The Children's Encyclopedia
1. Our Spaceflight Begins
Imagine it's the year 2030. From
a spaceport near your home town, we've flown in a rocket-powered space plane hundreds
of miles about the Earth. Now, inside an orbiting space station, we're waiting
for the most exciting part of our journey to begin – a space flight to the
Some Facts and Figures
We've tried to learn as much as we can about the world we'll be visiting. The
Moon is quite a bit smaller than the Earth. It's only 2,160 miles (3,476 kilometers)
in diameter; compared with Earth's 7,928 miles (12,756 kilometers). If the Earth
were the size of a basketball, the Moon would be no bigger than a baseball.
But even though it's small, the Moon is special to us. It is the Earth's only
natural satellite – the only object, not made by humans, that orbits, or
moves around, our planet. At a distance of 238,900 miles (384,400 kilometers),
it's also closer than the Sun or the planets. Because it's so close, the Moon
seems big and bright in our sky.
To get an idea of how close the Moon really is, imagine that the whole solar system
has been shrunk down. In this small scale, the distance from the Earth to the
Sun is only 100 feet (about 30 meters). Now, remember, compared with most things
in space, even the Sun is quite close by. But on the same scale, do you know how
far from the Earth the Moon would be? Just 3 inches! The Moon is easily our closest
neighbor in space.
The Moon is not a friendly world, though. It has no liquid water and no air. In
fact, it has no atmosphere of any kind. During the day, its surface is hot enough
to fry an egg. At night, it is colder than the North Pole. We will be visitors
to a world where there has never been any life and where everything is strange
Soon our spaceship will be leaving. The captain welcomes us aboard and tells us
that, traveling at several miles per second, it will take us less than a day to
reach the Moon. By comparison, he says, the old Apollo craft took about four days
to make the same journey.
We feel a steady, gentle push as the ship moves away from the space station and
gradually gains speed. After about an hour, we reach cruising speed. Lunch is
served, and then the captain announces today's in-flight movie, The Exploration
of the Moon. The cabin lights dim, the film starts to roll, and the sound
track begins ...