Is Mars Habitable?

"Few persons except astronomers fully realise that of all the planets of the Solar system the only one whose solid surface has been seen with certainty is Mars."In 1907, Alfred Russel Wallace wrote the short book "Is Mars Habitable?" in response to Professor Percival Lowell's book "Mars and its Canals." The latter seemed to invalidated the claims Wallace made in his 1902 book "Man's Place in the U...