92 results on '"Comparative planetology"'
Search Results
2. Seismic Scattering and Absorption Properties of Mars Estimated Through Coda Analysis on a Long‐Period Surface Wave of S1222a Marsquake.
- Author
-
Onodera, Keisuke, Takuto, Maeda, Nishida, Kiwamu, Kawamura, Taichi, Margerin, Ludovic, Menina, Sabrina, Lognonné, Philippe, and Banerdt, William Bruce
- Subjects
- *
MARS (Planet) , *SURFACE analysis , *QUALITY factor , *RADIATIVE transfer , *ABSORPTION , *MARTIAN meteorites , *MARTIAN atmosphere - Abstract
On 4 May 2022, the seismometer on Mars observed the largest marsquake (S1222a) during its operation. One of the most specific features of S1222a is the long event duration lasting more than 8 hr, in addition to the clear appearance of body and surface waves. As demonstrated on Earth, by modeling a long‐lasting and scattered surface wave with the radiative transfer theory under the isotropic scattering condition, we estimated the scattering and intrinsic quality factors of Mars (Qs and Qi). This study especially focused on the frequency range between 0.05–0.09 Hz, where Qs and Qi have not been constrained yet. Our results revealed that Qi = 1,000–1,500 and Qs = 30–500. By summarizing the Martian Qi and Qs estimated so far and by comparing them with those of other celestial bodies, we found that, overall, the Martian scattering and absorption properties showed Earth‐like values. Plain Language Summary: Since February 2019, NASA's InSight (Interior Exploration using Seismic Investigations, Geodesy, and Heat Transport) has been conducting quasi‐continuous seismic observation for more than three years. The seismic data from Mars has contributed significantly to a better understanding of the interior structure and the seismicity of the red planet. On 4 May 2022 (1222 Martian days after landing), another key event occurred, called S1222a. The event showed the largest seismic moment release (magnitude 4.7) and extremely long duration (>8 hr) with intense seismic scattering. As demonstrated on Earth, the long‐lasting scattered waves are useful for retrieving information about the structural heterogeneity within a planet. In this study, by applying the radiative transfer theory—which considers the energy transportation from the seismic source to the observation point—to Mars, we evaluated the energy decay rate due to seismic scattering and energy absorption by a medium. By comparing our results with those of other solid bodies, we found that the Martian scattering and absorption features were closer to the terrestrial ones than to the lunar ones. Key Points: We modeled the scattering effect of the largest marsquake (S1222a) using radiative transfer theory on a spherical MarsThe inversion revealed that the intrinsic and scattering quality factors below 0.1 Hz are 1,000–1,500 and 30–500, respectivelyWe summarized the Martian quality factors derived so far and found that they are relatively Earth‐like rather than Moon‐like [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
3. Comparative planetology as a foundation for associating space law with solar geoengineering governance: stratospheric aerosol injection and variations of sulfur dioxide in Venus’s atmosphere
- Author
-
Bekim Nuhija, Stefani Stojchevska, Adnan Jashari, and Arta Selmani-Bakiu
- Subjects
space law ,comparative planetology ,solar geoengineering ,legislation ,climate change ,stratospheric aerosol injection ,Law ,Law in general. Comparative and uniform law. Jurisprudence ,K1-7720 - Abstract
Mankind often seeks solutions to climate change and environmental crises, but rarely considers the feasibility of outer space to overcome such critical issues. Among many solar geoengineering approaches is stratospheric aerosol injection (SAI) whose concept suggests artificial control of the global temperature by spreading tones of sulfur dioxide into Earth’s stratosphere. Given that the classic ‘technology control dilemma’ represents the central problem of solar geoengineering governance, however, this paper adopts a VenusEarth comparative planetology method by addressing volcanology and atmospheric circulation aspects. An international regulatory framework engaging space law in solar geoengineering governance is consequently presented, which classifies two separate legislations: (1) research-based legislation (comparative planetology and Earth science) and (2) non-research-based legislation (national and international governance, ethical issues, economic factors, military utilization). Further highlighting climate change issues, SAI manifests the Anthropocene and regards Earth’s stratosphere as an “inner environment”, while comparative planetology manifests the Anthropocosmos and regards space as an “outer environment”. This polymorphous consideration of atmospheric and space elements identifies a new approach of climate change techniques. Human relations that concern both environments should examine how social scientists would regard these separate boundaries or perceive them as a mergence between the two major epochs.
- Published
- 2022
- Full Text
- View/download PDF
4. Seismic Scattering and Absorption Properties of Mars Estimated Through Coda Analysis on a Long‐Period Surface Wave of S1222a Marsquake
- Author
-
Keisuke Onodera, Takuto Maeda, Kiwamu Nishida, Taichi Kawamura, Ludovic Margerin, Sabrina Menina, Philippe Lognonné, and William Bruce Banerdt
- Subjects
planetary seismology ,marsquake ,seismic scattering ,surface wave ,Mars ,comparative planetology ,Geophysics. Cosmic physics ,QC801-809 - Abstract
Abstract On 4 May 2022, the seismometer on Mars observed the largest marsquake (S1222a) during its operation. One of the most specific features of S1222a is the long event duration lasting more than 8 hr, in addition to the clear appearance of body and surface waves. As demonstrated on Earth, by modeling a long‐lasting and scattered surface wave with the radiative transfer theory under the isotropic scattering condition, we estimated the scattering and intrinsic quality factors of Mars (Qs and Qi). This study especially focused on the frequency range between 0.05–0.09 Hz, where Qs and Qi have not been constrained yet. Our results revealed that Qi = 1,000–1,500 and Qs = 30–500. By summarizing the Martian Qi and Qs estimated so far and by comparing them with those of other celestial bodies, we found that, overall, the Martian scattering and absorption properties showed Earth‐like values.
- Published
- 2023
- Full Text
- View/download PDF
5. Scaling laws for ablation waves formed by ice sublimation and rock dissolution: applications to the Earth, Mars and Pluto
- Author
-
Sabrina Carpy, Maï Bordiec, and Olivier Bourgeois
- Subjects
sublimation ,dissolution ,instability ,scaling laws ,morphological markers ,comparative planetology ,Astronomy ,QB1-991 ,Geophysics. Cosmic physics ,QC801-809 - Abstract
Ablation waves involve solid substrate such as ice or soluble rocks. Ablation by sublimation or dissolution under turbulent winds or liquid flows may lead to the development of transverse linear bedforms (ablation waves) on volatile or soluble susbtrates. In glaciology, geomorphology, karstology and planetology, these ablation waves may provide relevant morphological markers to constrain the flows that control their formation. For that purpose, we describe a unified model, that couples mass transfers and turbulent flow dynamics and takes into account the relationship between the viscosity of the fluid and the diffusivity of the ablated material, for both sublimation and dissolution waves. From the stability analysis of the model, we derive three scaling laws that relate the wavelength, the migration velocity and the growth time of the waves to the physical characteristics (pressure, temperature, friction velocity, viscous length, ablation rate) of their environment through coefficients obtained numerically. The laws are validated on terrestrial examples and laboratory experiments of sublimation and dissolution waves. Then, these laws are plotted in specific charts for dissolution waves in liquid water, for sublimation waves in N2-rich atmospheres (e.g., Earth, Titan, Pluto) and in CO2-rich atmospheres (e.g., Mars, Venus). They are applied to rock dissolution on the walls of a limestone cave (Saint-Marcel d’Ardèche, France), to H2O ice sublimation on the North Polar Cap (Mars) and to CH4 ice sublimation in Sputnik Planitia (Pluto), to demonstrate how they can be used (1) either to derive physical conditions on planetary surfaces from observed geometric characteristics of ablation waves (2) or, conversely, to predict geometric characteristics of ablation waves from measured or inferred physical conditions on planetary surfaces. The migration of sublimation waves on regions of the Martian North Polar Cap and sublimation waves candidates on Pluto are discussed.
- Published
- 2023
- Full Text
- View/download PDF
6. Fluid Dynamics of Polar Vortices on Earth, Mars, and Titan.
- Author
-
Waugh, Darryn W.
