Space & PhysicsAnother Astronomical Puzzle SolvedThe Problem of the Nature of the Peculiar "Planetary Nebulae" Gives Way to the Modern AstrophysicistBy Henry Norris Russell on May 1, 1928AdvertisementABOUT THE AUTHOR(S)Recent Articles by Henry Norris RussellGalactic Gas CloudsAnthropocentrism's DemisePlanet Companions