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1

Ragossnig, Florian, Alexander Stökl, Ernst Dorfi, Colin P. Johnstone, Daniel Steiner, and Manuel Güdel. "Interaction of infalling solid bodies with primordial atmospheres of disk-embedded planets." Astronomy & Astrophysics 618 (October 2018): A19. http://dx.doi.org/10.1051/0004-6361/201832681.

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Context. Planets that form early enough to be embedded in the circumstellar gas disk accumulate thick atmospheres of nebular gas. Models of these atmospheres need to specify the surface luminosity (i.e. energy loss rate) of the planet. This luminosity is usually associated with a continuous inflow of solid bodies, where the gravitational energy released from these bodies is the source of energy. However, if these bodies release energy in the atmosphere instead of at the surface, this assumption might not be justified. Aims. Our aim is to explore the interactions of infalling planetesimals with
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2

Chance, Quadry, Sarah Ballard, and Keivan Stassun. "Signatures of Impact-driven Atmospheric Loss in Large Ensembles of Exoplanets." Astrophysical Journal 937, no. 1 (2022): 39. http://dx.doi.org/10.3847/1538-4357/ac8a97.

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Abstract The results of large-scale exoplanet transit surveys indicate that the distribution of small planet radii is likely sculpted by atmospheric loss. Several possible physical mechanisms exist for this loss of primordial atmospheres, each of which produces a different set of observational signatures. In this study, we investigate the impact-driven mode of atmosphere loss via N-body simulations. We compare the results from giant impacts, at a demographic level, to results from another commonly invoked method of atmosphere loss, photoevaporation. Applying two different loss prescriptions to
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3

Kimura, Tadahiro, and Masahiro Ikoma. "Formation of aqua planets with water of nebular origin: effects of water enrichment on the structure and mass of captured atmospheres of terrestrial planets." Monthly Notices of the Royal Astronomical Society 496, no. 3 (2020): 3755–66. http://dx.doi.org/10.1093/mnras/staa1778.

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ABSTRACT Recent detection of exoplanets with Earth-like insolation attracts growing interest in how common Earth-like aqua planets are beyond the Solar system. While terrestrial planets are often assumed to capture icy or water-rich planetesimals, a primordial atmosphere of nebular origin itself can produce water through oxidation of the atmospheric hydrogen with oxidizing minerals from incoming planetesimals or the magma ocean. Thermodynamically, normal oxygen buffers produce water comparable in mole number equal to or more than hydrogen. Thus, the primordial atmosphere would likely be highly
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Modirrousta-Galian, Darius, and Jun Korenaga. "The Diffusion Limit of Photoevaporation in Primordial Planetary Atmospheres." Astrophysical Journal 965, no. 1 (2024): 97. http://dx.doi.org/10.3847/1538-4357/ad276f.

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Abstract Photoevaporation is thought to play an important role in early planetary evolution. In this study, we investigate the diffusion limit of X-ray- and ultraviolet-induced photoevaporation in primordial atmospheres. We find that compositional fractionation resulting from mass loss is more significant than currently recognized, because it is controlled by the conditions at the top of the atmosphere, where particle collisions are less frequent. Such fractionation at the top of the atmosphere develops a compositional gradient that extends downward. The mass outflow eventually reaches a stead
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Sinclair, Catriona A., Mark C. Wyatt, Alessandro Morbidelli, and David Nesvorný. "Evolution of the Earth’s atmosphere during Late Veneer accretion." Monthly Notices of the Royal Astronomical Society 499, no. 4 (2020): 5334–62. http://dx.doi.org/10.1093/mnras/staa3210.

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ABSTRACT Recent advances in our understanding of the dynamical history of the Solar system have altered the inferred bombardment history of the Earth during accretion of the Late Veneer, after the Moon-forming impact. We investigate how the bombardment by planetesimals left-over from the terrestrial planet region after terrestrial planet formation, as well as asteroids and comets, affects the evolution of Earth’s early atmosphere. We develop a new statistical code of stochastic bombardment for atmosphere evolution, combining prescriptions for atmosphere loss and volatile delivery derived from
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6

Liu, Lin-gun. "The Proto-Atmosphere of Terrestrial Planets." European Journal of Applied Sciences 13, no. 02 (2025): 473–78. https://doi.org/10.14738/aivp.1302.18571.

