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Brenn and Dara looked sadly at each other. Brenn spoke first, asking, "How will we explain this to Mom and Dad, our camp counsellor, or Mission Control?"
A voice suddenly crackled out of the control panel. "Your thoughtlessness has created many problems for me to solve."
"Who is talking?" demanded Dara.
"I am SAM. My name is an acronym for Self-Activated Microchip. I provide information and explanation as needed. I have already begun to help you. I have arranged an agreement between your parents and Mission Control to permit you to conduct the exploration. The mission is very safe, with a pre-programmed route. I will instruct you at each step, although I will expect you to make decisions. You will be home in time for your next school term. Now to discuss our first stop, Earth's moon."
As Brenn and Dara stared, SAM continued. "The Moon is about the same age as Earth, 4.6 billion years, and is about 385,000 km from Earth. The Moon has no atmosphere, water, wind, clouds, or weather. The Moon's gravity is weak, and you will weigh only one-sixth of your Earth weight there.
"The surface is pitted with large craters, probably caused by meteors crashing into it long ago. There are vast areas once believed to be seas. These `seas' are really dusty deserts formed by ancient lava flow from volcanoes.
"The Moon spins on its axis every 27.3 days and revolves around Earth in exactly the same time. So the same side always faces Earth. With no atmosphere to even out temperatures, the Moon is always very hot or cold. During the day, rocks on the surface are hotter than boiling water. Prepare to land." The supply room and vehicle bay doors swung open. The control panel read SELECT EQUIPMENT AND SETTINGS and PREPARE TO COLLECT ENVIRONMENTAL SAMPLES.
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QUESTIONS
Help Dara and Brenn make some choices. Loop the correct ending to each sentence below.
1. The twins will explore the Moon's surface during the day. They will need to wear spacesuits that protect them against (1) acid in the atmosphere (2) high temperatures (3) heavy atmospheric pressure.
2. The lander vehicle will need (1) special high wind deflectors (2) flotation devices to travel across the watery surface (3) deep treads on its wheels to move across the dry, dusty surface.
3. The twins must wear (1) lightweight shoes, because of the strong gravity on the Moon (2) heavy shoes with good traction; gravity is relatively weak on the Moon (3) ice skates, because of the icy plains there.
4. Brenn and Dara will need to take along (1) tanks of air to breathe (2) radios to communicate with each other, because there is no air to carry sound (3) both kinds of equipment.
5. Scout reached the Moon swiftly because, compared with the vast distances between planets, the Moon's distance from Earth is relatively small. This distance is only (1) 385,000 km (2) 250 km (3) 1.5 million km.
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Writing Assignment: Use the back of this sheet to draw a picture of Dara and Brenn exploring the Moon's surface. What will the landscape look like? Will the twins see or be seen by any life forms? How might these beings look different from humans? Write a paragraph below your picture, explaining your reasons for drawing it as you did.