of you smartees elucidate us why the "far-side" of the moon stay that way.

No, I don't want to google or go to wiki. I want to read from here, /., the "news for nerds" where the SMART nerds hang.

Yeah right (1, Offtopic)

antifoidulus (807088) | more than 6 years ago | (#22509220)

everyone knows they are just going to use the telescope to watch the Amazon women change clothes.

Re:Yeah right (1)

geekoid (135745) | more than 6 years ago | (#22509242)

And there's a problem with that?

I wonder, what did you find buggy about the OS-X server?
Just curious, I never used it myself.

Re:Yeah right (0)

Anonymous Coward | more than 6 years ago | (#22509266)

He is right! Everyone knows Moon faces the earth ALL THE TIME!!!!!!!!!!!!!

Re:Yeah right (0)

Anonymous Coward | more than 6 years ago | (#22509450)

How do you know that's the moon's face?

Re:Yeah right (0)

Anonymous Coward | more than 6 years ago | (#22509504)

oblig: That's no moon....

Re:Yeah right (1)

UnknownSoldier (67820) | more than 6 years ago | (#22509586)

Does it _always_ face the earth 100%, or does the moon have a precession?

I can't seem to find any info on this...

Re:Yeah right (5, Informative)

Deadstick (535032) | more than 6 years ago | (#22509920)

The moon's orbit is not perfectly circular, and its axis of rotation is not quite perpendicular to the plane of the orbit. Those effects combine to produce an apparent rocking motion, on a time scale of weeks, called libration. Thanks to that, we can see almost 60 percent of the moon's surface at one time or another.


obligatory (0)

verbalcontract (909922) | more than 6 years ago | (#22509282)

During the cosmic Dark Ages, was there an interstellar search for the Holy Grail?


Re:obligatory (1)

Wandering Wombat (531833) | more than 6 years ago | (#22509352)

The French already had one. It was very nice.

Re:obligatory (1)

EntropyXP (956792) | more than 6 years ago | (#22509466)

Quote from Monty Python's Quest for the Holy Grail - On the Moon

"Your father was a hampster and your mother smelled like burnt gunpowder"

Re:obligatory (0)

Anonymous Coward | more than 6 years ago | (#22509622)

I think you even went over most slashdotters' heads with the burnt gunpowder thing. Don't you pretty much have to have read apollo transcripts to have picked up that part?

Re:obligatory (0)

Anonymous Coward | more than 6 years ago | (#22510646)

huh ? no. moondust oxidizes and smells of burnt gunpowder...everyone knows that factoid.

As I understand it (0)

LM741N (258038) | more than 6 years ago | (#22509588)

this telescope can't be pointed anywhere near earth without the same disruptions. So we have a whole part of the universe unexplored.

Here's an idea. For one hour there will be a total blackout on earth. Thats not to much to ask for the advancement of science. And think of the population explosion. I need somebody to pay for my SS. It could be done as part of a new holdiday called Festivus.

Re:As I understand it (2, Informative)

usul294 (1163169) | more than 6 years ago | (#22509628)

The moon goes around the Earth, one face always faces the Earth. Over the course of 28 days the dark side of the moon will see the entire sky with a giant ball of rock in between the observatory and Earth

Re:As I understand it (5, Insightful)

rijrunner (263757) | more than 6 years ago | (#22509856)

Well, not quite.

This type of observatory requires a lot of smaller units that add up to a total resolution of the receiving surface. The best resolution is directly overhead of the site. As you try to observe items that are low on the horizon, you lose a great deal of the quality of the observation as the effective size of the array is diminished.

For example:

                        **** (what you are observing)

                        ^^^^ (The array).

The array is effectively as wide as its deployment diameter.

Now, suppose you are observing from a couple other angles:



From that angle, the array is apparently smaller. You can angle them to make sure you have the same strength, but you have to increase the size of the array as a direct function of the observation angle to give equivalent baselines for the observation.

So, yes, you can see in any direction around the Moon, but placement on the Moon is not a simple matter.

Consider that you don't want it pointing towards the sun either. Or, maybe you do. That's an interesting argument right there. You'll get data from the sun, but you'll also have periods where you have nothing *but* data from the sun. Similarly, Jupiter kicks out a lot of radio signals. A lot of design decisions end up still needing a fairly complex shield to make sure that you're getting only the radio waves you are searching for.

