LROC Identifies 22-Meter Fresh Impact Scar North of Lunar Crater Römer

The team operating the Lunar Reconnaissance Orbiter Camera (LROC) formally disclosed in November 2025 the identification of a recently formed impact crater on the lunar surface. Researchers isolated this feature, colloquially termed a 'freckle,' through a temporal comparison of imagery captured between December 2009 and a later date after December 2012. The resulting crater measures approximately 22 meters, or about 72 feet, in diameter and is situated immediately north of the older, established Römer crater.

The most distinctive characteristic of this new scar is its pronounced brightness, which stems from impact ejecta forming brilliant rays in a distinct sunburst pattern. This high-albedo material creates a sharp visual contrast against the darker, more mature lunar regolith surrounding it, acting as a clear indicator of a relatively recent collision event. The Römer crater, which lends its name to the area, is located in the Moon's northeast quadrant, north of Sinus Amoris, and is named for the Danish astronomer Ole Rømer, who conducted the first quantitative measurements of the speed of light in 1676.

This scientific documentation is led by the LROC team, under the direction of Principal Investigator Mark Robinson, a professor at Arizona State University's School of Earth and Space Exploration (SESE). As of a 2016 report, the team, operating from the LROC Science Operations Center in Tempe, Arizona, had already cataloged over 200 impact craters confirmed to have formed during the operational lifespan of the LRO mission, which began in June 2009. The LROC team's capacity for temporal analysis using before-and-after orbital photographs has proven instrumental in these discoveries, demonstrating that the Moon's surface is actively changing on a human timescale.

Documenting these fresh craters is crucial for refining contemporary estimates of the impact flux rate striking the Moon. This data is foundational for hazard mitigation and risk assessment for forthcoming crewed and robotic endeavors, including NASA's Artemis program, which seeks to establish a sustained presence on the lunar surface. Furthermore, observing the gradual dimming of these bright rays allows scientists to calibrate sophisticated models used to date other lunar terrains based on crater morphology.

This darkening phenomenon is scientifically defined as space weathering, a continuous process spanning millennia, driven by solar wind particle bombardment and cosmic ray exposure on airless bodies. Space weathering causes the lunar surface to darken and redden over time due to the formation of nanophase iron particles within the regolith. The existence of this bright, fresh crater underscores the dynamic nature of the lunar environment, which is perpetually acquiring new surface modifications, contrasting with older surfaces where the bright ejecta have already been subdued by this weathering process.