Electric Space Above Us - The Ionosphere In the upper part of Earth’s atmosphere, right at the edge of space, lies a layer called the ionosphere. Its lower boundary is at an altitude of 70 km. The ionosphere is remarkable because it's able to conduct electricity. Here, X-rays and ultraviolet rays from the Sun and high-energy particles from outer space bombard the gases of our atmosphere. They collide with the atoms, knocking off electrons and leaving the positively charged nuclei (called ions) floating free. It’s because of these free-floating charged particles, or plasma, that the ionosphere can conduct electricity. It provides an important path for electric current generated in the magnetosphere.