The density measured by NEAR Shoemaker , 1,300 kg\/m Â , is less than half that of a normal carbonaceous chondrite ; this may indicate that the asteroid is very loosely packed rubble pile ( an asteroid that has been broken apart by a collision and pulled back together by gravity ) . The density measured by NEAR Shoemaker , 1,300 kg\/m Â , is less than half that of a typical carbonaceous chondrite ; this may indicate that the asteroid is very loosely packed rubble pile .