Joyce Dietrich, age 11, of Lancaster, Pa., for her question:

What is the solstice?

We have two solstices with the seasons. The summer solstice is the longest day of the year. After that, the days get shorter until the winter solstice, which is the shortest day of the year. All this happens because the earth's axis is tipped at an angle of 232 degrees. Through the year, this makes the sun travel higher or lower in the sky.

The word solstice is coined from Latin, and it means the sun stands still. Every day, of course, the sun marches in an arch over the sky, and We would be astonished if it stood still for even a little while on this daily journey. This does not happen, even on the two solstice days of the year. But throughout the year, the sun travels another path over the sky. And on this yearly path, the sun stops and turns twice each Year.

In the winter, north Of the equator, the sun's journey is lower in the sky. In the summer it is higher. If you checked its daily path for a year, you would have a broad highway over the sky. Astronomers call this yearly path the ecliptic. In winter, the sun moves to its lowest point on the ecliptic. There it stops for several days and its daily path remains the same. Then the sun turns and day by day it takes a higher path over the sky.

The low point on the ecliptic path is the winter solstice, Dec. 22, which is the shortest day of the year. Frcm this point, the sun climbs higher each day until the summer solstice on June 22, the longest day of the year. After the summer solstice, the days get shorter as the sun moves lower and lower on its ecliptic path

Twice a year the solstice is true to its name. The sun does stand still on its path. But this path is the ecliptic, the yeaxly path that swings up and down with the seasons. The highest point, where it stands and turns, is the summer solstice. The lowest point, where it stands and turns again, is the winter solstice.

Midway between the solstices are the equinoxes. The word equinox means equal nights. And at the spring and fall equinoxes, the night is 12 hours long all over the world from pole to pole. And it must follow that everywhere the day is also 12 hours long and equal. To the night of the equinox.