NASA’s Perseverance rover has sent back thousands of images from Mars, but one mystery has captured the attention of space enthusiasts worldwide. The SHERLOC Calibration Target, an essential feature of the rover’s onboard science suite, features a tiny, intricate maze etched onto a metallic plate.
The SHERLOC tool uses laser-based spectroscopy to scan Martian rocks for organic molecules and minerals that might indicate microbial life. To ensure accurate results, NASA equipped the rover with a small calibration plate on its robotic arm, which includes various reference materials like aluminum gallium nitride, a Martian meteorite, and UV-scattering Diffusil.
The microscopic maze made of chrome lines just 200 microns wide is used to check the precision and alignment of SHERLOC’s laser and measure its focus using contrasting materials. The unique design allows for extreme accuracy in calibration. At the center of the maze is a subtle silhouette of Sherlock Holmes, which can be resolved by SHERLOC’s spectral mapping.
The bottom half of the plate serves another purpose: testing spacesuit materials for future human missions. It includes five familiar materials used in modern spacesuit construction and exposes them to the Martian environment to evaluate their performance over time. The unique science being conducted on this material will help keep future astronauts safe.
In addition to its scientific role, the SHERLOC Calibration Target also includes nods to public engagement and storytelling, such as a geocache marker and references to Sherlock Holmes and his famous assistant WATSON.
Source: https://dailygalaxy.com/2025/06/nasas-perseverance-rover-tiny-maze-on-mars