This crystal of iron pyrite, just four hundredths of a millimeter in size, could function as the light absorbing layer of a tiny solar cell – potentially a promising future source of power on the Moon.

Working with Estonia’s Tallinn University of Technology (TalTech), ESA has studied the production of sandpaper-like rolls of such microcrystals as the basis of monograin-layer solar cells.

“We’re looking at these microcrystals in the context of future lunar settlement,” explains ESA advanced manufacturing engineer Advenit Makaya. “Future Moon bases will need to ‘live off the land’ in order to be sustainable, and the iron and sulfur needed to produce pyrite could be retrieved from the lunar surface.”