From the satellites in the sky to the cell phone in your pocket, rare earths play a key role in a host of advanced communications technologies for both civilian and military use, and they aid on both the sending and receiving end of communications links. Satellites, which are critical to everything from TV signals to global positioning information, utilize rare earths in a variety of ways. Rare earth magnets, using neodymium, praseodymium, and dysprosium – enable satellite guidance and positioning mechanisms, and they help to power transponders and signal amplification equipment, such as traveling wave tube amplifiers, on-board the satellite. Given the electromagnetic basis of communications frequencies, rare earth material is critical for signal transmission both in space and on land. Fiber optics cables increasingly carry internet, phone, and video data to both residential and commercial customers. The rare earth erbium is used as a doping agent – an additive that improves performance – in fiber optic cable material to amplify data signals and enhance the cable’s ability to move data very high speeds. Europium, yttrium, and terbium are also used as fiber optic doping agents. Cell phones have become one of the most ubiquitous communications tools, and the fact that cell phones are small enough to put in our pockets is due largely to rare earths. The magnets that power the cell phone’s speaker and the vibrating mechanism would have to be much larger if it wasn’t for tiny, powerful neodymium magnets. Additionally, the color LCD screens are made possible by rare earth phosphors europium, terbium and yttrium. Similar to the tiny speaker in your cell phone, manufacturers of audio speakers and headphones have used rare earth magnets to steadily reduce their products’ size while simultaneously improving sound quality and strength.