“But where is it?”
The door swung back, just as it had so many times before. Through the doorway, they saw what looked like a black and primrose-yellow world: a dark sky behind a pale, empty landscape with large soft flakes drifting down toward the surface.
“What’s this place?” Annie breathed softly into her transmitter, her voice emerging from the receiver in George’s space helmet as though it was right in his ear.
“Welcome,” said Cosmos, sniffling a little as he spoke, “to Enceladus, the sixth largest moon of Saturn. Please go through the doorway. Add additional space weights to your boots so you will be able to cope with the effects of Enceladus’s lower gravity.”
Annie ran back to the cupboard, grabbed the space weights, and attached them to their boots.
“Here we go!” Moving heavily in his weighted boots, George approached the doorway and crossed the threshold. He thumped down onto the distant moon. His heart was pounding so loudly that all he could hear was a sound like bongo drums. This was so cool! He had assumed that this vacation would be the most boring one ever, but it was suddenly turning out to be a blast.
Annie followed, and as they both stood by the portal on Saturn’s moon, they realized that the glass on their visors was quickly becoming covered with thickly falling snowflakes.
“I don’t believe it!” George laughed. “We’re on Enceladus! And it’s snowing!”
The light on this faraway moon was a strange yellowish color, casting deep shadows through the gloom that surrounded them.
“Watch your step!” warned George. He was thrilled to be back in space; he had waited for ages for another cosmic adventure—and now it was actually happening! But during his time at home, dreaming about space, he’d forgotten how dangerous it felt to be out in the Solar System, just him and Annie against the great backdrop of space itself. Inside his two pairs of gloves, his fingers felt tingly with excitement and nerves. He knew he had to be careful, though, in case he made movements on Enceladus that caused Ebot to react on Earth and knock something over in Eric’s study. He tried to keep his hands as still as possible. This time, there was no real Eric to help them if they got into trouble, and George realized he would have to make sure they were supercareful. He couldn’t imagine Ebot being able to rescue them if they had an accident on Enceladus.
ENCELADUS
It’s just a tiny white dot, orbiting the enormous frozen gas planet, Saturn, within the densest part of Saturn’s rings. It’s only one out of Saturn’s 60 moons. It’s not the biggest or the most visible in the night sky. And yet scientists now think that Enceladus, named after a giant in Greek legend who was buried under the volcano Mount Etna, may be one of the most habitable places in our Solar System! Why? The answer is simple… .
Water
This cueball of a moon—white, round, with an icy smooth surface—seems to have liquid water, one of the most important ingredients for life as we know it. Discovered as long ago as 1789 by the famous astronomer William Herschel, Enceladus remained pretty much a mystery until two Voyager spacecraft passed it in the early 1980s. Voyager 2 revealed that despite the small size of this little moon, it had all sorts of different landscapes. In some parts, Voyager 2 saw ancient craters; in others, ground that had recently been disturbed by volcanic activity.
Enceladus endures frequent eruptions. But whereas Mount Etna sends hot ashes, lava, and gas into the Earth’s atmosphere, on Enceladus, cryovolcanoes shoot out plumes of water ice into the atmosphere, some of which float down to the surface as snow. The Cassini space probe, which has been flying past Enceladus since 2005, has taken many photos of the ice fountains of Enceladus. So if you could visit there, you could build a real snowman in space!
A very special place
As well as liquid water, Enceladus may boast all sorts of other useful ingredients for life, such as organic carbon, nitrogen, and an energy source, and scientists who study Enceladus recently stated this makes this moon a very special place. Could it mean there are extraterrestrial life forms on Enceladus? Could there be aliens living deep within this secretive world? Maybe one day you will design a robotic spacecraft that can visit Enceladus and find out if an alien giant is sleeping under the surface of this distant and fascinating little moon!
“Those craters don’t look easy to climb out of—not even the tiny ones,” he commented.
