India to make “iris” of biggest telescope ever

India to make "iris" of biggest telescope ever

Sometime in 2023, a 30-metre man-made “eye” will open atop the Hawaiian volcanic dome of Mauna Kea in search of life beyond the solar system. And India would have contributed its “iris”.

Barely a month after signing in as a full partner in the $1.4 billion Thirty-Metre Telescope (TMT) project jointly developed by five nations, India is all set to make sensors and actuators that will keep the huge mirror of the biggest telescope in place.

An artist’s impression of the $1.4 billion Thirty-Metre Telescope.
An artist’s impression of the $1.4 billion Thirty-Metre Telescope.

“We have completed the tests. We are ready,” said Indian Institute of Astrophysics (IIA) scientist B Eswar Reddy. IIA, Aryabhatta Institute of Observational Sciences (ARIES), Nainital and Inter-University Centre for Astronomy and Astrophysics (IUCAA) constitute the Indian arm of the consortium that also comprises labs from Canada, the US, China and Japan.

Edge sensors and actuators are crucial components of the telescope as the huge mirror is not a single piece, but a composite of 492 hexagonal segments. Each segment is controlled by three activators and two edge sensors along each inter-segment gap to ensure accurate optical images.

Eswar told the 102nd Indian Science Congress that India plays a pivotal role in setting up the telescope with a resolution 12 times better than that of the Hubble Space Telescope. “India will be involved in polishing the primary mirror and setting up its control system, besides developing electronics, edge sensors and actuators,” Reddy said.

The US will make the primary mirror segments, while China comes up with the tertiary mirror. Canada will put in place the dome and Japan the telescope structure.

TMT will strengthen the perennial search for intelligent life elsewhere, as it provides direct imaging of planetary systems. It will also help astronomers study planetary atmospheres, their origin and development.

While collaboration replaces competition as the mantra of astronomy and space science, India is a sought after partner. On top of the cosmic ventures, along with TMT, is the Square Kilometre Array (SKA), a next-generation radio telescope project in which India leads one of the nine packages.

SKA will be 30 times more powerful than the best radio astronomy facility that exists today. Besides looking for extraterrestrial life, SKA hopes to help understand dark energy, sources of magnetic fields and the origin of stars and galaxies.

“India is leading the work package involving the telescope’s manager, which will effectively act as the telescope’s brain or central nervous system,” says Professor Yashwant Gupta, dean of the Giant Metrewave Radio Telescope (GMRT) located near Pune. GMRT has been designed and built by NCRA, a national centre of the Tata Institute of Fundamental Research.

India to make "iris" of biggest telescope ever
(From right) The Nasa Infrared Telescope Facility, Keck I, Keck II, and Subaru Telescopes at the Mauna Kea Observatories, Mount Mauna Kea, Hawaii. The world’s biggest telescope TMT will be built here. (Getty Images photo)