- Abstract
Polar vortices that share many similarities are found in Earth's stratosphere and the atmospheres of Mars and Saturn's moon Titan. These vortices all occur in the winter, and are characterized by high potential vorticity (PV) in polar regions, steep meridional PV gradients and peak zonal winds in middle latitudes, and a cold pole. There are, however, differences in the daily and subseasonal variability, zonal asymmetries, and PV structure among the vortices. These differences are related to differences in the disruption of polar vortices by Rossby waves, the poleward extent of the mean meridional circulation, and condensation of major gases. There are also differences in the transport of gases and particles among the vortices. The range of polar vortex characteristics is likely much larger for terrestrial exoplanets, which include planets with, for example, a wider range of obliquities. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
7. Quantitative Evaluation of the Lunar Seismic Scattering and Comparison Between the Earth, Mars, and the Moon.
- Author
-
Onodera, Keisuke, Kawamura, Taichi, Tanaka, Satoshi, Ishihara, Yoshiaki, and Maeda, Takuto
- Subjects
MOON ,SEISMIC waves ,PLANETARY science ,THEORY of wave motion ,MARS (Planet) ,LUNAR surface ,LUNAR craters - Abstract
The intense seismic scattering seen in Apollo lunar seismic data is one of the most characteristic features, making the seismic signals much different from those observed on the Earth. The scattering is considered to be attributed to subsurface heterogeneity. While the heterogeneous structure of the Moon reflects the past geological activities and evolution processes from the formation, the detailed description remains an open issue. Here, we present a new model of the subsurface heterogeneity within the upper lunar crust derived through a full 3D seismic wave propagation simulation. Our simulation successfully reproduced the Apollo seismic observations, leading to a significant update of the scattering properties of the Moon. The results showed that the scattering intensity of the Moon is about 10 times higher than that of the heterogeneous region on the Earth. The quantified scattering parameters could give us a constraint on the surface evolution process of the Moon and enable the comparative study for answering a fundamental question of why the seismological features are different on various planetary bodies. Plain Language Summary: In the past Apollo missions, several seismometers were installed on the nearside of the Moon and they brought us the first seismic records from an extraterrestrial body. The derived lunar seismic data surprised us because of their extremely long duration (1–2 hr) and spindle‐shaped form, which were barely observed on Earth. These characteristics, which are different from earthquakes, are thought to reflect the subsurface heterogeneity. However, the inhomogeneous structure within the lunar crust is poorly constrained. To improve our knowledge of wave propagation on an extraterrestrial body, this study evaluated the subsurface heterogeneity through 3D seismic wave propagation simulation. After running some simulations under various structure settings, we found that a certain set of parameters well reproduced the Apollo seismic data, resulting in a new heterogeneous structure model of the Moon. The evaluated parameters were compared with those measured on the Earth and Mars, and we found that the Moon is more heterogeneous than others by about 10 times. This kind of comparison makes it easier to interpret the observed seismic signals on each solid body. Also, it is useful to explain the differences in their surface evolution scenarios. We believe that our results contribute to further extending comparative planetology. Key Points: Through full 3D seismic wave propagation simulation, we quantitatively evaluated the lunar seismic scattering propertiesWe found that a 10‐km thick scattering layer with 10% velocity fluctuation well‐reproduced the Apollo seismic observationOur results show that the upper lunar crust is about 10 times more heterogeneous than that of the Earth and Mars [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
8. Likavčan, Lukáš: Introduction to Comparative Planetology
- Author
-
Simona Bajáková
- Subjects
introduction ,comparative planetology ,Literature (General) ,PN1-6790 - Abstract
Likavčan, Lukáš: Introduction to Comparative Planetology
- Published
- 2022
- Full Text
- View/download PDF
9. Comparative planetology as a foundation for associating space law with solar geoengineering governance: stratospheric aerosol injection and variations of sulfur dioxide in Venus’s atmosphere.
- Author
-
NUHIJA, Bekim, STOJCHEVSKA, Stefani, JASHAR, Adnan, and SELMANI-BAKIU, Arta
- Subjects
STRATOSPHERIC aerosols ,VENUSIAN atmosphere ,SPACE law ,DILEMMA ,PLANETARY science ,ENVIRONMENTAL engineering - Abstract
Mankind often seeks solutions to climate change and environmental crises, but rarely considers the feasibility of outer space to overcome such critical issues. Among many solar geoengineering approaches is stratospheric aerosol injection (SAI) whose concept suggests artificial control of the global temperature by spreading tones of sulfur dioxide into Earth’s stratosphere. Given that the classic ‘technology control dilemma’ represents the central problem of solar geoengineering governance, however, this paper adopts a VenusEarth comparative planetology method by addressing volcanology and atmospheric circulation aspects. An international regulatory framework engaging space law in solar geoengineering governance is consequently presented, which classifies two separate legislations: (1) research-based legislation (comparative planetology and Earth science) and (2) non-research-based legislation (national and international governance, ethical issues, economic factors, military utilization). Further highlighting climate change issues, SAI manifests the Anthropocene and regards Earth’s stratosphere as an “inner environment”, while comparative planetology manifests the Anthropocosmos and regards space as an “outer environment”. This polymorphous consideration of atmospheric and space elements identifies a new approach of climate change techniques. Human relations that concern both environments should examine how social scientists would regard these separate boundaries or perceive them as a mergence between the two major epochs. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
10. Lightning on exoplanets and brown dwarfs
- Author
-
Hodosán, Gabriella and Helling, Christiane
- Subjects
523.01 ,Exoplanets ,Brown dwarf ,Atmospheric electricity ,lightning ,Solar System ,Earth, Venus, Jupiter, Saturn ,Comparative planetology ,modelling, observations ,QB820.H73 ,Extrasolar planets ,Brown dwarf stars ,Atmospheric electricity - Abstract
Lightning is an important electrical phenomenon, known to exist in several Solar System planets. Amongst others, it carries information on convection and cloud formation, and may be important for pre-biotic chemistry. Exoplanets and brown dwarfs have been shown to host environments appropriate for the initiation of lightning discharges. In this PhD project, I aim to determine if lightning on exoplanets and brown dwarfs can be more energetic than it is known from Solar System planets, what are the most promising signatures to look for, and if these "exo-lightning" signatures can be detected from Earth. This thesis focuses on three major topics. First I discuss a lightning climatology study of Earth, Jupiter, Saturn, and Venus. I apply the obtained lightning statistics to extrasolar planets in order to give a first estimate on lightning occurrence on exoplanets and brown dwarfs. Next, I introduce a short study of potential lightning activity on the exoplanet HAT-P-11b, based on previous radio observations. Related to this, I discuss a first estimate of observability of lightning from close brown dwarfs, with the optical Danish Telescope. The final part of my project focuses on a lightning radio model, which is applied to study the energy and radio power released from lightning discharges in hot giant gas planetary and brown dwarf atmospheres. The released energy determines the observability of signatures, and the effect lightning has on the local atmosphere of the object. This work combines knowledge obtained from planetary and earth sciences and uses that to learn more about extrasolar systems. My main results show that lightning on exoplanets may be more energetic than in the Solar System, supporting the possibility of future observations and detection of lightning activity on an extrasolar body. My work provides the base for future radio, optical, and infrared search for "exo-lightning".
- Published
- 2017
11. Cratering
- Author
-
Ivanov, Boris
- Published
- 2020
- Full Text
- View/download PDF
12. PROBA2 LYRA Occultations: Thermospheric Temperature and Composition, Sensitivity to EUV Forcing, and Comparisons With Mars.
- Author
-
Thiemann, Edward M. B. and Dominique, Marie
- Subjects
EXTREME Ultraviolet Explorer Satellite ,SOLAR activity ,SOLAR radiation ,THERMOSPHERE ,UPPER atmosphere - Abstract
A method for retrieving temperature and composition from 150 to 350 km in Earth's thermosphere using total number density measurements made via extreme ultraviolet (EUV) solar occultations by the Project for OnBoard Autonomy 2/Large Yield Radiometer (PROBA2/LYRA) instrument is presented. Systematic and random uncertainties are calculated and found to be less than 5% for the temperature measurements and 5%–20% for the composition measurements. Regression coefficients relating both temperature and the [O]/[N2] abundance ratio with EUV irradiance at 150, 275, and 350 km are reported. Additionally, it is shown that the altitude where [O] equals [N2] decreases with increasing solar EUV irradiance, an effect attributed to thermal expansion. Temperatures from 2010 to 2017 are compared with estimates from the MSIS empirical model and show good agreement at the dawn terminator but LYRA is markedly cooler at the dusk terminator, with the MSIS‐LYRA temperature difference increasing with solar activity. Anthropogenic cooling can explain this discrepancy at periods of lower solar activity, but the divergence of temperature with increasing solar activity remains unexplained. LYRA measurements of the exospheric temperature sensitivity to EUV irradiance are compared with contemporaneous measurements made at Mars, showing that the exospheric temperature at Mars is approximately half as sensitive to EUV variability as that of Earth. Plain Language Summary: The Large Yield Radiometer (LYRA) instrument onboard the Project for OnBoard Autonomy 2 (PROBA2) satellite measures the structure of the upper atmosphere by tracking the absorption of sunlight as it passes through the atmosphere as the Sun sets or rises as viewed from the satellite. This paper presents a method for determining atmospheric temperature to a high degree of accuracy from 150 to 350 km from the PROBA2/LYRA measurements. Additionally, a method for determining the relative abundance of atomic Oxygen and molecular Nitrogen is presented. Both temperature and relative abundance are known to change with changing extreme ultraviolet (EUV) radiation from the Sun. The dependence of these values on solar EUV radiation is reported, and is shown to be different from predictions of the MSIS model, frequently used to estimate atmospheric temperature and composition. Additionally, these results for Earth are compared with similar measurements made at Mars and show that the Earth's atmosphere heats twice as efficiently from solar EUV radiation as the Mars atmosphere. Key Points: Temperature and composition from 150 to 350 km from 2010 to 2017 are presentedDusk temperatures are markedly cooler than MSIS predictionsMars exospheric temperature is half as sensitive to extreme ultraviolet variability as that of Earth [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
13. Santorini volcano as a potential Martian analogue: The Balos Cove Basalts.
- Author
-
Pantazidis, A., Baziotis, I., Solomonidou, A., Manoutsoglou, E., Palles, D., Kamitsos, E., Karageorgis, A., Profitiliotis, G., Kondoyanni, M., Klemme, S., Berndt, J., Ming, D., and Asimow, P.D.
