Relation between the rise time Δt (y-axis) and particle energy E (x-axis) based on statistical observations from Earth and Mars. The diamonds and inverted-triangles represent the statistical mean and geometric mean from log-normal distribution fits, respectively. Red and yellow denote MEPA data, and dark green and light blue denote ERNE data. The purple and dark blue arrows indicate the mean and median rise time derived from TGO dose-rate measurements.