Giant Moon Based Telescopes Will Detect Alien Life and Measure Mountains in Other Solar Systems

Fraser Cain at Universe Today reviews the giant space telescopes that will become possible. Space capabilities from SpaceX Super Heavy Starship and being able to build in space will enable 1000 to 1 million times larger projects on the moon and in cis-lunar orbits.


OWL-MOON: Very high resolution spectro-polarimetric interferometry and imaging
from the Moon: exoplanets to cosmology

A 100-meter space telescope on the moon will let us directly observe the height of mountains on exoplanets.

A giant moon telescope will let us answer three major questions in astronomy.
1) the detection of biosignatures on habitable exoplanets,
2) the geophysics of exoplanets and
3) cosmology.

Detecting Alien Life in Other Solar Systems

One of our main science objectives is the characterization of exoplanets and biosignatures. There are about ten potentially habitable planet candidates up to 10 pc. But there is no guarantee that even a single one will present biosignatures. We must enlarge the sample and go up to say 40 pc. An Earth-sized planet at 1 AU from a G star has a planet/star brightness ratio of 3.10^−9 for an albedo of 0.3. Thus, for a 8th magnitude star, it means a 32nd magnitude target. For 1 nm spectral resolution spectroscopy needed to detect atomic and molecular emission lines, consider the goal of 1000 photons detected in 3 hours. This needs a 50-meter telescope. To detect 500 photons in the bottom of absorption lines having a depth 10 times the continuum in 3 hours, one would need a 100-meter telescope.

To achieve this goal, two requirements are needed : 1/ a very large aperture to detect spectro-polarimetric and spatial features of faint objects such as exoplanets, 2/ continuous monitoring to characterize the temporal behavior of exoplanets such as rotation period, meteorology and seasons. An Earth-based telescope is not suited for continuous monitoring and the atmosphere limits the ultimate angular resolution and spectro-polarimetrical domain. Moreover, a space telescope in orbit is limited in aperture, to perhaps 15 meters over the next several decades (until we get on orbit space construction capabilities). Researchers propose an OWL-class lunar telescope with a 50-100 meter aperture for visible and infrared (IR) astronomy, based on ESO’s Overwhelmingly Large Telescope concept, unachievable on Earth for technical issues such as wind stress that are not relevant for a lunar platform. It will be installed near the south pole of the Moon to allow continuous target monitoring. The low gravity of the Moon will facilitate its building and manoeuvring, compared to Earth-based telescopes. As a guaranteed by-product, such a large lunar telescope will allow Intensity Interferometric measurements when coupled with large Earth-based telescopes, leading to pico-second angular resolution.

The Earth is 10 billion times fainter than the Sun and orbits close to its host star : viewed from 100 parsecs, the separation is only 0.01 arcsec. But this is well above the diffraction limit of a very large lunar telescope. We can study exoplanet atmospheres from a lunar platform, where there is no atmosphere to confuse our signal. Telescope size simultaneously guarantees a large number of earth-like targets. We cannot fail, if the will is there to develop known technology, with the aid of robotic resources in deep icy craters near the south pole, in permanent darkness and where temperatures approach 30K, with adjacent crater rims in perpetual sunlight to provide solar power.

Mountains and volcanos on planets

Some astronomy questions require the extremely high angular resolution from an Earth-Moon Intensity Interferometer. Telescopes on the Earth and Moon can work together to create a 380,000 kilometer telescope array.

Once an OWL-type telescope is installed on the Moon, or even a 10 meter lunar precursor, one could readily address optical Intensity Interferometry with unprecedented baselines and angular resolution. For instance it could measure the heights of mountains on transiting exoplanets. This is an important problem for the geophysics of planets. Weisskopf (1975) has shown that there is a relationship between the maximum height of mountains on a planet and its mass and the mechanical characteristics of
its crust.

The issue of mountain detectability has already been addressed for transiting planets (McTier & Kipping 2018). Researchers propose a significant improvement, Based on the principle of the detection of the silhouette of ringed planets by Intensity Interferometry as developed by Dravins (2016). With a 60 meter resolution at the 1.4 parsec distance of alpha Cen, for transiting planets, mountains will appear at the border of the planet silhouette during the transit. These observations will require very long exposures. During the exposure, the planet is rotating around its axis, leading to a washing-out of the features on the exoplanet.

