Mass and local topography measurements of Itokawa by Hayabusa.
The ranging instrument aboard the Hayabusa spacecraft measured the surface topography of asteroid 25143 Itokawa and its mass. A typical rough area is similar in roughness to debris located on the interior wall of a large crater on asteroid 433 Eros, which suggests a surface structure on Itokawa similar to crater ejecta on Eros. The mass of Itokawa was estimated as (3.58 +/- 0.18) x 10(10) kilograms, implying a bulk density of (1.95 +/- 0.14) grams per cubic centimeter for a volume of (1.84 +/- 0.09) x 10(7) cubic meters and a bulk porosity of approximately 40%, which is similar to that of angular sands, when assuming an LL (low iron chondritic) meteorite composition. Combined with surface observations, these data indicate that Itokawa is the first subkilometer-sized small asteroid showing a rubble-pile body rather than a solid monolithic asteroid.
Abe
Shinsuke
S
Graduate School of Science and Technology, Kobe University, Nada, Kobe 657-8501, Japan. avell@kobe-u.ac.jp
Mukai
Tadashi
T
Hirata
Naru
N
Barnouin-Jha
Olivier S
OS
Cheng
Andrew F
AF
Demura
Hirohide
H
Gaskell
Robert W
RW
Hashimoto
Tatsuaki
T
Hiraoka
Kensuke
K
Honda
Takayuki
T
Kubota
Takashi
T
Matsuoka
Masatoshi
M
Mizuno
Takahide
T
Nakamura
Ryosuke
R
Scheeres
Daniel J
DJ
Yoshikawa
Makoto
M