![](http://www.alamy.com/thumbs/6/237A1E5B-C2B3-49BA-8C6C-5AE2241A87C1/2ACT679.jpg)
Galactic hydrogen distribution. Diagram showing the distribution of neutral hydrogen in the Milky Way. The darker the area on the diagram, the more de
Galactic hydrogen distribution. Diagram showing the distribution of neutral hydrogen in the Milky Way. The darker the area on the diagram, the more dense the hydrogen. This shading shows a number of spiral arms and was the first attempt to map the spiral structure of our galaxy using observations of neutral hydrogen. Image from 'The Galactic System as a Spiral Nebula' by Jan Oort, Frank Kerr and Gart Westerhout, published in Reports on the Progress of Astronomy, No. 4 (1958).
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Photo credit: © ROYAL ASTRONOMICAL SOCIETY/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: 1958, 20th, arm, arms, artwork, astronomical, astronomy, black--white, century, density, distribution, frank, galactic, galaxy, gart, historical, history, hydrogen, illustration, jan, kerr, map, mapped, mapping, milky, monochrome, neutral, oort, plane, progess, reports, space, spiral, structure, system, westerhout