The collective monograph, written by prominent experts from Holland, Italy, Canada, the USA, Germany, presents the most valuable material of the international symposium (USA, Maryland, 1980), convened in direct connection with the upcoming return of Halley's comet to the Sun in 1986. According to modern ideas set out in the book, comets are ancient objects containing frozen "primary" matter, from which all the bodies of the solar system were formed. There is extensive discussion of the idea that organic compounds delivered by comets from space may have served as building blocks for the terrestrial biosphere.