Read George's Cosmic Treasure Hunt Online
Authors: Lucy Hawking
Until that moment, the spaceship seemed to be starting its cosmic journey in complete silence, as though they were watching it on television with the sound turned off. But seconds later the noise rolled over the intervening miles toward them. First they heard a strange crackling sound, then the full force of the boom hit them. The sound seemed to swallow them whole. It was so loud, it blocked out everything else. They felt a pounding in their chests so intense that they thought they might be knocked backward by the wave of sound.
HOW SOUND TRAVELS THROUGH SPACE
On Earth there are lots of atoms close together and knocking one another around. Giving atoms a kick can make them kick their neighboring atoms, and then those atoms kick other atoms, and so on, so the kick travels through the mass of atoms. Lots of little kicks can create a stream of vibrations traveling through a material. The air covering the Earth's surface consists of a large number of gas atoms and molecules bouncing off one another. The air can carry these vibrations, as can the sea, the rock beneath our feet, and even everyday objects. We call the vibrations that are the right sort to stimulate our ears
sound
.
It takes time for sound to travel through a material, because an atom has to pass each kick on to its neighbors. How much time depends on how strongly the atoms affect one another, which depends on the nature of the material and other things like the temperature. In air, sound travels at around one mile every five seconds. This is about one million times slower than the speed of light, which is why the light from a space shuttle launch is seen almost immediately by the spectators, while the noise arrives a bit later. In the same way a lightning flash arrives before the thunder, which is the kick given to the air molecules by the sudden and intense electrical discharge. In the sea, sound travels at around five times faster than it does in air.
In outer space it is very different. Between stars atoms are very rare, so there is nothing to kick against. Of course, if you have air in your spacecraft, sound inside it will travel normally. A small rock hitting the outside will make the wall of the craft vibrate, and then the air inside, so you might hear that. But sounds created on a planet, or in another spacecraft, would not carry to you unless someone there converted them into radio waves (which are like light and don't need a material to carry them), and you used your radio receiver to convert them back into sound inside your ship.
There are also natural radio waves traveling through space, produced by stars and faraway galaxies. Radio astronomers examine these in the same way that other astronomers examine visible light from space. Because radio waves are not visible, and we are used to converting them into sound using radio receivers, radio astronomy is sometimes thought of as “listening,” rather than “looking.” But both radio and visible-light astronomers are doing the same thing: studying types of electromagnetic waves from space. There isn't really any sound from space at all.
The roar of the engines rang through their whole bodies as the spaceship curved away, leaving a trail of white smoke behind it. As they stood and watched the craft climb ever upward, they saw the wispy white clouds form into a shape against the blue sky.
“That looks like a heart,” said Annie dreamily. “Like it's saying,
From the space shuttle with love
.” But a second later she shook herself back into action again. Looking around, she saw that all the adults were still gazing up at the sky. She grabbed George and Emmett.
“Okay, I'll give the countdown,” she said, “and then we run! Are you ready? Five, four, three, two,
one
⦔
A
s the spaceship disappeared into the skies above, the kids also vanishedâdown the same stairway Eric had taken. They found themselves inside a huge building with long corridors leading in all directions.
“I think it's this way,” said Annie, but she didn't sound at all sure. They rushed down the hallway after her, past framed pictures of astronauts and drawings done by the children of astronauts, which hung on the wall to commemorate each mission.
“Um, let's try this door.” Annie pushed hard, and they burst into a huge room full of giant pieces of machinery.
“Oops!” she said, backing out rapidly, treading on George and Emmett behind her. “Not that door, then.”
“Do you actually know where you're going?” asked George.
“Of course I do!” said Annie huffily. “I just got a little confused because all these places look alike. We need the Clean Room. That's where they keep the suits. Let's go this way.”
George's heart sank at the idea of Annie navigating her way around the Solar System. If she couldn't find her way around the Global Space Agency, which she claimed to have visited many times, could she really be trusted to take them to Mars and back?
But Annie was not to be deterred. She dragged them along to another door, which she shoved open. The room was in darkness, apart from an illuminated screen at the front, where a man was pointing to a picture of Saturn.
“And so we can see that the rings of Saturn,” he was saying, “are made up of dust and rocks in orbit around the giant gas planet.”
George thought back to the little rock from Saturn he had once pocketed when he and Annie were riding around the Solar System on a comet. Unfortunately a teacher at George's school had thought the precious rock was nothing more than a handful of dust and had made George throw it in the trash can.
If only!
he thought. If only he'd been able to bring that little rock here. What clues about the Universe might they have been able to discover from his fragment of Saturn?
They came to a door marked
COMETS
, but it was locked.
“Ping-pong!”
they heard from inside Annie's backpack. Cosmos seemed to have switched himself on.
“Cosmos!” said George. “You have to stay quiet! We're trying to find the Clean Room and we don't want anyone to notice us.”
“Do I sound like I care?” came the reply.
“Oh, shush!” said George urgently.
“Emmett, make him be quiet!” ordered Annie.
“Actually,” said Emmett, “it would be better to leave him switched on right now. If I close him down and then have to open him up quickly, we might have even more problems.”
“Over there!” said George, spotting a sign on a huge pair of double doors. It read,
CLEAN ROOM
. “Is that where the suits are?”
