“May we go down into the mines, Dad?” Steve asked.
“We’ll see if we can,” said his father.
As they walked toward the mining place, Mr. Shannon said, “Underneath us are pockets of poisonous gas like that found in Jupiter’s atmosphere. Sometimes it leaks into the mining tunnels causing danger from suffocation.”
“I sure hope the gas stays where it belongs while we’re down there!” Steve said and swallowed the lump of fear in his throat.
They turned their attention to Jupiter. It looked even more like a beach ball now with its stripes of beautiful colors. Mr. Shannon said the bands were floating ice bergs of the poisonous gases he was talking about.
“No ship can land on Jupiter,” he said. “Its gravity would crush a spaceman flat. Gravity pull is much stronger on the larger planets, you know. Jupiter’s atmosphere is many thousands of miles deep. Raging storms are going on beneath it all the time.”
“Ooo!” Sue gasped. “I guess we’re close enough to it then!”
Other wonders of the sky were the round beacons of Jupiter’s other moons, three of which were about the same size as Callisto. They hung like bright searchlights in the starry heavens.
The men at the mining place greeted the Shannons warmly. They had not seen anyone from Earth for so long that they had grown very lonely.
The chief mining engineer said he would be glad to take the visitors on an underground tour. His name was Dr. Harding. He was plump and short and wore black-rimmed glasses inside his space helmet.