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Giant Telescopes for the Moon

Start thinking about large telescopes on the Moon and the imagination quickly runs riot. With no atmosphere to contend with, a 50-meter instrument of the sort now under discussion would be able to dwarf what telescopes can do on Earth. Exoplanet detections would be commonplace, but that’s only a beginning, for this kind of telescope could take the spectra of the planets it finds and search for biomarkers.

Ponder this: Even a twenty-meter telescope would be seventy times more sensitive than Hubble, and able to detect objects 100 times fainter than what the James Webb Space Telescope will be able to see.

Now think about putting two telescopes on the Moon. Space them widely to take advantage of interferometry, creating an instrument that can, in essence, act as a single collecting surface. Mixing such possibilities with current work on detecting exoplanetary oceans and continents, we would be able to move quickly from the indirect signature of planets found by radial velocity, microlensing and transit methods to full-scale observation of planetary surfaces, key to the search for terrestrial-style worlds.

The trick, of course, is to get the necessary equipment to the Moon, but ponder the words of Peter Chen (NASA GSFC and Catholic University):

“We could make huge telescopes on the moon relatively easily, and avoid the large expense of transporting a large mirror from Earth. Since most of the materials are already there in the form of dust, you don’t have to bring very much stuff with you, and that saves a ton of money.”

Useful stuff, that dust. But Chen’s team has more than a few tricks up its sleeve. By using carbon nanotubes instead of carbon-fiber composite materials, they can bypass the need for glass to make telescope mirrors. The idea is to mix the carbon nanotubes with epoxies and lunar dust (the team used crushed rock of the same size and composition in their work) to create materials that can be spun to create a mirror blank. Coat this with aluminum and a highly reflective telescope mirror emerges. Says team member Douglas Rabin, “Our method could be scaled-up on the moon, using the ubiquitous lunar dust, to create giant telescope mirrors up to 50 meters in diameter.”

Spin-offs are also useful, and it doesn’t hurt the funding case one bit that this composite material could also be used to build the necessary habitats for a lunar base, not to mention mirrors needed for solar-power generation. Which goes to show that lunar dust, available in considerable abundance, can quickly be turned to our advantage. Sustaining a lunar observatory of this kind would inevitably lead to other kinds of science, including radio telescopes on the far side, placed so as to be free of present and future RF interference. All in all, a fine set of implications for a modest internal project at NASA running on a shoestring budget!

Comments on this entry are closed.

  • djlactin June 6, 2008, 11:44

    lack of atmosphere is a double-edged sword. yes, atmosphere distorts images, but it also protects against small meteorites. i just wonder how long before a high-speed dust mote would do the nasty to the optics…

  • Yoshi June 6, 2008, 17:37

    This is an very nice proposal, one gets not only one telescope on the moon, but one every some years. Together with optical interferometry, this implies the resolution would get better and better.
    And after another earth like planet in the habitable zone of another star is found, I believe funding will not be a big problem.

  • Bob Shaw June 6, 2008, 20:41

    As noted above, impacts would be a serious problem – not to mention electrostatically levitated dust. Monolithic Lunar optical telescopes are probably not such a good idea – but arrays of smaller telescopes would be rather interesting. If we were to see a large Lunar telescope, then a rotating liquid transit design would probably be the best design, rather than what seems to be something close to old-fashioned fibreglass!

    Bob Shaw

  • James M. Essig June 6, 2008, 21:04

    Hi Folks;

    I once read an article about a hypothetical lunar telescope wherein several hundred one hundred meter wide mirrors would be distributed over a area roughly a few hundred kilometers across in order, not only to produce a VLBI optical telescope, but also provide a large photon collection area.
    Accordingly, the tree lines of exo-planet mountains could be visible from as far away as 100 LY.

    An even more ambitious project would be to build membranous telescopes out beyond the orbit of Pluto composed of dozens to perhaps thousands of 10,000 km wide pressure deployable membranous reflector apparatus distributed over an area 100 million to one billion miles across is a VLBI on steroids. Such a telescope could in theory image the faces of ETI persons in the nearby galaxies and image buildings, tree lines, etc., at the edge of the observable universe. The membranes would have nanotech distortion correction devices to correct for Brownian motion based distortion, thermal distortion and the like. The caveat is the existence of powerful enough computers to link the optical signals gathered by all of the units into a single harmonious whole picture.

    I say let the fun begin with space based BLI telescopy.



  • george scaglione June 7, 2008, 14:37

    jim,everybody,tree lines on other planets visible from 100 light years!!! what a WONDERFUL INSTRUMENT that would be!! then you go on to mention being able to see alien faces!!!!! we are LUCKY TO BE ALIVE at a time when such ideas can be envisioned! yes my friend yes the light years will be crossed one way or another. lol stand by film at eleven! :) your friend george

  • James M. Essig June 8, 2008, 19:23

    Hi George;

    Thanks for the response.