“That's it!” said Annie. “I remember it now. I've never been inside, but it's where they keep all the equipment that goes into space. It's a super-duper clean environment so that bugs and stuff don't go from Earth into space.”
“Oh yes,” said Emmett nerdily. “It's very important that microbes don't travel into space with any of the machinery. Otherwise how would we ever know if we've found evidence of life in space or whether we're just seeing fingerprints that we ourselves left out there?”
Annie ran over to the double doors. “Follow me!” she said. “Most of the people should be upstairs, watching the launch.”
They went through, expecting to emerge in the Clean Room, but there was a surprise in store for them. They found themselves standing on a moving conveyor belt. Gusts of air started blowing at them from all sides as the belt dragged them along. Brushes emerged from the ceiling as they were sprayed with jets and buffed with a huge piece of fabric.
“What's happening?” shouted George.
“We're being
cleaned
!” Annie called back.
“Arrghh!” shouted Cosmos. “They're messin' with my ports!”
George saw a pair of robotic arms in front of him pick Annie up and drop her into an all-in-one
white plastic suit, pop a hat on her head, a mask on her face, and a pair of gloves on her hands. Before she had time to call out, she was ejected from the conveyor belt through another set of double doors, and it was his turn. George and then Emmett behind him were similarly outfitted by the machine and propelled through the doorway, where they stood, blinking at the incredible whiteness that surrounded them.
It was, thought George, like being inside a set of someone's very white teeth. On one side of the kids was a robot under construction; on the other, what looked like half a satellite. Everything seemed to gleam with an unusual brightness. Even the air felt somehow thinner and more transparent than normal air. On the wall, a sign read: 100,000.
“That's how many particles the air has in here,” whispered Emmett through his face mask. “This isn't the cleanest Clean Room. In there, they have a ten thousand ratingâthat means any cubic foot of air in there has no more than ten thousand particles in it larger than half a micron! And a micron is a millionth of a meter.”
“Is it clean enough for us to go to Mars from here?” asked George. “I mean, what if we take some evidence of life on Earth to Mars and then Homer finds it later on? Could we mess up the research program?”
“Theoretically, yes,” said Emmett, who was sounding much more confident now that he felt they'd entered his area of expertise. “But that depends on a) whether we can get Cosmos working, b) whether you actually manage to get to Mars, and c) whether Annie's alien message really
is
a threat to destroy the Earth. If she's rightâand I have to point out the probability is very lowâthen if you don't go, there won't be life on Earth, anyway. So it won't matter.”
In a corner of the Clean Room, Annie had found some space suits, but they were bright orange and didn't look at all like the ones George remembered from his travels around the Universe in the past.
“These aren't ours!” Annie said in disappointment. “These are the ones they use for the space shuttleâ
they're different from the ones me and my dad had.” She rooted around a bit farther. “Dad told me he'd put ours in here for safekeeping,” she said. “And I said, what if someone else took them by mistake? And he said they wouldn't because he'd labeled them as prototype suits, not to be used for shuttle missions.”
Emmett was tearing at the plastic wrapping that the Clean Room entry machinery had used to cover Annie's backpack. He fished Cosmos outâand at the same time found the bright yellow book,
The User's Guide to the Universe
.
“Okay, little computer,” he said, flexing his fingers. “Operation Alien Life-form is underway. Where to, Commander George?”
“See if you can get him to open the doorway,” said George. “We need to go to Mars, to the north polar region, destination Homer.”
“Bingo!” Annie shouted. “I've got the suits!” She emerged with an armful of white space suits in plastic coverings marked
PROTOTYPEâDO NOT USE!
She chucked one over to George. “Take off your face mask and then put this on over everything else.” She and George ripped the coverings off the suits and started clambering into the heavy space gear.
Meanwhile Emmett had called up some pictures of Mars on Cosmos's screen, zooming closer and closer to the red planet. However, Cosmos himself was being unusually silent.
“Why is he so quiet?” asked George.
“I had a great idea,” said Emmett simply. “I turned down the volume.”
He turned it up, and they heard Cosmos grumbling, “Nobody cares about me. No one understands me.”
Emmett turned down the volume again.
“We'll need to be able to talk to Cosmos when we're out there,” warned Annie. “We got stuck in space once, and once was enough. Can you handle him?”
Emmett turned up the volume once more.
“
Do this, do that
, that's all I ever hear,” whined Cosmos.
“Cosmos,” said Annie. “I've got a way you can show us how you feel.”
“Bet you want me to open up a doorway so you can go through it,” said Cosmos morosely.
“That's right,” said George. “But the thing is, we're not really allowed to do this. So we'll be in a lot of trouble if we get caught.”
“Cool!” said Cosmos, perking up a bit. “Then I'm in.”
“But we need you to help us,” said George. “We need you to look after us while we're on Mars. And you too, Emmett. If we need to leave quickly, you have to get us out of there immediately.”
“But,” said Emmett, “if you signal me from Mars, then won't there be a time delay? I mean, it takes four minutes and twenty seconds for light to travel from Mars. Or, if Mars is on the other side of the Sun, it
could be twenty-two minutes. So by the time you've said something to me and I've replied, it will have taken either eight minutes and forty seconds or forty-four minutes. And that might be too late.”