The world’s navigation systems, from GPS to Europe’s Galileo, depend on radio waves passing cleanly through the ionosphere, a charged atmospheric region extending from 80–1 000 km (50–620 miles) above Earth. After sunset, that layer…
The world’s navigation systems, from GPS to Europe’s Galileo, depend on radio waves passing cleanly through the ionosphere, a charged atmospheric region extending from 80–1 000 km (50–620 miles) above Earth. After sunset, that layer…