SMART-1 detection of titanium on the lunar surface
The D-CIXS X-ray spectrometer on SMART-1 provided the first ever detection of titanium (Ti) on the lunar surface.
Left: Spectra measured on 18 November 2005 during a solar flare, while SMART-1 was overflying Mare Nubium on the near side. (Solar X-rays typically excite low atomic number elements, for example, magnesium (Mg), aluminium (Al) and silicon (Si), which were detected by D-CIXS. The fortuitous occurrence of a number of solar flares during the lifetime of SMART-1 provided the extra energy needed to excite heavier elements and resulted in the first ever detection of titanium (Ti). In the figure above, the green, blue and red lines are model predictions based on the average soil composition determined from the Apollo 11, 12 and 16 missions, respectively.
Right: Close-up view of the region showing the Ti peak detection. Conversely, D-CIXS measurements over the centre of the lunar far side did not show the Ti peak.