- Subjects
- *
BASALT , *GALE Crater (Mars) , *MARTIAN meteorites , *GLASS-ceramics , *MINERALOGY , *PLAGIOCLASE , *VOLCANOES - Abstract
Αbstract The interpretation of geologic processes on Mars from sparse meteorite, remote sensing and rover data is influenced by knowledge gained from well-characterized terrestrial analogues. This calls for detailed study of candidate terrestrial analogues and comparison of their observable features to those encountered on the surface of Mars. We evaluated the mineralogical, geochemical, and physical properties of the Balos cove basalts (BCB) from the island of Santorini and compared them to Martian meteorites, Mars rover surface measurements, and other verified Martian analogues obtained from the International Space Analogue Rockstore (ISAR). Twenty rock samples were collected from the Balos cove area based on their freshness, integrity, and basaltic appearance in the field. Optical microscopy of BCB revealed a pilotaxitic to trachytic texture, with olivine and clinopyroxene phenocrysts in a fine groundmass of olivine, clinopyroxene, plagioclase, magnetite, and devitrified glass. All major minerals show normal zoning, including calcic plagioclase (An 78–85 at the core and An 60–76 at the rim), augite (En 36-48 Wo 41-44 Fs 11–21), and olivine (Fo 74–88). The dominant bands in the infrared-attenuated total reflectance (IR-ATR) spectra from BCB can be assigned to olivine (~875 cm−1), calcic plagioclase (~1130 cm−1), and augite (~970 cm−1). The whole-rock chemical compositions and mineralogy of the BCB are similar to published analyses of typical olivine-phyric shergottites and basalts and basaltic materials analyzed in Gusev and Gale craters on Mars. BCB porosity is in the range of 7–15% and is similar to the porosities of the ISAR samples. Although no terrestrial rock is ever a perfect match to Martian compositions, the differences in mineralogy and geochemistry between BCB and some classes of Martian samples are relatively subtle and the basalts of Santorini are as close a match as other accepted Mars basalt analogues. The Santorini site offers excellent field logistics that, together with the petrology of the outcrop, makes it a valuable locality for testing and calibration deployments, field training, and other activities related to current and future Mars exploration. Highlights • Santorini volcano as a viable terrestrial analogue of Mars • The BCB rocks are similar to published analyses of typical olivine-phyric shergottites. • The basalts of Santorini are in family with other Mars basalt analogues and surface samples. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
14. Ionospheric Ambipolar Electric Fields of Mars and Venus: Comparisons Between Theoretical Predictions and Direct Observations of the Electric Potential Drop.
- Author
-
Collinson, Glyn, Glocer, Alex, Xu, Shaosui, Mitchell, David, Frahm, Rudy A, Grebowsky, Joseph, Andersson, Laila, and Jakosky, Bruce
- Subjects
- *
MAGNETIC fields , *VENUS (Planet) , *MARS (Planet) , *NANOPARTICLES , *ELECTRONS - Abstract
We test the hypothesis that their dominant driver of a planetary ambipolar electric field is the ionospheric electron pressure gradient (∇Pe). The ionospheres of Venus and Mars are mapped using Langmuir probe measurements from NASA's Pioneer Venus Orbiter (PVO) and Mars Atmosphere and Volatile EvolutioN (MAVEN) missions. We then determine the component of the ionospheric potential drop that can be explained by the electron pressure gradient drop along a simple draped field line. At Mars, this calculation is consistent with the mean potential drops measured statistically by MAVEN. However, at Venus, contrary to our current understanding, the thermal electron pressure gradient alone cannot explain Venus' strong ambipolar field. These results strongly motivate a return to Venus with a comprehensive plasmas and fields package, similar to that on MAVEN, to investigate the physics of atmospheric escape at Earth's closest analog. Plain Language Summary: Every planet with an atmosphere generates a weak electric field, called an "ambipolar field," which plays a critical role in the escape of the ionosphere. Until recently, these fields had never been measured due to their low strength. However, by measuring the subtle shifts in the energies of electrons generated in the ionosphere, the total potential drop associated with this field has recently been measured at both Venus and Mars. These measurements permit us to make the first investigation of the fundamental physics that underpins this field. Specifically, we test the long‐held hypothesis that ambipolar fields are primarily generated by the gradient of electron pressure along magnetic field lines that connect the ionosphere to space. We find the potential drop at Mars is consistent with theory, but Venus' field is 10 times stronger than expected. Key Points: We map the ionospheres of Venus and Mars to investigate whether ambipolar fields are generated by the thermal electron pressure gradientMars' ambipolar potential drop is consistent with what would be expected from existing theory (∼0.7 V peaking at 220 km)Venus' potential drop (10 V) far exceeds what can be explained by the mean electron pressure gradient (1 V), motivating further research [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
15. Multifractal topography of several planetary bodies in the solar system.
- Author
-
Landais, François, Schmidt, Frédéric, and Lovejoy, Shaun
- Subjects
- *
ALTITUDE measurements , *MULTIFRACTALS , *INTERMITTENCY (Nuclear physics) , *PLANETARY science , *EARTH (Planet) , *TOPOGRAPHICAL surveying - Abstract
Abstract Topography is the expression of both internal and external processes of a planetary body. Thus hypsometry (the study of topography) is a way to decipher the dynamics of a planet. For that purpose, the statistics of height and slopes may be described by different tools, at local and global scale. We propose here to use the multifractal approach to describe fields of topography. This theory encompasses height and slopes and other statistical moments of the field, taking into account the scale invariance. Contrary to the widely used fractal formalism, multifractals are able to describe the intermittency of the topography field. As we commonly observe a juxtaposition of rough and smooth topographies at a given scale, the multifractal framework seems to be appropriate for hypsometric studies. Here we analyze the data at global scale of the Earth, Mars, Mercury and the Moon and find that the statistics are in good agreement with the multifractal theory for scale larger than ∼ 10 km. Surprisingly, the analysis shows that all bodies have the same fractal behavior for scale smaller than ∼ 10 km. We hypothesize that dynamic topography of the mantle may be the explanation at large scale, whereas the smaller scale behavior may be related to elastic thickness. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
16. Geologic Landforms and Chronostratigraphic History of Charon as Revealed by a Hemispheric Geologic Map.
- Author
-
Robbins, Stuart J., Beyer, Ross A., Spencer, John R., Grundy, William M., White, Oliver L., Singer, Kelsi N., Moore, Jeffrey M., Dalle Ore, Cristina M., McKinnon, William B., Lisse, Carey M., Runyon, Kirby, Beddingfield, Chloe B., Schenk, Paul, Umurhan, Orkan M., Cruikshank, Dale P., Lauer, Tod R., Bray, Veronica J., Binzel, Richard P., Buie, Marc W., and Buratti, Bonnie J.
- Subjects
GEOLOGICAL mapping ,STRATIGRAPHIC geology ,LANDFORMS ,OPTICAL astronomy ,PLANETARY scientists - Abstract
Geologic mapping has been used for over 200 years as a technique to synthesize a complicated surface into a more simplified product, identifying similar types of surface features, and placing them into a relative stratigraphy. Geomorphologic mapping has applied those principles to other terrestrial bodies throughout the solar system and has formed an important product set to understand these surfaces, plan future exploration, and conduct different scientific endeavors. We created a geomorphologic map of the New Horizons encounter hemisphere of Pluto's binary companion, Charon. Ten primary geomorphologic unit categories were identified, covering approximately 35% of Charon's surface, and we used lower resolution data to speculate about other regions of Charon. Over 1,000 linear features were mapped, nearly 90% of them are tectonic in nature, and we use these to provide evidence of Charon being active in its past. Additionally, we placed the mapped features into a chronostratigraphic sequence, and we present a possible surface history for the body. The northern terrain typified by large crustal blocks is the oldest, having fractured early in Charon's history, and potentially similar blocks were submerged in a cryoflow of which the now solid surface of Vulcan Planitia is the remnant today. Plain Language Summary: Planetary scientists will create geologic maps of a surface to perform different kinds of studies. Geologic maps identify features of different types and help to distill many different kinds of data into an easier to use format from which scientific investigations can be done. We have created such a map for Pluto's largest companion, Charon, imaged during the flyby of New Horizons in July 2015. This geologic map covers approximately 35% of the best‐imaged region of Charon, and we mapped 16 different geologic units, over 1,000 linear features, and a variety of albedo features. We developed a chronology that places these features in time‐order, and we provide potential interpretations of the different features that we mapped. We found that Charon has potentially one of the most convincing examples of possible large cryoflow(s) of any heretofore imaged body in the solar system. Key Points: We present a new geomorphologic map of New Horizons' encounter hemisphere of Charon, showing units, linear features, and albedo featuresWe introduce a chronostratigraphic system to place features and units in a historic sequence and contextWe interpret units and features in local, regional, and global context, pulling from knowledge of other solar system bodies [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
17. The diversity of tectonic modes and thoughts about transitions between them.
- Author
-
Lenardic, A.
