If ever a man looked and acted in accordance with the part that history had assigned him, astronomer Edwin Hubble was that man: tall and Hollywood handsome with a dimpled chin and the pipe-smoking gaze of an English gentleman. Champion athlete, war hero, lawyer, hero of the Wild West, he had it all. He interacted with others, an awed young astronomer once said, as might a god.

Seemingly without breaking a sweat, Hubble rode into history in the 1920s the way his patriarchal grandfather had ridden on a sorrel horse with white feet and a mane that touched its knees into Springfield, Mo., in 1856. The junior Hubble's horses were giant domed clockworks of steel and glass perched on the rugged, precarious heights of Mt. Wilson, north of Pasadena.

It was there that he described the first revolutionary hints of what we now call the expanding universe. By the 1940s, Hubble was the second most famous scientist in the world. Movie stars made pilgrimages to the telescope to see him; Hitler allegedly sent a U-boat to kill him. He was photographed with Albert Einstein. He was on the cover of Time magazine.

More books than are good for your sanity or your eyesight have been written about the big bang and the mysteries of its putative past and future. Cosmologists today travel the planet like rock stars, and when they want to have a meeting they have to hire a convention hall. In this expanding universe of publicity, it is something of a scandal that Hubble's own story has not been adequately told until now. Hubble wanted it that way. He produced no memoir.

After his death his wife, Grace, destroyed his personal papers. All that remains are her own idolatrous journals in which she recorded the exploits he recounted. As this fascinating and heroically researched biography makes clear, however, most of those tales were made up of whole cloth.

In "Edwin Hubble: Mariner of the Nebulae," Gale Christianson has dug through previously inaccessible archives, interviews with Hubble's sisters, friends, relatives, and colleagues, and Grace's eloquent and suspect journals to piece together a riveting portrait of a great scientist and a haunted man, and the best look we are likely to have of the real Hubble.

Christianson glides gracefully between the personal and the cosmic as he moves from Hubble's rock-ribbed American boyhood on the plains of Missouri to his journeys among the stars of both the celestial and earthly variety. Along the way there is a suitably Runyonesque cast of supporting characters, from Milton Humason, mule driver and dropout who rose to become a tobacco-chewing wise-cracking astronomer, to Nicholas Copernicus, the faithful cat.