Arguably, you would want to place it near the lunar poles. Not for any of the BS arguments about the potential for water there, but because they have the least interference from Earth and the Sun. It also means you can survey the same stretch of sky for longer periods as out-of-plane bodies there are a lot easier to track and remain in the same cone of observation irrespective of the current lunar position. (ie, something that is at zenith over the lunar pole is not going to vary more than about 6 degrees from being overhead over the course of a year. Even something 25 degrees, or so, would still be visible pretty much all the time). If you go to lower latitudes, then it gets closer to a 14-day non-observation lineup followed by a 14 day period of variable observation from minimal to optimal and back as the object traverses the sky. The closer you get to the lunar equator, the more of the sky you will see, but the less the observation time and the more variable the quality of the observation.

Ideally, they design a small inexpensive setup which can be done a few times on various areas of the Moon. Just choosing one set of criteria is going to be interesting. This is not like Hubble which can be pointed in any direction. There are a lot of rocks in the way.

If you don't get it on/near the poles (1)

artifex2004 (766107) | more than 6 years ago | (#22511308)

How do you get data to/from the Earth? You'll need a satellite or repeaters or something. But if you stick it at the pole, maybe you can peek back over :)

Re:If you don't get it on/near the poles (1)

PeterBrett (780946) | more than 6 years ago | (#22512284)

How do you get data to/from the Earth? You'll need a satellite or repeaters or something. But if you stick it at the pole, maybe you can peek back over :)

My intuition suggests that it would be cheaper to use relay satellites than to locate the observatory at the pole, if returning data was the only issue that affected where the observatory was placed (IIRC there's a slight delta-v advantage in landing near the lunar equator). However, other people have already pointed out some other good reasons why a lunar pole would be a good place to put it.

Re:As I understand it (0)

Anonymous Coward | more than 6 years ago | (#22509742)

You do realize the moon is in a phase locked orbit with the earth right?

Implementing is not that hard (0, Offtopic)

Daimanta (1140543) | more than 6 years ago | (#22509654)

Telescope[] MoonTelescopeArray;

Re:Implementing is not that hard (0, Offtopic)

clem (5683) | more than 6 years ago | (#22510318)

Just be sure you use the delete[] operator when you're done using the telescopes.

Re:Implementing is not that hard (1)

BotnetZombie (1174935) | more than 6 years ago | (#22513956)

I find it sad to see not only one, but two programming jokes modded offtopic. If you find them to be not funny, ignore it. And if you don't understand it, again ignoring is a much better policy than downmodding.

Welfare for engineers (3, Insightful)

Grandiloquence (1180099) | more than 6 years ago | (#22509680)

Like most of NASA's programs, this basically amounts to a jobs program for scientists/engineers. Notice that the funding is for the plans for an array of telescopes, not for the actual construction of said array. Building an array of telescopes on the Moon would likely require astronauts to spend months on the Moon, even if most of the telescopes came pre-assembled. Without any infrastructure on the Moon to support those astronauts, building an array of telescopes there is a pipe dream, and will remain so for the foreseeable future.

If any plans end up being actually produced, they'll likely be filed away in a drawer and forgotten. Pessimistic? Sure. But, that's the way NASA has worked for decades now.

Re:Welfare for engineers (1)

twiddlingbits (707452) | more than 6 years ago | (#22511700)

At this point in time we don't even have a Manned Moon Mission in the planning horizon. It's Mars first right now. Of course the same launch vehicle can be used for both but we don't have a Lunar Lander (revive the old one and modernize?) nor do we have a way for astronauts to stay on the moon more than a week or so. Neither one of those is insurmountable but they are essential precursors to building a large structure manned or unmanned on the Moon.

The Standard Objection Applies.. (2, Interesting)

QuantumG (50515) | more than 6 years ago | (#22509684)

Why not just put the telescopes in a geostationary orbit around the Moon so they are always on the dark side and therefore shielded from the Earth? Soft landing telescopes of any significant size is hard work. The only reason lunar telescopes makes more sense than space telescopes in lunar orbit is if you build the lunar telescopes from lunar materials... and we're not anywhere near that capability yet.

Re:The Standard Objection Applies.. (1)

phrostie (121428) | more than 6 years ago | (#22509764)

interesting. you'd get a cleaner signal but there would be other obsticals.

wouldn't you need some form of communications system im place to route the signals?

possible a satellite in a lunar polar orbit?

Re:The Standard Objection Applies.. (0)

Anonymous Coward | more than 6 years ago | (#22509772)

I'm pretty sure that geostationary orbit on the Moon is impossible. Think about it like this: with the Earth, geosynchronous orbit is at around 45,000 km. Now, decrease the mass by a large factor and lower the rotational speed by a large factor, and you'll get an orbit that is much bigger than the Moon's own orbit around the Earth (around 300,000 km), which basically means that it would be impossible.

