News regularly point out all the beauty but also the potential dangers of volcanic eruptions. If one can appreciate the show of these natural phenomena, one also seeks to understand them better in order to protect the neighbouring populations and to evaluate their impact on the climate evolution. Eruptions at Stromboli (Italy) occur as periodic explosions (~15 mn) projecting fragments of molten lava to a few hundred meters above the crater.

Samples from the spatial mission Stardust have been analysed by a team of the Pierre Süe Laboratory in Saclay (CEA-DSM/DRECAM et CNRS-Chimie). The technique used, nuclear reactions induced by a microbeam, allows an absolute measurement of the concentration in constitutive elements in the collected samples. The very first results for the samples of dust issued from the Wild2 comet show a great heterogeneity and variability of the collected grains.

The Stardust mission, which ended in success on January 15, 2006 after a tour lasting seven years in space, brought back to the Earth the first samples of material taken from the dust coma of comet Wild-2. This comet formed in the Kuiper Belt 4.5 Ga ago. Its orbit far from the Sun helped limit its alteration during its journey and consquently its composition must have been substantially unaltered since its birth.