As reported in last week's Lunar and Planetary Science Conference in Houston, two most promising candidates for stardust have been identified. They were collected during NASA´s Stardust mission that probed the interstellar stream during 15 months. Since 2006 not only scientists but also amateurs worldwide are scanning samples for the proverbial needle in the haystack: dust particles from others parts of our galaxy that were carried to our solar system via the interstellar stream. Several tons of matter will be transferred through our solar system each year. Geoscientists of Frankfurt's Goethe-University helped to identify the chemical structure of the particles.
Particle No. 30, now subdivided and named Orion and Sirius, were identified as the most likely interstellar candidates discovered to date. Part of this exiting research was performed by a team of researchers from the Goethe-University Frankfurt (Prof. Frank Brenker, Dr. Sylvia Schmitz) and the Gent University (Prof. Laszlo Vincze, Dr. Bart Vekemans, Dr. Tom Schoojans) at the European Synchrotron Radiation Facility ESRF in Grenoble, France. Like in a huge X-ray microscope the structure and chemical composition of particles was analysed non-destructively.
After the successful preliminary analysis and exiting beamtime in Grenoble the sample went back to Berkeley for further studies. Although team leader Dr. Andrew Westphal (University of California, Berkeley) stressed that the discovery "could be a false alarm" he added: "So far this particle is unique... if we drop it on the floor, it will cost $300m to get another one." If future work on the particles will confirm their interstellar nature the ESRF would be the place where the first chemical data of a contemporary interstellar particle were ever collected.
For further details contact f.brenker@em.uni-frankfurt.de , laslo.vincze@ugent.be or see http://www.nature.com/news/2010/100303/full/news.2010.106.html and http://news.bbc.co.uk/2/hi/science/nature/8550924.stm