Mirror, Mirror on the Wall, What's the Best Telescope of All?

Lenses are used to converge or diverge light in various optical and electronic devices and the first written records of the use of a lens date to Ancient Greece, in 424 BC. The optical zoom lenses in professional television cameras can have a magnification ratio as high as 100x.

A group of scientists claim to have created the most efficient telescope lens ever. It's actually a liquid surface of mercury, coated with a thin layer of silver metal that creates a highly reflective mirror with the ability to produce the sharpest images a telescope could ever see.

Researchers led by Ermanno Borra of Laval University in Quebec, Canada, coated the surface of an ionic liquid - a fluid made only of charged particles, much like the one produced by heating table salt above 1,472 degrees Fahrenheit (800 degrees Celsius) - with a silver film layer.

The production technique is not too complicated, since applying an electric current to silver strands suspended in the ionic liquid while in a vacuum environment, makes the silver evaporate and "that coats the liquid with a thin reflective layer of metal," Borra said. "It's basically the same technique used to coat a glass mirror with aluminum or gold."

They think that such a liquid lens could be used on a radical new telescope. The proposition of another American astronomer Roger Angel, at the University of Arizona who was also a co-author on the study, is that we build a giant liquid-mirror telescope on the Moon, saying that it will be hundreds of times more accurate and sensitive than even the Hubble Space Telescope.

He says it will have to use a rotating observation dish made of liquid and that it will be the largest in the world, well, the Moon, actually. This telescope could detect objects up to 1,000 times fainter than even the James Webb Space Telescope, a next-generation orbiting observatory set for launch in 2013.

"The mirror is liquid, so you can carry it in a jug on a rocket and take it to the moon," said Borra. "Then you pour it into a dish...if there is a dimple somewhere in the container, the liquid simply flows to fill it up."