The Phobos Giant Impact simulant has been developed at the University of Central Florida as part of ongoing work to investigate physical properties of Phobos surface materials. It is paired with PCA-1, and the two simulants reflect the two leading theories for the formation of Phobos: (1) a captured C- or D-type asteroid, or (2) a debris disc from a giant impact composed of part carbonaceous asteroid, part Mars mantle.

PGI-1 is based on a giant impact scenario that produces a debris disk of 57% asteroid, 43% Mars mantle, where the carbonaceous component is based on the UCF/DSI CI simulant, and the Mars mantle component is 60% olivine and 40% pyroxene, based on magma ocean crystallization models.

The simulant was created in the same way as the UCF/DSI CI carbonaceous chondrite simulant. Individual minerals were mixed with water, then dried. The dried material was crushed into a regolith-like particle size distribution. The <25 μm size fraction was sieved out, consistent with Phobos where this fraction is likely winnowed out by solar wind interactions.

Acknowledgements