Measuring the neutron’s lifetime from space could solve an enduring mystery
To really understand neutrons, physicists may have to take to space. When outside the confines of an atomic nucleus, a neutron decays into other particles in about 15 minutes on average. But exactly how long it lives has been tough to pin down, because two different methods of measuring disagree (SN: 2/1/17). Now, scientists have made a third type of measurement, using data from NASA’s MESSENGER spacecraft. Although the new measurement isn’t sensitive enough to resolve the discrepancy, a future space mission could help overcome the impasse, physicists report June 11 in Physical Review Research. Determining the neutron’s lifetime is essential to understanding cosmic questions like how certain elements formed after the Big Bang (SN: 5/9/18). The MESSENGER spacecraft orbited Mercury from 2011 to 2015 and flew by Venus on the way there, taking measurements of neutrons in the vicinity of the two planets. Neutrons are produced in reactions set off by high-energy particles from space slamming into the planets. By measuring how the...