- Subjects
- *
STRUCTURAL geology , *GEOCHEMICAL cycles - Abstract
Plate tectonics is a particular mode of tectonic activity that characterizes the present-day Earth. It is directly linked to not only tectonic deformation but also magmatic/volcanic activity and all aspects of the rock cycle. Other terrestrial planets in our Solar System do not operate in a plate tectonic mode but do have volcanic constructs and signs of tectonic deformation. This indicates the existence of tectonic modes different from plate tectonics. This article discusses the defining features of plate tectonics and reviews the range of tectonic modes that have been proposed for terrestrial planets to date. A categorization of tectonic modes relates to the issue of when plate tectonics initiated on Earth as it provides insights into possible pre-plate tectonic behaviour. The final focus of this contribution relates to transitions between tectonic modes. Different transition scenarios are discussed. One follows classic ideas of regime transitions in which boundaries between tectonic modes are determined by the physical and chemical properties of a planet. The other considers the potential that variations in temporal evolution can introduce contingencies that have a significant effect on tectonic transitions. The latter scenario allows for the existence of multiple stable tectonic modes under the same physical/chemical conditions. The different transition potentials imply different interpretations regarding the type of variable that the tectonic mode of a planet represents. Under the classic regime transition view, the tectonic mode of a planet is a state variable (akin to temperature). Under the multiple stable modes view, the tectonic mode of a planet is a process variable. That is, something that flows through the system (akin to heat). The different implications that follow are discussed as they relate to the questions of when did plate tectonics initiate on Earth and why does Earth have plate tectonics. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
18. Mars Analogue Sites
- Author
-
Léveillé, Richard, Gargaud, Muriel, editor, Irvine, William M., editor, Amils, Ricardo, editor, Cleaves, Henderson James (Jim), II, editor, Pinti, Daniele L., editor, Quintanilla, José Cernicharo, editor, Rouan, Daniel, editor, Spohn, Tilman, editor, Tirard, Stéphane, editor, and Viso, Michel, editor
- Published
- 2015
- Full Text
- View/download PDF
19. Surface-Atmosphere Connections on Titan: A New Window into Terrestrial Hydroclimate
- Author
-
Faulk, Sean
- Subjects
Planetology ,Atmospheric sciences ,Geomorphology ,Comparative planetology ,Geomorphology ,Hydroclimate ,Hydrology ,Titan ,Tropical dynamics - Abstract
This dissertation investigates the coupling between the large-scale atmospheric circulation and surface processes on Titan, with a particular focus on methane precipitation and its influence on surface geomorphology and hydrology. As the only body in the Solar System with an active hydrologic cycle other than Earth, Titan presents a valuable laboratory for studying principles of hydroclimate on terrestrial planets. Idealized general circulation models (GCMs) are used here to test hypotheses regarding Titan's surface-atmosphere connections. First, an Earth-like GCM simulated over a range of rotation rates is used to evaluate the effect of rotation rate on seasonal monsoon behavior. Slower rotation rates result in poleward migration of summer rain, indicating a large-scale atmospheric control on Titan's observed dichotomy of dry low latitudes and moist high latitudes. Second, a Titan GCM benchmarked against observations is used to analyze the magnitudes and frequencies of extreme methane rainstorms as simulated by the model. Regional patterns in these extreme events correlate well with observed geomorphic features, with the most extreme rainstorms occurring in mid-latitude regions associated with high alluvial fan concentrations. Finally, a planetary surface hydrology scheme is developed and incorporated into a Titan GCM to evaluate the roles of surface flow, subsurface flow, infiltration, and groundmethane evaporation in Titan's climate. The model reproduces Titan's observed surface liquid and cloud distributions, and reaches an equilibrium state with limited interhemispheric transport where atmospheric transport is approximately balanced by subsurface transport. The equilibrium state suggests that Titan's current hemispheric surface liquid asymmetry, favoring methane accumulation in the north, is stable in the modern climate.
- Published
- 2018
20. Pingo planetology: Comparative terrestrial analysis predicts pingos on Ceres - Hill elevation data, detailed methodology, and contextual information
- Author
-
Hughson, Kynan, Schmidt, Britney, Udell, Kathrine, Sizemore, Hanna, Schenk, Paul, Scully, Jennifer, Raymond, Carol, and Russell, Christopher
- Subjects
comparative planetology ,remote sensing ,planetary science ,geomorphology ,cryosphere ,pingos ,permafrost - Abstract
Here, we test the hypothesis that water-rich impact melt units in Occator crater on Ceres gave rise to pingo analog forming systems by quantitatively addressing whether morphology can distinguish pingo-like structures from other hill-forms. Our results indicate that the morphologies of the Occator hills and terrestrial pingos are demonstrably similar while also being quantifiably distinct from those of terrestrial volcanic cones.
- Published
- 2022
- Full Text
- View/download PDF
21. Investigation of Charon's Craters With Abrupt Terminus Ejecta, Comparisons With Other Icy Bodies, and Formation Implications.
- Author
-
Robbins, Stuart J., Runyon, Kirby, Singer, Kelsi N., Bray, Veronica J., Beyer, Ross A., Schenk, Paul, McKinnon, William B., Grundy, William M., Nimmo, Francis, Moore, Jeffrey M., Spencer, John R., White, Oliver L., Binzel, Richard P., Buie, Marc W., Buratti, Bonnie J., Cheng, Andrew F., Linscott, Ivan R., Reitsema, Harold J., Reuter, Dennis C., and Showalter, Mark R.
- Abstract
Abstract: On the moon and other airless bodies, ballistically emplaced ejecta transitions from a thinning, continuous inner deposit to become discontinuous beyond approximately one crater radius from the crater rim and can further break into discrete rays and secondary craters. In contrast, on Mars, ejecta often form continuous, distinct, and sometimes thick deposits that transition to a low ridge or escarpment that may be circular or lobate. The Martian ejecta type has been variously termed pancake, rampart, lobate, or layered, and in this work we refer to it as “abrupt termini” ejecta (ATE). Two main formation mechanisms have been proposed, one requiring interaction of the ejecta with the atmosphere and the other mobilization of near‐surface volatiles. ATE morphologies are also unambiguously seen on Ganymede, Europa, Dione, and Tethys, but they are not as common as on Mars. We have identified up to 38 craters on Charon that show signs of ATE, including possible distal ramparts and lobate margins. These ejecta show morphologic and morphometric similarities with other moons in the solar system, which are a subset of the properties observed on Mars. From comparison of these ejecta on Charon and other solar system bodies, we find the strongest support for subsurface volatile mobilization and ejecta fluidization as the main formation mechanism for the ATE, at least on airless, icy worlds. This conclusion comes from the bodies on which they are found, an apparent preference for certain terrains, and the observation that craters with ATE can be near to similarly sized craters that only have gradational ejecta. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
22. Investigating Earth’s Atmospheric Electricity: a Role Model for Planetary Studies
- Author
-
Aplin, K. L., Harrison, R. G., Rycroft, M. J., Leblanc, F., editor, Aplin, K. L., editor, Yair, Y., editor, Harrison, R. G., editor, Lebreton, J. P., editor, and Blanc, M., editor
- Published
- 2008
- Full Text
- View/download PDF
23. Planetary Atmospheric Electricity
- Author
-
Harrison, R. G., Aplin, K. L., Leblanc, F., Yair, Y., Leblanc, F., editor, Aplin, K. L., editor, Yair, Y., editor, Harrison, R. G., editor, Lebreton, J. P., editor, and Blanc, M., editor
- Published
- 2008
- Full Text
- View/download PDF
24. Composition and Measurement of Charged Atmospheric Clusters
- Author
-
Aplin, K. L., Leblanc, F., editor, Aplin, K. L., editor, Yair, Y., editor, Harrison, R. G., editor, Lebreton, J. P., editor, and Blanc, M., editor
- Published
- 2008
- Full Text
- View/download PDF
25. Gravity Waves in Planetary Atmospheres: Their Effects and Parameterization in Global Circulation Models
- Author
-
Alexander S. Medvedev and Erdal Yiğit
- Subjects
waves ,planetary weather forecasting ,comparative planetology ,Meteorology. Climatology ,QC851-999 - Abstract
The dynamical and thermodynamical importance of gravity waves was initially recognized in the atmosphere of Earth. Extensive studies over recent decades demonstrated that gravity waves exist in atmospheres of other planets, similarly play a significant role in the vertical coupling of atmospheric layers and, thus, must be included in numerical general circulation models. Since the spatial scales of gravity waves are smaller than the typical spatial resolution of most models, atmospheric forcing produced by them must be parameterized. This paper presents a review of gravity waves in planetary atmospheres, outlines their main characteristics and forcing mechanisms, and summarizes approaches to capturing gravity wave effects in numerical models. The main goal of this review is to bridge research communities studying atmospheres of Earth and other planets.
- Published
- 2019
- Full Text
- View/download PDF
26. Alternative Uses for Quantum Systems and Devices
- Author
-
Orchidea Maria Lecian
- Subjects
quantum optical systems ,astronomical and space-research instrumentation ,instruments, apparatus, and components common to several branches of physics and astronomy ,normal galaxies, extragalactic objects and systems ,field theory ,comparative planetology ,properties of specific particles ,quantum optics ,fundamental astronomy ,Mathematics ,QA1-939 - Abstract
Quantum optical systems and devices were analyzed to verify theories both predicting new particles on flat spacetime, and for the verification of Planck-scale physics for cosmological investigation.
- Published
- 2019
- Full Text
- View/download PDF
27. 火星表面含水矿物探测进展.
