Oxygen isotopes in CO3 chondrites

Oxygen isotope analyses were undertaken on seven CO3 chondrites. No correlation was seen between metamorphic grade in CO3s and oxygen isotopic compositions. Results suggest that ALH77307 should be reclassified as a unique chondrite

The oxygen isotopic composition of water extracted from unequilibrated ordinary chondrites

The oxygen isotopic composition of water extracted from the unequilibrated ordinary chondrites Semarkona and Bishunpur reveals differences in alteration mineralogy and levels of isotopic enrichment – reflecting key parameters in the alteration process

Continued investigation of the light element geochemistry of Tagish Lake

We have determined the abundance and isotopic composition of two separate carbonate generations within Tagish Lake. Nitrogen isotope analysis of the chondrite shows it to be organic-rich, with d15N values higher than in CI and CM chondrites

The Beagle landing site in Isidis Planitia

The Mars probe Beagle 2 will land in Isidis Planitia. This region satisfies the engineering constraints and has evidence for particularly volatile-rich subsoil. Isidis provides a suitable place for the lander to search for H2O and organic matter

L-VRAP-a lunar volatile resources analysis package for lunar exploration

The Lunar Volatile Resources Analysis Package (L-VRAP) has been conceived to deliver some of the objectives of the proposed Lunar Lander mission currently being studied by the European Space Agency. The purpose of the mission is to demonstrate and develop capability; the impetus is very much driven by a desire to lay the foundations for future human exploration of the Moon. Thus, LVRAP has design goals that consider lunar volatiles from the perspective of both their innate scientific interest and also their potential for in situ utilisation as a resource. The device is a dual mass spectrometer system and is capable of meeting the requirements of the mission with respect to detection, quantification and characterisation of volatiles. Through the use of appropriate sampling techniques, volatiles from either the regolith or atmosphere (exosphere) can be analysed. Furthermore, since L-VRAP has the capacity to determine isotopic compositions, it should be possible for the instrument to determine the sources of the volatiles that are found on the Moon (be they lunar per se, extra-lunar, or contaminants imparted by the mission itself

Simultaneous analysis of abundance and isotopic composition of nitrogen, carbon, and noble gases in lunar basalts: insights into interior and surface processes on the Moon

Simultaneous static-mode mass spectrometric measurements of nitrogen, carbon, helium, neon, and argon extracted from the same aliquot of sample by high-resolution stepped combustion have been made for a suite of six lunar basalts. Collecting abundance and isotopic data for several elements simultaneously from the same sample aliquot enables more detailed identification of different volatile components present in the basalts by comparing release patterns for volatiles across a range of temperature steps. This approach has yielded new data, from which new insights can be gained regarding the indigenous volatile inventory of the Moon. By taking into account N and C data for mid-temperature steps, unaffected by terrestrial contamination or cosmogenic additions, it is possible to determine the indigenous N and C signatures of the lunar basalts. With an average δ15N value of around +0.35‰, the indigenous N component seen in these samples is similar within error to other (albeit limited in number) isotopic measurements of indigenous lunar N. Average C/N ratios for indigenous volatiles in these six basalt samples are much lower than those of the terrestrial depleted mantle, or bulk silicate Earth, possibly suggesting much less C in the lunar interior, relative to N, than on Earth. Cosmogenic isotopes in these samples are well-correlated with published sample exposure ages, and record the rate of in situ production of spallogenic volatiles within material on the lunar surface

The microbiology of spacecraft hardware: Lessons learned from the planetary protection activities on the Beagle 2 spacecraft

We consider the aseptic assembly of the Beagle 2 Mars probe and how the requirements of COSPAR planetary protection category IVa were achieved. Several areas for future investigation became apparent. An ESA mission is outlined in which a microbial bioburden is recovered after Earth orbit to assess viability following re-entry through the atmosphere

Supercritical fluid extraction of the non-polar organic compounds in meteorites

The carbonaceous chondrite meteorites contain a variety of extraterrestrial organic molecules. These organic components provide a valuable insight into the formation and evolution of the solar system. Attempts at obtaining and interpreting this information source are hampered by the small sample sizes available for study and the interferences from terrestrial contamination. Supercritical fluid extraction represents an efficient and contamination-free means of isolating extraterrestrial molecules. Gas chromatography-mass spectrometry analyses of extracts from Orgueil and Cold Bokkeveld reveal a complex mixture of free non-polar organic molecules which include normal alkanes, isoprenoid alkanes, tetrahydronaphthalenes and aromatic hydrocarbons. These organic assemblages imply contributions from both terrestrial and extraterrestrial sources

Astrophysical significance of asymptotic giant branch Stellar wind energies recorded in meteoritic SiC grains

Using model calculations for ion implantation into spherical grains in free space, we have identified two noble gas components implanted with high and low energies into presolar SiC grains isolated from the Murchison meteorite. The low-energy component seems to be associated with the stellar winds of expanding asymptotic giant branch (AGB) stars during the main stage of their evolution. In contrast, the high-energy component was probably generated during the late, thermally pulsing peak of AGB evolution and was implanted into SiC grains as a high-speed, post-AGB wind during the planetary nebula formation stage. If true, this is the first time that such a planetary nebular component has been identified in the laboratory and provides astrophysics with a new arena of research possibilities. Possible involvement of chemically active elements in the implantation events established for noble gases is also discussed. Although we have concentrated on evidence provided by the implantation of noble gases, we also extend the discussions to chemically active elements such as Ba and Sr