Last year I wrote a few posts about NASA’s Genesis mission, explaining some of the background to the mission and why we need to know more about the original composition of the material our Solar System formed from. I wrote about the mission itself, and the aftermath of the “non-ideal” return of the sample capsule.
It is now time for me to follow-up those posts with the results of some of the analyses of the Genesis samples. Yeah I should have done this a long time ago, but there’s been so much to do in the lab I never quite got round to it till now…
Before the mission, a list of scientific objectives and priorities was published1. The highest priority objectives are analysis of:
- Oxygen isotope ratios
- Nitrogen isotope ratios
- Elemental and isotopic ratios of noble gases (helium, neon, argon, krypton and xenon)
These top 3 priorities are followed by a long list of further objectives which cover analysing the rest of the elements from lithium to uranium.
The low concentrations of solar wind implanted into the collector targets (104 to 1013 atoms per cm2) mean the analyses are challenging. The very best and most sensitive analytical techniques and instruments must be used to make measurements with the required precision. And a wide range of instruments and techniques are necessary to analyse all the elements.
Obviously no one research group would have the ability or expertise to analyse all the different elements. The Genesis Science Team is made up of planetary science researchers from all around the world. Each group is responsible for analysing a different element or group of elements, depending on their expertise.
Oxygen isotope ratios have been measured by a group of researchers from the University of California, Los Angeles (UCLA) in the USA. They built a unique mass spectrometer, known as the MegaSIMS, specifically for analysing the Genesis samples.
Nitrogen isotope ratios have been measured by a group from Nancy University in France.
A number of different groups have been working on the noble gases. We have determined the concentration and isotope composition of xenon. Research groups ETH in Zürich, Switzerland and Washington University in St Louis, USA have also been working on the noble gases, looking at both elemental and isotopic ratios.
It would be too much to write about all the types of analysis used and the findings in this article, so over the next few weeks I’ll take those 3 highest priority objectives in turn and tell you about oxygen, nitrogen and noble gas analyses. So come back soon, and we’ll start with oxygen…
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