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Analysis of Local Slopes at the InSight Landing Site on Mars
Kirk, R. L.; Golombek, M. P.; Fergason, R. L. +6 more
To evaluate the topography of the surface within the InSight candidate landing ellipses, we generated Digital Terrain Models (DTMs) at lander scales and those appropriate for entry, descent, and landing simulations, along with orthoimages of both images in each stereopair, and adirectional slope images. These products were used to assess the distr…
Particle Radiation Sources, Propagation and Interactions in Deep Space, at Earth, the Moon, Mars, and Beyond: Examples of Radiation Interactions and Effects
Downs, Cooper; Riley, Pete; Kozarev, Kamen +13 more
Particle radiation has significant effects for astronauts, satellites and planetary bodies throughout the Solar System. Acute space radiation hazards pose risks to human and robotic exploration. This radiation also naturally weathers the exposed surface regolith of the Moon, the two moons of Mars, and other airless bodies, and contributes to chemi…
The Life Cycle of Active Region Magnetic Fields
Cheung, M. C. M.; van Driel-Gesztelyi, L.; Martínez Pillet, V. +1 more
We present a contemporary view of how solar active region magnetic fields are understood to be generated, transported and dispersed. Empirical trends of active region properties that guide model development are discussed. Physical principles considered important for active region evolution are introduced and advances in modeling are reviewed.
Minimal Magnetic States of the Sun and the Solar Wind: Implications for the Origin of the Slow Solar Wind
von Steiger, R.; Cliver, E. W.
During the last decade it has been proposed that both the Sun and the solar wind have minimum magnetic states, lowest order levels of magnetism that underlie the 11-yr cycle as well as longer-term variability. Here we review the literature on basal magnetic states at the Sun and in the heliosphere and draw a connection between the two based on the…
Key Ground-Based and Space-Based Assets to Disentangle Magnetic Field Sources in the Earth's Environment
Milan, S. E.; Masson, A.; Matzka, J. +1 more
The magnetic field measured on the ground or in space is the addition of several sources: from flows within the Earth's core to electric currents in distant regions of the magnetosphere. Properly separating and characterizing these sources requires appropriate observations, both ground-based and space-based. In the present paper, we review the exi…
On-Ground Performance and Calibration of the ExoMars Trace Gas Orbiter CaSSIS Imager
Cremonese, G.; Da Deppo, V.; Thomas, N. +22 more
The European Space Agency's ExoMars Trace Gas Orbiter (TGO) seeks to investigate the biological or geological origin of trace gases found on Mars. The TGO carries a payload of four instruments in order to reach its scientific goals, including the Colour and Stereo Surface Imaging System (CaSSIS). CaSSIS is a colour and stereo telescopic camera tha…
Hard X-Ray/Soft Gamma-Ray Experiments and Missions: Overview and Prospects
Frontera, Filippo; Cavallari, Erica
Starting from 1960s, a great number of missions and experiments have been performed for the study of the high-energy sky. This review gives a wide vision of the most important space missions and balloon experiments that have operated in the 10-600 keV band, a crucial window for the study of the most energetic and violent phenomena in the Universe.…
Modern Geometric Methods of Distance Determination
Pietrzyński, Grzegorz; Thévenin, Frédéric; Falanga, Maurizio +2 more
Building a 3D picture of the Universe at any distance is one of the major challenges in astronomy, from the nearby Solar System to distant Quasars and galaxies. This goal has forced astronomers to develop techniques to estimate or to measure the distance of point sources on the sky. While most distance estimates used since the beginning of the 20t…
Data Timing, Time Transfer and On-board Clock Monitoring for Space Astrometry with Gaia
Butkevich, Alexey G.; Klioner, Sergei A.; Geyer, Robin +1 more
The paper discusses the problematic of data timing in the framework of the space astrometry mission Gaia. For various reasons related both to astrometry and to the measuring principles of the Gaia instrument it is mandatory to assign a highly stable and accurate time tag for each observational point. For this purpose Gaia has a Rb clock on board. …
Magnetospheric Multiscale Overview and Science Objectives
Torbert, R. B.; Burch, J. L.; Moore, T. E. +1 more
Magnetospheric Multiscale (MMS), a NASA four-spacecraft constellation mission launched on March 12, 2015, will investigate magnetic reconnection in the boundary regions of the Earth's magnetosphere, particularly along its dayside boundary with the solar wind and the neutral sheet in the magnetic tail. The most important goal of MMS is to conduct a…