An Investigation of Elemental Composition of Martian Satellites by Gamma-ray and Neutron Spectrometer
N. HasebeToru OhtaYoshiharu AMANOMasayuki NaitoHiroki KusanoHiroshi NagaokaKohei YoshidaTakuto AdachiT. J. FaganHaruyoshi KunoE. ShibamuraA. HitachiJ. A. M. LopesJesús Martínez‐FríasTomoki NakamuraShingo KamedaYuichiro ChoNaoki ShiraiHideaki MiyamotoTakafumi NiiharaT. MikouchiTatsuaki OkadaYuzuru Karouji
0
Citation
21
Reference
10
Related Paper
Keywords:
Gamma ray spectrometer
The Martian interaction with the solar wind is unique due to the influence of remanent crustal magnetic fields. The recent studies by the Mars Express and Mars Atmosphere and Volatile Evolution missions underline the strong and complex influence of the crustal magnetic fields on the Martian environment and its interaction with the solar wind. Among them is the influence on the dynamic plasma boundaries that shape this interaction and on the bow shock in particular.Compared to other drivers of the shock location (e.g. solar dynamic pressure, extreme ultraviolet fluxes), the influence of crustal magnetic fields are less understood, with essentially differences observed between the southern and northern hemispheres attributed to the crustal fields. In this presentation we analyze in detail the influence of the crustal fields on the Martian shock location by combining for the first time datasets from two different spacecraft (MAVEN/MEX). An application of machine learning techniques will also be used to increase the list of MAVEN shocks published to date. We show in particular the importance for analyzing biases due to multiple parameters of influence through a partial correlation approach. We also compare the impact of crustal fields with the other parameters of influence, and show that the main drivers of the shock location are by order of importance extreme ultraviolet fluxes and magnetosonic Mach number, crustal fields and then solar wind dynamic pressure.
Atmosphere of Mars
Dynamic pressure
Cite
Citations (0)
Liquid water
Life on Mars
Extraterrestrial Life
Subsurface Flow
Regolith
Cite
Citations (28)
<p>We present first results of laboratory experiments on extremely low frequency (ELF) electromagnetic (EM) field generation by moving sand and dust. This work is a part of our ongoing project to design and manufacture an autonomous ELF Mars Station that will enable studying electric properties of the Martian ionosphere as well as the subsurface of Mars.</p><p>ELF waves are very weakly attenuated in the planetary environments and propagate in a cavity made of two high-conductivity spherical boundaries: a planetary ionosphere and a planetary ground. On Mars, as there is no liquid water at the planetary surface, the high-conductivity layer of the ground is expected to be located at greater depths than on Earth, and therefore, ELF investigation on Mars can be used as a tool for studying the subsurface layers. It can be especially useful for groundwater detection. However, the main aim in ELF studies on Mars is related to investigating ELF sources.</p><p>ELF sources on Mars can be generated by frequently occurring phenomena: dust storms and dust devils. However, up till now, electromagnetic activity of these dust events on Mars has not been investigated <em>in situ</em>, and remote sensing measurements have been inconclusive. On Earth, many works indicate that dust storms and dust devils generate electromagnetic field, and some ELF fields in dust devils were detected. Also, some aeolian tunnel experiments showed that electric fields can be produced by moving sand.</p><p>Our laboratory experiments were performed in an aeolian environmental tunnel located at the Jagiellonian University in Krakow, designed to study aeolian transport. The measurements were carried out by dedicated ELF detectors and using a developed technique of signal processing and analysis. Several aeolian materials, different in mineralogical and granulometric composition, were tested.</p><p>This work has been supported by the National Science Center under grant 2015/19/B/ST9/01710.</p>
Dust storm
Cite
Citations (0)
The physical state of water on Mars has fundamental ramifications for both climatology and astrobiology. The widespread presence of “softened” Martian landforms (such as impact craters) can be attributed to viscous creep of subsurface ground ice. We present laboratory experiments designed to determine the minimum amount of ice necessary to mobilize topography within Martian permafrost. Our results show that the jammed‐to‐mobile transition of icy sand packs neither occurs at fixed ice content nor is dependent on temperature or stress, but instead correlates strongly with the maximum dry packing density of the sand component. Viscosity also changes rapidly near the mobility transition. The results suggest a potentially lower minimum volatile inventory for the impact‐pulverized megaregolith of Mars. Furthermore, the long‐term preservation of partially relaxed craters implies that the ice content of Martian permafrost has remained close to that at the mobility transition throughout Martian history.
