He also wrote two books on Pluto (noticed while changing the subject heading to dwarf planet...)
Asimov, Isaac. How did we find out about Pluto? illustrated by Erika Kors. New York : Walker and Co., c1991.
Isaac Asimov; Greg Walz-Chojnacki. A double planet? : Pluto and Charon. Milwaukee : Gareth Stevens Pub., 1996. (this must be a later edition but I can't find an earlier version)
no subject
(noticed while changing the subject heading to dwarf planet...)
Asimov, Isaac. How did we find out about Pluto? illustrated by Erika Kors. New York : Walker and Co., c1991.
Isaac Asimov; Greg Walz-Chojnacki. A double planet? : Pluto and Charon. Milwaukee : Gareth Stevens Pub., 1996. (this must be a later edition but I can't find an earlier version)