Advertisement
China’s FAST telescope finds biggest atomic cloud ever discovered
- Colossal cloud is 20 times larger than the Milky Way galaxy and probably a billion years old
- The finding could help scientists understand the origins of galaxies and reveal similar gaseous structures lurking elsewhere in the universe
Reading Time:2 minutes
Why you can trust SCMP
4

Ling Xinin Beijing
An international team led by Chinese scientists has discovered the biggest atomic cloud in the universe – a surprising finding that could help researchers better understand the origins of galaxies.
The cloud, made up of hydrogen atoms, measures about 2 million light years across and is 20 times larger than our Milky Way galaxy, according to a paper published in the journal Nature on Wednesday. One light year is about 9.46 trillion km (5.88 trillion miles).
The discovery was only possible with the help of an ultra-powerful telescope in southwestern China’s Guizhou province. Astronomers from China, Europe and the United States found the cloud after they pointed the Five-hundred-metre Aperture Spherical radio Telescope (FAST) – the world’s largest single-dish radio telescope – in the direction of a group of galaxies known as Stephan’s Quintet.
“Since its discovery 145 years ago, Stephan’s Quintet has been extensively studied by various ground-based and space telescopes,” said lead author Xu Cong from the National Astronomical Observatories under the Chinese Academy of Sciences in Beijing.
Advertisement
High-powered telescopes have captured stunning views of Stephan’s Quintet. For example, Nasa’s James Webb Space Telescope has caught one of the galaxies colliding with another at high speed, which generated a massive shock wave.
Xu’s team wanted to use the unparalleled sensitivity of FAST to better understand how the galaxies interacted with one another when they first came together as a group.
Advertisement
To do this, they looked for hydrogen atoms in the area around Stephan’s Quintet. The atoms give off a unique “signature” emission that can reveal information about events that happened long ago.
Advertisement
Select Voice
Choose your listening speed
Get through articles 2x faster
1.25x
250 WPM
Slow
Average
Fast
1.25x
