Solar System Voyage

It was a clear night on the farm, and the sky was full of stars. Spike, Suzy and Little Thunder lay on a blanket in the paddock.

"That bright one isn't a star," said Suzy, pointing. "It's Jupiter, the biggest planet."

"How far away is it?" asked Little Thunder.

"Scientists measure space in astronomical units," said Spike. "One unit is the distance from the Sun to Earth. About 150 million kilometres."

Little Thunder's eyes went wide. "That's further than the road to town!"

"A bit," laughed Suzy. "Jupiter is about five units from the Sun."

They decided to make a model. The next morning, Spike put a big yellow ball at the gate. "That's the Sun." Then they paced out the planets along the fence line, one big step for every tenth of a unit.

Mercury was just four steps from the gate. Venus was seven. Earth was ten. Mars was fifteen.

"These four are the rocky planets," said Suzy. "Small and solid, like stones."

Then came a long, long walk. Jupiter was fifty-two steps away. Saturn was ninety-five steps, past the dam!

"These are the giants," said Spike. "Huge balls of gas and ice."

Tokyo the cow watched from the paddock. "Where's Neptune?"

Little Thunder kept walking. And walking. Three hundred steps later, he was at the far boundary fence. "Here!" he puffed. "Neptune!"

"Sunlight takes about eight minutes to reach Earth," called Suzy from far away. "But it takes about four hours to reach Neptune."

Little Thunder sat down by the fence, very tired. "Space is really big," he said.

"And that's just our solar system," said Spike, trotting up. "There are billions of stars out there."

That night, Little Thunder looked up at Jupiter and waved.