For 25 years, physicists have used an exotic state of matter made from ultracold atoms to probe quantum behaviour at the macroscopic scale. Now, they can do it in space.

The feat — the creation of a Bose–Einstein condensate — comes from physicists behind NASA’s US$100-million Cold Atom Lab, which began operating on the International Space Station in June 2018. The results are a proof-of-principle showing that the laboratory can successfully exploit the microgravity of space in ways that should allow scientists to create phenomena that would be impossible on Earth. The facility is on track to become the coldest place in the known Universe.