Landform
Martian soil
Cite
Citations (29)
Active Ionospheric Sounding data (AIS) of MARSIS instrument on board Mars Express mission have been used to analyze the effect of the irregular Martian topography on the electron density and altitude of the main ionospheric peak.
Ionospheric sounding
Atmosphere of Mars
Cite
Citations (0)
Cite
Citations (16)
Atmosphere of Mars
Cite
Citations (0)
Laboratory simulation is the only feasible way to achieve Martian environmental conditions on Earth, establishing a key link between the laboratory and Mars exploration. The mineral phases of some Martian surface materials (especially hydrated minerals), as well as their spectral features, are closely related to environmental conditions. Therefore, Martian environment simulation is necessary for Martian mineral detection and analysis. A Mars environment chamber (MEC) coupled with multiple in situ spectral sensors (VIS (visible)-NIR (near-infrared) reflectance spectroscopy, Raman spectroscopy, laser-induced breakdown spectroscopy (LIBS), and UV-VIS emission spectroscopy) was developed at Shandong University at Weihai, China. This MEC is a comprehensive research platform for Martian environmental parameter simulation, regulation, and spectral data collection. Here, the structure, function and performance of the MEC and the coupled spectral sensors were systematically investigated. The spectral characteristics of some geological samples were recorded and the effect of environmental parameter variations (such as gas pressure and temperature) on the spectral features were also acquired by using the in situ spectral sensors under various simulated Martian conditions. CO2 glow discharge plasma was generated and its emission spectra were assigned. The MEC and its tested functional units worked well with good accuracy and repeatability. China is implementing its first Mars mission (Tianwen-1), which was launched on 23 July 2020 and successfully entered into a Mars orbit on 10 February 2021. Many preparatory works such as spectral databases and prediction model building are currently underway using MECs, which will help us build a solid foundation for real Martian spectral data analysis and interpretation.
Atmosphere of Mars
Cite
Citations (21)
Planet Mars past environmental conditions were similar to the early Earth, but nowadays they are similar to those of a very cold desert, irradiated by intense solar UV light. However, some terrestrial lifeform showed the capability to adapt to very harsh environments, similar to the extreme condition of the Red Planet. In addition, recent discoveries of water in the Martian permafrost and of methane in the Martian atmosphere, have generated optimism regarding a potentially active subsurface Mars' biosphere. These findings increase the possibility of finding traces of life on a planet like Mars. However, before landing on Mars with dedicated biological experiments, it is necessary to understand the possibilities of finding life in the present Martian conditions. Finding a lifeform able to survive in Martian environment conditions may have a double meaning: increasing the hope of discovering extraterrestrial life and defining the limits for a terrestrial contamination of planet Mars. In this paper we present the Martian environment simulators LISA and mini-LISA, operating at the Astronomical Observatory of Padua, Italy. They have been designed to simulate the conditions on the surface of planet Mars (atmospheric pressure,0.6-0.9 kPa; temperature from -120 to 20 °C, Martian-like atmospheric composition and UV radiation). In particular, we describe the mini-LISA simulator, that allows to perform experiments with no time limits, by weekly refueling the liquid nitrogen reservoir. Various kind of experiments may be performed in the simulators, from inorganic chemistry to biological activity. They are offered as experimental facilities to groups interested in studying the processes that happen on the Martian surface or under its dust cover.
Extraterrestrial Life
Atmosphere of Mars
Mars landing
Planetary habitability
Cite
Citations (5)
This paper discusses evidence for the abundance of water on Mars early in its history, based on the analysis of the Viking 1 and 2 images and the Martian-atmosphere water measurements. It is argued that integrated networks of small valleys in the ancient cratered terrain of Mars may indicate that the planet once possessed a warmer climate. It is pointed out that most Martian outflow channels originate from the regions of collapsed and disrupted terrain, suggesting that they were formed by a catastrophic release of groundwater. The question of the fate of Martian water is discussed, and arguments are presented suggesting that the Martian crust may retain significant porosity to a depth of 10 km and may possess a total pore volume sufficient to store a global layer of water 0.5-1.5 km deep.
Hesperian
Atmosphere of Mars
Tharsis
Cite
Citations (1)