Spirit rover’s dead wheel made big discovery
Channel: Mars Guy
Date: 2021-10-10

Episode 27
The Mars Exploration Rover (MER) Spirit was three years beyond its warranty period in 2007 when one of its wheel motors failed.  But the trench created by the dragging wheel led to one of the most important discoveries on Mars.  The published scientific paper is available here: https://www.nature.com/articles/ncomms13554