    I had a correction to make to the above telescope posting. The dozens to perhaps thousands of pressure deployable membranous reflectors would need to each be atleast 10,000,000 km to 100,000,000 km wide inorder to collect enough optical frequency light to make a meaningful image unless one wanted to collect one photon on the order of every minute or so. Still, the use of ultra thin, nanotech actuated and nanotech deformed membranes just might work here.

    The collection area of the above lunar telescope could stand an improvement by a couple orders of magnitude also in order to obtain adequate time exposure photos. Still, in theory, it should be doable.

    Note that it is my policy to correct gross mathematical errors in my online postings whenever I have discovered them. However, perhaps even telescope with much greater resolution could be built as stellar scale engineering projects.


    Your Friend Jim

  • James M. Essig June 9, 2008, 15:57

    Hi George and Other Folks;

    A really strange idea occurred to me today which I have thought at times before but which I have never really elaborated on until today. Probably, just about every high school or undergraduate college student of Newtonian Physics has thought of this idea at some level or another but I bring it up because it fascinates me.

    The idea essentially involves the concept of total situational awareness of everything at the atomic quantum level that is occurring within our observable universe. My thinking is that if we could get a snap shot of what our region of the universe looked like just instants after the Big Bang, then maybe we could use some sort of hidden determinism at some sub quantum level to calculate the current state of our universe. The problem with this concept of hidden determinism is that it suggests hidden quantum variables, a concept that is highly frowned upon by modern quantum theorists. Perhaps the effects of quantum indeterminism are truly washed out at the macroscopic level for macroscopic level energy or mass and spatial-temporal events. Perhaps, even though quantum mechanical events appear to happen at random and the so called random probability of these events is determined by the so called deterministic time evolution of the associated wave-functions, some or all of the aspects of the respective collapses of the wave functions is somehow determined by macroscopic events that are completely deterministic. When and how a wave-function actually decides to collapse is not the same thing as its time dependent evolution.

    Perhaps, since the force of gravity is about 10 EXP – 39 times the strength of the electromagnetic force, miniscule gravitational radiation signals could provide us a high resolution snap shot of epochs just after the instant of the Big Bang that might have many orders of magnitude, perhaps even 39 orders of magnitude greater resolution than that which electromagnetic radiation can provide.

    It would also be interesting to build a huge number of super high resolution optical telescopes to search the entire visible universe for all or nearly all planets containing ETI or for less advanced or developing animal life. Granted, that we would be only able to see back in time, approximately 4 years for the Proxima Centauri System to 13.7 billion light-years for the edge of the observable universe, we could still get a pretty good historical account of our visible universe this way.



  • george scaglione June 10, 2008, 9:08

    jim thank you very much for trying to provide more correct information…as always i find large engineering projects to be very exciting! good stuff buddy!!! also, i just read an e mail from a buddy in the air force advising that mccain is for a trip to mars and that obama thinks that space should become “news” again! one quote from obama too…”i grew up on star trek ad believe in the final frontier”.encouraging things to hear cause heck lets face it one of those guys will be the new president in seven months! thank you all,your friend george

  • ljk June 16, 2008, 11:57

    A cryogenic liquid-mirror telescope on the moon to study the early universe

    Authors: Roger Angel, Simon P. Worden, Ermanno F. Borra, Daniel J. Eisenstein, Bernard Foing, Paul Hickson, Jean-Luc Josset, Ki Bui Ma, Omar Seddiki, Suresh Sivanandam, Simon Thibault, Paul van Susante

    (Submitted on 13 Jun 2008)

    Abstract: We have studied the feasibility and scientific potential of zenith observing liquid mirror telescopes having 20 to 100 m diameters located on the moon. They would carry out deep infrared surveys to study the distant universe and follow up discoveries made with the 6 m James Webb Space Telescope (JWST), with more detailed images and spectroscopic studies.

    They could detect objects 100 times fainter than JWST, observing the first, high-red shift stars in the early universe and their assembly into galaxies. We explored the scientific opportunities, key technologies and optimum location of such telescopes.

    We have demonstrated critical technologies. For example, the primary mirror would necessitate a high-reflectivity liquid that does not evaporate in the lunar vacuum and remains liquid at less than 100K: We have made a crucial demonstration by successfully coating an ionic liquid that has negligible vapor pressure. We also successfully experimented with a liquid mirror spinning on a superconducting bearing, as will be needed for the cryogenic, vacuum environment of the telescope. We have investigated issues related to lunar locations, concluding that locations within a few km of a pole are ideal for deep sky cover and long integration times.

    We have located ridges and crater rims within 0.5 degrees of the North Pole that are illuminated for at least some sun angles during lunar winter, providing power and temperature control. We also have identified potential problems, like lunar dust. Issues raised by our preliminary study demand additional in-depth analyses. These issues must be fully examined as part of a scientific debate we hope to start with the present article.

