June 21, 2007 — The first big telescope on the moon could be poured out of a barrel if Quebec astronomer Ermanno Borra has anything to do with it.
Borra and his colleagues have managed to float a thin layer of silver on a non-evaporating "ionic liquid" — sort of a room-temperature, molten salt — to make a liquid mirror that could be used on the moon as a gigantic, super-powerful telescope.
Ionic liquids are up to the task because they stay fluid down to about -145 degrees Fahrenheit (-98 degrees Centigrade) and don’t evaporate in a vacuum. The fluid could be poured out into a giant dish and gently spun — causing some of the liquid to move to the edges and form a naturally smooth and perfect curved surface to reflect and concentrate starlight.
"The liquid wants to stay parabolic," Borra told Discovery News. Micrometeorites or other minor disturbances on the moon would be fleeting and the liquid surface would return to its perfectly smooth curve again. "Whereas with a glass mirror, Nature conspires to wreck it."
Other than the unusual liquid mirror, the telescope would work just like glass-mirrored telescopes called Newtonian reflectors, named for their inventor, Sir Isaac Newton. A report on the ionic fluid telescope appears in the June 21 issue of the journal Nature.
"You could have a one-kilometer (wide) liquid mirror telescope," said Borra. Shipping a massive traditional glass mirror of even a small fraction of that size is completely impractical.
