When the Hooker telescope was first turned towards the sky in 1917, no one knew what observations and
breakthroughs it might bring in the future. Within a Decade astronomer Edwin Hubble used
it to observe the distant galaxies and predict the expansion of the universe. Whether it is the
Hubble telescope, Hale telescope or the James Webb, telescopes have always been a marvel in
human engineering. Today in this video we are going to talk about one such Revolutionizing
telescope that is currently under construction and will help us answer the questions of our origin.
The glass is produced in Japan. Although the end result will gaze toward the future,
the preliminary steps draw on glass making processes of millennia past.
Large handmade clay pots are filled with 1.5 tons of silica and boron oxide particles by artisans.
The sandy mixture is placed in a large furnace and burned for more than two days at temperatures as
high as 1,500 degrees Celsius (2,732 degrees Fahrenheit), melting the raw material until
the 800-liter pots are full of molten glass. The explanation for all this strenuous hard
work is the Giant Magellan Telescope, which will become the largest optical telescope in the world.
The Giant Magellan Telescope or GMT will be located at 8,200 feet on the peak of
Chile's Cerro Las Campanas, in a 22-story structure that is now under construction.
The ultra-dry air at high elevations in the Atacama Desert provides some of the best views of
the night sky anywhere in the world. The massive telescope will have ten times the resolving
capability of the Hubble Space Telescope, allowing it to show distant galaxies, star birth, and the
compositions of exoplanet atmospheres—a critical field of research in the hunt for alien life.
The start of telescope operations, known as first light, is scheduled for 2023 and
will employ just four mirrors. In 2025, the first observations with all seven mirrors will be made.
Today, the pots are being filled in Japan, the furnace is being lighted in Arizona, the earth
is being broken in Chile, and construction on the Giant Magellan Telescope is underway.
The Giant Magellan telescope will be one of the few super giant earth-based telescopes that will
revolutionize our understanding of the cosmos. The GMT is a segmented mirror telescope composed
of seven of today's biggest rigid monolithic mirrors. Six off-axis 8.4 meter segments circle
a center-on-axis section, producing a single 24.5 meter diameter optical surface with a total
collecting area of 368 square meters. The GMT main mirrors are manufactured at Tucson's Steward
Observatory Mirror Lab. Each piece is curled to a highly exact form and polished to within
a wavelength of light—approximately one-millionth of an inch. The manufacturing of the telescope’s
mirror is a modern marvel in engineering, making the GMT one of the most sophisticated telescopes
on Earth. The first GMT mirror is now finished. It's in Tucson, sitting in a climate-controlled
storage container on a trailer, waiting to start its voyage to Chile. The Mirror Lab has been
granted the go-ahead to cast more mirrors, despite only having one in the basket. At the Arizona lab,
four GMT mirrors are in various levels of construction. Now that the procedure has
been validated, the team wants to create the potato chips quicker. The mirror blanks will be
coated with a tiny layer of aluminum to make them reflective in the last part of the process, which
will take place at the telescope's construction location in Chile. The Giant Magellan Telescope is
getting closer to first light, when these mirrors will turn to face the heavens for the first time.
Two new technologies have enabled telescopes to measure the universe with more accuracy
than ever before since the 1990s. The first is interferometry, which combines several telescope
observations to stitch together an image with the same resolution as a single massive telescope,
and is excellent for viewing the surfaces of other stars. The Mirror Lab's test tower
employs interferometry to generate contour maps of the glass surfaces.
The GMT will employ adaptive optics, which is the second big development in telescope technology.
"Adaptive optics" is one of the most complicated engineering features used in this telescope.
The secondary mirrors of the telescope are bendable. The adaptive secondary mirror is
specifically designed to keep the telescope in focus. This 3.25-meter-diameter mirror will
likewise feature seven circular segments, similar to the primary mirror segments,
however the secondary mirror segments will be just 1.6 mm thick. Even in the high Atacama Desert,
air interference may degrade the accuracy of astronomical observations greatly.
Adaptive optics technologies enable telescopes like GMT to attain extraordinary precision,
equivalent to a space telescope. Hundreds of actuators are located beneath each secondary
mirror surface and are continually adjusting the mirrors to compensate for air turbulence.
These actuators, guided by powerful control algorithms, will convert flashing stars into
bright, steady points of light ten times sharper than the Hubble Space Telescope. The Center for
Astrophysics' scientists and engineers are vital in the design and installation of these control
systems. The GMT's position also provides a significant advantage in terms of viewing
through the Earth's atmosphere. The GMT will enjoy exceptional conditions for more than 300 nights a
year in Chile's Atacama Desert, which is one of the highest and driest regions on the planet.
