Radio Telescopes on Moon to Study Cosmic Dark Ages

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."

Comments

Outstanding

[Protonk]

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

[Dr. Eggman]

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

[Protonk]

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

[Protonk]

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

[CodeBuster]

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, 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

[Nazlfrag]

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

The Standard Objection Applies..

[QuantumG]

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..

[F�an�ro]

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 L2 behind the moon.

To send signals back you would need a relay satelite thougth

A number of other interesting concept studies ...

[boot_img]

are also being funded. Follow the last link

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.

Why do you say that?

[WindBourne]

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:Hrrmmm

[urcreepyneighbor]

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

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.

Regards,

Padi Boyd
for the Ask an Astrophysicist HTH.

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

[rijrunner]

The observatory does not have to be directly opposite the Earth. Just behind the edge would work. You could then run a fibre-optic cable to a location nearby that is visible to Earth.

Next Generation?

[His Shadow]

Didn't Sagan want this before the end of the Millennium? Could have been done, too.