Exploring Dangers in Space: Asteroids, Space Junk, and More
Chapter 1 SPACE ROCKS Look at the night sky in this photo What is streaking across the sky in the center Look at the sky on a clear night in August You might see a streak of light flash above you This is called a shooting star But it is not really a star It is a small rock from outer space It burns and lights up as it enters Earth’s atmosphere The atmosphere is the layer of gases surrounding Earth 4
Billions of rocks circle the Sun The paths they take are called orbits Some space rocks are just grains of dust Others are much larger The largest space rock is about the size of Texas This drawing shows two large space rocks near Earth The Moon is in the background 5
Thousands of space rocks reach Earth every day Most are small They do no harm But large rocks can cause great damage Some of them have hit our planet in the past Astronomers scientists who study outer space watch the sky They look for new threats This is a piece of a space rock found in Australia It is made of nickel and iron 6
Entering Earth’s Atmosphere All objects have gravity This force pulls objects together Earth’s gravity can pull in space objects that come near it A space object enters Earth’s atmosphere in this drawing 7
