Secondary ions of a cometary grain collected next to comet 67P/C-G
![](https://cdn.sci.esa.int/documents/34878/35534/1567216653478-Rosetta_COSIMA_Boris_mass_spectrum_625.jpg)
Date: 28 October 2014
Satellite: Rosetta
Copyright: See below
This spectrum shows the positive mass per charge from 22.5 amu/e to 24.5 amu/e obtained on 7 August 2014, before exposure of the first COSIMA target-holders (shown in black) and from the "shot and hit" grain Boris (shown in red) collected during the second exposure week (18-24 August 2014) at about 80 km from comet 67P/Churyumov-Gerasimenko. Each spectrum is the sum of two spectra taken at the same position, each taken for a period of 2.5 minutes. The two clear peaks in the red spectrum show that among the grain's components are magnesium and sodium.
Credit: ESA/Rosetta/MPS for COSIMA Team MPS/CSNSM/UNIBW/TUORLA/IWF/IAS/ESA/BUW/MPE/LPC2E/LCM/FMI/UTU/LISA/UOFC/vH&S
Last Update: 1 September 2019