Around them lay hundreds of small craters and one enormous one, the bottom covered in some kind of mysterious bright substance that glowed in the amber light. Nearby stood a ridge that overlooked the pockmarked ground, while running under their feet was a thin line, like the crack in a sidewalk—only it went on and on into the distance in both directions, as far as they could see.
However many times George traveled in space, he never got used to it. He would always be amazed by the incredible cosmic scenery. There would never come a time when he was bored of space—it was so extraordinary, enormous, and beautiful … And there was no one there: just him and Annie and the whole empty, perfect world that lay around them, waiting to be explored.
“Awesome!” breathed Annie as she looked at the view.
George followed her gaze. On the horizon, he could see a sharp curve of brilliant light across the empty void of this weird little moon; it was creeping very slowly toward them.
“That’s the light of the Sun… .” Annie pointed. “Over there, it’s daylight.”
“Then what’s this funny yellow glow?” asked George. “Where’s that coming from?”
Above the horizon on the other, dark side, away from the Sun, hung the giant frozen ball of gas that was the planet Saturn. Saturn’s rings, made up of dust and rocks, encircled the magnificent planet.
“It’s the light from Saturn,” said Annie in a whisper—she wasn’t quite sure why. “Light from the Sun reflects off Saturn and illuminates the dark side of Enceladus. And look!” She pointed to a dot in the sky. “That must be Titan! Hey!” She fumbled in the pocket of her space suit. “Do you think I could get a photo of Saturn?”
“You could try,” said George. He wished he’d thought to bring a camera. Annie’s photo of Saturn was going to be much better than the one he was trying to take from Earth. Saturn seemed so close here; it was almost as if they could reach out and touch it.
But Annie was clicking and clicking her camera without any success.
“I think it might have frozen,” George realized. “It must be pretty cold up here.” Perhaps after all, he thought, he was going to be the one who ended up with a photo of Saturn. That made him wonder what was happening back on Earth.
“Have you checked Ebot’s field of vision?” he asked.
“I’ve got the remote-access glasses on,” said Annie. “I can switch frames by moving my eyeballs, and it gives me … Ebot! Here we are. I can see home—wow! That’s weird. But no—no sign of Mom yet. I expect she’s still trying to buy a bazillion pillows or something.” It seemed really odd to be talking about Annie’s mom doing her shopping back on Earth. It felt like all those things were happening not just on a different planet but in another universe.
George reached out a hand, wondering if Ebot was making the same movement. “The snow’s slowing down,” he observed. He had never seen such huge snowflakes before. They made him want to dance across the pristine surface of this strange little moon.
“Ohmigod, look in that crater!” Annie had taken a few steps forward.
George edged gingerly after her and peered over the edge into the vast bowl.
“It’s full of snow!” continued Annie. “If we went down there, we could make the most amazing snow angel ever!”
“But we don’t know how deep it is,” warned George. “It might have been snowing for millions of years—we could sink in and never come up.”
“It would be like swimming—but in snow!” squeaked Annie.
“Don’t try it!” George didn’t believe she would really sprint down into an unknown crater, but he decided to take no chances. �
��I might never get you out!” Suddenly, as though from far away, like distant thunder, he felt a rumble.
“Did you feel that?” he asked Annie.
She nodded.
Then he felt a harder jolt, right under his feet, as if it was coming from the thin crack in the surface. “Cosmos?” he asked the supercomputer via his instant-messaging device. But he got no reply. Cosmos’s silence was starting to make him feel uneasy.
Annie checked in again to see the view from Ebot’s eyes back in her father’s study. “Nothing happening on Earth,” she said. “Cosmos is just sitting on the desk, and Ebot’s keeping an eye on the door. No reason why he shouldn’t answer.”
“Cosmos!” George tried again. “Are you sure you’ve landed us in a safe location?”
The ground lurched beneath their feet, and they bumped into each other. For a second George felt as frozen as Annie’s camera, unable to move or react. Pure terror glued him to the spot. He looked around for some kind of escape: there was no sign of the space portal, and no way for them to escape—except by …
“Move!” Annie grabbed George and dragged him after her as fast as she could. He stumbled along, roused from his petrified state by her urgent voice in his ear. “Come on, George! I can’t carry you! We’ve got to run—faster!”
