Q: (L) When and how did planet earth acquire its moon?
A: Was caused by the regular passage of a large comet cluster which caused a gravitational disruption allowing a large chunk of the original earth's surface, which was somewhat less solid at that point in space/time, to break away from the main body and assume a locked in orbit around the main body.
Q: (L) When did this happen?
A: This occurred approximately 3 billion years ago.
Go to this board: https://cassiopaea.org/forum/index.php/board,51.0.html
On the top right corner, type "moon" on the search function (choosing the "on this board" option in the scroll-down menu), and you will see all the times when the word "moon" appears in a session. Of course, many of them may not be relevant to your search, but you can see from there which ones interest you.
Take a virtual tour of the Moon in all-new 4K resolution, thanks to data provided by NASA's Lunar Reconnaissance Orbiter spacecraft. As the visualization moves around the near side, far side north and south poles, we highlight interesting features, sites, and information gathered on the lunar terrain.