As mentioned earlier, the discovery that many asteroids have very low densities( as low as1.2 grams per cubic centimeter) indicates that many of these bodies are highly porous piles of rubble.

• 但如前所述的发现，许多小行星密度很低（至低到每立方公分1.；2公克）显示这类天体有许多是充满空隙的碎石集合体。