Vocabulary Preview
Match each word or phrase with the correct definition.
1. blast
a. the distance across a circle or sphere
2. detect
b. to change
to gas by some process
3. diameter
c. an explosion
4. locate
d. to know by seeing or measuring
5. strike
e. to hit
6. vaporize
f. to find
Pre-Reading Questions
Think about the following questions.
1. Why did the dinosaurs all die out?
2. When was the last time a large rock from
space or an asteroid hit
Earth?
3. Which do you think are more dangerous, big asteroids or small
asteroids?
Asteroid Impacts
on Earth
S p a c e & E x p l o r a t i o n 2
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Asteroid Impacts on Earth
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A
steroids are small objects in space. They are small compared to the
Earth and the other planets. They are made
of different kinds of rock
or metal. They orbit the sun, mostly between the paths of
Mars and
Jupiter. Astronomers know where many asteroids are, but not all. Though they
may
seem small and far away, asteroids have hit the Earth many times, sometimes
causing extreme destruction. It also seems clear that
an asteroid will hit the
Earth again in the future.
Most asteroids are located in what is called the “Main Belt.” This is an orbit
between Mars and Jupiter. All of these asteroids are very far from the Earth and
will never come close. Several hundred asteroids follow Jupiter in its orbit.
These are called “Trojans.” Asteroids can
also be found in the outer solar
