The Worlds of Galileo: A Jovian Odyssey (Hardcover)

Drawing upon interviews with the key participants, Hanlon explains the project's origin in the cash-strapped 1970s, the political travails of the early 1980s, and the redesign in the aftermath of the Challenger accident. After the spacecraft's epic voyage out to Jupiter, he focuses upon the astonishing 'fire and ice' moons of volcanic Io and Europa, where there appears to be an ocean beneath a thin shell of ice.

Hanlon handles the geological discussion with ease, so this is a highly readable account. Certainly, Sir Arthur C. Clarke, who contributed the foreword, was impressed. Finally, St Martins Press is to be congratulated for having produced a very handsome volume with colour imagery throughout.

The Galileo Mission was spurred by the preceding Pioneer and Voyager missions of the 1970s. These four robots cruised through the outer solar system, returning stunning views of the largest planet and its associates beyond. In doing so, they raised numerous and unanswerable questions about our neighbours in space. Unlike the previous probes, Hanlon takes us through the planning that led Galileo's flight to Venus, back past Earth to its final destination far out in the solar system. The efforts put into the flight brought Galileo to within 5 km of its intended position when it arrived at Venus - a staggering achievement.

All the planning and engineering couldn't prevent problems, however. NASA's attempt to open the main transmitting antenna failed when some minor pins failed to release. When Galileo arrived at its primary destination, the antenna looked like an umbrella wracked by high winds. NASA used other methods to maintain communication, resulting in the stunning images seen here. It was a frustrating experience for the mission team, yet Galileo added a treasure house of new information about our neighbours in space.

We are so accustomed to the notion that we are the sole home of life, that the problems surrounding Galileo's termination render this issue the most bizarre of the trip. Europa, the ice-coated satellite of Jupiter, may contain living organisms in its hidden sea. In order not to contaminate that life, if it exists, Galileo had to be purposely sacrificed. Hanlon describes the options and why each was considered worthwhile. Galileo went to explore the Jovian system and was still transmitting images as he completed this vividly descriptive work. He is to be commended for a gripping account. We may be the only life in this group of planets, but Galileo's records give us a major argument to continue our search for life elsewhere. [stephen a. haines - Ottawa, Canada]