Due to a lack of rainfall, Las Campanas Peak has a height of about 2,550 metres (8,500 feet) and
is virtually totally devoid of vegetation. Las Campanas Peak is a great location for the GMT
due to the combination of seeing, frequency of clear nights, height, weather, and vegetation.
When it all comes together in the 2020s, the GMT will be able to resolve
an object the size of a dime at a distance of 60 miles, which is an order of magnitude more
than Hubble's resolving capacity. Such a range of vision offers up a world of possibilities.
But the most important use of GMT will be to answer: ARE WE ALONE?
The main purpose of the GMT is to look for habitable planets in habitable zones around stars.
Scientists want to look for biosignatures to know whether there is life on those planets.
This topic will be addressed by the GMT-Consortium Large Earth Finder, or G-CLEF, the first
sophisticated instrument planned for GMT, the design and construction of which is being overseen
by the Center for Astrophysics. G-CLEF has been tuned for extreme precision velocity detection,
allowing it to identify the presence of an Earth-mass exoplanet orbiting Sun-like stars.
To identify the compositions of celestial objects, sophisticated spectrometers will measure the light
captured by GMT. When an exoplanet passes in front of the star it orbits from our perspective,
the instruments on the massive telescope will be sensitive enough to distinguish the
light passing through the planet's atmosphere from the rest of the starlight. Light passing
through the atmosphere will have gaps in the electromagnetic spectrum—absorption
lines that disclose the presence of certain chemicals in the sky of that world.
The GMT will direct its attention on neighboring exoplanets such as Proxima b,
which orbits the nearest star to us, and the seven Earth-sized planets around TRAPPIST-1,
which is less than 40 light-years away. The telescope will also seek for indications
of life in alien atmospheres on hundreds of additional planets discovered by astronomers
all around the Milky Way. With its massive light-collecting surface, the gigantic telescope
sitting in the high Atacama will also be able to identify extremely faint objects. Early star
formation will be investigated with unparalleled accuracy, and galaxies further distant, older,
and less luminous than any ever seen will be discovered. In addition to looking for life in
the galaxy, the GMT will allow astronomers to explore the universe's most primordial eras,
probing the firmament to put our fundamental rules of physics to the test.
NASA recently launched the 10 Billion dollar James Webb into space. Compared to the GMT,
The GMT's 24.5 meter aperture will dwarf James Webb, but it will provide an unrivaled view of
the stars beyond the atmosphere. Furthermore, James Webb will conduct observations mostly in
the infrared, whereas GMT is designed to detect light in the visible range.
GMT has the potential to be complementary to the James Webb space telescope.
James Webb, for example, will be well-suited to researching the very early cosmos since light that
has been traveling for billions of light-years has been extensively Doppler shifted into the infrared
section of the spectrum. Infrared light may also be detected in space, penetrating through clouds
and nebulae to expose the things hidden behind them. Optical observations, such as those made
by Hubble and GMT, are ideal for spectroscopy and determining the compositions of bodies such
as exoplanets. GMT's massive size will also allow it to identify extremely faint and distant things.
However before the Giant Magellan telescope can power on,
there is still a lot of work to do. The fifth mirror is already cooling in the furnace, and
three more must be cast—one additional outer mirror to keep the telescope operational
while mirrors are cleaned and recoated with aluminum. The 17-ton mirrors must also be
delivered from Arizona to Chile in articulated, temperature-controlled, shock-absorbing boxes
by port in either Houston or Los Angeles. The GMT project is a paradigm change. Private interests,
foreign partners, universities, and research organizations from across the world have joined
forces to create this magnificent monument to science in the high Atacama Desert.
Boeing is performing fluid dynamics research for the telescope's housing construction, while NASA's
Jet Propulsion Laboratory is offering mirror understanding gained from Hubble's errors. Several
universities and institutions all around the world have come together to make this project possible.
The fact that research organizations all around the world are eager to get engaged with the Giant
Magellan Telescope demonstrates its potential, adaptability, and the profundity that astronomers
hope to encounter via its 119-ton mirror glinting on a mountainside in the Atacama Desert.
GMT's exceptional light gathering power and resolution will also aid with many
other intriguing topics in twenty-first-century astronomy. What exactly are dark matter and dark
energy, two enigmatic entities that make up the vast majority of our universe? How did the first
stars emerge from the Big Bang's diffuse gas? What caused the earliest galaxies to form? What is the
fate of our universe? GMT will help us to gain a deeper understanding of all these questions.
So what do you think about this revolutionizing telescope? Let us know what you think in the
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