Tim Rohovie, age 10, of Lethbridge, Alberta, Canada, for his question:     

Who discovered Mars?

The Red Planet is visible to the naked eye and it was up there in plain sight when our caveman ancestors first beheld the starry heavens. Since that time, it has been seen by anybody and everybody who cared to look up at the night sky. Hence, it is quite impossible to know who discovered it or saw it first. In many ancient civili¬zations, early astronomers named the outstanding heavenly bodies    way back before the dawn of history.

Names were given to all the visible planets long before written records were invented, but their original names have been forgotten. Mars was given its present name just a few thousand years ago, in honor of the Roman god of war. Before that, it was known by other names in other lands. All the five planets that are visible from the earth were identified in prehistory. The other three were discovered one by one, with the help of telescopes and advanced astronomical skills.