AUSTIN, TEXAS — Astronomers from The University of Texas at Austin have revived a plan to build a massive 100-meter wide mirror — made of liquid — on the surface of the moon.
The scientists described the importance of such a huge project in a new paper published in The Astrophysical Journal.
They say a giant moon-based telescope would be able to capture light from objects nearly as old as the Big Bang.
Liquid mirrors are lighter, simpler, faster to construct, and ten times cheaper than conventional glass telescope mirrors.
The key to a liquid mirror telescope is that the liquid must be rotated constantly.
When the liquid rotates, gravity pulls down on its surface, while inertia pulls it sideways at the edge of the dish.
As a result, the liquid forms a uniform and perfect parabola, the ideal reflecting surface for a telescope.
Work is underway to find the perfect mix of liquids, as it requires a liquid metal to drift on top of other liquids, plus a thin layer of material on top to minimize evaporation.
Liquid mirrors usually use mercury, but that won't work on the moon, as mercury will freeze in the very cold moon temperatures.
