ISSN:
1573-0794
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Physics
Notes:
Abstract Carbon and oxygen isotopes show no large anomalies on Venus (≤10–15%) or Mars (〈5%); the high value of15N/14N found on Mars is explained by non-thermal escape of nitrogen. The isotopes of non-radiogenic noble gases in the atmosphere of Mars exhibit abundance patterns similar to those in the primordial component of meteoritic gases and in the Earth's atmosphere. This implies that gas fractionation took place in the inner solar nebula prior to planet formation. The relatively high value of129Xe on Mars emphasizes its deficiency on Earth, implying a difference in accretion histories of volatiles for the two planets. In the outer solar system, we find normal isotope ratios for nitrogen and carbon on Jupiter, and for carbon on Saturn, but precision is low (±15% at best). Controversy exists about the correct value of D/H, with current estimates ranging from 2.3±1.1 to 5.1±0.7×10−5. Planetary missions planned for the next few years should add considerably to the quantity and quality of these data.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00897003
