Cindy Hall, age 7, of High Point, North Carolina, for her question:

How do meteors start?

Scientists think that the meteors are as old as the solar system. This means that they were made when the planets were made which was more than four billion years ago. All this time, they have been traveling around the spaces between the planets. And swarms of them also swing around and around the outside edge of the solar system. Most of them are no bigger than a grain of sand. Some are as big as pebbles and a few are as big as boulders.

So far as we know, billions of meteors have been zooming around the solar system for billions of years. And many of these little travelers come near enough to us for the earth's gravity to pull them down, down to the surface. As they fall through the air, they heat up and become red hot. And these falling meteors look like falling stars. After they fall, they can never return to space traveling through the solar system.