Scientists aboard China’s Tiangong space station have cooled a cloud of atoms to 9.7 picokelvin, the lowest temperature ever recorded in space. The result, published in the journal Science, beats the previous record by roughly four times.
The team cooled about 20,000 rubidium atoms with lasers until they formed a Bose-Einstein condensate, a state where thousands of atoms behave as a single quantum wave. In the station’s microgravity, the cloud drifted apart so slowly that researchers tracked its expansion for seven seconds.
The figure is an equivalent temperature, worked out from how slowly the cloud spread after release, and carries an uncertainty range of 7.0 to 12.9 picokelvin. The equipment around the atoms never came close to that cold.
The previous record stood at 38 picokelvin, set in a German drop tower in 2021. NASA’s Cold Atom Laboratory on the International Space Station reached 52 picokelvin.
Researchers from Peking University and the Shanghai Institute of Optics and Fine Mechanics ran the experiment in the Mengtian module’s cold atom physics rack. They say the long, stable observation window opens the way to sharper quantum physics experiments and precision measurements in orbit.
Source: Phys.org
