PyNAPLE: Lunar Surface Impact Crater Detection

TL;DR

PyNAPLE is a new software pipeline that systematically detects lunar impact craters linked to observed impact flashes, enabling large-scale analysis of lunar cratering and impactor properties.

Contribution

The paper introduces PyNAPLE, the first automated tool for linking lunar impact flashes to crater detection, facilitating systematic studies of impact events and crater formation.

Findings

Impact angle estimated between 10-30 degrees.

Predicted crater diameter ranges from 24.1 to 55.3 meters.

Ejecta analysis supports impact characterization.

Abstract

In the last 20 years, over 600 impact flashes have been documented on the lunar surface. This wealth of data presents a unique opportunity to study the meteoroid flux of the Earth-Moon environment, and in recent years the physical properties of the impactors. However, other than through serendipitous events, there has not been yet a systematic search and discovery of the craters associated to these events. Such a meteoroid-crater link would allow us to get insight into the crater formation via these live observations of collisions. Here we present the PyNAPLE (Python NAC Automated Pair Lunar Evaluator) software pipeline for locating newly formed craters using the location and epoch of an observed impact flash. We present the first results from PyNAPLE, having been implemented on the 2017-09-27 impact flash. A rudimentary analysis on the impact flash and linked impact crater is also performed, finding that the crater's ejecta pattern indicates an impact angle between 10-30 degree, and although the rim-to-rim diameter of the crater is not resolvable in current LRO NAC images, using crater scaling laws we predict this diameter to be 24.1-55.3 m, and using ejecta scaling predict a diameter of 27.3-37.7 m. We discuss how PyNAPLE will enable large scale analyses of sub-kilometer scale cratering rates and refinement of both scaling laws, and the luminous efficiency.