- Author
-
芶盛, 岳宗玉, 邸凯昌, and 张霞
- Abstract
Copyright of Journal of Remote Sensing is the property of Editorial Office of Journal of Remote Sensing & Science Publishing Co. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2017
- Full Text
- View/download PDF
28. Theoretical Investigations of the Water Cycle on Earth and Other Planets
- Author
-
Loftus, Kaitlyn
- Subjects
- cloud, comparative planetology, exoplanet, microphysics, raindrop, water cycle, Planetology, Atmospheric sciences
- Abstract
From exoplanets to Solar System bodies to modern Earth, the multi-scale and interconnected processes of the water cycle are fundamental drivers of planetary climate, evolution, and habitability. This thesis confronts problems stemming from the water cycle’s complexity across diverse planetary environments from a theoretical perspective. I construct simplified representations of more complicated systems within planetary water cycles to infer observable consequences of system behavior, to elucidate fundamental controls on system behavior, and to parameterize system behavior. I begin by using the coupling between the water cycle and the sulfur cycle to propose two new observational diagnostics for the absence of an exoplanet ocean—a challenging but highly desirable observable for constraining the prevalence of Earth-like worlds. Next, from a generalized planetary perspective, I use the simplicity of how raindrops fall and evaporate to place constraints on aspects of cloud evolution independent of the complex processes governing raindrop growth. I demonstrate across broad planetary conditions that raindrop size is the predominant determiner of raindrop ability to vertically transport condensed mass (i.e., precipitate) and that a new non-dimensional number can capture the fundamental behavior of falling raindrops. Finally, from a modern-Earth perspective, I consider the initiation of rain via liquid drop coagulation (i.e., collision and subsequent coalescence). I document the parameterizations of coagulation in global climate models participating in the most recent phase of the Coupled Model Intercomparison Project (CMIP6)—representing the world’s most comprehensive attempts to model modern-Earth climate. These coagulation parameterizations share five conceptual assumptions that I demonstrate lead to too rapid rain initiation in a manner consistent with a widespread and longstanding global model bias predicting too frequent precipitation relative to observations. To address the deficient conceptual assumptions underlying the CMIP6 coagulation parameterizations, I design and implement three approaches (two novel) for parameterizing coagulation that show improved rain initiation timing relative to the CMIP6-based approaches in an idealized test. Overall, the work of this thesis highlights the productivity of a comparative planetology approach for studying the water cycle.
- Published
- 2023
29. Planetary space weather: scientific aspects and future perspectives
- Author
-
Plainaki Christina, Lilensten Jean, Radioti Aikaterini, Andriopoulou Maria, Milillo Anna, Nordheim Tom A., Dandouras Iannis, Coustenis Athena, Grassi Davide, Mangano Valeria, Massetti Stefano, Orsini Stefano, and Lucchetti Alice
- Subjects
Space weather ,Planetary atmospheres ,Planetary magnetospheres ,Exospheres ,Interactions ,Comparative planetology ,Future missions ,JUICE ,BEPI COLOMBO ,Meteorology. Climatology ,QC851-999 - Abstract
In this paper, we review the scientific aspects of planetary space weather at different regions of our Solar System, performing a comparative planetology analysis that includes a direct reference to the circum-terrestrial case. Through an interdisciplinary analysis of existing results based both on observational data and theoretical models, we review the nature of the interactions between the environment of a Solar System body other than the Earth and the impinging plasma/radiation, and we offer some considerations related to the planning of future space observations. We highlight the importance of such comparative studies for data interpretations in the context of future space missions (e.g. ESA JUICE; ESA/JAXA BEPI COLOMBO). Moreover, we discuss how the study of planetary space weather can provide feedback for better understanding the traditional circum-terrestrial space weather. Finally, a strategy for future global investigations related to this thematic is proposed.
- Published
- 2016
- Full Text
- View/download PDF
30. Geological Evidence of Planet‐Wide Groundwater System on Mars
- Author
-
Salese, Francesco, Pondrelli, Monica, Neeseman, Alicia, Schmidt, Gene, and Ori, Gian Gabriele
- Subjects
010504 meteorology & atmospheric sciences ,Earth science ,Mars ,Fluvial ,01 natural sciences ,Oceanography: Biological and Chemical ,Planetary Sciences: Solar System Objects ,Gilbert Delta ,Geochemistry and Petrology ,groundwater ,lakes ,Comparative Planetology ,Earth and Planetary Sciences (miscellaneous) ,sapping valley ,Groundwater discharge ,Global Change ,Research Articles ,Geomorphology: General ,0105 earth and related environmental sciences ,Martian ,geography ,geography.geographical_feature_category ,Bedrock ,sedimentology ,Mars Exploration Program ,15. Life on land ,6. Clean water ,Groundwater Transport ,Geophysics ,13. Climate action ,Space and Planetary Science ,Geomorphology and Weathering ,Hesperian ,Sedimentary rock ,Hydrology ,Sedimentation ,Geology ,Groundwater ,Research Article - Abstract
The scale of groundwater upwelling on Mars, as well as its relation to sedimentary systems, remains an ongoing debate. Several deep craters (basins) in the northern equatorial regions show compelling signs that large amounts of water once existed on Mars at a planet‐wide scale. The presence of water‐formed features, including fluvial Gilbert and sapping deltas fed by sapping valleys, constitute strong evidence of groundwater upwelling resulting in long term standing bodies of water inside the basins. Terrestrial field evidence shows that sapping valleys can occur in basalt bedrock and not only in unconsolidated sediments. A hypothesis that considers the elevation differences between the observed morphologies and the assumed basal groundwater level is presented and described as the “dike‐confined water” model, already present on Earth and introduced for the first time in the Martian geological literature. Only the deepest basins considered in this study, those with bases deeper than −4000 m in elevation below the Mars datum, intercepted the water‐saturated zone and exhibit evidence of groundwater fluctuations. The discovery of these groundwater discharge sites on a planet‐wide scale strongly suggests a link between the putative Martian ocean and various configurations of sedimentary deposits that were formed as a result of groundwater fluctuations during the Hesperian period. This newly recognized evidence of water‐formed features significantly increases the chance that biosignatures could be buried in the sediment. These deep basins (groundwater‐fed lakes) will be of interest to future exploration missions as they might provide evidence of geological conditions suitable for life., Key Points Geological evidence supporting Martian planet‐wide groundwater upwellingWater‐saturated zone intercepted by basins reaching more than ‐4000m below the Mars DATUMPutative relations between groundwater‐saturated level (groundwater‐fed lakes) and the ocean shorelines around ‐4000m below the DATUM
- Published
- 2019
31. New advances in interdisciplinary observation and understanding of the solar system
- Author
-
Jörn Helbert and Shuanggen Jin
- Subjects
comparative planetology ,IUGG ,0209 industrial biotechnology ,Solar System ,Engineering ,business.industry ,020208 electrical & electronic engineering ,Mars ,Astronomy and Astrophysics ,Mercury ,02 engineering and technology ,020901 industrial engineering & automation ,Space and Planetary Science ,0202 electrical engineering, electronic engineering, information engineering ,Systems engineering ,Moon ,business ,small bodies - Published
- 2018
32. Impact Craters with Circular and Isolated Secondary Craters on the Continuous Secondaries Facies on the Moon.
- Author
-
Zhou, Shangzhe, Xiao, Zhiyong, and Zeng, Zuoxun
- Subjects
- *
LUNAR craters , *LUNAR eclipses , *LUNAR transient phenomena , *HIGH temperatures , *PLANETARY science - Abstract
On airless bodies such as the Moon and Mercury, secondary craters on the continuous secondaries facies of fresh craters mostly occur in chains and clusters. They have very irregular shapes. Secondaries on the continuous secondaries facies of some Martian and Mercurian craters are more isolated from each other in distribution and are more circular in shape, probably due to the effect of target properties on the impact excavation process. This paper studies secondaries on the continuous secondaries facies of all fresh lunar complex craters using recently-obtained high resolution images. After a global search, we find that 3 impact craters and basins on the Moon have circular and isolated secondaries on the continuous secondaries facies similar to those on Mercury: the Orientale basin, the Antoniadi crater, and the Compton crater. The morphological differences between such special secondaries and typical lunar secondaries are quantitatively compared and analyzed. Our preliminary analyses suggest that the special secondaries were probably caused by high temperature gradients within the local targets when these craters and basins formed. The high-temperature of the targets could have affected the impact excavation process by causing higher ejection angles, giving rise to more scattered circular secondaries. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
33. Del cálido Venus a los helados cometas, pasando por las guerras marcianas : algunas claves del Sistema Solar
- Subjects
Sistema solar ,Geologia planetaria ,Planetologia comparada ,Comparative planetology ,Planetary geology - Published
- 2021
34. The ridges of Europa: Extensions of adjacent topography onto their flanks.
- Author
-
Greenberg, Richard and Sak, Peter B.
