In 1964, the Rand Corporation issued a landmark study entitled Habitable Planets for Man by Stephen H. Dole. This is one of the important references for writers of hard science fiction. Rand’s precis is:
“An attempt to make an estimate of the probabilities of finding planets habitable to man, where they might be found, and the number there may be in our own galaxy. The characteristics of a planet that can provide an acceptable environment for man are presented in detail. The stars nearest the earth, most likely to possess habitable planets, are itemized. The author also discusses special and unusual planets that may be discovered, how new environments might affect people who migrate to them, how to search for habitable planets. He also gives an appraisal of the earth as a planet and describes how its habitability would be changed if some of its basic properties were altered. An attempt to make an estimate of the probabilities of finding planets habitable to man, where they might be found, and the number there may be in our own galaxy. The characteristics of a planet that can provide an acceptable environment for man are presented in detail. The stars nearest the earth, most likely to possess habitable planets, are itemized. The author also discusses special and unusual planets that may be discovered, how new environments might affect people who migrate to them, how to search for habitable planets. He also gives an appraisal of the earth as a planet and describes how its habitability would be changed if some of its basic properties were altered. 171 pp. Bibliog.”
Author Robert J. Sawyer, who reported the document’s availability, says: “This is it, folks, the world-building bible; I paid a fortune years ago for a used hard copy.”
It’s available on Rand’s web site at this link.