Contributions of healthier diets and agricultural productivity toward sustainability and climate goals in the United States

Meeting ambitious climate targets will require deploying the full suite of mitigation options, including those that indirectly reduce greenhouse-gas (GHG) emissions. Healthy diets have sustainability co-benefits by directly reducing livestock emissions as well as indirectly reducing land use emissions. Increased crop productivity could indirectly avoid emissions by reducing cropland area. However, there is disagreement on the sustainability of proposed healthy U.S. diets and a lack of clarity on how long-term sustainability benefits may change in response to shifts in the livestock sector. Here, we explore the GHG emissions impacts of seven scenarios that vary U.S. crop yields and healthier diets in the U.S. and overseas. We also examine how impacts vary across assumptions of future ruminant livestock productivity and ruminant stocking density in the U.S. We employ two complementary land use models—the US FABLE Calculator, an agricultural and forestry sector accounting model with high agricultural commodity representation, and GLOBIOM, a spatially explicit partial equilibrium optimization model for global land use systems. Results suggest that healthier U.S. diets that follow the Dietary Guidelines for Americans reduce agricultural and land use greenhouse gas emissions by 25–57% (approx 120–310 MtCO2e/y) and pastureland area by 28–38%. The potential emissions and land sparing benefits of U.S. agricultural productivity growth are modest within the U.S. due to the increasing comparative advantage of U.S. crops. Our findings suggest that healthy U.S. diets can significantly contribute toward meeting U.S. long-term climate goals for the land use sectors

Geoscientific mapping of Vesta by the Dawn mission

The geologic objectives of the Dawn Mission [1] are to derive Vesta’s shape, map the surface geology, understand the geological context and contribute to the determination of the asteroids’ origin and evolution. Geomorphology and distribution of surface features will provide evidence for impact cratering, tectonic activity, volcanism, and regolith processes. Spectral measurements of the surface will provide evidence of the compositional characteristics of geological units. Age information, as derived from crater size-frequency distributions, provides the stratigraphic context for the structural and compositional mapping results into the stratigraphic context and thus revealing the geologic history of Vesta

Exploring the Bimodal Solar System via Sample Return from the Main Asteroid Belt: The Case for Revisiting Ceres

Abstract: Sample return from a main-belt asteroid has not yet been attempted, but appears technologically feasible. While the cost implications are significant, the scientific case for such a mission appears overwhelming. As suggested by the “Grand Tack” model, the structure of the main belt was likely forged during the earliest stages of Solar System evolution in response to migration of the giant planets. Returning samples from the main belt has the potential to test such planet migration models and the related geochemical and isotopic concept of a bimodal Solar System. Isotopic studies demonstrate distinct compositional differences between samples believed to be derived from the outer Solar System (CC or carbonaceous chondrite group) and those that are thought to be derived from the inner Solar System (NC or non-carbonaceous group). These two groups are separated on relevant isotopic variation diagrams by a clear compositional gap. The interface between these two regions appears to be broadly coincident with the present location of the asteroid belt, which contains material derived from both groups. The Hayabusa mission to near-Earth asteroid (NEA) (25143) Itokawa has shown what can be learned from a sample-return mission to an asteroid, even with a very small amount of sample. One scenario for main-belt sample return involves a spacecraft launching a projectile that strikes an object and flying through the debris cloud, which would potentially allow multiple bodies to be sampled if a number of projectiles are used on different asteroids. Another scenario is the more traditional method of landing on an asteroid to obtain the sample. A significant range of main-belt asteroids are available as targets for a sample-return mission and such a mission would represent a first step in mineralogically and isotopically mapping the asteroid belt. We argue that a sample-return mission to the asteroid belt does not necessarily have to return material from both the NC and CC groups to viably test the bimodal Solar System paradigm, as material from the NC group is already abundantly available for study. Instead, there is overwhelming evidence that we have a very incomplete suite of CC-related samples. Based on our analysis, we advocate a dedicated sample-return mission to the dwarf planet (1) Ceres as the best means of further exploring inherent Solar System variation. Ceres is an ice-rich world that may be a displaced trans-Neptunian object. We almost certainly do not have any meteorites that closely resemble material that would be brought back from Ceres. The rich heritage of data acquired by the Dawn mission makes a sample-return mission from Ceres logistically feasible at a realistic cost. No other potential main-belt target is capable of providing as much insight into the early Solar System as Ceres. Such a mission should be given the highest priority by the international scientific community

The Color of 4 Vesta and Lithology Diversity: First Results from Dawn Survey Orbit

The FC cameras onboard the Dawn spacecraft are expected to map the asteroid 4 Vesta in seven different colors from Survey Orbit in August 2011. We will present the first immediate results of the spectral mapping of the visible surface from FC images along with their association with surface compositional units. The first medium resolution observations of Vesta have been performed in July 201

Vesta Mineralogy in the Light of Dawn

The data from Dawn VIR characterized and mapped the mineral distribution on Vesta,strengthened the Vesta-HED linkage, discovered hydrated materials, found olivine in an unexpected location, providing new insights into Vesta’s formation and evolution

Dawn Discovery Mission: A journey to the beginning of the solar system

In December 2001, NASA announced the selection of the Dawn mission to Vesta and Ceres as the next mission to be undertaken in the Discovery series. Dawn examines the role of size and water content in planetary evolution, contrasting the primitive and apparently wet protoplanet, Ceres, with its dry and highly evolved neighbor, Vesta. Dawn maps the surface in visible and infrared wavelengths to determine its mineralogical composition and crustal properties, uses gamma ray and neutron spectroscopy to determine its elemental composition and magnetometry and radio science to probe the interior and laser altimetry to provide precise topography. Dawn is a partnership between UCLA, representing the science team members, the Jet Propulsion Laboratory, Orbital Sciences Corporation, the German Aerospace Center, DLR and the Italian Institute for Space Astrophysics, IAS. The mission uses ion propulsion to fly to Vesta, orbit it at a variety of altitudes for close to a year, leave Vesta orbit, fly to Ceres and orbit it similarly. The spacecraft carries a framing camera provided by DLR’s Institute of Space Sensor Technology and Planetary Exploration in Berlin; a mapping spectrometer provided by the Istituto di Astrofisica Spaziale in Roma, a gamma ray and neutron spectrometer provided by the Los Alamos National Laboratory, a laser altimeter provided by NASA’s Goddard Space Flight Center and a magnetometer provided by UCLA. This paper summarizes the mission goals, and the trajectory, orbits, and instruments that enable the mission to attain those goals