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Data from the Gravity Recovery and Interior Laboratory (GRAIL) mission have revealed that ∼98% of the power of the gravity signal of the Moon at high spherical harmonic degrees correlates with the topography. The remaining 2% of the signal, which cannot be explained by topography, contains information about density variations within the crust. These high-degree Bouguer gravity anomalies are likely...
We present a global spectrophotometric characterization of the Ceres surface using Dawn Framing Camera (FC) images. We identify the photometric model that yields the best results for photometrically correcting images. Corrected FC images acquired on approach to Ceres were assembled into global maps of albedo and color. Generally, albedo and color variations on Ceres are muted. The albedo map is dominated...
Remote sensing data acquired during Dawn’s orbital mission at Vesta showed several local concentrations of high-albedo (bright) and low-albedo (dark) material units, in addition to spectrally distinct meteorite impact ejecta. The thermal behavior of such areas seen at local scale (1–10km) is related to physical properties that can provide information about the origin of those materials. We use Dawn’s...
On February 14, 2011 Stardust-NExT (SN) flew by Comet Tempel 1, the target of the Deep Impact (DI) mission in 2005, obtaining dust measurements and high-resolution images of areas surrounding the 2005 impact site, and extending image coverage to almost two thirds of the nucleus surface. The nucleus has an average radius of 2.83±0.1km and a uniform geometric albedo of about 6% at visible wavelengths...
The Deep Impact spacecraft flew by Comet 103P/Hartley 2 on November 4th, 2010 (EPOXI mission) and Comet 9P/Tempel 1 on July 4th, 2005 (Deep Impact mission). During the two flybys, spatially resolved infrared (1.05–4.8μm) spectra of the surface of the nucleus were acquired by the HRI-IR instrument. The analysis of these two data sets, obtained by the same instrument, offers a unique opportunity to...
Observations from the second encounter of Comet 9P/Tempel 1 by the Stardust-NExT spacecraft provide an improved shape model and rotational pole for the nucleus (Thomas, P.C. et al. [2012]. Icarus 222, 453–466) that allows us to greatly improve our knowledge of its rotational evolution beyond that outlined earlier in Belton et al. (Belton, M.J.S. et al. [2011]. Icarus 213, 345–368). Model light curves...
We present results from our study of the Stardust-NExT NAVCAM images of Comet 9P/Tempel 1, in which we analyze the dust coma and derive the locations and directions of 11 isolated jets detected around closest approach. Seven of the jets form a cluster that is associated with terraced terrain near the equator. Other jets arise from the nightside of the nucleus, having been in darkness for as long as...
The nucleus of comet Tempel 1 has been investigated at close range during two spacecraft missions separated by one comet orbit of the Sun, 5½years. The combined imaging covers ∼70% of the surface of this object which has a mean radius of 2.83±0.1km. The surface can be divided into two terrain types: rough, pitted terrain and smoother regions of varying local topography. The rough surface has round...
Observations of the Moon obtained by the Moon Mineralogy Mapper (M 3 ) instrument were acquired at various local viewing geometries. To compensate for this, a visible near-infrared photometric correction for the M 3 observations of the lunar surface has been derived. Images are corrected to the standard geometry of 30° phase angle with an incidence of 30° and an emission of 0°. The...
We present a new method to perform disk-resolved photometry in order to investigate the intrinsic photometric properties of the surface of small Solar System bodies. We adopt the standard approach where a shape model is combined with a photometric formalism – in practise the Hapke formalism – to remove the effects of topography and recover the photometric (Hapke) parameters of either the global surface...
The Deep Impact (DI) spacecraft encountered Comet 9P/Tempel 1 on July 4th, 2005 and observed it with several instruments. In particular, we obtained infrared spectra of the nucleus with the HRI-IR spectrometer in the wavelength range of 1.0–4.9 μm. The data were taken before impact, with a maximum resolution of ∼120 m per pixel at the time of observation. From these spectra, we derived the first directly...
We present an overview of the dust coma observations of Comet Tempel 1 that were obtained during the approach and encounter phases of the Deep Impact mission. We use these observations to set constraints on the pre-impact activity of the comet and discuss some preliminary results. The temporal and spatial changes that were observed during approach reveal three distinct jets rotating with a 1.7-day...
We present an overview of the dust coma observations of Comet Tempel 1 that were obtained during the approach and encounter phases of the Deep Impact mission. We use these observations to set constraints on the pre-impact activity of the comet and discuss some preliminary results. The temporal and spatial changes that were observed during approach reveal three distinct jets rotating with a 1.7-day...
The Deep Impact (DI) spacecraft encountered Comet 9P/Tempel 1 on July 4th, 2005 and observed it with several instruments. In particular, we obtained infrared spectra of the nucleus with the HRI-IR spectrometer in the wavelength range of 1.0–4.9 μm. The data were taken before impact, with a maximum resolution of ∼120 m per pixel at the time of observation. From these spectra, we derived the first directly...
Experimental studies related to the sublimation of ice, in bulk or as small particles, alone or mixed with dust similar to that expected on the surface of Mars, are reported. The experiments, a cloud physics particle sublimation model, and a convection model presented by Ingersoll, all indicate a strong dependence of sublimation rate on temperature, and this appears to be the dominant factor, assuming...
The calculation of the orbit of the potentially hazardous Asteroid 2001 YB 5 suggests a possible meteor shower around January 7.5, 2002 UT. Video observations revealed an unidentified radiant around the predicted maximum time, at RA=121.5 o , Dec=+11.5 o (for solar longitude 287.30 o ). Visual observers also reported unusually high rates from that region on the same...
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