Gary West, age 13, of Huntsville, Ala., for his question:
Is Jupiter a solid body?
The answer to one good question often leads to another. Andy's column on the heaviest planet provoked a slew of wide awake queries about the nature of Jupiter. Since it is more than five times farther from the sun than We are, We might expect all the Jovian substances to be frozen solid..
No sensible space traveler would land on Jupiter unless the experts change their present picture of conditions on the giant planet. However, their deductions are based en sound data and are not likely to change greatly. They think that the densest lower atmosphere becomes a soupy mixture and at ground level blends with a somewhat thicker soup of compressed gases, mixed with fragments of ice and"suspended crystals of poisonous methane and ammonia.
According to this picture the Jovian landscape is a soggy quicksand, unable to support a spaceman or his ship on solid ground. Under Jupiter's gravity every 100 pounds of earth equipment would increase its weight to 264 pounds. Add to these hazards the enormous pressure of Jupiter's atmosphere, which is much denber and some eight times thicker than our own. And throw in a thermometer for good measure. A warm Jovian day may soar to minus 130 degrees Centigrade. After only five hours it is followed by the cooler Jovian night. Even if a spaceman should survive these impossible conditions, he would need a thrust equal to 37 miles a second to escape the clutching gravity of the giant planet.
The earth and Jupiter are two vastly different worlds, though both are made from the same basic chemical elements. The atmosphere of Jupiter is thought to be hydrogen
Cluttered with dense and turbulent clouds of methane and frozen fragments of ammonia. Experts have deduced the presence of nitrogen, oxygen, helium and vast quantities of Hydrogen. The average composition of its surface materials is about one third the density of water.
We know how these substances behave on earth and something of how they might behave under extreme Jovian conditions. Most of the bulky planet is thought to be in a plastic state with fluid qualities. But until We know more We cannot compare it with the familiar solids, liquids and gases of our warm little world.
Jupiter's average density is 1.3, but experts differ about the nature of the heavier materials below the light surface. The soupy surface may rest on thick layers of Somewhat fluid ices having an average density of 1.5. The Central core may be plastic rock, metal or compressed hydrogen perhaps six times denser than water.