Detection of a deep 3-microm absorption feature in the spectrum of Amalthea (JV).
Near-infrared spectra of Jupiter's small inner satellites Amalthea and Thebe are similar to those of D-type asteroids in the 0.8- to 2.5-micrometer wavelength range. A deep absorption feature is detected at 3 micrometers in the spectra of the trailing side of Amalthea, which is similar to that of the non-ice components of Callisto and can be attributed to hydrous minerals. These surface materials cannot be explained if the satellite formed at its present orbit by accreting from a circumjovian nebula. Amalthea and Thebe may be the remnants of Jupiter's inflowing building blocks that formed in the outer part or outside of the circumjovian nebula.
Takato
Naruhisa
N
Subaru Telescope, National Astronomical Observatory of Japan, 650 North Aohoku Place, Hilo, Hawaii 96720, USA. takato@naoj.org
Bus
Schelte J
SJ
Terada
Hiroshi
H
Pyo
Tae-Soo
TS
Kobayashi
Naoto
N
D007053:Ice; D018538:Jupiter; D008903:Minerals; D019265:Spectroscopy, Near-Infrared; D013696:Temperature; D014867:Water
D007053:Ice; D008903:Minerals; D014867:Water