DescriptionPioneerplaquehydrogen.svg English: Hyperfine transition of neutral hydrogen. Date 25 February 1972 Source Extracted from the Pioneerplaque.svg. Author
accuracy of pulsar diagram by copying from [[:File:Pioneer plaque.svg]] and added dots to hydrogen diagram 2010-01-03T00:05:53Z PleaseStand 737x565 (50189
DescriptionPPlaqueA.png Detail of hyperfine transition of neutral hydrogen from the PioneerPlaques. Source This file is lacking source information. Please edit