The Landing Procedure

The gravity and slope information and estimates of the density of boulders and regolith distribution on the surface, combined with comparisons with meteorites, will advance our interpretation and understanding of asteroid planetology.

D) Using the laser altimeter and optical navigation camera, along with range and range-rate measurements fromground-tracking stations, have led to a successful mass and density estimate for Itokawa. The density has been estimated to be 2,3 +/-0,3 gram/cc, which is a little lower than that measured for rocks on the ground or for other S-type asteroids measured to date. This may indicate that there is substantial porosity for this body and forces conventional views of these small objects to be changed drastically. When the samples are successfully returned and recovered, the actual porosity will be clarified and our knowledge of how the Earth relates to meteorites will be greatly improved.