Harry and Ralph visit the moon, the planets, and a comet in their spaceship and discuss the stars, the Milky Way, and the possibility of life on other planets.
- ISBN10 0812017617
- ISBN13 9780812017618
- Publish Date 1 September 1993
- Publish Status Out of Print
- Out of Print 12 July 2011
- Publish Country US
- Publisher Peterson's Guides,U.S.
- Imprint Barron's Educational Series Inc.,U.S.
- Format Paperback
- Pages 29
- Language English