German Helium-3 Cited by user Crazy1880 on 13 Oct 2022 Helium-3 (3He) ist neben Helium-4 eines der beiden stabilen Isotope des Heliums. Sein Atomkern enthält zwei Protonen und ein Neutron.
English Space archaeology Cited by user Citation bot on 05 Oct 2021 It includes launch complexes on Earth, orbital debris, satellites, and objects and structures on other celestial bodies such as the Moon and Mars.