The calibration target for SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals) an instrument on the end of the Perseverance Mars rover's 7-foot-long (3-meter-long) robotic arm, includes a geocaching target, spacesuit materials, and a slice of a Martian meteorite. Scientists rely on calibration targets to fine-tune instrument settings using materials with known properties.

The bottom row of this target features spacesuit materials that scientists will observe to see how they react over time to the irradiated Martian atmosphere. The first sample at left is polycarbonate for use in a helmet visor; inscribed with the address of the fictional detective Sherlock Holmes, it doubles as a geochache for the public. Other materials in the bottom row, from left: Vectran; Ortho-Fabric; Teflon; coated Teflon.

Top row, from left: aluminum gallium nitride on sapphire; a quartz diffuser; a slice of Martian meteorite; a maze for testing laser intensity; a separate aluminum gallium nitride on sapphire with different properties.