Re:The Standard Objection Applies.. (4, Interesting)

Fanro (130986) | more than 6 years ago | (#22509892)

There are no geostationary orbits that stay behind the moon. But we could maybe put a satellite in a Lissajous orbit around the lagrange point [wikipedia.org] L2 behind the moon.

To send signals back you would need a relay satelite thougth

Re:The Standard Objection Applies.. (1)

kryten_nl (863119) | more than 6 years ago | (#22510300)

What a great idea and so original too. I'll help by thinking of a snazy name for the satellite .... got it. How about James Webb Space Telescope [wikipedia.org] ?

Re:The Standard Objection Applies.. (0)

Anonymous Coward | more than 6 years ago | (#22511844)

Sun-Earth L2 != Earth-Moon L2

Re:The Standard Objection Applies.. (1)

kryten_nl (863119) | more than 6 years ago | (#22513098)

From the GP's link:

The Earth-Moon L2 point has been proposed as a location for a communication satellite covering the far side of the Moon
Now, why do you think all those observing satellites are planned at SEL2 and there are only plans for a com-sat at EML2?

Re:The Standard Objection Applies.. (4, Insightful)

Steneub (1070216) | more than 6 years ago | (#22510316)

Logged in to post exactly this. Putting a telescope in a lagrange point solves the problem of not being able to directly communicate with it due to it being on the other side of the moon. Another advantage of direct communication is getting visual confirmation of any movements or adjustments made. Sensors are great, but I don't care how good the tech is - something will always go wrong that you didn't think of.

Re:The Standard Objection Applies.. (1)

DelawareGT (905614) | more than 6 years ago | (#22510846)

A halo orbit about the Lagrange 2 point in the Earth-Moon system would be sufficient. From Earth it would appear as a ring behind the moon. Keep in mind that the L2 point is in unstable equilibrium. That type of orbit would require about 100 m/s delta V maintenance per year. I have not read the proposal but perhaps a trade study showed a significant mass savings over the long term by landing your equipment. Maintaining an array of satellites might *actually* be more expensive

Re:The Standard Objection Applies.. (1)

rijrunner (263757) | more than 6 years ago | (#22509946)

Because there is no stable geo-synchronous orbits around the Moon?

Also, for the wavelengths they are looking at, you need something that is kilometers wide and able to be effectively controlled.

They are not talking about some telescope with a mirror and camera. This is closer to a huge array of dish antennas that are linked together and point in a given direction. They actual dish can be fairly small and moved about to change the size of the baseline.

Re:The Standard Objection Applies.. (1)

SlashWombat (1227578) | more than 6 years ago | (#22510930)

Actually, they appear to be talking about LOW frequency Radio astronomy. That is, from 1Hz to probably 30..60 MHz.

Parabolic dishes need to be several wavelengths across to exhibit significant gain. EG: 1MHz has a wavelength of 3e8/1e6 = 300 metres. So for 1MHz, a single dish would probably need to be at least 1kM in diameter. This is a big ask, even for NASA. (and, in the kHz range, even the whole moon isn't big enough!)

The type of astronomy that can leverage reasonable size parabolic reflectors is at a much higher frequency. At these higher frequencies the ionosphere is less of an issue. (Although, there is still extra attenuation due to the earths atmosphere, but this is relatively small.)

LF radio astronomy relies more on arrays of wire antenna's. No atmosphere would definitely be a huge advantage at LF.

If it were me (1)

WindBourne (631190) | more than 6 years ago | (#22509996)

I would not build them on earth and transport. I would simply build them out of the material on the moon. It really is the only way. Far cheaper and it will leave an infrastructure in place to build other things.

Re:The Standard Objection Applies.. (1)

Dachannien (617929) | more than 6 years ago | (#22510386)

You could make a lunar telescope array far, far larger than anything you could park at the Earth-Moon L2.

Re:The Standard Objection Applies.. (1)

QuantumG (50515) | more than 6 years ago | (#22510510)

But we won't.

Why do you say that? (2, Interesting)

WindBourne (631190) | more than 6 years ago | (#22510816)

If done in the right way, this could be used to build infrastructure on the moon. It seems to me, that if we BUILD a radio telescope on the moon, then the same machinery used to build that will go into building other structures such as a regular scope. In addition, if this is outsourced to somebody like bigelow, they will use that as a means of constructing a lunar base.

