Napsal 34 knih, většinou na astronomická témata, jako je The Quest for Comets, životopis objevitele Pluta Clyde Tombaugha v roce 2006, a jeho pocta Eugenovi Shoemakerovi, kniha Shoemaker by Levy.
The opposition by the workers, their organisations and the scientific community to the lifting of the ban must oblige the Commission to revise its decision.WikiMatrix WikiMatrix