Porosity of the moon's crust reveals bombardment history
Around 4.4 billion years ago, the early solar system resembled a game of space rock dodgeball
the team has shown through simulations that, early on in the bombardment period,
the moon was highly porous—almost one-third as porous as pumice.
Scientists have assumed that a continuous onslaught of impacts would slowly build up porosity.
the team found that nearly all the moon's porosity formed rapidly with these massive imapcts,
These later, smaller impacts acted instead to squeeze and compact some of the moon's existing cracks and faults.
the researchers also estimated that the moon experienced double the number of impacts as can be seen on the surface