Raymond Partridge, age 12, of Alpine, Calif., for his question:

Where did the Tropics of Cancer and Capricorn get their names?

As our summer advances, the noon sun climbs a little higher in the sky each day. It reaches its highest point at the summer solstice, around June 21st. By this time, the sun is in the constellation Cancer, the crab.

After the summer solstice the noon sun is a little lower in the sky each day. Its lowest point occurs at the winter solstice, around December 21st. At this time it stands in the zodiacal sign of Capricorn, the Fish‑tailed Goat.

The Tropic of Capricorn corresponds to the place in the heavens where the sun turns from its southernmost journey. The Tropic of Cancer corresponds to the place in the heavens where the sun turns from its northernmost journey. Each is named for a constellation in the zodiac.

The Tropics, as they are called, run parallel with the equator, forming circles clear around the world. The Tropic of Cancer is 23 degrees and 27 minutes north of the equator. The Tropic of Capricorn is 23 degrees and 27 minutes south of the equator.