Answer

---

Iridium was originally planned to have 77 active satellites and was named after the element with 77 electrons.  The idea of electrons orbiting an atomic nucleus is supposed to be analogous to satellites orbiting the earth, although the analogy doesn't really hold in quantum physics.

The element Iridium is named after the Latin word iris, meaning rainbow, because of the colorful nature of Iridium compounds.  The Iridium system was later redesigned to need fewer satellites -- 66 active ones, not counting in-orbit or ground spares.  But its name was not changed to Dysprosium, the element with 66 protons and often 66 surrounding electrons whose Latin root means 'bad approach'. . .

Adapted from Lloyd's Satellite Constellations overview of Iridium.
 

Back to Teich's Tech Tidbit of the Week for May 8, 2000.

Back to Teich's Tech Tidbit of the Week for January 21, 2002.