    Comments: 35 pages, 11 figures. To appear in Astrophysical Journal June 20 2008

    Subjects: Astrophysics (astro-ph)

    Cite as: arXiv:0806.2241v1 [astro-ph]

    Submission history

    From: Ermanno F. Borra [view email]

    [v1] Fri, 13 Jun 2008 13:14:09 GMT (581kb)


  • forrest noble June 24, 2008, 19:40

    Hey Jim, George, ljk

    Nice to discuss something close to certainty. Seems like with such a EM radiation protected base, cryogenic liquid lenses for optical telescopes would be really something. How about a VLB radio telescope array that would be close to the entire circumference of the dark side of the moon. They’re not thinking big right now because the BB asserts that we are “close to seeing the dark ages” of the universe. Their contention is that nothing will be seen much beyond what we are now seeing . I think they are 100% wrong on this their only current prediction. I just looked it up on Google. Nothing! No other present predictions.

    your friend forrest

  • george scaglione June 25, 2008, 10:14

    forrest and everybody, thank you very interesting points but who knows where it can all end up! lol just told somebody else that i do wish that i could acess a computer from the year 2208 ! could have alot of questions answered! tragically at the moment i can not. we are just,lol,going to have to wait and see.but hahahaha just like kirk, I WANT ANSWERS! thank you very much guys your friend george

  • ljk July 9, 2008, 15:15

    A Telescope Made of Moondust

    NASA Science News for July 9, 2008

    Mix moondust with epoxy, add a dash of carbon nanotubes, and spin. The result? A parabolic mirror perfectly suited for a giant lunar observatory. A NASA-supported scientist has discovered this new recipe for making telescopes out of moondust, and to prove it works he has spun a “moondust mirror” here on Earth.



  • ljk September 9, 2009, 12:04

    Science from the Moon: The NASA/NLSI Lunar University Network for Astrophysics Research (LUNAR)

    Authors: Jack O. Burns (1,2), the LUNAR Consortium ((1) University of Colorado, (2) NASA Lunar Science Institute)

    (Submitted on 8 Sep 2009)

    Abstract: The Moon is a unique platform for fundamental astrophysical measurements of gravitation, the Sun, and the Universe. Lacking a permanent ionosphere and, on the farside, shielded from terrestrial radio emissions, a radio telescope on the Moon will be an unparalleled heliospheric and astrophysical observatory.

    Crucial stages in particle acceleration near the Sun can be imaged and tracked. The evolution of the Universe before and during the formation of the first stars will be traced, yielding high precision cosmological constraints.

    Lunar Laser Ranging of the Earth-Moon distance provides extremely high precision constraints on General Relativity and alternative models of gravity, and also reveals details about the interior structure of the Moon.

    With the aim of providing additional perspective on the Moon as a scientific platform, this white paper describes key research projects in these areas of astrophysics from the Moon that are being undertaken by the NLSI-funded LUNAR consortium.

    The NASA Lunar Science Institute (NLSI) recently funded 7 mostly university-based teams to study science of, on, and from the Moon. The LUNAR consortium was selected by the NLSI for astrophysical research and education that focuses on the key, unique instruments that most effectively take scientific advantage of sites on the lunar surface – low frequency heliophysics and cosmology, and lunar laser ranging.

    We are submitting this white paper to the Planetary Sciences Decadal Survey to provide additional perspective on the value of Moon for conducting cutting-edge research in astrophysics and gravitational physics by describing our key projects for LUNAR.

    This program of astrophysics from the Moon complements as well as takes advantage of expected scientific infrastructure on the Moon during the next few decades.

    Comments: 8 Pages: Submitted as a white paper to the planetary sciences decadal review

    Subjects: Cosmology and Extragalactic Astrophysics (astro-ph.CO); Solar and Stellar Astrophysics (astro-ph.SR)

    Cite as: arXiv:0909.1509v1 [astro-ph.CO]

    Submission history

    From: Eric Hallman [view email]

    [v1] Tue, 8 Sep 2009 15:40:04 GMT (611kb)


  • ljk December 29, 2011, 22:55


    Posted on December 21, 2011

    by Jon Lomberg

    One of the many pleasures of living on the Big Island of Hawaii is that astronomy and space exploration are considered local news. I like that idea of “local”. It’s similar to the concept of “galacticity”, as coined by Steve Durst, founder and president of the International Lunar Observatory Association (ILOA)..

    Galacticity is the perspective that sees our world set against its real backdrop—the vast Milky Way Galaxy. I recently returned from a trip to Asia with Steve, where he brought me to speak about the Galaxy Garden at his Galaxy Forum events in Beijing and Tokyo, where we hope to find partners in creating “sister” galaxy gardens in China and Japan.(News about that exciting trip in an upcoming post)

    Steve is working with another old friend, Bob Richards, a lunar explorer whose company Moon Express (ME) is vying for the $30 million Google X Prize. The prize will be awarded to the first private, non-governmental group that can send a small spacecraft to soft-land on the Moon, traverse a distance of 500 meters, and transmit a hi-def image and video back to Earth. Bob’s venture, ME, is considered a serious contender by our knowledgable sources.

    The payload that ME will carry is the ILOA’s project—the first astronomical observatory to operate remotely on the lunar surface. As a gesture of galacticity, the “first light” image that traditionally heralds the existence of new observatories will take as its first image, the center of the galaxy. One more small step for Man, or at least machine.

    Full article here: