Near Brazil, in the Atacama Desert in Chile, one of the most impressive engineering structures of the 21st century is being formed—the Giant Magellan Telescope (GMT). This project is part of a new era of mega-telescopes designed to overcome all boundaries of human knowledge about the cosmos.
When GMT begins operation in the early 2030s, it will provide unprecedented clarity among ground-based observatories. According to the statement, the main mirror equipment will have a diameter of 25.4 meters and a light-collecting area of 368 square meters, allowing observations of galaxies that formed just 100 million years after the Big Bang.
The scale of the project reflects an international consortium of 15 institutions, in which Brazil plays a fundamental role thanks to the State Research Support Fund of São Paulo (FAPESP). By investing 50 million US dollars, the country created the GMT-BRO Brazilian office to ensure that Brazilian scientists and engineers take a central role in the development of the observatory's advanced instruments.
Despite the impressive size of the structure, light collection is only the first stage. Without appropriate instruments to analyze this cosmic radiation, astronomy cannot progress.
During the first 'Looking at the Stars' seminar organized by the GMT-BRO office last year, Claudia Mendes de Oliveira, a PhD in astronomy from Columbia University, senior lecturer at the Institute of Astronomy, Geophysics, and Atmospheric Sciences of the University of São Paulo (IAG-USP) and a member of the Brazilian Academy of Sciences (ABC), explained the project timelines.
She noted: 'The telescope should be ready between 2032 and 2035. The exact date depends on the final funding of the instruments, but it should happen in the middle of the next decade. Thus, we have a comfortable eight to ten years ahead to work on instrumentation.'
She emphasized that despite initial difficulties, the Brazilian team is fully involved with international groups in developing these technologies. The country's participation is focused on vital systems, ranging from exoplanet searches to the study of dark matter and energy.
One of the significant achievements of Brazilian investments is DIMEX (Visible Range Multi-Object Spectrograph in Moderate Scattering). Developed in partnership with the Harvard-Smithsonian Astrophysical Observatory, this instrument operates in the visible spectrum through two independent channels—one optimized for blue light, the other for red.
DIMEX is considered the true 'workhorse' of GMT, as it is expected to become the most frequently used instrument for the entire scientific community. The device's goals cover stellar astronomy and cosmology, helping to understand the acceleration of the Universe and mapping cosmic structures.
Professor Rafael Ribeiro, PhD in astronomy from IAG-USP and coordinator of the Brazilian team for this instrument, spoke about the importance of this achievement at the event. He recalled that Brazil joined the consortium a little later, which required effort to secure a place in technology development. 'It is not easy to get into such highly complex projects that are world-class. And we are here, despite our experience since the 60s, we are still beginners in this high-performance instrumentation.'
He noted that national competence provided the country's researchers with a decisive role in the DIMEX project. 'We demonstrated quality, commitment to the quality of our work, and because of this, we gained significance. And today we are proudly an active partner of this organization.'
As explained in the GMT-BRO institutional video, the Brazilian team is involved in the optical design, mechanical engineering, software development, and systems engineering of DIMEX. Researchers and engineers also collaborate to operate the instrument in an enhanced imaging mode, using low-atmosphere adaptive optics technology.
Adaptive optics is a revolutionary method capable of correcting turbulence and aberrations caused by the Earth's atmosphere in real time. Thanks to it, light coming from distant corners of space is corrected with exceptional precision, providing perfectly sharp images on detectors.
The search for planets outside the Solar System is further strengthened by technology developed by IAG-USP. The team designed, assembled, and successfully tested a prototype Exposure Meter (high-efficiency exposure meter), which is responsible for calibrating the CLERC spectrograph (high-resolution visible range spectrograph) and its DCLERC version.
Another promising innovation is Astrocomb—a high-precision instrument installed on high-resolution spectrographs, such as the GMT High-Resolution Echelle Spectrograph for characterizing exoplanets (GCLEF). This instrument generates an 'optical frequency comb,' creating perfectly evenly spaced lines of light that serve as a standard for calibrating cosmic observations.
At the seminar, Professor Flavio Cruz, PhD in physics, lecturer at the State University of Campinas (Unicamp) and coordinator of the Astrocomb development project, explained how this measurement allows the detection of distant worlds. 'When a planet orbits a star, it causes a small wobble in the star's mass. If a star has a planet in orbit, the planet's gravity induces a small stellar wobble—a very subtle phenomenon. This shift causes a small Doppler shift in the star's spectral lines of light.'
This phenomenon is known as the Doppler effect. By measuring subtle changes in the spectrum of light emitted by stars using Astrocomb, astronomers can detect the presence of new exoplanets and calculate their masses with unprecedented accuracy.
To maximize the potential of GMT, MANIFEST was created—a robotic optical fiber positioning system that covers a field of view equivalent to 40% of the full Moon's diameter. The robot moves hundreds of optical fibers in about five minutes. This allows the light collected by the telescope to be directed to several instruments simultaneously, such as GCLEF and GMAX, increasing the number of observed objects per night.
According to engineer and researcher Vitor Neves Hartman from the João Steiner Institute and USP, who coordinates the MANIFEST subproject in Brazil, this system transforms observatory operation. 'It won't conduct scientific research; it will redirect the light captured by the telescope to one or more instruments so that scientific research can be conducted. The ability to operate allows the telescope to use more than one instrument simultaneously,' Hartman emphasized at the meeting.
Within the international consortium developing MANIFEST, Brazilian engineering bears exceptional responsibility for a critical subsystem called the Filterbox. This component is responsible for conditioning the light signals directed to the spectrographs.
Brazil's presence in GMT encompasses many other crucial commissioning and testing projects. The national team of scientists is actively involved in the development of the Adaptive Optics Test Chamber (AOTC), designed to test the resolution limits of the observatory's adaptive optics. Brazilians are also collaborating on the Commissioning Chamber (ComCam), which assesses the initial image quality produced by the mirror assembly. In this, the country participates in the software architecture and mechanical engineering in partnership with the international consortium.
All this involvement places Brazilian science in a prominent position in global astronomy. Instead of just using data collected by international observatories, our researchers are designing the instruments that will shape the discoveries of the coming decades.
When GMT finally opens its eyes to the Universe, the knowledge and engineering solutions developed in Brazil will be there, in every ray of captured light, helping to decipher the mysteries of the cosmos and write the next chapters of our knowledge of the Universe.


