CRAYEX

Meteorite impacts are one of the major surface modifying processes on moon.These impact craters are remarkably well preserved owing to the absence of atmosphere, andthus, making them valuable to resolve several geological conundrums. Of the different impact features, the ejecta from these craters, particularly the distinct rays of material, remain well-preserved. But the overprinting of subsequent impact events hinders the visibility of earlier crater rays. Here we utilize the optical maturity of ejecta materials using Terrain Camera and OMAT images. This helped to distinguish the albedo effect to discern both the younger and older rayed ejecta material. A toolkit, named CRAYEX (acronym for crater ray explorer), was developed to delineate the ejecta rays. This was demonstrated through a preliminary study of ten different craters covering both the lowlands and highlands. Python, a modern programming language, together with its librariessuch as GDAL, NumPy, SciPy, Matplotlib, Scikit-image, and Pillowwere involved in image enhancement techniques such asimage normalization, noise removal, contrast stretching, histogram equalisationand thresholding to extract ejecta around younger craters. The thresholding method employed is Otsu thresholding, and the threshold values used for delineating ejecta around each crater fall within the range of 0.4 to 0.5, rounded to the nearest value.Through iterative processes employing established methods, we delved into refinement and validation against existing lunar data. Initially, we navigated through various techniques, including CraterPy for crater extraction, density slicing for segmenting regions based on variations in pixel intensity and manual thresholding using values for delineating ejecta. However, through further research and leveraging the capabilities of modern programming, we encountered a novel technique that could be seamlessly integrated into our toolkit. This evolution enabled us to successfully mitigate challenges and achieve precise delineation of rayed ejecta. Thus, CRAYEX, through integratingtheseremote sensing methods, pave way for a more comprehensive exploration of lunar impact craters and their implications for understanding planetary bodies.