- Subjects
- *
SEDIMENTS , *MID-ocean ridges , *OCEAN surface topography , *SEDIMENTATION & deposition , *REMOTE sensing - Abstract
Abstract: The surface of Europa displays numerous generations of intersecting arrays of linear ridges. At some locations along these ridges, older ridges on adjacent terrain appear to extend up the flank of a more recent ridge. It has thus been suggested that the ridges may have formed by upturning of that adjacent terrain. However, the newer ridges generally appear to be material deposited over the older terrain. Here we consider how the morphology of the overprinted topography may have been inherited by the more recent ridges. An analogous process occurs along some sediment-starved convergent plate boundaries on Earth, where the poorly consolidated material of a frontal prism of an overriding plate is pushed over preexisting ridges and seamounts on the downgoing plate. The overriding plate inherits the morphology of the downgoing plate even though the actual extension of that topography has been underthrust and buried. A well-studied example lies offshore of Costa Rica where the Caribbean plate overrides the Cocos plate. Experiments show other mechanisms as well: mass-wasting down a flank can result in extensions of adjacent ridges thanks to the geometry imposed by a constant angle of repose; in addition, more pronounced extensions of the older ridges result if the new ridge grows as it is bulldozed from behind (i.e., from the central groove of a double ridge on Europa). The shapes of the ridge extensions are distinctly different in these two cases. If tidal pumping extrudes material to the surface at the center of a double ridge, it might drive the latter mechanism. The ridge extensions observed on the flanks of more recent ridges may provide a crucial diagnostic of dominant ridge-building mechanisms when and if additional images are obtained at high resolution from future exploration. In additional to their morphology, the distribution of ridge extensions at only isolated locales may also provide constraints on ridge formation processes and their diversity. [Copyright &y& Elsevier]
- Published
- 2014
- Full Text
- View/download PDF
35. Lava tubes on Earth, Moon and Mars: A review on their size and morphology revealed by comparative planetology
- Author
-
Jo De Waele, Tommaso Santagata, Matteo Massironi, Francesco Sauro, Pierluigi De Berardinis, Riccardo Pozzobon, Sauro, Francesco, Pozzobon, Riccardo, Massironi, Matteo, De Berardinis, Pierluigi, Santagata, Tommaso, and De Waele, Jo
- Subjects
010504 meteorology & atmospheric sciences ,Lava ,Morphology (biology) ,Volcanospeleology ,010502 geochemistry & geophysics ,01 natural sciences ,Lava tube ,Astrobiology ,Subsurface ,Comparative planetology ,0105 earth and related environmental sciences ,Martian ,geography ,geography.geographical_feature_category ,Mars Exploration Program ,Inflation ,Tectonics ,Lava tube Inflation Subsurface Comparative planetology Volcanospeleology ,Planetary science ,Shield volcano ,Volcano ,General Earth and Planetary Sciences ,Earth (classical element) ,Geology - Abstract
Sinuous collapse chains and skylights in Lunar and Martian volcanic regions have often been interpreted as collapsed lava tubes (also known as pyroducts, [1]). This hypothesis has fostered a forty years debate among planetary geologists trying to define if analogue volcano-speleogenetic processes acting on Earth could have created similar subsurface linear voids in extra-terrestrial volcanoes. On Earth lava tubes are well known thanks to speleological exploration and mapping in several shield volcanoes, with examples showing different genetic processes (inflation and overcrusting [1, 2, 3]) and morphometric characters. On the Moon subsurface cavities have been inferred from several skylights in maria smooth plains [4], and corroborated using gravimetry and radar sounder [5, 6] while on Mars several deep skylights have been identified on lava flows with striking similarities with terrestrial cases [7]. Nonetheless, a clear understanding of the potential morphologies and dimensions of martian and lunar lava tubes remains elusive. Although it is still impossible to gather direct information on the interior of martian and lunar lava tube candidates, scientists have the possibility to investigate their surface expression through the analysis of collapses and skylight morphology, morphometry and their arrangement, and compare these findings with terrestrial analogues. In this work we performed a morphological and morphometric comparison with lava tube candidate collapse chains on Mars and the Moon. By comparing literature and speleological data from terrestrial analogues and measuring lunar and martian collapse chains on satellite images and digital terrain models (DTMs), this review sheds light on tube size, depth from surface, eccentricity and several other morphometric parameters among the three different planetary bodies. The dataset here presented indicates that martian and lunar tubes are 1 to 3 orders of magnitude more voluminous than on Earth and suggests that the same processes of inflation and overcrusting were active on Mars, while deep inflation and thermal entrenchment was the predominant mechanism of emplacement on the Moon. Even with these outstanding dimensions (with total volumes exceeding 1 billion of m3), lunar tubes remain well within the roof stability threshold. The analysis shows that aside of collapses triggered by impacts/tectonics, most of the lunar tubes could be intact, making the Moon an extraordinary target for subsurface exploration and potential settlement in the wide protected and stable environments of lava tubes. References [1] Kempe, S., 2019. Volcanic rock caves, Encyclopedia of Caves (Third edition). Academic Press, pp. 1118-1127 [2] Calvari, S. and Pinkerton, H., 1999. Lava tube morphology on Etna and evidence for lava flow emplacement mechanisms. Journal of Volcanology and Geothermal Research, 90(3-4): 263-280. [3] Sauro, F., Pozzobon, R., Santagata, T., Tomasi, I., Tonello, M., Martínez-Frías, J., Smets, L.M.J., Gómez, G.D.S. and Massironi, M., 2019. Volcanic Caves of Lanzarote: A Natural Laboratory for Understanding Volcano-Speleogenetic Processes and Planetary Caves, Lanzarote and Chinijo Islands Geopark: From Earth to Space. Springer, pp. 125-142. [4] Haruyama, J., Morota, T., Kobayashi, S., Sawai, S., Lucey, P.G., Shirao, M. and Nishino, M.N., 2012. Lunar holes and lava tubes as resources for lunar science and exploration, Moon. Springer, pp. 139-163. [5] Chappaz, L., Sood, R., Melosh, H.J., Howell, K.C., Blair, D.M., Milbury, C. and Zuber, M.T., 2017. Evidence of large empty lava tubes on the Moon using GRAIL gravity. Geophysical Research Letters, 44(1): 105-112 [6] Kaku, T., Haruyama, J., Miyake, W., Kumamoto, A., Ishiyama, K., Nishibori, T., Yamamoto, K., Crites, S.T., Michikami, T. and Yokota, Y., 2017. Detection of intact lava tubes at marius hills on the moon by selene (kaguya) lunar radar sounder. Geophysical Research Letters, 44(20). [7] Cushing, G.E., 2012. Candidate cave entrances on Mars. Journal of Cave and Karst Studies, 74(1): 33-47
- Published
- 2020
36. Comparative study of the surface roughness of the Moon, Mars and Mercury
- Author
-
Pommerol, A., Chakraborty, S., and Thomas, N.
- Subjects
- *
SURFACE roughness , *COMPARATIVE studies , *OPTICAL resolution , *ASTRONOMICAL observations , *MARS (Planet) , *MERCURY (Planet) - Abstract
Abstract: We analyze and compare the surface roughness of the Moon, Mercury and Mars by characterizing the scale-dependence of the slope distribution. We calculate the absolute and differential slopes at baselines ranging between a few hundreds of meters and hundred kilometers depending on the spatial resolutions of the datasets. For each planetary body, we analyze two types of terrains: the rough and old heavily cratered “highlands” regions and smoother and younger “plains” terrains, Mare on the Moon, northern plains on Mercury and Mars. The resulting curves are discussed in terms of the geological processes that shape the surfaces of terrestrial planets. We concentrate in particular on the Median Differential Slope (MDS), a measure of roughness that has already proven its relevance for the analysis of Martian and Lunar topography. The comparison of the MDS vs. baseline curves for different types of terrains on each planet reveals interesting common trends as well as intriguing differences. The Lunar highlands display the highest values of MDS at baselines larger than 2km but Mercury highlands seem to be slightly rougher at shorter baselines. Mars southern plateaus appear much smoother at all scales. On each planet, younger terrains show lower roughness than old terrains at long baselines. However, because they display a strong negative slope of MDS vs. baseline, the contrast of roughness between young and old terrains is fainter at short baseline. [Copyright &y& Elsevier]
- Published
- 2012
- Full Text
- View/download PDF
37. Oxygen airglow emission on Venus and Mars as seen by VIRTIS/VEX and OMEGA/MEX imaging spectrometers
- Author
-
Migliorini, A., Altieri, F., Zasova, L., Piccioni, G., Bellucci, G., Cardesín Moinelo, A., Drossart, P., D’Aversa, E., Carrozzo, F.G., Gondet, B., and Bibring, J.-P.
- Subjects
- *
PLANETARY atmospheres , *AIRGLOW , *SPECTROMETERS , *PLANETARY science , *PHOTOCHEMISTRY , *GRAVITY waves , *VENUS (Planet) , *MARS (Planet) - Abstract
Abstract: Imaging spectrometers are highly effective instruments for investigation of planetary atmospheres. They present the advantage of coupling the compositional information to the spatial distribution, allowing simultaneous study of chemistry and dynamics in the atmospheres of Venus and Mars. In this work, we summarize recent results about the O2(a1 Δ g) night and day glows, respectively obtained by VIRTIS/Venus Express and OMEGA/Mars Express, the imaging spectrometers currently in orbit around Venus and Mars. The case of the O2(a1 Δ g – X3 Σ g −) IR emission at 1.27μm on the night side of Venus and the day side of Mars is analyzed, pointing out dynamical aspects of these planets, like the detection of gravity waves in their atmospheres. The monitoring of seasonal and daily airglow variations provides hints about the photochemistry on these planets. [Copyright &y& Elsevier]
- Published
- 2011
- Full Text
- View/download PDF
38. Elements of comparison between Martian and terrestrial mesoscale meteorological phenomena: Katabatic winds and boundary layer convection
- Author
-
Spiga, A.
