. 2015 Sep 25;1(8):e1500377. doi: 10.1126/sciadv.1500377

Table 1. Argon isotopic ratio and relative abundances to H₂O and N₂.

The isotopic ratio of the comet’s argon is in agreement with the solar system values.

³⁶Ar/³⁸Ar	5.4 ± 1.4
³⁶Ar/H₂O	(0.1 to 2.3) × 10⁻⁵
³⁶Ar/N₂	(9.1 ± 0.3) × 10⁻³

The ratio of argon to water is given as a range because of heterogeneity in the coma (Fig. 2A). ³⁶Ar and N₂ are closely correlated owing to their similar volatility; an average ratio of (9.1 ± 0.3) × 10⁻³ has been determined for the investigated periods (Fig. 2B).

Table 1. Argon isotopic ratio and relative abundances to H2O and N2.

Table 1. Argon isotopic ratio and relative abundances to H₂O and N₂.