Liquid mirror telescope technology is a fairly new and rapidly progressing technology that already shows a huge potential, reminding us of the need to never stop improving the telescope technology we use today. Liquid mirror telescopes are telescopes that use reflective liquids such as mercury instead of solid glass as mirrors.
The history of liquid mirror telescope can be traced to Ernesto Capocci of the Naples Observatory in 1850, who described the concept of a parabolic mirror formed by rotating a vessel of liquid mercury. He did not follow up on this idea, and it is not until 1872 when an English astronomer Henry Skey build a first working liquid mirror telescope, with two different, but equally successful techniques: an electromagnetic engine and a small hydroelectric turbine.
Further research was needed to build a high-quality instrument that could be used for astronomical purposes, and only thirty-five years later Prof. Robert Wood of Johns Hopkins University began experimenting with the idea of the Mercury paraboloid as a reflecting telescope. While he was able to obtain photographs of two double star systems, abd published three papers in 1909, he did not pursue the idea of liquid mirror telescopes further, due to restrictions of the technology. The1980s brought a new wave of interest towards the technology due to a Canadian researcher Ermanno Borra, who, together with his colleagues, built on Woodâ€™s findings and conducted optical tests that showed that large, direction-limited mirrors are a reality and can have practical astronomical applications. (Gibson, 1991).
When the use of large diffraction-limited mirrors was successfully tested in the lab, the researchers focused on applying this technology to real world scenarios. Liquid mirror telescopes have seen limited adoption since 1990s, with the biggest telescope to date, a 6-meter Large Zenith Telescope, used for atmospheric measurements and operated by the University of British Columbia in Vancouver. (Dorminey, 2012). A project of The International Liquid Mirror Telescope is under development at Devasthal, India, and the feasibility and potential of using liquid mirror technology for large telescopes on the Moon is explored. Such telescopes could provide more detailed images and detect objects 100 times fainter than James Webb Space Telescope (Angel et al., 2008).