- Subjects
- *
KATABATIC winds , *ATMOSPHERIC boundary layer , *METEOROLOGY , *PLANETARY science , *HEAT flux , *SPACE exploration , *MARTIAN meteorology , *EARTH (Planet) , *OUTER space , *MARS (Planet) - Abstract
Abstract: Terrestrial and Martian atmospheres are both characterised by a large variety of mesoscale meteorological events, occurring at horizontal scales of hundreds of kilometres and below. Available measurements from space exploration and recently developed high-resolution numerical tools have given insights into Martian mesoscale phenomena, as well as similarities and differences with their terrestrial counterparts. The remarkable intensity of Martian mesoscale events compared to terrestrial phenomena mainly results from low density and strong radiative control. This is exemplified in the present paper by discussing two mesoscale phenomena encountered in the lowest atmospheric levels of both planets with notable differences: nighttime katabatic winds (drainage flow down sloping terrains) and daytime boundary layer convection (vertical growth of mixed layer over heated surfaces). While observations of katabatic events are difficult on Earth, except over vast ice sheets, intense clear-cut downslope circulations are expected to be widespread on Mars. Convective motions in the daytime Martian boundary layer are primarily driven by radiative contributions, usually negligible on Earth where sensible heat flux dominates, and exhibit turbulent variances one order of magnitude larger. Martian maximum heat fluxes are not attained close to the surface as on Earth but a few hundreds of metres above, which implies generalised definitions for mixing layer scales such as vertical velocity w ⁎. Measurements on Mars of winds in uneven topographical areas and of heat fluxes over flat terrains could be useful to assess general principles of mesoscale meteorology applicable to both terrestrial and Martian environments. [Copyright &y& Elsevier]
- Published
- 2011
- Full Text
- View/download PDF
39. Hydroxyl airglow on Venus in comparison with Earth
- Author
-
Migliorini, A., Piccioni, G., Cardesín Moinelo, A., and Drossart, P.
- Subjects
- *
OH airglow , *INFRARED spectra , *ATMOSPHERE , *OZONE layer , *PLANETARY science , *VENUS (Planet) , *MARS (Planet) , *EARTH (Planet) - Abstract
Abstract: Hydroxyl nightglow is intensively studied in the Earth atmosphere, due to its coupling to the ozone cycle. Recently, it was detected for the first time also in the Venus atmosphere, thanks to the VIRTIS-Venus Express observations. The main Δν=1, 2 emissions in the infrared spectral range, centred, respectively, at 2.81 and 1.46μm (which correspond to the (1-0) and (2-0) transitions, respectively), were observed in limb geometry () with a mean emission rate of 880±90 and 100±40kR (1R=106 photoncm−2 s−1 (4πster)−1), respectively, integrated along the line of sight. In this investigation, the Bates–Nicolet chemical reaction is reported to be the most probable mechanism for OH production on Venus, as in the case of Earth, but HO2 and O may still be not negligible as mechanism of production for OH, differently than Earth. The nightglow emission from OH provides a method to quantify O3, HO2, H and O, and to infer the mechanism of transport of the key species involved in the production. Very recently, an ozone layer was detected in the upper atmosphere of Venus by the SPICAV (Spectroscopy for Investigation of Characteristics of the Atmosphere of Venus) instrument onboard Venus Express (); this discovery enhances the importance of ozone to the OH production in the upper atmosphere of Venus through the Bates–Nicolet mechanism. On Venus, OH airglow is observed only in the night side and no evidence has been found whether a similar emission exists also in the day side. On Mars it is expected to exist both on the day and night sides of the planet, because of the presence of ozone, though OH airglow has not yet been detected. In this paper, we review and compare the OH nightglow on Venus and Earth. The case of Mars is also briefly discussed for the sake of completeness. Similarities from a chemical and a dynamical point of view are listed, though visible OH emissions on Earth and IR OH emissions on Venus are compared. [Copyright &y& Elsevier]
- Published
- 2011
- Full Text
- View/download PDF
40. Investigating Earth’s Atmospheric Electricity: a Role Model for Planetary Studies.
- Author
-
Aplin, K., Harrison, R., and Rycroft, M.
- Subjects
- *
ATMOSPHERIC electricity , *PLANETARY atmospheres , *ELECTRIC circuits , *RESONANCE , *IONOSPHERE , *UPPER atmosphere - Abstract
The historical development of terrestrial atmospheric electricity is described, from its beginnings with the first observations of the potential gradient to the global electric circuit model proposed by C.T.R. Wilson in the early 20th century. The properties of the terrestrial global circuit are summarised. Concepts originally needed to develop the idea of a global circuit are identified as “central tenets”, for example, the importance of radio science in establishing the conducting upper layer. The central tenets are distinguished from additional findings that merely corroborate, or are explained by, the global circuit model. Using this analysis it is possible to specify which observations are preferable for detecting global circuits in extraterrestrial atmospheres. Schumann resonances, the extremely low frequency signals generated by excitation of the surface-ionosphere cavity by electrical discharges, are identified as the most useful single measurement of electrical activity in a planetary atmosphere. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
41. Composition and Measurement of Charged Atmospheric Clusters.
- Author
-
Aplin, K.
- Subjects
- *
SOLAR system , *CHEMICAL reactions , *IONIZATION (Atomic physics) , *PLANETS , *REMOTE sensing - Abstract
Atmospheric charged clusters are formed in a series of rapid chemical reactions after ionisation, leaving a central ion X+ or X− clustered with n ligands (Y) n . In solar system tropospheres and stratospheres there are two distinct cluster regimes: the terrestrial planets contain largely hydrated clusters (i.e. Y=H2O), whereas the gas planets and their moons have organic or nitrogenated cluster species. These classifications are largely based on model predictions, since hardly any measurements are available. The few existing composition measurements are reviewed, including the recent detection of massive charged particles in Titan’s upper atmosphere. Technologies for both remote sensing and in situ measurements of atmospheric charged clusters are discussed. Preliminary measurements in the terrestrial atmosphere are presented indicating that ambient charged cluster species interact with downwelling infra-red radiation at 9.15 μm, even in the presence of cloud. This supports the possibility of future infrared detection of charged clusters. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
42. Planetary Atmospheric Electricity.
- Author
-
Harrison, R., Aplin, K., Leblanc, F., and Yair, Y.
- Subjects
- *
ATMOSPHERIC electricity , *ELECTRIFICATION , *PLANETARY atmospheres , *SOLAR system , *AEROSOLS - Abstract
Electrification is a fundamental process in planetary atmospheres, found widely in the solar system. It is most evident through lightning discharges, which can influence an atmosphere’s chemical composition, but electrification also affects the physical behaviour of aerosols and cloud droplets that determine an atmosphere’s radiative balance. In the terrestrial atmosphere, lightning has been implicated in the origin of life. [ABSTRACT FROM AUTHOR]
- Published
- 2008
- Full Text
- View/download PDF
43. EARLY CRUSTAL EVOLUTION OF MARS.
- Author
-
Nimmo, Francis and Tanaka, Ken
- Subjects
- *
MARTIAN crust , *MAGMAS , *MAGNETIZATION , *VOLCANISM , *PLANETARY science - Abstract
The bulk of the ∼50-km-thick Martian crust formed at ∼4.5 Gyr B.P., perhaps from a magma ocean. This crust is probably a basaltic andesite or andesite and is enriched in incompatible and heat-producing elements. Later additions of denser basalt to the crust were volumetrically minor, but resurfaced significant portions of the Northern hemisphere. A significant fraction of the total thickness of the crust was magnetized prior to 4 Gyr B.P., with the magnetization later selectively removed by large impacts. Early large impacts also modified the hemispheric contrast in crustal thickness (the dichotomy), which was possibly caused by long-wavelength mantle convection. Subsequent Noachian modification of the crust included further impacts, significant fluvial erosion, and volcanism associated with the formation of the Tharsis rise. Remaining outstanding questions include the origin of the dichotomy and the nature of the magnetic anomalies. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
44. Gravity Waves in Planetary Atmospheres: Their Effects and Parameterization in Global Circulation Models
- Author
-
Erdal Yiğit and Alexander S. Medvedev
- Subjects
comparative planetology ,Atmospheric Science ,010504 meteorology & atmospheric sciences ,Gravitational wave ,Atmospheric circulation ,Forcing (mathematics) ,Geophysics ,Environmental Science (miscellaneous) ,lcsh:QC851-999 ,01 natural sciences ,planetary weather forecasting ,Coupling (physics) ,Atmosphere of Earth ,Planet ,General Circulation Model ,0103 physical sciences ,waves ,lcsh:Meteorology. Climatology ,Gravity wave ,Astrophysics::Earth and Planetary Astrophysics ,010303 astronomy & astrophysics ,Geology ,Physics::Atmospheric and Oceanic Physics ,0105 earth and related environmental sciences - Abstract
The dynamical and thermodynamical importance of gravity waves was initially recognized in the atmosphere of Earth. Extensive studies over recent decades demonstrated that gravity waves exist in atmospheres of other planets, similarly play a significant role in the vertical coupling of atmospheric layers and, thus, must be included in numerical general circulation models. Since the spatial scales of gravity waves are smaller than the typical spatial resolution of most models, atmospheric forcing produced by them must be parameterized. This paper presents a review of gravity waves in planetary atmospheres, outlines their main characteristics and forcing mechanisms, and summarizes approaches to capturing gravity wave effects in numerical models. The main goal of this review is to bridge research communities studying atmospheres of Earth and other planets.
