Liquid Mirror Telescope For Moon Studied By NASA

A Lunar Liquid Mirror Telescope (LLMT) is under study thanks to a grant from NASA. J. Roger Angel, a regents professor at the University of Arizona, is leading a project to study the feasibility of a 100 meter LLMT at the moon's south pole.

Why liquid mirrors? Ever since 1668, when Isaac Newton built the first reflector telescope with a one-inch diameter mirror made of metal, astronomers have longed for bigger parabolic mirrors. Opticians expend a great deal of effort to grind larger and larger pieces of glass to just this shape.

Liquid Mirror Telescopes were first talked about several hundred years ago. Imagine a bowl of mercury at the center of a lazy susan. When you give it a spin, the surface of the liquid forms that highly prized shape - a parabola. The bigger the bowl, the bigger the resulting mirror.

The first serious attempts to actually build a LMT took place in the early twentieth century. Robert W. Wood, a physicist at Johns Hopkins University, built a working telescope, but could not accurately control the speed of the turntable, resulting in a mirror with a variable focal length. (The rotation must be controlled to less than one part in 100,000 during exposure.) Pictures of star trails were focused in some places, but blurry in others.


(The Large Zenith Telescope mirror)

The LMT concept has been made to work. The Large Zenith Telescope at the University of British Columbia uses a 6-meter mirror, making it the third largest optical telescope in North America. It was built at a cost of approximately $1 million. A telescope with a conventional glass mirror of the same size would cost $100 million.

It is hoped that similar savings might apply when constructing telescopes on the moon. In addition, the moon is completely free from atmospheric absorptions and distortion.

The only disadvantage of the LMT is that you cannot tilt it; it must remain perpendicular to the local gravitational field. You can only use it to look at what is directly above the telescope; however, a mirror of this size could take a very penetrating look at its patch of sky.

"You would be seeing things farther back in time than anyone has ever seen any galaxy or star or quasar," [Angel] explained. "It could give you a chance to see what was happening at a very early time."
(From J. Roger Angel and the LLMT)

Obviously, for such a project to be attempted, there would need to be substantial infrastructure already im place on the moon. As Dr. Angel remarked, "You could not justify that kind of infrastructure (just) to build this kind of telescope, but if the infrastructure already were there, this is something that looks feasible to do."

There is a very early reference to a large liquid mirror telescope in science fiction; but this LMT is on Mars, not the moon. In his excellent 1934 novella Old Faithful, author Raymond Z. Gallun writes about a Martian named 774, who has a desperate need to contact Earth:

Piercing the dome, opposite the upper end of the cylinder, was a circular opening through which a portion of the starlit sky was visible; and at the base of the cylinder a great bowl rotated rapidly, like a huge wheel... The bowl contained mercury. As the container spun on its perfectly balanced axis, centrifugal force caused the mercury to spread in a thin, precisely distributed layer over the inside of the bowl, forming a concave surface that acted admirably as a mirror for Number 774's gigantic reflecting telescope. It's area, and its consequent light-gathering capacity, was many times greater than any rigid mirror that could have been constructed without flaws.
(Gallun appears to err in his use of the LMT; read more about the Martian LMT)

Read more about J. Roger Angel and the LLMT, read more about LMTs at Space.com or take a look at the Large Zenith Telescope. Thanks to Winchell Chung for the tip and the sf for this story.

Scroll down for more stories in the same category. (Story submitted 2/5/2006)

Follow this kind of news @Technovelgy.

| Email | RSS | Blog It | Stumble | del.icio.us | Digg | Reddit |

Would you like to contribute a story tip? It's easy:
Get the URL of the story, and the related sf author, and add it here.

Comment/Join discussion ( 23 )

Related News Stories - (" Space Tech ")

Humanity Star LEO Advertisement?
'Everyone has noticed those enormous advertisements...' Jules Verne, 1889.

Bigelow Prepares Inflatable Lunar Hotel
'Suddenly, hitherto unheard-of sums of money became available for investment in civilian orbital stations.' - Carl Sagan, 1985.

NASA SEXTANT First With X-Ray Nav In Space
'You need at least four beacons for an accurate fix.' - Harry Harrison, 1956.

Subsurface Martian Ice Slabs Piece Of Cake For Miners
'One shy little fellow with bloodshot eyes of old-time drillman stood up. 'I'm an ice miner,' he said.' - Robert Heinlein, 1966.

 

Google
  Web TechNovelgy.com   

Technovelgy (that's tech-novel-gee!) is devoted to the creative science inventions and ideas of sf authors. Look for the Invention Category that interests you, the Glossary, the Invention Timeline, or see what's New.

 

 

 

 

 

Current News

A 'Genuine Nanorobotic Production Factory'
'Microscopic machinery, smaller than ants, smaller than pins, working energetically, purposefully - constructing something...'

Neuromorphic Computer Offers Non-von Neumann Architecture
Fires faster than brain at 1/10K energy.

Evorus Your Crowd-Powered Conversational Assistant
'...the DS [Daily Schedule] was suddenly transformed into a valued confidante.'

Mealworms Food Of The Future
Get your grubs on.

Alibaba's AI May Read Better Than You
'Mike ... could accept other languages and was doing technical translating - and reading endlessly.'

Musk's Boring Flamethrower
'Skeletons in tatters. Burned by a flesh gun'

Humanity Star LEO Advertisement?
'Everyone has noticed those enormous advertisements...'

Nissan ProPILOT Slippers Are Self-Parking, Autonomous
Beyond science and fiction.

Atomristors - Atomic Memristors - Using Thin Nanomaterials
'I could almost feel those little tunnel junction neuristors working, forming their own interconnections as I operated it.'

Bigelow Prepares Inflatable Lunar Hotel
'Suddenly, hitherto unheard-of sums of money became available for investment in civilian orbital stations.'

Drunk Driver Of Tesla Claims Autopilot Was In Charge
'Mr. Garden, you are in no condition to drive.'

Medical Exoskeleton From Cyberdyne Gets FDA Approval
It's been a long road for HAL-5; I started writing about it in 2005.

Fungi-Infused Concrete Repairs Itself
'I noticed that curious mottled knots were forming, indicating where the room had been strained and healed faultily.'

Shiftwear Display Shoes
'He unlaced her shoe and glanced at its readout.'

NASA SEXTANT First With X-Ray Nav In Space
'You need at least four beacons for an accurate fix.'

GM Introduces Cruise AV With No Steering Wheel
'How about the steering wheel?' ... 'I do not need one.'

More SF in the News Stories

More Beyond Technovelgy science news stories

Home | Glossary | Invention Timeline | Category | New | Contact Us | FAQ | Advertise |
Technovelgy.com - where science meets fiction™

Copyright© Technovelgy LLC; all rights reserved.