Table 2.
Summary of published SW 36Ar/38Ar ratios before and after Genesis mission and best estimates of the two calculated as weighted averages. Interestingly, in both cases the most accurate values were obtained in the very first analyses.
| SW-collector, mission (reference) | SW 36Ar/38Ar (±1σ) |
|---|---|
| 71501, Apollo Benkert et al. (1993) | 5.48 ± 0.05 |
| Kapoeta howardite Becker et al. (1998) | 5.58 ± 0.03 |
| Regolith grains, Apollo Palma et al. (2002) | 5.80 ± 0.06 |
| Kapoeta howardite Palma et al. (2002) | 5.74 ± 0.06 |
| Al-foil, Apollo Geiss et al. (2004) | 5.4 ± 0.15 |
| Weighted average before Genesisa | 5.61 ± 0.02 |
| AloS, Genesis Meshik et al. (2007) | 5.501 ± 0.005 |
| BMG, Genesis Grimberg et al. (2008) | 5.30 ± 0.13 |
| DOS, Si Genesis Heber et al. (2009) | 5.47 ± 0.01 |
| CZ-Si, Genesis Vogel et al. (2011) | 5.50 ± 0.01 |
| AuoS, Genesis Pepin et al. (2012) | 5.501 ± 0.014 |
| PAC, Genesis (this work) | 5.498 ± 0.011 |
| Weighted average after Genesisb | 5.5005 ± 0.0040 |
a
The scatter of the ratios exceeds formally calculated uncertainties indicating a presence of unaccounted systematical errors.
b
Current best estimate is calculated as a weighted average among most accurate analyses. Only the latest analysis from the Zürich lab is used in the estimation of the weighted average, assuming that two earlier published values measured in BMG and DOS were preliminary.