The planet rotation period will be well known from the periodicity of its photometric data. Therefore, the mountain silhouette will appear in a 2D Fourier transform of long series of short exposure images at the planet rotation frequency. Moreover, volcanos can be detected as a temporary excess of red emission of the planet.

Oceans and Continents

The flux received from the glint of the ocean of an Earth-sized planet around a solar-type star at 10 pc and for an ocean albedo 6 %, 7 photons/sec with 30 m telescopes. The monitoring of this image would reveal the contours of the continents.

Earth Atmosphere as a Lens to Map the Surface of Pulsars – Terrascope » detector

It has recently been proposed to use the Earth atmosphere as a gigantic annular chromatic lens (Kipping 2019). It happens that the focal length of this lens is approximately the Earth-Moon distance, depending on the wavelength. Given the size of this lense, the amplification of the source flux is 20,000 compared to a 1 m telescope meter. With a 100 meter telescope on the Moon, the amplification would thus be 200,000 compared to a 30 meter telescope. Of course the images are of very poor quality, but this terrascope would be suited for very high spectral resolution or extremely high speed photometry of extremely faint sources (e.g.
very faint, yet undetected, optical pulsars). Given the 5° inclination of the lunar orbit with the ecliptic, this terrascope could explore a ± 5° band on the sky above and below the ecliptic, depending on the season.

An array telescopes on the Moon and earth (baseline of 380.000 km on average) corresponds to an angular resolution of 200 picoarcsecond at 600 nanometers. An Earth-Moon intensity interferometer would partially resolve the Crab pulsar.

New Telescope Technology

The Nautilus project or the WAET project should soon begin. The Nautilus project has designed new technology for cheap and light 8-
meter-class telescopes. This is based on a modified version of Fresnel lenses, made in light plastic. The WAET project is a very large 10 meter x 100 meter rectangular aperture. The optical quality of these two projects would not be suited for standard interferometry, but suffices for Intensity Interferometry and high resolution spectroposcopy.

A 100-meter diameter will allow statistical searches for life on the nearest 100 or so exoplanets (many of them Earth-like).

SOURCES- Universe Today, ESA, ESA Voyage 2050 White Paper- OWL-MOON: Very high resolution spectro-polarimetric interferometry and imaging from the Moon: exoplanets to cosmology
Written By Brian Wang,

47 thoughts on “Giant Moon Based Telescopes Will Detect Alien Life and Measure Mountains in Other Solar Systems”

  1. Help whom? Humans? Invariant with any success or lack of it in Terra-Luna transport, on cost parity basis, for each unit of mass of humans one can have about a hundred units of mass in machines. That follows from order-of-magnitude cost scales of human and machine lunar programs. So the very concept of “servicing”, as in “Bob drops by to turn screws and replace parts” is irrelevant to any lunar developments. It is machines or stay home, because if one team brings a 100kg of Bob, and another 10 tons of machines, Bob’s team invariably loses and goes home. Machines do not have a “down” unless it is built into them.

  2. it’s about time we figured out how many planets the alpha centauri star systems have and along with basic idea’s what their like. If even one planet is relatively nice we’ll be aspiring to get there.

  3. I’m open to any valid experiments. You must remember that finding the *majic* potion that works for an individual may be idiosyncratic, yet still work. More interested in allowing the experiment than legislating the result. Chiropractors had tough time getting permission in US, now they are trying to enforce their own monopoly. The market is not perfect, but power is corruption. (edit: I have heard multiple Swiss and Germans be surprised h is not here in US)

  4. I don’t see anything in the US, I live in Italy, and homeopathy here is
    well renowned for its excellent placebo effect. Worthless rubbish.

  5. Next time offer to pay up front, if you can pay what the insurance company would pay, it may work out for you. Insurance companies often only pay about 30% of what a doctor charges, this of course leads the doctor to charge more.

  6. Homeopathy is well practiced in Europe, for example. The U of Michigan med school was the American leader in this, until the AMA took over. Current stuff you see in US, esp the diluted to extreme stuff, is an intentional distraction so you won’t learn about it, give it a bad rep.

  7. They should treat the AMA worse than the Mafia for limiting the number of doctors, but not for preventing homeopathy, which
    takes your purse without even sparing your life.

  8. The U.S. healthcare system is pure armed robbery. If I were an elderly
    American with some money I would relocate in Cuba. Or at least in England. It is difficult to understand how you can put up with this.

  9. Pretty awesome. I was thinking about thermal dynamics, but probably not a problem to just cover the whole darned thing.
    Too bad we don’t have companies with equipment and experience to bid on these projects. Or facilities to provide building materials which do not need to be lifted from Earth.
    We will.

