A plausible link between the asteroid 21 Lutetia and CH carbonaceous chondrites

A crucial topic in planetology research is establishing links between primitive meteorites and their parent asteroids. In this study we investigate the feasibility of a connection between asteroids similar to 21 Lutetia, encountered by the Rosetta mission in July 2010, and the CH3 carbonaceous chondrite Pecora Escarpment 91467 (PCA 91467). Several spectra of this meteorite were acquired in the ultraviolet to near-infrared (0.3 to 2.2 {\mu}m) and in the mid-infrared to thermal infrared (2.5 to 30.0 {\mu}m or 4000 to ~333 cm^-1), and they are compared here to spectra from the asteroid 21 Lutetia. There are several similarities in absorption bands and overall spectral behavior between this CH3 meteorite and 21 Lutetia. Considering also that the bulk density of Lutetia is similar to that of CH chondrites, we suggest that this asteroid could be similar, or related to, the parent body of these meteorites, if not the parent body itself. However, the apparent surface diversity of Lutetia pointed out in previous studies indicates that it could simultaneously be related to other types of chondrites. Future discovery of additional unweathered CH chondrites could provide deeper insight in the possible connection between this family of metal-rich carbonaceous chondrites and 21 Lutetia or other featureless, possibly hydrated high-albedo asteroids.Comment: 26 pages, 7 figures and 2 tables, Meteoritics and Planetary Science, manuscript #2225 (2016

First mineralogical maps of 4 Vesta

Before Dawn arrived at 4 Vesta only very low spatial resolution (~50 km) albedo and color maps were available from HST data. Also ground-based color and spectroscopic data were utilized as a first attempt to map Vesta’s mineralogical diversity [1-4]. The VIR spectrometer [5] onboard Dawn has ac-quired hyperspectral data while the FC camera [6] ob-tained multi-color data of the Vestan surface at very high spatial resolutions, allowing us to map complex geologic, morphologic units and features. We here re-port about the results obtained from a preliminary global mineralogical map of Vesta, based on data from the Survey orbit. This map is part of an iterative map-ping effort; the map is refined with each improvement in resolution

MarcoPolo-R: Near Earth Asteroid Sample Return Mission candidate as ESA-M3 class mission

MarcoPolo-R is a sample return mission to a primitive Near-Earth Asteroid (NEA) selected in February 2011 for the Assessment Study Phase at ESA in the framework of ESAfs Cosmic Vision 2 program. MarcoPolo-R is a European-led mission with a proposed NASA contribution. MarcoPolo-R takes advantage of three industrial studies completed as part of the previous Marco Polo mission (see ESA/SRE (2009)3). The aim of the new Assessment Study is to reduce the cost of the mission while maintaining its high science level, on the basis of advanced studies and technologies, as well as optimization of the mission. MarcoPolo-R will rendezvous with a unique kind of target, a primitive binary NEA, scientifically characterize it at multiple scales, and return a unique pristine sample to Earth unaltered by the atmospheric entry process or terrestrial weathering. The baseline target of MarcoPolo-R is the primitive binary NEA (175706) 1996 FG3, which offers a very efficient operational and technical mission profile. A binary target also provides enhanced science return: the choice of this target will allow new investigations to be performed more easily compared to a single object, and also enables investigations of the fascinating geology and geophysics of asteroids that are impossible to obtain from a single object. Precise measurements of the mutual orbit and rotation state of both components can be used to probe higher-level harmonics of the gravitational potential, and therefore the internal structure. A unique opportunity is offered to study the dynamical evolution driven by the YORP/Yarkovsky thermal effects. Possible migration of regolith on the primary from poles to equator allows the increasing maturity of asteroidal regolith with time to be expressed as a latitude-dependent trend, with the most-weathered material at the equator matching what is seen in the secondary. MarcoPolo-R will allow us to study the most primitive materials available to investigate early solar system formation processes. Moreover, MarcoPolo-R will provide a sample from a known target with known geological context. Direct investigation of both the regolith and fresh interior fragments is also impossible by any means other than sample return. The main goal of the MarcoPolo-R mission is to return unaltered NEA material for detailed analysis in ground-based laboratories. The limited sampling provided by meteorites does not offer the most primitive material available in near-Earth space. More primitive material, having experienced less alteration on the asteroid, will be more friable and would not survive atmospheric entry in any discernible amount. Only in the laboratory can instruments with the necessary precision and sensitivity be applied to individual components of the complex mixture of materials that forms an asteroid regolith, to determine their precise chemical and isotopic composition. Such measurements are vital for revealing the evidence of stellar, interstellar medium, pre-solar nebula and parent body processes that are retained in primitive asteroidal material, unaltered by atmospheric entry or terrestrial contamination. It is no surprise therefore that sample return missions are considered a priority by a number of the leading space agencies

Temporal variability of 67P/Churyumov-Gerasimenko nucleus spectral properties from VIRTIS-M onboard Rosetta

We investigate the variability, on both diurnal and seasonal scale, of the spectral properties of the nucleus of comet 67P/Churyumov-Geresimenko as observed by the VIRTIS-M imaging spectrometer onboard the Rosetta spacecraft. The spectrum is described by means of spectral indicators: visible and infrared slopes, band areas and band position

Physical characteristics of Centaurs annd TNOs

Highlights of Astronomy. 2005. vol. 13Beyond the orbit of Neptune exists a population of bodies remaining from the formation of the solar system. These are the Kuiper Belt or Trans-Neptunian Objects (TNOs). Scientific interest in these bodies arises because this region of the solar system may preserve some of the most primitive materials available to direct investigation. We have started since 1997 a multicolor photometric survey with the aim of collecting a large and homogeneous set of color data for TNOs and Centaurs objects. With this large dataset obtained mostly at CFHT and ESO we performed relevant statistical analyses to search for compositional structures interrelations with related populations and correlations with physical and orbital parameters. One of the most puzzling features of the Kuiper Belt is the optical color diversity that seems to prevail among the observed TNOs. In this work we will present results on the strong correlations found with some orbital parameters (i e q) for the Classical Kuiper Belt. The correlations found are important because they are diagnostic of some physical effects processing the surfaces of these icy and primitive objects. We will give a global picture of the color properties and trends within the Kuiper Belt

Physical characteristics of Centaurs annd TNOs

Highlights of Astronomy. 2005. vol. 13Beyond the orbit of Neptune exists a population of bodies remaining from the formation of the solar system. These are the Kuiper Belt or Trans-Neptunian Objects (TNOs). Scientific interest in these bodies arises because this region of the solar system may preserve some of the most primitive materials available to direct investigation. We have started since 1997 a multicolor photometric survey with the aim of collecting a large and homogeneous set of color data for TNOs and Centaurs objects. With this large dataset obtained mostly at CFHT and ESO we performed relevant statistical analyses to search for compositional structures interrelations with related populations and correlations with physical and orbital parameters. One of the most puzzling features of the Kuiper Belt is the optical color diversity that seems to prevail among the observed TNOs. In this work we will present results on the strong correlations found with some orbital parameters (i e q) for the Classical Kuiper Belt. The correlations found are important because they are diagnostic of some physical effects processing the surfaces of these icy and primitive objects. We will give a global picture of the color properties and trends within the Kuiper Belt

Space Weathering Effects on Small Body Surfaces: Laboratory Fast Ions Bombardment

International audienc

Space Weathering Effects on Small Body Surfaces: Laboratory Fast Ions Bombardment

International audienc

Space Weathering Effects on Small Body Surfaces: Laboratory Fast Ions Bombardment

International audienc

Observations from Orbiting Platforms

International audienc