On the sublimation of ice particles on the surface of Mars; with applications to the 2007/8 Phoenix Scout mission

Taylor, Peter A.; Baibakov, Konstantin; Brown, Stephen; Hecht, M. H.; Hudson, T. L.; Li, P.-Y.; Lange, Carlos F.; Prieto, Luís; Savelyev, Sergiy

doi:10.1016/j.icarus.2005.10.031

Cited by 23 publications

(5 citation statements)

References 7 publications

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“…Pada prinsipnya, pembelajaran melibatkan penerimaan Pemahaman mengenai suatu subjek atau keahlian tertentu (Taylor et al 2006). Menurut (Afandi 2014) menambahkan dimensi lain dengan menyatakan bahwa pembelajaran adalah tindakan yang sengaja untuk memperoleh kemampuan (berbahasa).…”

Section: Pendahuluanunclassified

Analisis Pendekatan komunikatif Pembelajaran Bahasa Indonesia

Mubarok,

Haryadi,

Agus Nuryatin

2024

Onoma

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Istilah pendekatan menggambarkan posisi awal atau sudut pandang yang mengarahkan seseorang sepanjang proses belajar. Salah satu aspek pembelajaran bahasa Indonesia yang perlu ditingkatkan adalah pendekatan pedagogi. Salah satu metode peningkatan pembelajaran yang bersifat komunikatif adalah salah satu pendekatan. Pendekatan komunikatif menekankan pada pertumbuhan dan perkembangan keterampilan komunikatif siswa dalam berbagai konteks, termasuk suasana formal dan informal. Pemeriksaan terhadap atribut pendekatan komunikatif dilakukan sehubungan dengan sudut pandang peserta didik, fungsi instruktur, sumber pengajaran, dan tujuan pendidikan. Pendekatan komunikatif membedakan diri dengan menitikberatkan pada partisipasi siswa, perkembangan belajar, dan sasaran pembelajaran. Pusat perhatian utama dari pendekatan ini adalah memberikan siswa keterampilan komunikasi yang efektif. Siswa menjadi subjek utama dalam penerapan pendekatan komunikatif yang secara penuh melibatkan mereka (siswa berpusat), guru memiliki peran terbatas sebagai penyedia fasilitas.

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Section: Pendahuluanunclassified

Analisis Pendekatan komunikatif Pembelajaran Bahasa Indonesia

Mubarok,

Haryadi,

Agus Nuryatin

2024

Onoma

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“…S s is a mass flux; its units are kg m −2 s −1 , and it represents the analytic solution for the total mass flux emitted from a planar surface at a temperature T s . Consequently, this equation has been widely used to obtain the sublimation rate of ice for different applications in planetary sciences (Andreas, 2007; Mangold, 2011; Taylor et al., 2006; Vasavada et al., 1999).…”

Section: Model Equationsmentioning

confidence: 99%

Molecular Transport Conditions Required for the Formation of Penitentes on Airless, Ice‐Covered Worlds, With Specific Application to Europa, Enceladus, and Callisto

et al. 2023

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The surface morphology of airless, ice‐covered moons of the outer solar system, such as Europa, Enceladus, and Callisto, is not well known at centimeter‐ to meter‐scales. Ice and snow erode differently on such worlds in part because sublimation is the dominant process. On Earth, ice penitentes have been observed in sublimation‐driven environments, and may provide a guide for similar formations on ice‐covered worlds. Penitentes are blade‐like snow features observed on Earth in high‐altitude, low‐latitude snowfields. Models of penitente formation on Earth break down within the free‐molecular regime of airless bodies, leaving a major gap in understanding whether such morphologies can form on their surfaces. To investigate the morphologic evolution of icy bodies, we developed a Sublimation Monte Carlo (SMC) model that enables a numerical approach to modeling exosphere‐surface interactions at free‐molecular conditions. The SMC model uses Monte Carlo tracking of molecules emitted from the surface to determine the net molecular interchange that drives surface changes. We validated results against experiments, matching the evolution of pre‐formed penitentes as they receded in height and became less pronounced. Our results reveal the importance of molecular redeposition on topology, indicating that the stable morphology of isothermal topographies is a planar morphology on regions of net sublimation, regardless of initial surface shape. A study of parametrically varying temperature profiles for sinusoidal penitentes resulted in the following requirement for penitente growth: the trough temperature must exceed the peak temperature by a threshold value, which notably depends on the surface aspect ratio and peak temperature.

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“…The calculated pressure values are lower than the equilibrium data because the stability of the brine is better due to the presence of the CO 2 atmosphere. Hence, approximately 6 mbar (0.06 Pa) CO 2 of the Martian atmosphere reduces the vaporization rate in the diurnal circle (day vaporization/night condensation and deliquescence) significantly (based on Taylor et al 2006). Accordingly, NaCl brine should 'survive' below 265 K to sustain biological processes of halotolerant cyanobacterial biofilm communities.…”

Section: Implications Of the Martian Surface Conditions On Habitabilitymentioning

confidence: 99%

Provision of water by halite deliquescence forNostoc communebiofilms under Mars relevant surface conditions

Jänchen

Feyh

Szewzyk

et al. 2015

International Journal of Astrobiology

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Motivated by findings of new mineral related water sources for organisms under extremely dry conditions on Earth we studied in an interdisciplinary approach the water sorption behaviour of halite, soil component and terrestrial Nostoc commune biofilm under Mars relevant environmental conditions. Physicochemical methods served for the determination of water sorption equilibrium data and survival of heterotrophic bacteria in biofilm samples with different water contents was assured by recultivation. Deliquescence of halite provides liquid water at temperatures <273 K and may serve as water source on Mars during the morning stabilized by the CO 2 atmosphere for a few hours. The protecting biofilm of N. commune is rather hygroscopic and tends to store water at lower humidity values. Survival tests showed that a large proportion of the Alphaproteobacteria dominated microbiota associated to N. commune is very desiccation tolerant and water uptake from saturated NaCl solutions (either by direct uptake of brine or adsorption of humidity) did not enhance recultivability in long-time desiccated samples. Still, a minor part can grow under highly saline conditions. However, the salinity level, although unfavourable for the host organism, might be for parts of the heterotrophic microbiota no serious hindrance for growing in salty Mars-like environments.

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On the sublimation of ice particles on the surface of Mars; with applications to the 2007/8 Phoenix Scout mission

Cited by 23 publications

References 7 publications

Analisis Pendekatan komunikatif Pembelajaran Bahasa Indonesia

Analisis Pendekatan komunikatif Pembelajaran Bahasa Indonesia

Molecular Transport Conditions Required for the Formation of Penitentes on Airless, Ice‐Covered Worlds, With Specific Application to Europa, Enceladus, and Callisto

Provision of water by halite deliquescence forNostoc communebiofilms under Mars relevant surface conditions

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