First images of asteroid 243 ida.
The first images of the asteroid 243 Ida from Galileo show an irregular object measuring 56-kilometers by 24 kilometers by 21 kilometers. Its surface is rich in geologic features, including systems of grooves, blocks, chutes, albedo features, crater chains, and a full range of crater morphologies. The largest blocks may be distributed nonuniformly across the surface; lineaments and dark-floored craters also have preferential locations. Ida is interpreted to have a substantial regolith. The high crater density and size-frequency distribution (-3 differential power-law index) indicate a surface in equilibrium with saturated cratering. A minimum model crater age for Ida-and therefore for the Koronis family to which Ida belongs-is estimated at 1 billion years, older than expected.
Belton
M J
MJ
Chapman
C R
CR
Veverka
J
J
Klaasen
K P
KP
Harch
A
A
Greeley
R
R
Greenberg
R
R
Head
J W
JW
McEwen
A
A
Morrison
D
D
Thomas
P C
PC
Davies
M E
ME
Carr
M H
MH
Neukum
G
G
Fanale
F P
FP
Davis
D R
DR
Anger
C
C
Gierasch
P J
PJ
Ingersoll
A P
AP
Pilcher
C B
CB