At last, his limbs started to propel him away from the place where Cosmos had brought them, which was now shaking continually, the ground shifting and buckling.
“It’s a fault line!” panted Annie. “You know—the ones where earthquakes happen. It must be. I think it’s going to erupt!”
The two friends struggled over the rupturing ground. George followed Annie in a desperate bid to avoid tumbling into the abyss opening up as the sides of the fault line moved apart.
“This way!” Annie pointed at the ridge above the cratered ground, from which little jets of water vapor and gas were now spewing forth.
Staggering onward, George wondered if he would ever get back home. Would he ever again know the happiness of being angry with his baby sisters or eating his mom’s strange food? A lump came to his throat as he pushed himself forward. Perhaps planet Earth wasn’t so bad after all.
Annie had chosen a good route. Together, they scrambled up the ridge, finding hand-and footholds, clambering up the near-vertical incline, their hearts pounding with fear. The low cliff face seemed to mark the edge of the moving ground—it seemed to form a natural border to the moonquake.
Once they reached the top, Annie threw herself onto her front, pulling George down next to her. Inching forward, they gazed over the edge of the ridge at the spot where they had been standing.
As he lay there, George felt his heart rate slow a little. They might just be safe after all, he thought. But looking back, he realized that if Annie hadn’t been so quick to spot the danger, they really wouldn’t have been going home again.
In the exact place where Cosmos had positioned the portal to drop them off, they saw the fault line widen and the ground finally split apart entirely. A huge belch of steam flew up into the air, twisting and curling as the vapor hit the freezing atmosphere. A second later, an enormous jet of water exploded out of the ground, rising many meters above the surface of the planet. Against the pure blackness of the sky, the spray made a beautiful lacy pattern as the droplets of water shot up into the atmosphere, froze, then drifted down as an ice fountain.
“Wow, it’s a cold-water geyser!” said Annie in wonder. “Cosmos has found us water in space!”
“Yeah, but he nearly got us killed, too,” said George in horror. Annie didn’t seem to realize that she had just saved their lives. “Annie, if we hadn’t moved, we’d be dead by now. Either we would have fallen into that hole or we’d have been blasted into space or frozen into ice statues. This isn’t good.”
“I’m sure Cosmos didn’t do it deliberately.” Annie watched the play of water and ice against the dark starry sky, with the curve of Saturn’s pale globe in the background. “He wouldn’t do that! Would he?” She suddenly sounded less sure. “It must have been a mistake.”
“I don’t know!” George was puzzled too. “Perhaps it’s because he’s not feeling well … but that was really dangerous: he put us on top of a cryovolcano just minutes before it erupted!”
“Ew—horrible!” Annie sounded shocked. “You don’t think … ?”
“I don’t know what to think,” said George. “But we definitely need to get out of here before anything else blows up underneath us.”
“I’ll summon Cosmos,” said Annie. “Yoo-hoo! Cosmos!”
“Yello!” Cosmos checked in suddenly, using a very unfamiliar, smarmy-sounding voice. “How it’s going on Enceladus?”
“That doesn’t sound anything like him,” George whispered to Annie. Inside his space suit, he was nice and snug, as it was perfectly temperature controlled, but all at once his blood ran cold. Why was Cosmos turning into someone they didn’t recognize?
“Er, terrific, thanks,” replied Annie bravely. “A great view of the geyser erupting from a cryovolcano—so says my friend Factoid George over here.”
“A view?” Cosmos sounded surprised. “What do you mean, a view? Weren’t you—?” He stopped very suddenly.
“Uh-oh,” said George quietly. It was as though his worst fears had been confirmed. Cosmos had purposely put them in danger!
“Yes, a lovely view,” continued Annie. “But we’ve seen water in space now, and we’d like to come home.”
