Simulated example of an exomoon event (a triple-lens caustic) observed from both Roman and Euclid. The top row displays the event geometry centered on the planetary caustic. The right column is a zoom-in on the time of the exomoon caustic crossing. The expected separation of the source tracks is comparable in scale to the perturbation induced on the caustic by the exomoon. The planet, with mass ratio q₁ = 10⁻³, is at separation s₁ = 1.3, and the moon has q₂ = 10⁻² and s₂ = 0.032 relative to the planet. The Einstein timescale is t_E = 47 days. The middle row is for a normalized source radius ρ = 0.00033, while the bottom row is for ρ = 0.001.