Penetrometer
A scientific instrument used to measure the physical properties of a surface by penetrating it. On Venus, Venera 14 used its penetrometer to assess the density and compressibility of the soil.
Source: nssdc.gsfc.nasa.gov
APODs including "Penetrometer"
Apollo 14: Rickshaw Tracks Across the Moon
27/04/1996
Brilliant sunlight glints off tracks gently winding across the the Moon's Frau Maro highlands. The tracks were made by the Apollo 14 crew's two-wheeled Modularized Equipment Transporter (MET), fondly known as the "rickshaw". The MET was designed as an aid to surface exploration. Serving as a workbench with a place for the lunar handtools, it also carried cameras, sample containers, spare film and a Lunar Surface Penetrometer. The path outlined in the lunar soil leads away from Alan Shepard and Edgar Mitchell's Lunar landing Module, tracing the path of their first venture across the lunar landscape.