A dynamic study of the post-impact transport of Lunar rocks to Earth and its application to the Sept. 11th, 2013 impact

Lunar meteorites constitute direct, varied samples of the materials forming the lunar surface, allowing to study its bulk chemistry, mineralogy and even geological history. The study of these meteorites not only sheds light on the composition of the Moon but also on its formation and the origin of the Solar System itself. Nowadays we know that these Lunar rocks are delivered to Earth in relative short timescales after being ejected by the impact of an asteroid or a comet from the lunar surface. So far, no lunar meteorite has ever been associated with a crater, not even has been witnessed to fall on Earth. The atmosphere of the Moon is extremely thin, being unable to decelerate particles that are either impacting or escaping from the Moon. It is due to the impact of these high-velocity projectiles that some lunar rocks can be ejected with a velocity above the escape velocity of the Moon (2.38 km/s) [3]. When a projectile of a certain mass impacts the surface of the Moon excavates an impact crater and releases a mass between 3-4 orders of magnitude higher than the projectile mass [3, 4]. Most of the ejected mass falls near the crater and forms continuous ejecta blankets, while the rest follows an impact trajectory far away from the initial impact, while a small part of the ejecta achieves enough velocity to escape the Moon. Our study focuses on the dynamic evolution of these Lunar rocks once they left our satellite, and their ability to reach the Earth as meteorites.
The authors acknowledge financial support from the Spanish Ministry (PGC2018-097374-B-I00, PI:JMTR).