“You don’t really, Sue,” Bobby told her. “You couldn’t stand up in its heavy gravity. Saturn’s almost as big as Jupiter, you know.”

“What are Saturn’s rings made of?” Steve asked.

“Oodles and oodles of rocks,” Bobby replied. “They are traveling so fast that they make the rings look like one solid piece.”

Wind was beginning to howl around them and this seemed to make Bobby very excited.

The coming storm must be something special, Steve thought. His curiosity had been aroused strongly.

The clouds gathered darker and more thickly behind the mountains. The wind was driving harder.

“Hadn’t we better go inside?” Sue asked, worriedly.

“Shucks, no!” Bobby said. “It won’t be any fun unless we’re right out in it! There won’t be any rain. It’s too cold on Titan for rain.”

Suddenly the three heard a loud siren wail.

“That means a jet plane is coming in,” Bobby said. “All planes have to land when word of a storm gets around.”