Rotating Mercury Lunar Observatory

Fraser Cain writes "Universe Today is reporting on a proposal under consideration by NASA from Dr. Robert Angel at the University of Arizona. He wants to build a 100-meter liquid mirror telescope into a crater on the Moon. It would only be able to look at a specific spot in the sky, but the view would bury Hubble's Deep Field Survey." The challenges of off-Earth construction are left as an exercise for the reader.

Comments

Great idea

[mnmn]

I used to imagine a telescope of a pan filled with mercury, spinning, and attached to the lens assembly via rods on top, and the whole device turning to create gravity for the mercury so it stays in the pan, while the whole telescope like a lighthouse scans the skies.

The moon will allow greater sized assemblies, and gravity doesnt have to be induced. The problem is the lack of control, which can be offset by building multiple telescopes at various lattitudes.

So whats difficult? A large container which can carry mercury, even a large plastic bag in a satellite dish mesh can do. The structure will sit on a motor that spins. The motor will not induce any vibrations into the mercury pan, for the former telescope I had a magnetic levitation rotation device, or at least a string that dangles the pan while magnets rotate it. The magnets cannot be in two D structures like regular motors since thats vibration there, so a uniform magnetic field is applied while current is passed between the center of the pan and its sides to allow for a continuous DC motor. If the current can be passed with no contacts, we can achieve real smooth rotations and no frictions or vibrations... again magnetic levitation would be a great idea here since the moon can be cold enough for ceramic superconductors, and clear enough for solar panels to power the thing.

The smaller we make the mercury pan, the more vibration prone it gets as we increase the resolution, so we can expect moon earthquakes to be a problem whenever something hits the surface. Shouldnt be frequent enough to cause a problem...

Unlike Hubble, the structure should be radiation-hardened, low-maintenance, no mechanical parts, no chemical reserves object, except for the mercury container. If spun fast enough, the container can reflect light from greated angles removing the problem of lack of control.