The KT event, marking the temporal border between the Cretaceous and Tertiary eras of geological time, was identified by a thin stratum of iridium of extraterrestrial origin, attributed to a comet thought to have struck near what is now the Yucatan Peninsula
Iridium is also a system of 66 communication satellites around the earth. Named for the element Iridium, it was originally to have 77 satellites, but was later redesigned to have its current number, though the name was retained. Iridium allowed worldwide voice and data communications using handheld devices. The Iridium service failed financially and the earth stations were shut down. Its financial failure was largely due to insufficent demand for the service, and the excessive bulkiness of the handheld devices compared to celluar mobile phones. The satellites were however retained in orbit, and their services were then leased to the US Department of Defence for its communication purposes.
Phone rates from land lines to iridium phones are $5 to $10 per minute. Iridium and other satellite phones may be identifiable to the listener because of the particular "clipping" effect of the data compression.