29.10.2025
U.S.-Chinese tensions have left nearly complete observatory in limbo, jeopardizing research into pulsars and other celestial objects
The China-Argentina Radio Telescope, under construction in western Argentina, is facing a series of new obstacles.RICARDO CÉSAR PODESTÁ
Later this year, astronomers in Argentina expected to begin testing the largest radio telescope in Latin America: a 40-meter-diameter instrument designed to detect electromagnetic whispers from the distant cosmos. The Argentine and Chinese governments launched the project a decade ago as a symbol of scientific cooperation between the two nations. But now the China-Argentina Radio Telescope (CART), which is nearly finished, is stuck in limbo—a victim of growing tensions between the United States and China.
“We’re 90% complete. Very close. That’s why what’s happening is so difficult, because we don’t want it to become scrap metal,” says María Verónica Benavente, a senior official at the National University of San Juan (UNSJ), which is leading the project.
Researchers trace CART’s difficulties to efforts by Argentina’s libertarian president, Javier Milei, to forge close ties with U.S. President Donald Trump, whose administration has made curbing China’s global influence a priority. The first signs of trouble came in June, when Argentina’s science agency missed a deadline for renewing a scientific cooperation agreement with China. Then, in September, customs officials in Buenos Aires held up a shipment of key dish parts made in China, which has contributed some $15 million in equipment and engineering to the project. Last month brought another setback when U.S. Secretary of the Treasury Scott Bessent said the Trump administration would provide up to $20 billion to shore up Argentina’s beleaguered economy—but only if Milei’s government suspended strategic ties with China, including efforts to build “observational facilities.”
That policy was aimed “directly” at CART, believes Benavente, who is the former science secretary for San Juan, the mountainous western province where the observatory is located. “There is direct interference from the White House here.”
The Chinese embassy in Argentina condemned Bessent’s comments, saying they represented a “Cold War mentality.” In a second statement, it warned that “Latin America and the Caribbean are no one’s backyard.”
The latest setback came on 17 October, when Milei’s government issued a requirementthat the Ministry of Defense approve “any installation of radars, observatories, or aerospace systems.” That rule is especially vexing because “CART is 100% scientific,” says Ricardo Podestá, director of the Félix Aguilar Astronomical Observatory, where the radio telescope is being built. “If this were a military project, everyone would notice.”
Others note that the requirement seems redundant because CART already received Defense Ministry approval in 2016 under a previous president who is politically aligned with Milei. “I don’t know what else this government wants,” says Jorge Castro, a science dean at UNSJ. “I hope they’re simply unaware of this objective fact.”
The Milei administration’s policies are “simply an over-the-top move to show themselves obsequiously aligned with the Trump administration, to the detriment of the entire astronomical community in Argentina,” Roberto Salvarezza, head of the Buenos Aires Scientific Research Commission, told the media outlet Página/12.
The delays have left astronomers frustrated. “If the equipment is released, we could have the antenna ready this year or early next year,” Podestá says, opening the way to a wide range of research, including studies of celestial objects such as pulsars and quasars, as well as collaborations with the more than 100 other radio telescopes around the world. “San Juan has some of the clearest skies in the world,” Podestá notes. “You can see the galactic nucleus high in the sky.”
To ensure that such observing opportunities don’t go to waste, the government should issue an “immediate guarantee of [CART’s] continuity,” UNSJ’s science faculty said in a statement. “The development of science has no borders,” it added, “and a cosmopolitan vision must prevail.”
Quelle: AAAS