Mark Kissling, age 9, of Philadelphia, Pennsylvania, for his question:

When will Halley's Comet return?

This razzle dazzle comet visits our skies once every 76 or 77 years or so. It appeared last in 1910 and its last visit was in the year 1986. Halley's comet is one we can count on to give us a splendid show and we know more or less when to expect it. However, other bright comets also appear now and then when we do not expect them. Astronomers report that one of these glamorous strangers may appear in our sky during the next Christmas season.

Telescopes have spotted this comet headed toward the sun. Right now it is nothing more than a dark cold blob, still outside the Solar System. But astronomers have computed where and how fast it is traveling. Of course, several things could happen to throw it off course. But if all goes well, it will display its dazzling tail . Halley's comet, we hope, will appear again  about 2062.