- Published
- 2019
45. Modern Mars' geomorphological activity, driven by wind, frost, and gravity.
- Author
-
Diniega, Serina, Bramson, Ali M., Buratti, Bonnie, Buhler, Peter, Burr, Devon M., Chojnacki, Matthew, Conway, Susan J., Dundas, Colin M., Hansen, Candice J., McEwen, Alfred S., Lapôtre, Mathieu G.A., Levy, Joseph, Mc Keown, Lauren, Piqueux, Sylvain, Portyankina, Ganna, Swann, Christy, Titus, Timothy N., and Widmer, Jacob M.
- Subjects
- *
MARS (Planet) , *FROST , *SOLAR system , *PLANETARY surfaces , *SEDIMENT transport - Abstract
Extensive evidence of landform-scale martian geomorphic changes has been acquired in the last decade, and the number and range of examples of surface activity have increased as more high-resolution imagery has been acquired. Within the present-day Mars climate, wind and frost/ice are the dominant drivers, resulting in large avalanches of material down icy, rocky, or sandy slopes; sediment transport leading to many scales of aeolian bedforms and erosion; pits of various forms and patterned ground; and substrate material carved out from under subliming ice slabs. Due to the ability to collect correlated observations of surface activity and new landforms with relevant environmental conditions with spacecraft on or around Mars, studies of martian geomorphologic activity are uniquely positioned to directly test surface-atmosphere interaction and landform formation/evolution models outside of Earth. In this paper, we outline currently observed and interpreted surface activity occurring within the modern Mars environment, and tie this activity to wind, seasonal surface CO 2 frost/ice, sublimation of subsurface water ice, and/or gravity drivers. Open questions regarding these processes are outlined, and then measurements needed for answering these questions are identified. In the final sections, we discuss how many of these martian processes and landforms may provide useful analogs for conditions and processes active on other planetary surfaces, with an emphasis on those that stretch the bounds of terrestrial-based models or that lack terrestrial analogs. In these ways, modern Mars presents a natural and powerful comparative planetology base case for studies of Solar System surface processes, beyond or instead of Earth. • Mars' surface is actively shaped in the present due to wind, frost/ice, and gravity. • Overlapping, high-resolution images from orbit are key for detection of activity. • In situ and orbital data are needed to fully characterize the active Mars processes. • Mars studies provide critical information about activity beyond that seen on Earth. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
46. Drôles de climats sur les planètes
- Author
-
Maryse, Chabalier, Planchon., Olivier, Espace des Sciences, Littoral, Environnement, Télédétection, Géomatique (LETG - Rennes), Littoral, Environnement, Télédétection, Géomatique UMR 6554 (LETG), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Université d'Angers (UA)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Brest (UBO)-Université de Rennes 2 (UR2), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Géographie et d'Aménagement Régional de l'Université de Nantes (IGARUN), Université de Nantes (UN)-Université de Nantes (UN)-Université de Caen Normandie (UNICAEN), Université de Nantes (UN)-Université de Nantes (UN), and Planchon, Olivier
- Subjects
[SDU] Sciences of the Universe [physics] ,comparative planetology ,seasonality ,[SDU]Sciences of the Universe [physics] ,atmospheric circulation ,paleoclimatology ,climatology - Published
- 2018
47. Reflectance spectrum of (1154) Astronomia
- Author
-
Birlan, Mirel, Nedelcu, Dan Alin, Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Astronomical Institute of Romanian Academy, Romanian Academy, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)
- Subjects
comparative planetology ,spectroscopy ,asteroid ,Solar System ,[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] - Abstract
International audience; First reflectance spectrum in the near-infrared region between 0.9 and 2.5 μm of asteroid (11154) Astronomia is presented. Taxonomic and comparative planetology studies show similarities with carbonaceous and enstatitic chondrite meteorites. Spectral data together with thermal albedo conclude to a surface rich in CM, CM-like regolith. Numerical integration of clones for this object shows no marked chaoticity.
- Published
- 2018
48. Lava tubes on Earth, Moon and Mars: A review on their size and morphology revealed by comparative planetology.
- Author
-
Sauro, Francesco, Pozzobon, Riccardo, Massironi, Matteo, De Berardinis, Pierluigi, Santagata, Tommaso, and De Waele, Jo
- Subjects
- *
MARTIAN atmosphere , *COMPARATIVE anatomy , *MORPHOLOGY , *LAVA , *PLANETARY science , *TUBES , *DIGITAL elevation models - Abstract
Sinuous collapse chains and skylights in lunar and Martian volcanic regions have often been interpreted as collapsed lava tubes (also known as pyroducts). This hypothesis has fostered a forty years debate among planetary geologists trying to define if analogue volcano-speleogenetic processes acting on Earth could have created similar subsurface linear voids in extra-terrestrial volcanoes. On Earth lava tubes are well known thanks to speleological exploration and mapping in several shield volcanoes, with examples showing different genetic processes (inflation and overcrusting) and morphometric characters. On the Moon subsurface cavities have been inferred from several skylights in Maria smooth plains and corroborated using gravimetry and radar sounder, while on Mars several deep skylights have been identified on lava flows with striking similarities with terrestrial cases. Nonetheless, the literature on this topic is scattered and often presents inaccuracies in terminology and interpretation. A clear understanding of the potential morphologies and dimensions of Martian and lunar lava tubes remains elusive. Although it is still impossible to gather direct information on the interior of Martian and lunar lava tube candidates, scientists have the possibility to investigate their surface expression through the analysis of collapses and skylight morphology, morphometry and their arrangement, and compare these findings with terrestrial analogues. In this review the state of the art on terrestrial lava tubes is outlined in order to perform a morphological and morphometric comparison with lava tube candidate collapse chains on Mars and the Moon. By comparing literature and speleological data from terrestrial analogues and measuring lunar and Martian collapse chains on satellite images and digital terrain models (DTMs), this review sheds light on tube size, depth from surface, eccentricity and several other morphometric parameters among the three different planetary bodies. The dataset here presented indicates that Martian and lunar tubes are 1 to 3 orders of magnitude more voluminous than on Earth, and suggests that the same processes of inflation and overcrusting were active on Mars, while deep inflation and thermal entrenchment was the predominant mechanism of emplacement on the Moon. Even with these outstanding dimensions (with total volumes exceeding 1 billion of m3), lunar tubes remain well within the roof stability threshold. The analysis shows that aside of collapses triggered by impacts/tectonics, most of the lunar tubes could be intact, making the Moon an extraordinary target for subsurface exploration and potential settlement in the wide protected and stable environments of lava tubes. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
49. Planetary atmospheric electricity
- Author
-
Yoav Yair, Karen Aplin, Jean-Pierre Lebreton, F. LeBlanc, R. G. Harrison, Michel Blanc, Department of Meteorology [Reading], University of Reading (UOR), Space Science and Technology Department [Didcot] (RAL Space), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC)-Science and Technology Facilities Council (STFC), Service d'aéronomie (SA), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Life and Natural Sciences [Israël], and Open University of Israël
- Subjects
Solar System ,Meteorology ,010504 meteorology & atmospheric sciences ,7. Clean energy ,01 natural sciences ,Charge ,Lightning ,Electromagnetic radiation ,0103 physical sciences ,Aerospace engineering ,010303 astronomy & astrophysics ,Cosmic rays ,Comparative planetology ,Physics::Atmospheric and Oceanic Physics ,0105 earth and related environmental sciences ,Physics ,[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,business.industry ,Astronomy and Astrophysics ,Planetary system ,Field (geography) ,Planetary science ,Electrostatic discharge ,13. Climate action ,Space and Planetary Science ,Physics::Space Physics ,Thunderstorm ,Astrophysics::Earth and Planetary Astrophysics ,Atmospheric electricity ,Space Science ,business ,Primordial atmosphere - Abstract
This volume presents our contemporary understanding of atmospheric electricity at Earth and in other solar system atmospheres. It is written by experts in terrestrial atmospheric electricity and planetary scientists. Many of the key issues related to planetary atmospheric electricity are discussed. The physics presented in this book includes ionisation processes in planetary atmospheres, charge generation and separation, and a discussion of electromagnetic signatures of atmospheric discharges. The measurement of thunderstorms and lightning, including its effects and hazards, is highlighted by articles on ground and space based instrumentation, and new missions.Theory and modelling of planetary atmospheric electricity complete this review of the research that is undertaken in this exciting field of space science. This book is an essential research tool for space scientists and geoscientists interested in electrical effects in atmospheres and planetary systems. Graduate students and researchers who are new to the field will benefit from the introductory overviews and can quickly expand their knowledge by studying the subsequent sections.
- Published
- 2016
50. Mercury exploration and its significance compared with lunar exploration
- Author
-
Okada, Tatsuaki
- Subjects
水星探査 ,comparative planetology ,planetary geology ,ミッション立案 ,Mercury exploration ,planetary crater ,宇宙探査 ,水星 ,mission planning ,比較惑星学 ,星形成 ,Mercury surface ,Mercury ,planetary evolution ,star formation ,提案 ,惑星地質学 ,コンドライト ,proposal ,水星表面 ,chondrite ,惑星クレータ ,惑星進化 ,space exploration - Abstract
資料番号: AA0063351015
- Published
- 2007
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.