Liquid telescope on moon now a step closer to reality

Construction of a liquid telescope on the moon has taken another step forward.

Washington, June 21 : Construction of a liquid telescope on the moon has taken another step forward.

The international team of researchers collaborating on the project have found a combination of materials that can be help create a highly reflective liquid mirror capable of functioning even under harsh lunar conditions.

Liquid mirror telescopes differ from conventional telescopes by their primary mirrors-the ones that gather and focus light-which are made from a reflective liquid instead of polished glass.

Poured into a spinning container, the liquid spreads out and forms a thin, perfectly smooth, and parabolic shape that can be used as a telescope mirror.

Way back in 1991, in a paper published in the Astrophysical Journal, Professor Ermanno Borra, from Universite Laval's Center for Optics, Photonics, and Laser, had suggested the building of a liquid telescope on the moon.

In that paper, he had demonstrated the practical and economic advantages of liquid mirror telescopes over their conventional counterparts and explained how an observatory free from the Earth's atmospheric disturbance could further man's understanding of the early universe.

The project finally saw the light of the day, when it received financial support from the NASA Institute for Advanced Concepts.

According to Prof. Borra, the project's main challenge was to find a liquid capable of resisting the conditions on the moon's surface and functioning in temperatures below -143 degrees Celsius, which is required for infrared observations.

Now Prof. Borra and his team have reported in the June 21 edition of Nature, how they successfully coated an ionic liquid with silver by vaporizing it in a vacuum, something never before achieved in the field of optics.

According to him, the resulting silver layer is perfectly smooth, highly reflective, and remains stable for months.

The ionic liquid on which it lies, also, does not evaporate.

"The liquid mirror envisioned for the lunar telescope would be 20 to 100 meters in diameter, making it up to 1,000 times more sensitive than the proposed next generation of space telescopes," said Prof. Borra.

However, such a lunar telescope will not be available to researchers in the near future, he said.

"If we hadn't found the solution described in our article in Nature, it would have meant the end of the whole project," he added.

ANI