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The detection of olivine on Vesta is interesting because it may provide critical insights into planetary differentiation early in our Solar Systems history. Ground-based and Hubble Space Telescope (HST) observations of asteroid (4) Vesta have suggested the presence of olivine on the surface. These observations were reinforced by the discovery of olivine-rich HED meteorites from Vesta in recent years. However, analysis of data from NASAs Dawn spacecraft has shown that this olivine-bearing unit is actually impact melt in the ejecta of Oppia crater. The lack of widespread mantle olivine, exposed during the formation of the 19 km deep Rheasilvia basin on Vestas South Pole, further complicated this picture. Ammannito et al., (2013a) reported the discovery of local scale olivine-rich units in the form of excavated material from the mantle using the Visible and InfraRed spectrometer (VIR) on Dawn. Here we explore alternative sources for the olivine in the northern hemisphere of Vesta by reanalyzing the data from the VIR instrument using laboratory spectral measurements of meteorites. We suggest that these olivine exposures could be explained by the delivery of olivine-rich exogenic material. Based on our spectral band parameters analysis, the lack of correlation between the location of these olivine-rich terrains and possible mantle-excavating events, and supported by observations of HED meteorites, we propose that a probable source for olivine seen in the northern hemisphere are remnants of impactors made of olivine-rich meteorites. Best match suggests these units are HED material mixed with either ordinary chondrites, or with some olivine-dominated meteorites such as R-chondrites.
We present the results of photometric observations carried out with four small telescopes of the asteroid 4 Vesta in the $B$, $R_{rm C}$, and $z$ bands at a minimum phase angle of 0.1 $timeform{D}$. The magnitudes, reduced to unit distance and zero p
From a single, 3.8-hour observation of asteroid (4) Vesta at $13.7^circ$ phase angle with the POLISH2 polarimeter at the Lick Observatory Shane 3-m telescope, we confirm rotational modulation of linear polarization in $B$ and $V$ bands. We measure th
Returning humans to the Moon presents an unprecedented opportunity to determine the origin of volatiles stored in the permanently shaded regions (PSRs), which trace the history of lunar volcanic activity, solar wind surface chemistry, and volatile de
Dawns framing camera observed boulders on the surface of Vesta when the spacecraft was in its lowest orbit (LAMO). We identified, measured, and mapped boulders in LAMO images, which have a scale of 20 m per pixel. We estimate that our sample is virtu
This work reports high quality NIR spectra, and their respective interpretations, for eight Vp type asteroids, as defined by Carvano et al. (2010), that were observed at the NASA Infrared Telescope Facility on January 14, 2013 UT. They include (3867)