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Structure and density of cometary nuclei

Weissman, Paul R.; Lowry, Stephen C.

Understanding the nature of the cometary nucleus remains one of the major problems in solar system science. Whipple’s (1950) icy conglomerate model has been very successful at explaining a range of cometary phenomena, including the source of cometary activity and the nongravitational orbital motion of the nuclei. However, the internal structure of…

Rosetta target asteroid 2867 Steins: An unusual E-type asteroid

Weissman, Paul R.; Hicks, Michael D.; Choi, Young-Jun +2 more

ESA's Rosetta spacecraft will fly by main-belt asteroid 2867 Steins on September 5, 2008. We obtained new visible wavelength spectra of 2867 Steins on December 19, 2006 (UT), using the Palomar 5 m telescope and the facility Double Spectrograph. Two sets of spectra, taken ∼3 h apart, one half of the rotation period for 2867 Steins, show it to be an…

Finite difference time domain simulation of radar wave propagation through comet nuclei dielectric models

Heggy, Essam; Carley, Ruth A.

The 90 MHz radar-wave experiment, Comet Nucleus Sounding Experiment by Radiowave Transmission (CONSERT), on board the Rosetta mission (ESA, 2004) is expected to probe the nucleus of the comet 67P/Churyumov-Gerasimenko (67P/C-G) to reveal information on its physical properties, chemical composition, and internal structure. This investigation assess…

A review of penetrometers for subsurface access on comets and asteroids

Ball, Andrew J.; Glaser, David L.; Zacny, Kris A.

The characterization of comet and asteroid interiors will eventually require in situ exploration with drills, penetrators/penetrometers, hypervelocity impactors, excavators or other devices. Because they offer desirable scientific capabilities and relative mechanical simplicity, penetrators and penetrometers, which use only axial force to push ben…