Humans have been fascinated with space since time immemorial. Man has looked to the skies in hopes that the cosmos will provide answers to a multitude of questions from the very beginning of time. While Aristotle might have been the first to systematically record planetary movements and devise models about the universe, he will certainly not be the last to do so.
Mankind’s fascination with spatial objects and the cosmos has led to research spanning over 2,000 years and continuing to this day. Early astronomers created and studied models of the universe that featured the Earth at the very centre of the cosmos. Over time, human understanding of space has evolved, not just in terms of the treasure trove of knowledge we have amassed, but also in how we study the universe. From staring up at the sky with the naked eye to using rudimentary telescopes, modern technological advancements have enabled the construction of space stations and observatories that further our knowledge of the universe every single day. One such endeavour to understand our universe better came in the form of the Thirty Meter Telescope International Observatory. This telescope stands on centuries of research and scientific innovation and represents a massive leap forward in our study of the world we live in. The successful functioning of such an endeavour would be a huge testament to the progress made in improving and strengthening our technological and research capabilities.
The Thirty Meter Telescope International Observatory has been conceived to become one of the greatest scientific endeavours ever undertaken. The TMT International Observatory aims to create a facility that will help man on his quest to better understand the universe he is a part of. Not only does this project have the potential to revolutionize our understanding of our solar system and what exists outside of it, it also endeavours to forge a model of community, inclusion, mutual respect, and collaboration. This project is an international collaboration between leading astrophysics and scientific institutions in the USA, Canada, China, Japan, and India. The California Institute of Technology, the University of California, the National Research Council of Canada, the National Institutes of Natural Sciences of Japan, and the Department of Science and Technology of India are all members of the international observatory. The Association of Universities for Research in Astronomy acts as an associate member.
The preferred site for the international observatory is Mauna Kea in Hawaii, but an alternative site in the Canary Islands is being explored after the natives of Mauna Kea opposed the project.
Purpose and goals of the project:
The primary purpose of the TMT is to answer fundamental questions about the universe. This infrared telescope aims to enable scientists to observe, research, and subsequently add to the body of existing knowledge on subjects like black holes, dark matter, and deep space. The driving force behind the idea of such a telescope is to further our understanding of the cosmos. By creating an international observatory, this project attempts to bridge the knowledge gap in astronomical research by harnessing the knowledge and resources of its member nations.
The Thirty Meter Telescope will attempt to answer several questions about the universe that have been plaguing astronomers from the beginning of time. For instance, questions about the nature and composition of the universe—how did the first galaxies come to exist after the Big Bang? This project will also be able to offer insights into the evolution of galaxies and further our understanding of the relationship between galaxies and “supermassive” black holes.
Further, the brilliant minds behind the TMT say that it will also strive to answer the fundamental question of whether life exists beyond our solar system. This will be done by improving the knowledge base on the processes involved in the formation and birth of planets and stars and by furthering research on “extrasolar” planets.
The Thirty Meter Telescope will allow scientists to observe spatial objects in much better detail, as it is said that the images from the TMT will be four times sharper than those from the James Webb Space Telescope. This is because the TMT’s light-gathering power will be more than the combined light-gathering power of ten of the largest existing telescopes.
TMT’s primary mirror for gathering light will be the largest of all the planned extremely large telescopes that are currently in operation in the Northern Hemisphere. This mirror will be 30 meters in diameter and consist of 492 separate hexagon-shaped segments, each measuring 1.4 meters, that are positioned to create a single surface for collecting light. The mirror system also consists of a secondary mirror, composed of 118 hexagonal segments, and a tertiary mirror that is positioned centrally within the primary mirror. All these segments will act as a single reflective surface with a diameter of 30 meters when perfectly aligned.
The TMT’s cage is only slightly taller and twice the diameter as the greatest optical/infrared telescopes now in use, despite the fact that its mirror is roughly three to four times larger and will collect nine to sixteen times as much light. The TMT will process and analyse light from its primary mirror using a state-of-the-art adaptive optics facility and an instrument suite.
The telescope configuration is that of an altitude-over-azimuth mount (alt-az). Altitude-over-azimuth is a system of coordinates that assigns angles to a combination of horizontal, side-to-side movements and up-and-down vertical movements. The term “azimuth” is the angle of an object travelling clockwise from north around the cardinal points of east, south and west, and then returning to north, while “altitude” is the distance of an object from the horizon. This type of design configuration allows for direct channels to the pier and foundation from the telescope, enabling the telescope to be relatively compact.
Direct drive “linear” motors will be curved to fit the radii of the drive arcs so as move the telescope in azimuth and elevation. Linear tape encoders will provide position feedback. The Telescope Control System (TCS) handles control. The telescope’s optics, science instruments, adaptive optics systems, and structure are all under the direction and/or coordination of the TCS.
Due to the size of TMT, access to all subsystems mounted on the telescope will be provided by an elevator, an aerial service platform, stairs, and walkways. The Telescope Utility Services will be integrated into the telescope to provide the infrastructure needed to route and support the utility lines including electricity, cooling water, refrigerants, compressed air, cryogen, data, etc. that are needed by the telescope mounted subsystems.
