The centerpiece of the story is the monstrous Hale Telescope, built in the 1930s – a huge battleship of a telescope, seven stories tall, with a mirror that is two hundred inches wide and took fourteen years to cast and polish by hand. No one understands exactly how the Hale Telescopes works – its designers are dead, and the parts are fifty years old. The telescope is used by astronomers like the remarkable James E. Gunn, a "gadgeteer" who scavenges for junk parts and fashions them into instruments he uses to look into the glittering depths of the universe. Preston's rendering of the obsessions and adventures of Jim Gunn and his colleagues is a witty and beautiful portrait of scientists in action, and a luminous story about one of the deepest quests in human knowledge.

First Light won the American Institute of Physics award in science writing. An asteroid has been named "Preston" in honor of First Light. Preston is a lump of rock the size of lower Manhattan. It is likely someday to collide with Mars or the Earth.

"This is Preston's best book, and it is the best book ever written about astronomers and the things they do. The science is accurate, the portraits of the human characters are true to life, and the story whizzes along like a ride on a roller coaster.
--Freeman Dyson

"In this extraordinary account, Preston has spun a tale of science as a very human endeavor . . . . First Light should be required reading for students, teachers, and anybody else who wants to know how science is really done."
--Sky & Telescope

"First Light is a reviewer's nightmare: you want to quote the whole thing. . . . Richard Preston has deep pockets, and they are filled with literary black arts."
--The Hampshire Gazette

"First Light beautifully depicts astronomers' deepened understanding of earth as the merest speck in time and space."
--The New York Times Book Review