Representative contact angle measurement interface from the Ossila goniometer software for tholin produced at ARC/COSmIC with 10% CH₄ in N₂ on glass. Each panel shows a still frame (left) with the region of interest box (red) and fitted contact angles (blue line: left angle; red line: right angle), alongside numerical data (top right) displaying the left angle, right angle, and their average with rms errors, and a time-series plot (bottom right) of contact angle versus frame number. (a) Diiodomethane droplet showing consistent contact angle measurements over time (angles range 45^∘–51^∘) with a smooth trend in the time series. (b) Water droplet showing greater variability in contact angle measurements over time (angles range 80^∘–98^∘) with more scatter in the time series, likely due to faster evaporation and possible dissolution effects (J. Li et al. 2022).