The Apollo astronauts found the Moon to be geologically dead.
With only one-eightieth Earth's mass, the Moon long ago cooled to the core, leaving it geologically dead.
It has a higher density than the geologically dead Rhea, the largest inner moon, but lower than that of active Enceladus.
The observations of plasma in the vicinity of Tethys demonstrated that it is a geologically dead body producing no new plasma in the Saturnian magnetosphere.
Mercury and Mars have no significant internal heating because they are only 5 and 11% the mass of Earth respectively; they are "geologically dead".
Without such internal ferment the planet would be geologically dead, featureless and uniformly covered with water.
Added to other recent discoveries, the finding reinforces the idea that, far from being geologically dead, the planet may harbor volcanoes, liquid water and possibly life.
Scientists had seen no signs of contemporary magnetic fields in data from Mars, leading them to write off the planet as geologically dead.
Without this tidal heating, Io might have been similar to the Earth's moon, a world of similar size and mass, geologically dead and covered with numerous impact craters.
The deep was once thought of as geologically dead and having only a thin population of bizarre fish, mainly scavengers living off a drizzle of detritus from above.