A study of the upper atmosphere’s composition has successfully measured an increased presence of 18O, a heavier oxygen isotope with 10 instead of eight neutrons. Helmut Wiesemeyer (MPIfR Bonn) and his colleagues have measured the 18O fraction of the upper mesosphere/lower thermosphere for the first time, using the GREAT instrument aboard SOFIA and found that the upper atmosphere has an 18O fraction close to that of the lower atmosphere.
Click here for original story, Researchers detect heavy oxygen isotope in Earth’s stratosphere
Source: Phys.org