Darryl Eskin, age 9, of Rochester, New York; for his question:

How were the planets discovered?

The planets Mercury, Venus, Mars, Jupiter and Saturn can be seen emong the stars in the sky. These planets are so close to us that we need no telescope to see them. They were seen and studied by early stargazers long before the telescope was invented. In fact, they were named ages ago by men whose names have been lest to history for four ancient gods and one goddess.

Three more planets were discovered when science was able to scan the heavens through the telescope. Uranus, the sizeable planet beyond Saturn, was discovered In 1781. Neptune, somewhat smaller and still farther from us, was spotted in 186. And little Pluto, on the outside rim of the Solar System, did not have his telescope picture taken until 1930.

It is possible to see Uranus as a dim dot in the sky if you know just where and when to look. Neptune and Pluto cannot be seen without a telescope.