Astronomer Giovanni Bignami has obviously written this book with the intention of providing information for young people who might be interested in pursuing a scientific career. He introduces his account of the progress of astronomy and space exploration, manned and unmanned, by telling his readers, in considerable detail, how he was influenced by the works of Jules Verne.
The descriptions of human progress, beginning with the expansion of humanity to occupy all the inhabitable parts of the Earth, and going on to describe exploration of the atmosphere, the seas, the moon and planets, and the study of the stars, is given in interesting detail. The idea of the Seven Spheres used in these descriptions is based on ancient cosmology in which the universe was imagined as a series of crystal spheres with Earth in the centre. This idea, we are told, was developed by Eudoxus of Cnidas, who in the first half of the fifth century, guessed there to be 27 spheres to account for the motions of the planets and the stars. Later, Aristotle devised a system that needed 55 spheres.
After dicussing the exploration of land and oceans, and the development of earth sciences, we are given an often fascinating account of the development of rockets, leading to the moon landings.
Details are given of the development of orbiting space stations, stimulated by rivalry between the USA and USSR, culminating in the agreement, in 1993, to jointly build a large space station, the International Space Station. Bignami notes that the ISS is within the Earth's magnetic field, which protects it from hard radiation which astronauts venturing into deep space would have to be protected from.
This is followed by a lengthy description of the Moon landings, with details of the technical problems which had to be overcome to make them possible. We are then given a chapter on the exploration of Mars, including details of the construction of nuclear powered spacecraft to send astronauts there, and what would need to be done to make Mars habitable in the long term.
Bignami does not stop at the solar system but goes on to consider the technical aspects of possible interstellar travel, in the distant future presumably. Of course, finding the money and resources for intensive space travel would be rather difficult, but the book ends with a consideration of the possibilities.
The translation from Italian is somewhat clumsy in places, but this work will undoubtedly appeal to technically minded readers. -- John Harney