Holly Williams, age 9, of Gastonia, North Carolina, for her question:

Which planet is closest to the earth?

On January 23, the distance between Earth and the planet Venus was about 25 million miles. This is the closest that any planet can come to us and it doesn't happen very often. And when it does happen, the other planet is always Venus. Our second closest planet neighbor is Mars. Once in a great while, Mars comes as close as 35 million miles. As the planets swing around their orbits, those on the inside lanes keep catching up and passing those in the outer lanes. This is why the distances of all the planets change from moment to moment.

After January 23, when Venus came within 25 million miles, it began moving farther away. During early January, the distance of Mars was 78 million miles. By the end of the month it had moved as far away as 106 million miles. Mars can come as close as 35 million miles but golden Venus can come ten million miles closer.