"Packed with facts and written in an absorbing style, this book leaves you in no doubt that extraterrestrial microbes could yet be found in our Solar System."

– BBC Sky at Night

"A compelling landmark book that will take you on an exhilarating ride."

– Daily Express

"Informative, thought-provoking, and entertaining" (4/5 Stars)

– BBC Focus

"An exhilarating ride. The arguments advanced for the prevalence of life in the solar system are well developed and highly stimulating. I'm glad that I read it."

– The Times Higher Educational Supplement

"Well-written and provocative."

– New Scientist

"Compelling arguments and sound reasoning make a convincing case that primitive life forms exist on Mars and at various other places in our solar system." "A highly recommended case that brings the new possibility to readers of life at various levels. Conditions which are probably too hostile to permit life to exist - certainly life as we know it."

– Choice Magazine

"Bang up to date and utterly riveting. An absorbing account of one of the greatest unresolved debates in the search for life."

– Lewis Dartnell

"Well written, concise and elegant. I was barely able to put it down."

– Felisa Wolfe-Simon - Research Fellow, Department of Earth and Planetary Sciences, Harvard University

"Interesting, accessible, and refreshingly upbeat."

– Seth Shostak - Senior Astronomer at the SETI Institute, and author of “Confessions of an Alien