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The theoretically derived composition of the proto-atmosphere, which evolved during accretion, of terrestrial planets is composed primarily of CO2, Ar and N2 when the mass of a planet became greater than 3.30 x 1026 g. This is identical to the atmospheric compositions of Venus and Mars observed today. Therefore, both Venus and Mars most likely retained their proto-atmospheres till now. The Earth is situated between Venus and Mars, there is no reason whatsoever that the Earth’s proto-atmosphere should be any different from those of Venus and Mars. Yet, today’s Earth atmospheric composition is d
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Saxena, Prabal, Lindy Elkins-Tanton, Noah Petro, and Avi Mandell. "A model of the primordial lunar atmosphere." Earth and Planetary Science Letters 474 (September 2017): 198–205. http://dx.doi.org/10.1016/j.epsl.2017.06.031.

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8

Kurosaki, Kenji, Yasunori Hori, Masahiro Ogihara, and Masanobu Kunitomo. "Evolution of a Water-rich Atmosphere Formed by a Giant Impact on an Earth-sized Planet." Astrophysical Journal 957, no. 2 (2023): 67. http://dx.doi.org/10.3847/1538-4357/acfe0a.

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Abstract The atmosphere of a terrestrial planet that is replenished with secondary gases should have accumulated hydrogen-rich gas from its protoplanetary disk. Although a giant impact blows off a large fraction of the primordial atmosphere of a terrestrial planet in the late formation stage, the remaining atmosphere can become water-rich via chemical reactions between hydrogen and vaporized core material. We find that a water-rich postimpact atmosphere forms when a basaltic or CI chondrite core is assumed. In contrast, little postimpact water is generated for an enstatite chondrite core. We i
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9

Melosh, H. J., and A. M. Vickery. "Impact erosion of the primordial atmosphere of Mars." Nature 338, no. 6215 (1989): 487–89. http://dx.doi.org/10.1038/338487a0.

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10

Ueda, Hisahiro, and Takazo Shibuya. "Composition of the Primordial Ocean Just after Its Formation: Constraints from the Reactions between the Primitive Crust and a Strongly Acidic, CO2-Rich Fluid at Elevated Temperatures and Pressures." Minerals 11, no. 4 (2021): 389. http://dx.doi.org/10.3390/min11040389.

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The Hadean was an enigmatic period in the Earth’s history when ocean formation and the emergence of life may have occurred. However, minimal geological evidence is left from this period. To understand the primordial ocean’s composition, we focused on the ocean’s formation processes from CO2- and HCl-bearing water vapor in the high-temperature atmosphere. When the temperature of the lower atmosphere fell below the critical point, high-temperature rain reached the ground surface. Then, hydrothermal reactions between the subcritical fluid and primordial crust started. Eventually, a liquid ocean e
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11

Biersteker, John B., and Hilke E. Schlichting. "Losing oceans: The effects of composition on the thermal component of impact-driven atmospheric loss." Monthly Notices of the Royal Astronomical Society 501, no. 1 (2020): 587–95. http://dx.doi.org/10.1093/mnras/staa3614.

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ABSTRACT The formation of the Solar system’s terrestrial planets concluded with a period of giant impacts. Previous works examining the volatile loss caused by the impact shock in the moon-forming impact find atmospheric losses of at most 20–30 per cent and essentially no loss of oceans. However, giant impacts also result in thermal heating, which can lead to significant atmospheric escape via a Parker-type wind. Here we show that H2O and other high-mean molecular weight outgassed species can be efficiently lost through this thermal wind if present in a hydrogen-dominated atmosphere, substanti
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12

Zhou, Li, Bo Ma, Yonghao Wang, and Yinan Zhu. "Hubble WFC3 Spectroscopy of the Rocky Planet L 98–59 b: No Evidence for a Cloud-free Primordial Atmosphere." Astronomical Journal 164, no. 5 (2022): 203. http://dx.doi.org/10.3847/1538-3881/ac8fe9.

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Abstract We are using archived data from HST of transiting exoplanet L 98-59 b to place constraints on its potentially hot atmosphere. We analyze the data from five transit visits and extract the final combined transmission spectrum using Iraclis. Then we use the inverse atmospheric retrieval code TauREx to analyze the combined transmission spectrum. There is a weak absorption feature near 1.40 μm and 1.55 μm in the transmission spectrum, which can be modeled by a cloudy atmosphere with abundant hydrogen cyanide (HCN). However, the unrealistically high abundance of HCN derived cannot be explai
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Amaral, Laura N. R. do, Evgenya L. Shkolnik, R. O. Parke Loyd, and Sarah Peacock. "The Impact of Stellar Flares on the Atmospheric Escape of Exoplanets Orbiting M Stars. I. Insights from the AU Mic System." Astrophysical Journal 985, no. 1 (2025): 100. https://doi.org/10.3847/1538-4357/adc932.

