The first edition of Planets has the letters ABCDEF on page 160. © 1990 by Western Publishing Company, Inc. Illustrations © 1990 Ron Miller. Published by Golden Press, New York, N.Y. No price is listed. The ISBN number on the back cover is 0-307-24077-0. Listed as a Golden Guide.
This title also exists in a large (5 ¼ by 7 ¾ inch) hardcover. ISBN number on the back cover is 0-307-64077-9.
No Golden Press revised edition or cover variant exists. Still in print by St. Martin's Press.