The two of them reached out their space gloves and grasped the other’s hand with a squeeze of solidarity. They were in this together. It might have been Annie’s idea to come on this adventure, but George knew that he had gone along with it because he really wanted to take a moon walk. They could never have known that their great friend and ally Cosmos would let them down like this. But now they were right in the middle of this awful adventure, with no one to help them out.
“But you haven’t really,” insisted Cosmos. He seemed to be speaking fluently now—no sign of his cold—only with someone else’s voice; and he was saying none of the things they expected. It was very odd and very mysterious, as though a friend had become an enemy and no longer wished to look after them.
“There’s lots more water in space,” Cosmos continued in his new strange voice. “Why don’t I take you to a supermassive black hole that has so much water vapor around it, it would fill up all the lakes and oceans on Earth trillions of times over? You can’t want to come home already.”
“I do, actually,” said Annie. “I’ve been as close to a black hole as I ever want to be.” She and George had once rescued her father from a black hole, using Cosmos. An evil scientist had sent him on a journey with the wrong coordinates—and he had plunged into the heart of the darkest place in space. “I’d like you to take us home.”
“No,” said Cosmos flatly. “The Earth return portal cannot be activated until I am convinced your mission has been accomplished. You need to visit another location in order to investigate the phenomenon of water in space before I can authorize your homeward journey.”
“What?” whispered Annie. “I’ve never heard that rule before… . This is bonkers.”
“Even if he won’t take us home,” muttered George, “perhaps we could get closer.” Clearly, they could no longer trust Cosmos as they used to, and needed to manipulate him into doing what they wanted rather than asking him outright.
“What about the Moon?” he suggested. “There’s water on the Moon!”
“The dark side of the Moon?” asked Cosmos rather unpleasantly.
“No!” said Annie sharply. “As you know perfectly well, it isn’t called the dark side of the Moon. We call it the ‘far side.’ But we want the near side, please. Or at least, wherever the water is.”
THE DARK SIDE OF THE MOON
It sounds like it should always be night on the dark side of the Moon, but that’s not true, as any friendly astronomer will tell you. First of all, astronomers don’t talk about the dark
side. They call it the far side of the Moon, because the far side of the Moon has night and day, just like we do on Earth.
When we look up at the Moon in the night sky, it looks familiar to us, no matter where we are on the Earth. We see the same features each time because we are always looking at the near side of the Moon. So how come we never get to see the other side of our old friend the Moon?
Why can’t we see the far side?
The Moon orbits around the earth while rotating on its axis. It takes the Moon the same amount of time to complete one orbit of the Earth as it does for our rocky satellite to rotate—29 days. If the Moon didn’t rotate, we would see all of its faces or sides, near and far, as the Earth rotates while orbiting around the Sun. But because the Earth is turning and the Moon is turning—and the gravity of the Earth has slowed down the Moon’s rotation to its current speed—it means we always see the same face of the Moon.
Phases of the Moon
The positions of the Earth and the Moon in their orbits around the Sun give us the phases of the Moon.
• When the Moon is between the Earth and the Sun, we call it a new moon. The Moon looks dark to us from Earth, as it is lunar nighttime on the near side of the Moon (the side nearest to us).
• When the Earth is between the Sun and the Moon, that’s a full moon. If you were standing on the near side of the Moon, we might be able to see you from Earth, as you would be standing in the midday sunshine of a lunar day!
Even though we can’t see the far side of the Moon, it has been visited by astronauts, one of whom said it reminded him of his kids’ sandbox!
“Opening up the intra-solar-system transportation portal now.”
The familiar doorway appeared in front of them, shining in the odd burnished glow of Saturn’s reflected light. The door swung back, and the two friends could see beyond it the dimly lit grayish-white surface of the Moon, with a clear black sky behind the mountain range.
“Quick,” said George, who was eager to get moving: anywhere would be better than here. “Let’s leave before Cosmos changes his mind and decides we should stay on Enceladus forever.”
George and the Unbreakable Code Page 8