Timeline of knowledge about the interstellar and intergalactic medium

Timeline of the interstellar medium and intergalactic medium

• 1848 - Lord Rosse studies M1 and names it the Crab Nebula\n* 1864 - William Huggins studies the spectrum of the Orion Nebula and shows that it is a cloud of gas\n* 1927 - Ira Bowen explains unidentified spectral lines from space as forbidden transition liness\n* 1930 - Robert Trumpler discovers absorption by interstellar dust by comparing the angular sizes and brightnesses of globular clusters\n* 1944 - Hendrik van de Hulst predicts the 21 cm hyperfine line of neutral interstellar hydrogen\n* 1951 - H.I. Ewen and Edward Purcell observe the 21 cm hyperfine line of neutral interstellar hydrogen\n* 1956 - Lyman Spitzer predicts coronal gas around the Milky Way\n* 1965 - James Gunn and Bruce Peterson use observations of the relatively low absorption of the blue component of the Lyman-alpha line from 3C9 to strongly constrain the density and ionization state of the intergalactic medium\n* 1969 - Lewis Snyder, David Buhl, Ben Zuckerman, and Patrick Palmer find interstellar formaldehyde\n* 1970 - Arno Penzias and Robert Wilson find interstellar carbon monoxide\n* 1970 - George Carruthers observes molecular hydrogen in space\n* 1977 - Christopher McKee and Jeremiah Ostriker propose a three component theory of the interstellar medium

Category:Science timelines