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Abstract The X-ray and extreme ultraviolet (XUV) emission from M stars can drive the atmospheric escape on planets orbiting them. M stars are also known for their frequent emission of stellar flares, which will increase the high-energy flux received by their orbiting planets. To understand how stellar flares impact the primordial atmospheres of planets orbiting young M stars, we use UV spectroscopic data of flares from the Habitable Zones and M dwarf Activity across Time and Measurements of the Ultraviolet Spectral Characteristics of Low-mass Exoplanetary Systems programs as a proxy for the XU
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14

Scarsdale, Nicholas, Nicholas Wogan, Hannah R. Wakeford та ін. "JWST COMPASS: The 3–5 μm Transmission Spectrum of the Super-Earth L 98-59 c". Astronomical Journal 168, № 6 (2024): 276. http://dx.doi.org/10.3847/1538-3881/ad73cf.

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Abstract We present a JWST Near-InfraRed Spectrograph (NIRSpec) transmission spectrum of the super-Earth exoplanet L 98-59 c. This small (R p = 1.385 ± 0.085R ⊕, M p = 2.22 ± 0.26 R ⊕), warm (T eq = 553 K) planet resides in a multiplanet system around a nearby, bright (J = 7.933) M3V star. We find that the transmission spectrum of L 98-59 c is featureless at the precision of our data. We achieve precisions of 22 ppm in NIRSpec G395H’s NRS1 detector and 36 ppm in the NRS2 detector at a resolution R ∼ 200 (30 pixel wide bins). At this level of precision, we are able rule out primordial H2–He atm
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15

NAKAZAWA, Kiyoshi, Hiroshi MIZUNO, Minoru SEKIYA, and Chushiro HAYASHI. "Structure of the primordial atmosphere surrounding the early-earth." Journal of geomagnetism and geoelectricity 37, no. 8 (1985): 781–99. http://dx.doi.org/10.5636/jgg.37.781.

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16

Mukhopadhyay, Sujoy, and Rita Parai. "Noble Gases: A Record of Earth's Evolution and Mantle Dynamics." Annual Review of Earth and Planetary Sciences 47, no. 1 (2019): 389–419. http://dx.doi.org/10.1146/annurev-earth-053018-060238.

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Noble gases have played a key role in our understanding of the origin of Earth's volatiles, mantle structure, and long-term degassing of the mantle. Here we synthesize new insights into these topics gained from high-precision noble gas data. Our analysis reveals new constraints on the origin of the terrestrial atmosphere, the presence of nebular neon but chondritic krypton and xenon in the mantle, and a memory of multiple giant impacts during accretion. Furthermore, the reservoir supplying primordial noble gases to plumes appears to be distinct from the mid-ocean ridge basalt (MORB) reservoir
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17

Misener, William, and Hilke E. Schlichting. "To cool is to keep: residual H/He atmospheres of super-Earths and sub-Neptunes." Monthly Notices of the Royal Astronomical Society 503, no. 4 (2021): 5658–74. http://dx.doi.org/10.1093/mnras/stab895.

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ABSTRACT Super-Earths and sub-Neptunes are commonly thought to have accreted hydrogen/helium envelopes, consisting of a few to ten percent of their total mass, from the primordial gas disc. Subsequently, hydrodynamic escape driven by core-powered mass-loss and/or photoevaporation likely stripped much of these primordial envelopes from the lower mass and closer-in planets to form the super-Earth population. In this work, we show that after undergoing core-powered mass-loss, some super-Earths can retain small residual H/He envelopes. This retention is possible because, for significantly depleted
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18

Micca Longo, Gaia, Luca Vialetto, Paola Diomede, Savino Longo, and Vincenzo Laporta. "Plasma Modeling and Prebiotic Chemistry: A Review of the State-of-the-Art and Perspectives." Molecules 26, no. 12 (2021): 3663. http://dx.doi.org/10.3390/molecules26123663.

