8 Jupiter’s fireworks

Chapter Eight JUPITER'S FIREWORKS. Roshni and Ollie had front-row seats for the most spectacular cosmic fireworks display they could ever hope to see. They looked out through the spacecraft's windshield, breathless with excitement. The last few seconds were ticking away on the countdown clock. "Three, two, one… zero!" Roshni yelled.

The first of the comet fragments plunged into Jupiter's atmosphere. A tremendous fireball erupted at the point of impact. Roshni shielded her eyes. This was amazing! Enormous shock waves went rippling out across Jupiter's surface, like rings spreading out on a lake.

"How come we can't hear it?" Ollie asked. "An explosion that size ought to be deafening us!" "Because sound waves need air to travel, and there isn't any air in space," Roshni explained. The next fragment went tumbling down into the seething storm. Another gigantic explosion went up. "Look at that," Ollie said. "I bet the ground's shaking down there!" "Jupiter's not solid—it's made of gas," Roshni said. "It might be solid right at the core, but scientists aren't sure about that. There's a lot scientists don't know about space, which is why they need probes like Odin to do investigations." Another fireball expanded across Jupiter's surface. Ollie whistled. "Just

imagine if a comet hit Earth!" "A comet did hit Earth, millions of years ago," Roshni explained. "Well, scientists think it was either a comet or a meteorite. That's why the dinosaurs were all wiped out. The impact shook up our entire planet." "Whoa, really?" "The crater's still there, in Mexico," Roshni said. "Ask Tamiko about it!" Outside, the Odin probe was busily collecting data. Its camera was recording image after image, capturing the moment the comet smashed into Jupiter.

That gave Roshni an idea. "Hey, Beagle, can you tune in to the probe's broadcast channel? We might be able to listen in." BEEEEEEP-BOOP! chirped the Beagle. It sounded like, "Sure thing!" The computer screens in front of them filled up with information. Roshni grinned. They were getting to watch a science broadcast as it happened and learn cool stats just like the scientists back on Earth!

"Look how fast that comet was going when it hit!" Ollie said. "134,000 miles per hour!" Roshni's mind boggled. An Olympic athlete running a hundred-meter dash would get up to about 28 miles per hour. The speedometer in her parents' car only went up to about 110 miles per hour. The speed of sound itself was a stunning 767 miles per hour. But the comet was going more than one hundred and seventy times faster than sound! "No wonder the fragments exploded like that!" she said. "Hey, how hot were those fireballs, anyway?" Ollie tapped the screen and looked confused. "I'm not sure the probe's working right. These figures are incredible." "Incredible how?"