Meteorite

A meteorite was, in the words of expert Liz Shaw, "the debris from comets". Most didn't reach the Earth's surface, but rather burnt up in the atmosphere. (TV: Spearhead from Space) Some fraction of them proved to be vessels for alien energies or entities.

It was commonly believed that a meteor wiped out the dinosaurs, but it was in fact Briggs' freighter. (TV: Earthshock)

Self-replicating robots on Zazz's moon were forced to periodically hide underground to avoid meteorite showers. (COMIC: The Gift)

Known meteorites
In 1976, a meteorite landed in New York City's Central Park, temporarily giving Alice Trefusis super-powers. (AUDIO: Starfall)
 * In 1283, a meteorite from the Jeggorabax Cluster landed in the Weserbergland Mountains of Lower Saxony, in present-day Germany. The Weserbergland Meteorite housed an energy entity that became known as the Pied Piper. (TV: The Day of the Clown)
 * In 1913, the Family of Blood arrived at Farringham in an invisible spaceship. John Smith dismissed it as a meteorite. (TV: Human Nature)
 * In the 1970s, the Nestene Consciousness fashioned plastic meteorites and sent them to Earth to prepare for an invasion. (TV: Spearhead from Space)
 * In 2007, Sex Gas came to Earth in a meteorite which fell near Cardiff. (TV: Day One)
 * In 2008, the meteorite K67 almost impacted with the Earth, but this was averted. (TV: Whatever Happened to Sarah Jane?)
 * In the late 21st century, Space Station W3 warned spacecraft of meteorite storms. (TV: The Wheel in Space)
 * In the late 22nd century, the Daleks used meteorites to spread a plague on Earth prior to their invasion six months later. (TV: The Dalek Invasion of Earth)