NASA's Curiosity Rover Captures Rare Nighttime View of Martian Drill Hole Using LED Illumination

NASA's Curiosity rover has successfully captured a high-definition nighttime photograph of the Martian landscape, utilizing the specialized LED lighting system integrated into its Mars Hand Lens Imager (MAHLI). This striking image, which was made public in January 2026, was originally recorded on December 6, 2025, corresponding to the 4740th sol of the rover's ongoing mission within Gale Crater. While the MAHLI LEDs provided the necessary illumination for the interior of the drill hole—unofficially named 'Nevado Sahama'—the primary visual data was gathered by the Mast Camera (Mastcam) mounted on the rover's mast.

The mission's scientific team has a history of using MAHLI’s LEDs to probe areas shrouded in deep shadow, such as the internal structures of drill holes during the Martian day. However, the recent revival of this specific nighttime technique was prompted by the discovery that the walls of the 'Nevado Sahama' target, drilled on November 13, 2025 (Sol 4718), were sufficiently smooth for high-quality analysis. Previous iterations of the drilling process had produced walls that were far too irregular, which had temporarily halted the use of this nocturnal lighting method. The return to nighttime imaging allows researchers to more clearly identify distinct geological layers and enhance the precision of their soil composition analysis.

This specific drilling campaign was conducted in a region defined by its 'boxwork' formations. These geological structures appear as a network of durable ridges separated by hollowed-out, eroded depressions, which look like giant, intersecting spiderwebs when viewed from orbital altitudes. Boxwork formations are of significant interest to geologists because they often indicate the presence of mineralized fluids that once flowed through ancient rock fractures. Such environments are critical to study, as they represent areas where organic molecules might have been preserved over billions of years.

The Curiosity mission is overseen by NASA’s Jet Propulsion Laboratory (JPL), managed by the California Institute of Technology (Caltech) in Pasadena, California, as part of the broader Mars Exploration Program. The Mastcam and MAHLI instruments were developed and are currently operated by Malin Space Science Systems (MSSS). The MAHLI camera is uniquely equipped with both white light and long-wave ultraviolet LEDs for operation in the dark or for specialized fluorescence imaging. For the Sol 4740 image, the Group 1 and Group 2 white light LEDs were active, while the UV lights were not used. The 'Nevado Sahama' site was also used to collect samples for the Sample Analysis at Mars (SAM) instrument to search for organic compounds.

Deputy Project Scientist Abigail Fraeman explained that the team had paused nighttime drill hole illumination for a period due to the structural instability of the walls in earlier samples. Beyond the night photography, the exploration of 'Nevado Sahama' between Sols 4731 and 4742 involved the construction of a comprehensive 360-degree stereo mosaic using the M34 wide-angle camera and the 100 mm Mastcam telephoto lens. The study of these boxwork formations on the slopes of Mount Sharp (Aeolis Mons), where Curiosity has been exploring since August 2012, is central to finding evidence of Mars' aqueous history. The successful nighttime illumination of the 'Nevado Sahama' hole marks a vital step forward in understanding the stratigraphy and morphology of the materials in this fascinating region.