The Giant Magellan Telescope received official approval from the National Science Foundation (NSF) confirming that the observatory will advance into its Major Facilities Final Design Phase, one of the final steps before becoming eligible for federal construction funding. This critical milestone recognizes the Giant Magellan’s scientific merit, construction progress, and alignment with U.S. priorities in science and technology.
The Center for Astrophysics | Harvard & Smithsonian (CfA), a partnership between the Harvard College Observatory and Smithsonian Astrophysical Observatory (SAO), is playing a major role in the Giant Magellan with the development of the GMT-Consortium Large Earth Finder (G-CLEF) spectrograph. G-CLEF will measure the slight wobbles of stars created by the gravitational pull of an orbiting planet, allowing the Giant Magellan to measure masses of Earth-class planets, including possibly those in the habitable zone where liquid water could exist on the planet’s surface. The G-CLEF spectrograph will also be able to detect many important molecules in the atmospheres of exoplanets, including those created by life on Earth. Other important science to be tackled by the GMT include studies of supernovas, the earliest galaxies and the progenitors of planets.
In addition to G-CLEF, engineers and scientists from SAO are leading work on the Moderate Dispersion Optical Spectrograph for the Giant Magellan, which will be used for research ranging from the formation of stars and planets to cosmology.
“We are thrilled to take the next steps with the Giant Magellan Telescope and are eagerly anticipating the many discoveries that lie ahead,” said CfA Director Dr Lisa Kewley. “We are grateful that the NSF is supporting this transformational, next generation telescope.”
“What a great moment for the future of American astronomy,” said Dr. Robert Shelton, President of the Giant Magellan Telescope. “The NSF’s decision to advance us into its Final Design Phase reaffirms the strength of our observatory and the decades of preparation by our dedicated team. With significant construction already underway across the United States and at our site in Chile, this milestone positions our nation to lead the next era of discovery. We greatly appreciate the NSF’s vote of confidence and its continued commitment to maintaining American leadership in science, engineering, and precision manufacturing.”
Backed by nearly $1 billion in private funding – the largest private investment ever made in ground-based astronomy – the Giant Magellan is built by an international consortium of 15 universities and research institutions, including the University of Arizona, Carnegie Institution for Science, The University of Texas at Austin, Korea Astronomy and Space Science Institute, University of Chicago, São Paulo Research Foundation, Texas A&M University, Northwestern University, Harvard University, Astronomy Australia Ltd., Australian National University, Smithsonian Institution, Weizmann Institute of Science, Academia Sinica Institute of Astronomy and Astrophysics, and Arizona State University.
The Giant Magellan is already 40% under construction, with major components manufactured and tested in facilities across 36 states in the U.S., including advanced optics and primary mirrors in Arizona, science instruments in multiple states including Texas, and the telescope mount structure in Illinois. At the observatory’s privately owned site in Chile, major infrastructure progress includes utilities, roads, support structures, and a fully excavated foundation for the enclosure.
The NSF’s decision follows the release of its FY2026 Budget Request to Congress and the recent U.S. Extremely Large Telescope External Evaluation Panel Report. The report expressed “confidence that the Giant Magellan Telescope will progress through FDP [Final Design Phase] to a successful FDR [Final Design Review] and construction, if approved.”
Over the last five years, the observatory has successfully passed all federally required reviews and is prepared to privately finance the Final Design Phase. This reflects the project’s advanced progress and expertise of its international consortium, with many design elements already exceeding NSF Final Design Review benchmarks.
“This is more than an investment in a telescope,” said Dr. Walter Massey, Board Chair of the Giant Magellan Telescope and former NSF Director. “It is a strategic necessity for the United States to maintain leadership in astrophysics, engineering, and artificial intelligence. The Giant Magellan Telescope will work in synergy with billions of dollars already invested in U.S. research facilities around the world, creating a powerful ecosystem of tools that ensure American scientists have the best resources to lead discovery.”
Strategically located in Chile’s Atacama Desert, the Giant Magellan occupies one of the most scientifically valuable observing sites on Earth. Chile offers more than 300 clear nights each year, exceptional atmospheric stability, and direct access to the southern sky and the galactic center of the Milky Way. The observatory amplifies billions in existing NSF investments in Chile, including the Vera C. Rubin Observatory, ALMA, and Gemini South, forming the cornerstone of a U.S.-led, multi-decade astronomical strategy in the Southern Hemisphere.
The Rubin Observatory, which is now nearing full operations, will conduct an unprecedented all-sky survey to discover rare, fast-changing cosmic events that offer powerful new ways to understand the evolution and structure of our Universe. But Rubin is only the first step. As part of a multi-decade strategy to ensure U.S. leadership in the Southern Hemisphere, astronomers will need the Giant Magellan’s greater sensitivity, resolution, and spectroscopic capabilities to fully investigate these discoveries. Without access to the Giant Magellan, Rubin’s survey potential will be largely out of reach for U.S. astronomers, and the transformational science it enables will be led by other nations with access to the next generation of “extremely large telescopes.”
The Giant Magellan Telescope is committed to the science goals of the U.S. Extremely Large Telescope Program, the top-ranked priority in the National Academies’ 2020 Decadal Survey on Astronomy and Astrophysics. The report called the program “absolutely essential if the United States is to maintain a position as a leader in ground-based astronomy.”
About the Center for Astrophysics
The Center for Astrophysics | Harvard & Smithsonian is a collaboration between Harvard and the Smithsonian designed to ask—and ultimately answer—humanity’s greatest unresolved questions about the nature of the universe. The Center for Astrophysics is headquartered in Cambridge, MA, with research facilities across the U.S. and around the world.
