Journal: Rubble pile asteroids

As a child I learned about asteroids and have pictured them as solid pieces of rock of different sizes. Apparently, though, there have been suggestions since the 1970s and recent empirical data that some asteroids are actually collections of smaller rocks held loosely together by mutual gravity.

http://assorted-experience.blogspot.com/2010/01/rubble-pile-asteroids.html (blogspot, no advertising, single page :) )