Detection of X-ray calcium line from lunar surface
Top Left: GOES X-ray spectrum showing the Solar input. Note the flares around 06:00 UT on 15 January 2005 (GOES Data Courtesy NOAA).
Lower Left: D-CIXS spectrograms showing fluorescence emission from the Moon as a response. The three panels show the summed outputs of the three separate D-CIXS facets.
Top Right: Area of the Moon overflown during this observation, running from 15° to 45° North, at 60° East longitude, including Mare Crisium in the southern part of the region.
Bottom Right: The derived X-ray spectrum, indicating lunar elemental composition. Note the prominent calcium feature, as well as visible aluminium, silicon and iron.