International Liquid Mirror Telescope (ILMT)

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International Liquid Mirror Telescope (ILMT) Blog Image


Recently, the Union Minister of Science & Technology inaugurated Asia’s largest 4-meter International Liquid Mirror Telescope at Devasthal in Uttarakhand.

About International Liquid Mirror Telescope:

  • ILMT is the first liquid mirror telescope designed exclusively for astronomical observations and is the first optical survey telescope in India.
  • It has a 4-meter-diameter rotating mirror made up of a thin layer of liquid mercury to collect and focus light.
  • The metal mercury is in liquid form at room temperature, which is highly reflective and designed to survey the strip of the sky passing overhead each night. 
  • The Devasthal observatory is equipped with the largest aperture telescope available in India that will use Big Data and Artificial Intelligence/Machine Learning (AI/ML) algorithms to classify objects in the sky.
  • The telescope has three components: A bowl containing a reflecting liquid mercury metal, an air bearing (or motor) on which the liquid mirror sits, and a drive system.
  • The mercury is protected from the wind by a scientific grade thin transparent film of mylar.
  • The reflected light passes through a sophisticated multi-lens optical corrector that produces sharp images over a wide field of view and a 4k CCD camera, located above the mirror at the focus, records 22 arc-minute wide strips of the sky.
  • The data collected from the ILMT, over an operational time of 5 years, will be ideally suited to perform a deep photometric and astrometric variability survey.
  • Maintained by the Aryabhata Research Institute of Observational Sciences (ARIES).


Q1: What is element mercury?

Elemental or metallic mercury is a shiny, silver-white metal, historically referred to as quicksilver, and is liquid at room temperature. It is used in older thermometers, fluorescent light bulbs and some electrical switches. When dropped, elemental mercury breaks into smaller droplets which can go through small cracks or become strongly attached to certain materials.

Source: Union Minister Dr Jitendra Singh inaugurates Asia's largest 4-metre International Liquid Mirror Telescope at Devasthal in Uttarakhand in the presence of the Governor of Uttarakhand Lt. Gen (Retd.) Gurmeet Singh