The research project conducted by students from Blenheim High School, alongside Orbyts Fellow Rebecca Warrilow, investigated whether the ExoMars Rosalind Franklin rover's Panoramic Camera (PanCam) could detect photosynthetic biosignatures within Martian surface materials. The project focused on Oxia Planum, the rover's 2030 landing site, which contains ancient clay-bearing deposits formed through past interaction with liquid water.

The students used CRISM data to identify minerals representative of Oxia Planum and then built their own 13-mineral regolith analogue, ARES (Analogue Regolith for ExoMars Science), in the school laboratory. They ground and sieved the minerals to produce representative grain sizes before combining them in proportions based on the Martian mineralogy. This created a realistic geological background against which potential biosignatures could be tested.

The team then mixed chlorophyll, spirulina (cyanobacteria), and moss into ARES at concentrations between 1% and 50%. The mixtures were imaged using the PanCam Training Model (the only operational replica of the flight instrument in the world!), and the resulting multispectral images were analysed to investigate whether biological spectral features could be distinguished from the surrounding Mars regolith.

All three photosynthetic materials produced a distinct "red edge", characterised by a steep increase in reflectance between 670–740 nm. Crucially, this feature remained detectable at concentrations as low as 1%, demonstrating that PanCam multispectral observations could distinguish the spectral signature of photosynthetic material from a realistic Martian geological background, even when present in trace amounts.

These results show that, if photosynthetic life once existed on Mars, its spectral signature could potentially be distinguished from the surrounding geology using PanCam, even at trace abundances. This provides an exciting insight into how the Rosalind Franklin rover could search for evidence of past life when it begins exploring Oxia Planum.