Kevin Holcomb, age 11, of Des Moines, Iowa, for his. question:

What is the surface gravity of Jupiter?

The surface gravity of giant Jupiter is somewhat surprising. The big planet could swallow all the other planets of the Solar System and you would expect its force of gravity to be immense. It is more than 1,300 times bigger than the earth, but size is only one factor in surface gravity. The other factor is mass and Jupiter is only 317 times more massive than the earth. The total weight of our world is 5 1/2 times more than an equal volume of water. The density of Jupiter is only 134 times that of water.

The surface gravity we know best, naturally, is the earth's. The force it exerts is estimated by the weight it gives to objects on its surface. And we estimate the surface gravity of other heavenly bodies in terms of the earth's. Jupiter's surface gravity is 2.64 times that of the earth. A bag of beans that weighs 10 pounds on the earth would weigh 26 1/2 pounds on Jupiter. A 200 pound earthman would weigh 528 pounds. This, to be sure, is a lot of weight for his earth muscles to move around. But it seems less than you would expect from the giant planet of the Solar System.