"William Morrison - From Out of This World" - читать интересную книгу автора (Morrison William)

FROM OUT OF THIS WORLD
THE campfire had died down, and as a song came to an end, John looked up. Far overhead, the
stars twinkled through the clean air. And then, suddenly, there was a flash of light.
"Look!" cried Johnny. "A star just fell down!"
"There's another one!" shouted the boy next to him.
"And another! Gosh, soon there won't be any left in the sky!тАЭ
But you don't have to worry about that. What Johnny and his friends had seen falling were not real
stars, but "shooting stars,тАЭ also known as "meteors."
A real star is like our sun, only so far away that it looks very small. There are trillions of miles
between us and the nearest star, and even light takes many years to travel that distance.
But a shooting star is very much closer. Actually, it's usually very little. It may be no bigger than a
lump of sugar, and is sometimes even smaller. It travels many miles a second, but not nearly as fast as
light.
How, you ask, can we see a tiny thing that moves so fast? Because, when it enters the earth's
atmosphereтАФthat's the layer of air around the earthтАФit warms up. In fact, as it rushes through the air, it
gets very hot, and that's why we can see the streak of light which looks like a star falling.
The earth's atmosphere not only lets us see the meteors, it protects us from them. Tens of thousands
of meteors enter the earth's atmosphere every day. Imagine what it would be like if all of them landed
around us! It would be like being in a battle that never ends.
But the air slows the meteors down, heats them up, and in a few seconds most of them vanish. They
just change into gas and dust and we don't even realize that most of them have existed. For instance, you
don't see shooting stars during the day, and yet as many hit the earth's atmosphere in the day as at night.

WHAT SHOOTING STARS ARE
How do we know what shooting stars are made of? Well, for one thing, not all of than vanish in the
air. Some are so large that they get through the atmosphere and hit the ground. When that happens,
people usually see a great streak of light, and hear a boom similar to a shell exploding.
A meteor is like a shell in other ways too. Either before it lands, or just after, the meteor may explode
with pieces flying in every direction. If it doesn't explode, it may bury itself deep in the ground, burning up
the trees and grass all around it.
About forty years ago, a great meteor landed in Siberia with a tremendous roar that could be heard
miles away. In fact, people who were a long distance off saw a great ball of fire rushing through the sky.
This meteor roasted everything within miles, and must have weighed thousands of tons. It did as much
damage as an atomic bomb, although by good luck it landed in an unpopulated wasteland.
When a shooting star actually lands, and we see the pieces, they are not called meteors any longer,
but "meteorites." Most of these meteorites are smaller than the one that hit Siberia, some weighing only a
few pounds, others a good part of a ton. At any rate, they're big enough to be examined.
Practically all those found so far are of two kinds. The first kind is of stone, like the rocks you see all
around you. The second kind is of iron and metals like iron. Some meteors have carbon in them and
carbon is the element needed by all living things. But there's no life in a meteor. If there were any, the
swift trip through the air would roast and kill it. The carbon, however, is sometimes changes into tiny
diamonds. You can't get rich from a meteorite, because the diamonds are too small to be worth much,
but the information a scientist can get from one is worth plenty.

WHERE SHOOTING STARS COME FROM
 There are certain seasons of the year when meteors are most often seen. In the early and middle
parts of August, for instance, you can see them every night in great numbers.
These meteors them to travel together swarms, and the reason we see so many is that the earth has
entered the path of a swarm. Where did the swarms come from?
After many years of study, scientists think they know the answer. Many swarms come from comets.