Decoded: What is Thirty Meter Telescope? Why is it significant for India?

The Thirty Meter Telescope, featuring a 30-meter primary mirror and advanced adaptive optics, aims to explore fundamental questions about the universe

The United States, India, Canada, China, and Japan are joining forces on a groundbreaking international project — the Thirty Metre Telescope (TMT)— set to transform our understanding of space and the universe.

What is the Thirty Metre Telescope?
 

The Thirty Metre Telescope is a state-of-the-art astronomical observatory designed to explore some of the most fundamental questions about the universe. With its enormous 30-meter primary mirror and advanced adaptive optics, the TMT will enable scientists to observe cosmic objects in unprecedented detail, offering new insights into the cosmos.

https://youtu.be/RsDhHoWTiVk

Scientific goals of the TMT
 

The TMT will address several key questions in astronomy, including:

 

- Formation of the first galaxies and stars: Investigating how the first galaxies and stars formed after the Big Bang.

- Galactic evolution: Understanding how galaxies evolve over time.

- Supermassive black holes: Exploring the relationship between supermassive black holes and their host galaxies.

- Star and planetary system formation: Studying the processes behind the formation of stars and planetary systems.

- Exoplanet characteristics: Examining the properties of planets outside our solar system.

Site selection challenges
 

Originally planned to be built on Mauna Kea in Hawaii, a premier location for astronomical observations, the TMT faced opposition from indigenous Hawaiians who consider the site sacred. As a result, alternative locations such as the Observatorio del Roque de los Muchachos in Spain’s Canary Islands are now being considered.

Cutting-edge equipment
 

The TMT will feature several high-tech instruments:

- Infrared Imaging Spectrometer (IRIS): Designed for detailed infrared observations.

- Wide-Field Optical Spectrograph (WFOS): Capable of conducting a broad range of optical observations.

One of the standout features of the TMT is its mirror system:

- Primary mirror: Comprising 492 hexagonal segments, the primary mirror spans an impressive 30 meters in diameter.

- Secondary mirror: Made up of 118 smaller hexagonal segments.

- Tertiary mirror: Measuring 3.5 meters by 2.5 meters, this mirror is centrally positioned within the primary mirror.

Advanced Adaptive Optics
 

The TMT’s Adaptive Optics System, known as the Narrow Field Infrared Adaptive Optics System (NFIRAOS), uses deformable mirrors and laser guide stars to correct for atmospheric turbulence, significantly enhancing image clarity. Indian scientists have been instrumental in this endeavour, developing a tool that generates an all-sky catalog of near-infrared (NIR) stars, ensuring the TMT produces superior images.

India’s significant contribution to the TMT project

India has played a crucial role in the Thirty Meter Telescope (TMT) project, significantly supported by institutions such as the Indian Institute of Astrophysics (IIA) in Bengaluru, the Inter-University Centre for Astronomy and Astrophysics (IUCAA) in Pune, and the Aryabhatta Research Institute for Observational Sciences (ARIES) in Nainital. These institutions have contributed hardware, instruments, software, and funding totalling $200 million.

A notable contribution from Indian researchers is the development of an open-source tool that creates an infrared star catalog for the TMT’s Adaptive Optics System (AOS). This tool is essential for the telescope's ability to produce sharp and clear images by compensating for atmospheric distortions. Researchers at the IIA in Bengaluru, led by Sarang Shah, have developed an automated code to generate this catalog, allowing the TMT to use Natural Guide Stars (NGS) to correct atmospheric effects and ensure successful operation.