Re:Why do you say that? (1)

QuantumG (50515) | more than 6 years ago | (#22510882)

It's a chicken and egg problem. You need to have a large industrial base on the Moon before you can build anything significant and a large industrial base is significant.

Exactly (1)

WindBourne (631190) | more than 6 years ago | (#22511328)

I think that a few projects will kick start this. In particular, I think that bigelow will be there by 2016 (maybe 2015). I know that sounds like a wag, but I suspect that there will be strong financial encouragement for him to do so. In particular, I believe that the DOD will push us there, and will offer up incentives to bigelow to do it. Keep in mind that bigelow is expected to be out next year in some of the interesting x-prizes. From what I understand, they will be at the lunar digging one. That one could be very useful.

Re:Exactly (1)

QuantumG (50515) | more than 6 years ago | (#22511518)

Most no-one thinks the Google Lunar X-Prize will be won.. and that's just soft-landing a rover on the Moon by 2015.

So a lunar base by 2015? Don't think so.

Some sort of lunar resource utilization? No chance.

If shit doesn't go down hill between now and 2050, we might expect there to be a "permanent" base on the Moon by then.. with two or three astronauts being replaced every 6 to 12 months - in other words, the ISS on the Moon.

Re:Exactly (1)

WindBourne (631190) | more than 6 years ago | (#22511666)

Most no-one thinks the Google Lunar X-Prize will be won.. and that's just soft-landing a rover on the Moon by 2015. Hummmm. Everybody swore that America's space prize was un-winnable. And yet, I think that Musk will win it, with the remote possibility that several others could still do it. By the same token, I would be surprised to not see musk pursue the Lunar X-prize. The easy way is work with armadillo or perhaps blue origin. Why use one of those? Because they make a very nice lunar transporter.

Bigelow has a great deal in mind. I know that you have seen what he is up to. He is wanting to land his systems straight down on the moon. Once it is there, he will need transport up and down for cargo and ppl, hence the reason that Musk/(carmack or bezos). Keep in mind that it is the prizes that is allowing Musk to make money. He was won cots (270M), shooting for American's space prize which is 50M, and will almost certainly land contracts with DOD, NASA, and Bigelow, in addition, to picking up more launches with other groups. If he can win the Lunar X-prize with a partner who can provide the lunar access, then he will have helped created the market that Bigelow (and others) want desperately.

My prediction: Musk wins the American space prize, followed by Lunar X prize, and then bigelow is on the moon by 2016, and MAYBE, just maybe, even 2015. That is only 7-8 years away. Sounds like a lot, but the x-prize was won in 8 years ago and that was with ZERO infrastructure. Now, there is an up and coming infrastructure, with multiple prizes to lead the way.

Re:The Standard Objection Applies.. (1)

DelawareGT (905614) | more than 6 years ago | (#22510770)

The problem with high altitude lunar orbits is that they are unstable. The earth/sun tend to perturb them such that satellites would require significant orbit maintenance (aka lots of fuel, which eventually runs out).

Hrrmmm (1)

AIFEX (1036394) | more than 6 years ago | (#22509792)

The universe is a huge place, what makes NASA think that our telescopes are able to see the "earliest stars and galaxies"? Or is this one of those "We are in the center of the universe" ideologies again?

If you really want to know... (5, Informative)

TrekkieGod (627867) | more than 6 years ago | (#22510084)

The universe is a huge place, what makes NASA think that our telescopes are able to see the "earliest stars and galaxies"?

The cosmic microwave background left over from the big bang as measured by WMAP [wikipedia.org] tells us the approximate age of the universe. Red-shift measurements tells us the distances of the stars we observe. The speed of light tells us how long it takes for the light of those stars to get here. Ta-da.

Or is this one of those "We are in the center of the universe" ideologies again?

We ARE at the center of the universe. So is everywhere else. The Big Bang wasn't an explosion that filled out existing space from which there's a center. Space itself expands from that point on, so the same infinitesimal point where the big bang started is the place where you're standing in now. The standard analogy is the surface area of a balloon as you fill the balloon up. There's just no preferred center.

