Fig. 1. Water isotope measurements throughout the solar system.

All measurements are compared to terrestrial VSMOW values (dashed lines). Several species have been reported for the Rosetta target comet 67P/Churyumov-Gerasimenko (67P/C-G; open black diamonds with blue error bars) and are compared to results from this work (open black squares with blue error bars). (A) Several D/H measurements are available including chondrites (gray), Saturn’s moons (cyan and orange), two TNOs (steel blue), and several Oort Cloud (blue filled) and Jupiter Family (blue with black outline) comets. (B) ¹⁶O/¹⁷O is available for the Sun, Mars, and chondrites (gray); Titan (orange); and comet 67P/C-G. (C) ¹⁶O/¹⁸O is also available for Jupiter, Venus, several Oort Cloud comets (OCCs; blue filled), and one additional Jupiter Family (blue with black outline) comet (see the Supplementary Materials and tables S1 to S3).