Near-infrared spectrophotometry of phobos and deimos

A. S. Rivkin, R. H. Brown, David E Trilling, J. F. Bell, J. H. Plassmann

Research output: Contribution to journalArticle

45 Citations (Scopus)

Abstract

We have observed the leading and trailing hemispheres of Phobos from 1.65 to 3.5 μm and Deimos from 1.65 to 3.12 μm near opposition. We find the trailing hemisphere of Phobos to be brighter than its leading hemisphere by 0.24 ± 0.06 magnitude at 1.65 μm and brighter than Deimos by 0.98 ± 0.07 magnitude at 1.65 μm. We see no difference larger than observational uncertainties in spectral slope between the leading and trailing hemispheres when the spectra are normalized to 1.65 μm. We find no 3-μm absorption feature due to hydrated minerals on either hemisphere to a level of ∼5-10% on Phobos and ∼20% on Deimos. When the infrared data are joined to visible and near-IR data obtained by previous workers, our data suggest the leading (Stickney-dominated) side of Phobos is best matched by T-class asteroids. The spectral slope of the trailing side of Phobos and leading side of Deimos are bracketed by the D-class asteroids. The best laboratory spectral matches to these parts of Phobos are mature lunar soils and heated carbonaceous chondrites. The lack of 3-μm absorption features on either side of Phobos argues against the presence of a large interior reservoir of water ice according to current models of Phobos' interior (F. P. Fanale and J. R. Salvail 1989, Geophys. Res. Lett. 16, 287-290; Icarus 88, 380-395).

Original languageEnglish (US)
Pages (from-to)64-75
Number of pages12
JournalIcarus
Volume156
Issue number1
DOIs
StatePublished - 2002
Externally publishedYes

Fingerprint

Deimos
Phobos
spectrophotometry
near infrared
hemispheres
asteroid
lunar soil
carbonaceous chondrite
asteroids
ice
mineral
slopes
carbonaceous chondrites
water
minerals

Keywords

  • Asteroid composition
  • Infrared observations
  • Satellites of Mars
  • Spectrophotometry

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Rivkin, A. S., Brown, R. H., Trilling, D. E., Bell, J. F., & Plassmann, J. H. (2002). Near-infrared spectrophotometry of phobos and deimos. Icarus, 156(1), 64-75. https://doi.org/10.1006/icar.2001.6767

Near-infrared spectrophotometry of phobos and deimos. / Rivkin, A. S.; Brown, R. H.; Trilling, David E; Bell, J. F.; Plassmann, J. H.

In: Icarus, Vol. 156, No. 1, 2002, p. 64-75.

Research output: Contribution to journalArticle

Rivkin, AS, Brown, RH, Trilling, DE, Bell, JF & Plassmann, JH 2002, 'Near-infrared spectrophotometry of phobos and deimos', Icarus, vol. 156, no. 1, pp. 64-75. https://doi.org/10.1006/icar.2001.6767
Rivkin, A. S. ; Brown, R. H. ; Trilling, David E ; Bell, J. F. ; Plassmann, J. H. / Near-infrared spectrophotometry of phobos and deimos. In: Icarus. 2002 ; Vol. 156, No. 1. pp. 64-75.
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