Re:If you really want to know... (0)

Anonymous Coward | more than 6 years ago | (#22511282)

So the way that this works to explore the so called "Dark ages" of the universe is by looking at the 21-cm line from neutral hydrogen. According to our best knowledge of the history of the universe, after the big bang, the universe was pretty boring, consisting of neutral hydrogen gas and not much else. Neutral hydrogen emits 1.4 GHz radio waves from the hyperfine spin-flip of the electron, but when the first stars/galaxies turned on the light they emitted ionized bubbles of the surrounding hydrogen, which then ceased to emit this radio emission (since only neutral hydrogen emits in radio). The universe is pretty much totally ionized now, so we are targeting the era in the universe when it was transitioning from all neutral to all ionized. This is called the epoch of reionization (EoR for short).

The expansion of the universe means that any emission from neutral hydrogen in the early universe is actually "redshifted" to lower frequencies, so our best guess from the known data of Gunn-Petersen troughs in quasars and HI density from WMAP is that the interesting period for studying the reionization of the universe is at redshifts of 6-7 and greater, which means that the 1.4 GHz radio emission gets shifted down to ~200 MHz or less.

The advantages of putting this on the moon is that you really have a tough time doing radio astronomy below say 50 MHz (which would let us see the early stages of reionization) from earth because at these frequencies the ionosphere starts becoming really opaque to radio emission, so we can't see anything. Also, these arrays will literally consist of thousands of antennae, so it would be really hard to put something that big / with that many independent elements in an orbiting configuration. Also, the earth emits a fair bit of low frequency radio emission so putting it on the lunar far side dramatically reduces the background.

Hope that was informative. Check out the MWA project [mit.edu] for my personal favorite array being built to look for the higher frequency pieces of this signal.

Re:Hrrmmm (2, Interesting)

urcreepyneighbor (1171755) | more than 6 years ago | (#22511010)

Or is this one of those "We are in the center of the universe" ideologies again?
From Ask an Astrophysicist [nasa.gov] :

Question: If all the distant galaxies are flying away from us, does that mean that we're in the center of the Universe?

Answer: Thanks for your question. Astronomers and physicists interpret the result that all distant galaxies are flying away from us as evidence for the uniform expansion of the Universe. In this case, any observer, at any location in the Universe, observes the same general motion: that the further a galaxy is from us, the faster its relative velocity with respect to the observer is. The famous (and very illustrative) example of this is to imagine a loaf of raisin bread as it is baking. The raisins in the bread spread away from one another as the loaf rises and expands during the baking. Pick any raisin and pretend you are standing on it (you're very small now!) and measuring the rate at which the other raisins are moving away from you. You will find that, no matter which raisin you choose, all other raisins appear to be moving away from you, with the furthest raisins receding the fastest.

The current cosmological model of the Universe supposes that our position within the Universe is typical, not special. We are not located at the center of the Universe, but are rather taking part in its global expansion. I hope this answers your question.


Padi Boyd
for the Ask an Astrophysicist

A number of other interesting concept studies ... (2, Interesting)

boot_img (610085) | more than 6 years ago | (#22509938)

are also being funded. Follow the last link [nasa.gov]

I particularly like the idea

Imaging nearby Earth-sized worlds using large telescopes with multiple instruments and separate spacecraft to block the light from these exoplanets' host star (Webster Cash, University of Colorado, Boulder; David Spergel, Princeton University, N.J.).
This seems very cool - the idea is that you put a big screen out in space to block the light of the host star, but not that of the star's planet. This is not a new idea - the problem is diffraction around the screen (occulter). But it looks like Cash and Spergel have found a design that minimizes the diffraction.

Thats no moon (0)

Anonymous Coward | more than 6 years ago | (#22510118)

it's a radio station!

What a joke (1)

Dunbal (464142) | more than 6 years ago | (#22510182)

NASA can't even afford to keep flying the shuttle, and they want to put a radio telescope on the moon? I guess they're allowed to dream.

Re:What a joke (1)

Farmer Tim (530755) | more than 6 years ago | (#22512754)

That's kind of like saying I can't send the payments on my Honda because hiring a vintage limo to get to the post office is too expensive.

Sorry, this discussion was strangely lacking in bad car analogies...

Do they need any placement? (1)

mlush (620447) | more than 6 years ago | (#22512828)

Why do they need to place the antenna? Could the build a thousand antenna in 'beachaballs' and just scatter them over the lunar surface. Then determine their positions by radar and compensate for the scatter in software.

Spam (1)

GottliebPins (1113707) | more than 6 years ago | (#22513558)

Once the array is built, to help pay for the service, satelites will be placed in orbit around the moon to broadcast commercials every 15 minutes for rogaine, viagra, cialis and dietary supplements. For an extra $5 a month you can also get unlimited text messaging.
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