  10. No. Nothing like that. I believe that the majority of our space research dollars should support human expansion into space. At this juncture, we are witnessing sufficient national and commercial competition, that we can make up for lost momentum of the past few decades. We need more NASA involvement with commercial operators, but I believe that what we need most is nuclear power.
    We have done loads of research over the years, and have even built and tested the prototype engines.
    We need new engines using modern design and materials, infrastructure to deliver them, space law, and some reasonable business models.

  11. Luna is seismically active, with multiple scarcely understood seismic processes: tidal, tectonic, regolith dynamics, etc.

    If submicron dimensional stability is required, a tethered, slowly spinning, shielded structure in Solar orbit may be the best choice.

  12. The hope is we can go further out and get the same quiet as the Moon far side quiet is degraded. But a good place to start!

  13. One thing Luna gives for this application is a very large stable rigid body that all these separate mirrors and sensors can be mounted on.

    Their positions relative to each other must be stable to within wavelengths of light or better, and that’s much easier if you have a great slap of rock to mount them all on, compared to getting them to flying in formation in orbit somewhere.

    Flying in precise formation is a tech that we want to develop, but at this point it’s still on the wish list.

  14. Recently had shoulder surgery. The office quoted me for $2500.
    Now they want $2500 more. The total bill was over $45,000.
    Freaking ridiculous, considering that it was a two hour outpatient procedure.

  15. So many great things we can do on Earth still. We haven’t scratched the surface. Don’t get me wrong, I’d love to see moon bases and such, but we have spent ourselves into oblivion and need to focus on what can make the biggest difference now.

  16. Humans don’t just build things because they’re feasible.
    How much more will the super sized version cost? Can existing industry produce it? Can existing infrastructure transport & install it?
    etc etc etc…

  17. As the devil’s advocate, the hosp will often get nothing from the uninsured. But the big problem in US is the 100 year monopoly of the AMA, the power to prevent competition from homeopathy, for example, limit number of docs, on and on.
    The market has no chance.

  18. As Mr. Harlan Smith pointed out years ago, the far side of the Moon is the quietest possible place in the solar system for a radio telescope.

  19. I’ve recently been wondering if the easiest way to get >50 MW delivered to a lunar base wouldn’t be to send it down from a solar power satellite at L1 or L2. But that would mess up the chances of doing far-side radio telescopy.

  20. What we need is that bigger telescope but more telescopes. There is a lot of things going on in the universe that we are missing. What we need is a set of telescope in SPACE like TESS continuously monitoring the universe. The more the better.

  21. Solar orbit has unlimited capacity. The only benefit of Lx points is relative ease of communication. Now, as Mars is crawling with robots and satellites, that is evidently not worth any effort. A telescope in Solar orbit can do its work and send data via fat link to Lunar station, for example, where there is no limit on bands or bandwidth (no atmosphere, no legal mud, etc).

    What Luna should be used for is mining and materials manufacturing. Construction is better done in space. Also a comm station for reasons above.

  22. I have to agree to “why Lunar”?

    Space seems a better place. I guess the only thing I can think of here as a limitation is running out of Lagrange points to place them, at least within a serviceable radius of Earth.

    While the logistics of building on the Moon are greater than space, at least in the early days, I think there are many more possible locations for telescopes, etc..

    Once the initial infrastructure is there I suppose ISRU will help. Anyway, that’s maybe a trillion dollars into the future.

  23. I would guess that asteroid/comet mining are, at this point, a matter of when rather than if.
    At which point, the latest SDUHT (SuperDooperUnrealisticallyHumoungousTelescope) will switch from pure science to a straight resource exploration asset.

  24. I’ll take the mystery away now…there are mountain ranges on other planets and they don’t matter hill of beans to us. IF there is life out there, so what? I’m not going to change what I would eat for breakfast tomorrow. If there is life, we can’t do anything about it or with it. They might be coming right now to stomp us out anyway. Spend the money on studying our planet, namely the oceans.

  25. Did you attend then? I was with the ERPS group, helping to host the event. If Henry does one for 2020, it will be back in Phoenix. No word yet.

  26. Could be quite huge (many kilometers), but the problem is the limited ‘points of view’. Off axis aberrations are a bear for ultra-large, low f-number optics. 

