Geologic control of jet formation on Comet 103P/Hartley 2

► We correlate source locations of jets with surface features, such as pits and scarps. ► We build a numerical model of jet initiation from material slumping into a vent. ► Initial geometric conditions affect the expression of jet activity. ► Observations and model results indicate a role for surface geology in jet formation. ► Ongoing jet activity can produce knobby/spired terrain at Hartley 2.