The air you breathe is precious, and the farther from Earth's surface you go, the less there is. But Earth's atmosphere extends farther into space than you might realize, affecting the orbits of spacecraft more than 200 miles high. OurAmazingPlanet looks at what's in the atmosphere, from way out there, to up where the clouds hang out, to right down here [See Also: Earth from the Tallest Mountain to the Deepest Ocean Trench].