BOOK REVIEW / SCIENCE : Personal Insights Into Galactic Discoveries : VOYAGE TO THE GREAT ATTRACTOR: Exploring Intergalactic Space <i> by Alan Dressler</i> ; Alfred A. Knopf $25, 337 pages

Never with fiction, but occasionally with accounts of great insights--such as discovering the extent of the universe, its nature, or its origin--I begin my reading with the conclusion. I like to know the author’s thoughts on the implications of whatever it is that has just been recounted before I begin.

Alan Dressler’s startling prognostications in a concluding essay in “Voyage to the Great Attractor” drove me with some excitement to Page 1. Dressler, an astronomer based at the Pasadena office of the Carnegie Institution (which controls the Mount Wilson Observatories as well as a telescope in Las Companas in Chile) is an expert in intergalactic space. He is also an excellent observer of human nature.

His talent as an astronomer got him invited to participate in a unique galactic survey that resulted in a discovery that compelled his colleagues to re-conceptualize the texture of the universe. His skill as a writer enabled him to describe the strengths and weaknesses of each member of the survey team, including himself, which explains the startling coda.

Dressler sees humankind on the verge of mastering the molecular biology of the human genetic package as well as the equally complicated and related biology of the human brain. Because he believes we will be unable to resist opening the Pandora’s box of manipulating our own DNA, he suggests that “we are most likely near the end of what we have known as humanity,” and predicts that a new species will appear “either here on Earth, or out among the stars,” where “humans may be destined to evolve a variety of sentient creatures who will carry on the exploration of the hyperspatial domain.”

Hyperspace, where galaxies beyond galaxies recede from us even as we race toward them, includes the stars that compose the supercluster of galaxies known as the Great Attractor. That object, however, was unknown when the seven astronomers joined in 1980 to make an unprecedented large-scale map of about 500 elliptical galaxies, probably the oldest galaxies in the universe.

Writing in the first person, and frequently in elegant poetic language, he introduces each member of the team, like an astronaut who is recounting a group adventure. Dressler’s team, later dubbed the “seven samurai,” was led by the then-36-year-old Sandy Faber from the Lick Observatory near Santa Cruz. She had mentored four of the participants and knew their work intimately. They would be using telescopes on four continents in both hemispheres. Dressler tells us about how each one came to astronomy and eventually to the project from their home bases around the United States and Great Britain.

Dressler has been able to distill these personalities, describe insights and errors, and maintain suspense as he moves from revelation to frustration to reconsidered revelation. All the while he gently explains how astronomers work, how bigger telescopes do not see “deeper” but rather gather ever more faint sources of light, which they study through spectroscopy, a way of analyzing the chemical makeup of distant objects.

Dressler takes us along with him as he discovers that he has made the kind of trivial mistake anyone could have made. In correcting it, however, he revealed a phenomenon so preposterous that all the team members had to convince themselves that it was right before they could present their conclusions to the world.

And he describes the ecstasy of discovery.

Ramifications of the discovery of the Great Attractor include acknowledging that the universe is lumpier than had been assumed (a view recently verified by the pictures from NASA’s COBE satellite), filled with huge areas of cold dark matter and vast empty spaces.

Frank and personal, Dressler exposes his astronomers, their egos and temperaments in conflict at the blackboard, the telescope and the computer, as they feud and fuss but finally come together in their 1986 presentation to present evidence that an enormous galactic structure is distorting an expanding universe.