Earth's Spheres

Earth's outer atmosphere is the transition zone between the planet and outer space. This sphere begins at the upper levels of the atmosphere and stretches out thousands of miles from Earth. While it appears empty, this sphere actually contains small amounts of gas, but the atoms of gas are so widely spaced that no life can exist. As the place where Earth first interacts with the Sun's energy, the outer atmosphere is crisscrossed by radiation and intense magnetic fields. You might think only astronauts are concerned about the outer atmosphere, but it plays an important role in protecting and sustaining life on Earth.