We all know that the pock marked face of the Moon looks the way it does because it was hit by meteors. But not many people know that this is still happening today. While the era of major impacts is over, lunar meteorites still cause flashes and puffs of gas, vaporized rock, and dust that we can observe.

The Moon itself has a fascinating history. It is now thought to have been formed after a Mars-sized object collided with Earth and stripped off a portion of its mass. This debris took shape within a few hundred years and was originally much closer to our planet. The craters on its surface were largely formed by intense meteorite and asteroid bombardment between 4.6 billion and 3.8 billion years ago.

In this comprehensive book, Brian Cudnik, one of the first people to observe a meteorite impact on the Moon in real time, shows how both amateur and practical astronomers can look for these 'lunar transient phenomena,' or LTPs. He explains in detail the processes that formed the craters and impact marks we see on the Moon and elsewhere in the Solar System, and he details the events leading up to our recognition that the Moon is not a 'dead' world in terms of meteors but is still being hit by space debris.

Meteors and asteroids have melted the Moon's crust, forming the lunar magma ocean, and caused enormous impact craters that, like an old warrior's battle scars, give us a visual history of the planet. As amateur astronomy becomes ever more sophisticated, this book interprets the Moon's scars and acts as a guide to observing our nearest planetary neighbor, showing how amateurs can support and even compete with the professionals in this field.

Résumé
The genesis of modern searches for observable meteoritic phenomena on the Moon is the paper by Lincoln La Paz in Popular Astronomy magazine in 1938. In it he argued that the absence of observed fashes of meteoritic impacts on the Moon might be interpreted to mean that these bodies are destroyed as luminous meteors in an extremely rarefed lunar atmosphere. The paper suggested the possibility of systematic searches for such possible lunar meteors. With these concepts in mind, I was surprised to note a transient moving bright speck on the Moon on July 10, 1941. It appeared to behave very much as a lunar meteor would except that the poorly estimated duration would lead to a strongly hyperbolic heliocentric velocity. Thus, the idea of systematic searches for both p- sible lunar meteors and meteoritic impact fashes was born. It was appreciated that much time might need to be expended to achieve any positive results. Systematic searches were carried out by others and myself chiefy in the years 19451965 and became a regular program at the newly founded Association of Lunar and Planetary Observers, or ALPO.

Contenu
The Moon and Meteoroids.- Widespread Evidence.- Lunar Impact Features.- Remarkable Collisions.- Possible Impact Phenomena (PIPs).- Beyond the Moon.- An Observer's Guide to Lunar Meteor Impacts, Past and Present.- Guide to Observing Impact Features on the Moon.- Impacts Today.- Lunar Impact Observation Programs.- Observing Impacts as They Happen with Contributions by Many Members of the International Occultation Timing Association.- Finding Collisions.- Spurious Flash or True Impact Event?.- Professional and Amateur Collaboration.