China’s FAST telescope maps neutral hydrogen, the cosmic gas for making stars
Por Ling Xin — South China Morning Post – News feed
Advertisement Science China Science China’s FAST telescope maps neutral hydrogen, the cosmic gas for making stars
Survey identifies more than 156,000 extragalactic sources, offering an unprecedented pool for studying the universe’s biggest questions
2 -MIN READ 2 -MIN Listen
Ling Xin in Ohio Published: 8:00pm, 13 Sep 2026 China’s FAST telescope has compiled the world’s largest catalogue of neutral hydrogen beyond the Milky Way, replacing a long-dominant US survey as the main reference for mapping the gas that fuels the formation of stars and galaxies . The FAST All-Sky H I Survey (FASHI), conducted with the 500-metre (1,640-foot) radio dish in southwest China’s Guizhou province, released its second batch of data this week. It contains 156,411 extragalactic sources – nearly five times the number detected by the now-defunct Arecibo Telescope in Puerto Rico .
The publicly available data gives astronomers worldwide an unprecedented pool of galaxies to investigate some of the universe’s biggest questions – from how the vast cosmic web took shape, to why some galaxies thrive while others fade away.
Compared with ALFALFA – the landmark US survey carried out with Arecibo from 2005 to 2012 – FASHI covered about three times as much sky and detected galaxies that were much smaller, fainter and further away, a team led by researchers from the National Astronomical Observatories reported.
The work established “a legacy data set that bridges the gap” between earlier surveys and the coming Square Kilometre Array – a massive international radio telescope now being built in Australia and South Africa, they wrote in a study published in the peer-reviewed journal Science China Physics, Mechanics & Astronomy this month.
For more than half a century, Arecibo’s 305-metre dish was an icon of radio astronomy.
Completed in 1963, it remained the world’s largest single-aperture radio telescope until FAST overtook it in 2016, and was behind a string of major astronomical discoveries before its giant observing platform collapsed in 2020.
Advertisement Select Voice Select Speed 0.8x 0.9x 1.0x 1.1x 1.2x 1.5x 1.75x 00:00 00:00 1x AI-generated voice
