Research

High precision laboratory-based analysis of planetary materials has greatly helped our understanding of the origin and evolution of the Solar System, but with more than 99% of the mass of the solar system in the Sun a very significant gap exists in our data set. Our knowledge of the composition of the Sun is essentially limited to astronomical observation which unfortunately offers poor abundance data compared to lab analyses and even less well constrained isotopic information.

Samples from the surface of the Sun are clearly unobtainable but fortunately vast amounts of material in the form of the solar wind are continually ejected from its surface.

Some information about solar wind noble gases and some light elements can be extracted from samples of lunar soils, which have been exposed on the surface of the Moon for many millions of years.  However, the processing of material on the lunar surface is very complex over many millions of years making interpretation of results problematic. This is an area of research that PSSRI has been involved in for many years – investigating the abundance and isotopic composition of the implanted nitrogen and noble gases using the FINESSE mass spectrometer system.

The NASA Discovery Mission Genesis was designed to collect a sample of solar wind which would be easier to analyse and interpret the data from.  This is a mission which PSSRI have been heavily involved in from its very conception.  After 884 days exposing ultra-pure collectors to the solar wind – the spacecraft returned its precious cargo of Solar material in Sept 2004.  Unfortunately the parachute mechanism failed to deploy, resulting in most of the collectors being heavily fragmented and exposing them to lots of spacecraft debris and local dirt from the landing site.  PSSRI continues to be involved in this mission, working hard on the clean-up of the salvaged collector material, and developing analytical techniques for the carbon, and most importantly, oxygen isotopic measurements of the solar wind.