The world’s largest liquid telescope is ideal for observing the stars.
Located at the Devasthal Observatory in the Himalayas of India, at an altitude of 8,038 meters (2,450 meters), the 15-meter International Liquid Mirror Telescope (ILMT) is the first liquid telescope to be built directly for astronomy.
Most telescopes use glass mirrors, but as the name ILMT indicates, its mirror is made of a thin layer of Mercury that floats in 10 microns of compressed air and rotates every eight seconds. “By comparison, human hair is about 70 microns,” said Paul Hickson, an astronomer at the University of British Columbia. The latter helps create a telescope in a statement (opens in a new tab). “Air bearings are so sensitive that even smoke particles can damage them.”
Rotation causes the liquid Mercury to form a parabolic state like a contact lens. This condition allows the telescope to focus light into the deep atmosphere. Glass binoculars are also parabolic, but shaping a solid object requires extra effort, so liquid crystal mirrors are more expensive than conventional ones.
The tradeoff is that ILTM is positioned in one place, so it only looks at the one-night skyline as the Earth orbits under it. But as the telescope will focus on one area, it is best to see passing objects such as supernovas and asteroids.
“The data collected will be well suited to conduct a comprehensive study of the diversity of images and stars over a five-year period,” Jean Surdej, program director and astronomer at the University of Liège, Belgium, and the University of Poznan, Poland, said in a statement.
Expected to begin exploring science later this year, the ILTM will be operational from October to June each year, closed during the monsoon season in India. The project is an international collaboration between institutions in India, Belgium, Poland, Uzbekistan, and Canada.