India's Role in TMT project
India is one of the member nations of the TMT International Observatory. The TMT will receive contributions from India’s leading institutes for astrophysics research in the form of hardware, software, and funding worth 200 million dollars. The Inter-University Centre for Astronomy and Astrophysics (IUCAA) in Pune, the Institute of Astrophysics in Bengaluru, and the Aryabhatta Research Institute for Observational Sciences (ARIES) in Nainital form the core of TMT-India and have contributed to building an online tool that will ensure high-quality images from the telescope by creating an “all-sky extensive NIR star catalogue” to mitigate atmospheric distortion. This catalogue is essential for the functioning of the telescope’s Adaptive Optics system.
Atmospheric distortion is one of the biggest challenges faced by ground-based telescopes like the Giant Magellan Telescope. The Narrow Field Infrared Adaptive Optics System (NFIRAOS) is the Adaptive Optics System of the TMT and is designed to compensate for these aberrations.
According to Dr. Sarang Shah of the Indian Institute of Astrophysics (IIA), the NFIRAOS will make use of a Laser Guide Star facility that will create artificial guide stars by projecting nine lasers into the sky and will subsequently correct for atmospheric distortions using inputs from three real stars or Natural Guide Stars (NGS). Researchers at IIA and their collaborators have created a new automated code that can calculate the expected near-infrared magnitudes of star sources found in different optical sky surveys. Since there is currently no comprehensive catalogue that can consistently offer NGS for all sky regions, this tool is of utmost importance for the proper functioning of the TMT.
The researchers identified stars and estimated their near-infrared magnitudes using multi-band optical photometry from the PAN-STARRS observatory, according to co-author and IIA faculty member Dr. Smitha Subramanian. Using data from the UKIDSS survey, the approach was tested, and predictions of NIR magnitude were made with over 85% accuracy.
Current status of the Project and the controversy that surrounds it:
In October 2020, the Telescope Utility Services Final Design was completed. There are numerous subsystems that make up the overall telescope. November 2019 saw the completion of the Telescope Structure Subsystem’s final stage closeout review, and April 2021 saw the start of the first of six production readiness evaluations. The Telescope Control System, the Cryogenic Cooling System, and the Refrigeration System are all undergoing design development. The work done on the Segment handling system has been lauded by industry experts and has received industry awards as well.
While there is no doubt that this telescope will advance future astronomical research, concerns have been raised about the ethics of the project. The preferred site of the TMT international observation is Maunakea. Maunakea is a dormant volcano in Hawaii, with its peak about 14,000 feet above sea level, making it one of the best viewing conditions of the night sky, as there exists little to no light pollution, enabling researchers to observe galaxies when the sky is clear. However, Maunakea, or “white mountain” is considered to be the most sacred volcano for Hawaiians. It is considered to be a region of the Gods, a place where Wakea, the sky god, met with Papa Hanau Moku, the earth goddess. There are several other cultural sites on the volcano, including a quarry where stone tools were forged and a sacred lake. For this reason, visitors are not encouraged to visit the volcano beyond a certain point. This inactive volcano is the highest point in all of Hawaii and is a hub of astronomic research activity, as it is home to several telescopes. However, locals say that the construction of these telescopes has hurt the sanctity of the volcano. They also do not trust the platitudes that have been offered to them, saying that false promises have been made before. They do not believe that the TMT international observatory will be the last one to be built there.
The problem is not with the telescope itself, but with its location. The natives have expressed their displeasure and opposed any new alterations to the summit. Since Mauna Kea was chosen as the preferred site in 2009, the project has undergone numerous legal, construction, and environmental permit reviews. Although the project received a traditional Hawaiian blessing in 2014, construction has been halted since 2015 due to protests and court battles. Permits for the TMT were invalidated in 2015, but the Supreme Court of Hawaii reinstated them in 2018. Several older telescopes were also decommissioned.
While the immediate goal of the protestors is to halt the construction of the telescope, their larger hope is that officials and the wider public will listen to the grievances of the natives. They argue that the state’s economic progress is being prioritized at the expense of native Hawaiian culture and traditions. In 2019, there was a wave of protests in solidarity in Honolulu and mainland cities like Las Vegas as well. However, not all residents of Hawaii agree with the protestors. Some support the telescope’s construction, believing it will enhance the state’s development by creating 140 well-paying technical jobs and adding approximately 150 million dollars per year to the state’s economy.
It is essential to find a holistic solution to this problem. While the TMT International Observatory will advance space research significantly, if it is done at the expense of the sentiments and beliefs of the natives, the very core of this project—one that aims to create optimistic technology—will be compromised. An inability to reconcile modern technological advancements with the sentiments and traditions of the natives will set a dangerous precedent, suggesting that no cost is too high for a perceived ‘greater’ good, regardless of whether that good truly encompasses the development and happiness of all stakeholders. How can we create an instrument to help us understand our universe if we cannot first reconcile the grievances of our people and understand our own planet?
Written by Nandini Pillai
Edited by Yashvi Vasani