    Better would be to hollow out and harden a large crater, line with fused regolith, and polish to a near-perfect spherical shape … but NOT make it into a mirror. Instead, build a very large parabolic mirror on an equally precise spherical bottomed platform, and establish a gas bearing to loft it a millimeter or so … and collect the gas at the edges to re-pump thru the bearing without appreciable loss. 

    Such a huge mirror could then be pointed at a MUCH larger field, making it an order of magnitude or two more useful. 

    Just Saying,
    GoatGuy ✓

  27. Tho’, technically and to be entirely fair, neither telescopes, super-colliders, ginormous magnets, or so far at least, hydrogen fusion research has helped drive the “standard of living” much. Hardly at all, actually.

    Investment in Science is a fine thing, and I’m not decrying the sentiment. Investment in human-kind is also a fine thing, and i’m not decrying THAT sentiment, either!

    If we REALLY want to “do something for the common good” that would revolutionize the economics of living in our First World country, it would be to pass a hard, cold, inescapable Law mandating (with NO exception) that all medical procedures from any institution, doctor, clinic or healthcare collective MUST be priced (and paid for) exactly the same, whether by insurance funny-money, or out of one’s wallet with cash.  

    It is stunningly duplicitous for ‘medical insurance’ companies to get between an 80% and a 93% pay-out discount for just about everything they ‘cover’. Its rape-of-the-cash-paying-public writ huge. My ’emergency clinic’ bill of $900 to get 14 stitches and a party bag of bandages … was paid by my insurance company to the tune of $110 cash-out.  

    If I had to pay the 900 dollar bill … it would have been an outrage. If my bill were the SAME $110 bill as the insurance company, I would have just paid for it right then and there.  

    See? Good for the common bloke and lass.
    Fair, too.

    Just Saying,
    GoatGuy ✓

  28. be practical if the main optics were supported by the regolith, perhaps with an intermediate material, and the secondary optics moved, ala Arecibo?

  29. Thing tho’ about Lunar dust is that quite unlike Terran dusts, there’s no air to comport them about. So, each dusty mote travels in essentially the same parabolic arc as if one were to chuck a brick at the same velocity. There is electrostatic dispersion, though. This mustn’t be underestimated.  

    For the most part though, just having a wall around the proposed scope, with a ‘no one enters here’ policy … would pretty much block most dust from the outside.  

    Just Saying,
    GoatGuy ✓

  30. So…

    I’m not exactly clear why a 100 meter OWL (“Over-Whelmingly Large”) telescope is being essentially copied from the whole OWL project. Freed from the problems of wind stresses and atmospheric aberrations, one might as well design a truly Lunar Out-Rageously Large … LORL (and we can pronounce it!) that is a straight engineering doable-with-out-too-much-credibility-stretching device. 

    Obviously larger than Earth-OWL (100 meters) because of Lunar surface ⅙ G.  Since mechanical sag and flexure would dominate larger designs, mass going up per cube of size mostly, its probably fair to take the square root of the G difference.  

    100 / √(⅙) = 250 m rounded…

    Now THAT is a telescope of serious power and undertaking. Easily able to get those 1 nanometer spectral line 500 photon counts in the same 2.9 hour exposure as the 100 meter Lunar OWL, but out to 100 parsec (328 LY). Still nowhere near large enough to directly image planets more finely than a single dim pixel, but still … in terms of angular resolution, the mother star would be 18 min-res units away. 35 pixels or more. 

    That’s at least what I think…
    Just Saying,
    GoatGuy ✓

  31. ⊕1 … which I almost didn’t give, ‘cuz of that last bit. But you’re also right there. GoatGuy ✓

  32. Like a new super collider?
    Certainly hope you aren’t saying “welfare state”
    Nothing drives a standard of living like science.

  33. Just imagine the dust. Landing or driving anywhere near this monstrosity
    would cause damage. Dust is abrasive and without an atmosphere it doesn’t
    just settle but can travel like a bullet.
    Best to set up an orbiting telescope – no dust, no gravity.

  34. The best place for a large telescope is in space, not on any rock with meaningful gravity.

    In space, there is no restriction on size, required structural strength is minimal, and there is no neutron halo as on the surface of Luna. Neutrons are BAD for sensitive electronics, or any solid-state electronics. Galactic radiation hits anything massive, makes neutron flux, mass moderates neutrons, they stick to any nucleus and produce nuclear reactions with high-energy chunks flying out – that is BAD for electronics that has that happening inside it.

    Acedemics are like children in a spanking-free jurisdiction. Insufferable.

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