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We review the recent progress in the modeling of plasmas or ionized gases, with compositions compatible with that of primordial atmospheres. The plasma kinetics involves elementary processes by which free electrons ultimately activate weakly reactive molecules, such as carbon dioxide or methane, thereby potentially starting prebiotic reaction chains. These processes include electron–molecule reactions and energy exchanges between molecules. They are basic processes, for example, in the famous Miller-Urey experiment, and become relevant in any prebiotic scenario where the primordial atmosphere
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19

Rogers, James G., Caroline Dorn, Vivasvaan Aditya Raj, Hilke E. Schlichting, and Edward D. Young. "Most Super-Earths Have Less Than 3% Water." Astrophysical Journal 979, no. 1 (2025): 79. https://doi.org/10.3847/1538-4357/ad9f61.

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Abstract Super-Earths are highly irradiated, small planets with bulk densities approximately consistent with Earth. We construct combined interior atmosphere models of super-Earths that trace the partitioning of water throughout a planet, including an iron-rich core, silicate-rich mantle, and steam atmosphere. We compare these models with exoplanet observations to infer a 1σ upper limit on the total water mass fraction of ≲3% at the population level. We consider end-member scenarios that may change this value, including the efficiency of mantle outgassing, escape of high mean molecular weight
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20

Trafton, L., S. A. Stern, and G. R. Gladstone. "The Pluto-Charon system: The escape of charon's primordial atmosphere." Icarus 74, no. 1 (1988): 108–20. http://dx.doi.org/10.1016/0019-1035(88)90033-4.

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21

Alam, Munazza K., Peter Gao, Jea Adams Redai, et al. "JWST COMPASS: The First Near- to Mid-infrared Transmission Spectrum of the Hot Super-Earth L 168-9 b." Astronomical Journal 169, no. 1 (2024): 15. https://doi.org/10.3847/1538-3881/ad8eb5.

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Abstract We present the first broadband near- to mid-infrared (3–12 μm) transmission spectrum of the highly irradiated (T eq = 981 K) M-dwarf rocky planet L 168-9 b (TOI-134 b) observed with the Near-infrared Spectrograph and Mid-infrared Instrument (MIRI) instruments aboard JWST. We measure the near-infrared transit depths to a combined median precision of 20 ppm across the three visits in 54 spectroscopic channels with uniform widths of 60 pixels (∼0.2 μm wide; R ∼ 100), and the mid-infrared transit depths to 61 ppm median precision in 48 wavelength bins (∼0.15 μm wide; R ∼ 50). We compare t
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22

Kubyshkina, Daria, and Aline A. Vidotto. "How does the mass and activity history of the host star affect the population of low-mass planets?" Monthly Notices of the Royal Astronomical Society 504, no. 2 (2021): 2034–50. http://dx.doi.org/10.1093/mnras/stab897.

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ABSTRACT The evolution of the atmospheres of low- and intermediate-mass planets is strongly connected to the physical properties of their host stars. The types and the past activities of planet-hosting stars can, therefore, affect the overall planetary population. In this paper, we perform a comparative study of sub-Neptune-like planets orbiting stars of different masses and different evolutionary histories. We discuss the general patterns of the evolved population as a function of parameters and environments of planets. As a model of the atmospheric evolution, we employ the own framework comb
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Atri, Dimitra, and Shane R. Carberry Mogan. "Stellar flares versus luminosity: XUV-induced atmospheric escape and planetary habitability." Monthly Notices of the Royal Astronomical Society: Letters 500, no. 1 (2020): L1—L5. http://dx.doi.org/10.1093/mnrasl/slaa166.

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ABSTRACT Space weather plays an important role in the evolution of planetary atmospheres. Observations have shown that stellar flares emit energy in a wide energy range (1030–1038 erg), a fraction of which lies in X-rays and extreme ultraviolet (XUV). These flares heat the upper atmosphere of a planet, leading to increased escape rates, and can result in atmospheric erosion over a period of time. Observations also suggest that primordial terrestrial planets can accrete voluminous H/He envelopes. Stellar radiation can erode these protoatmospheres over time, and the extent of this erosion has im
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Amsler Moulanier, Alizée, Olivier Mousis, Alexis Bouquet, and Christopher R. Glein. "The Role of Ammonia in the Distribution of Volatiles in the Primordial Hydrosphere of Europa." Planetary Science Journal 6, no. 1 (2025): 1. https://doi.org/10.3847/psj/ad9925.

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Abstract The presence of a hydrosphere on Europa raises questions about its habitability, and studies of its volatile inventory can provide insight into its formation process. Different scenarios suggest that Europa's volatiles could be derived from cometary ices or devolatilized building blocks. The study of post-accretion processes—in particular, the “open-ocean” phase that likely occurred before the formation of the icy crust—is crucial to distinguishing these origins, as this phase is likely to have influenced the volatile inventory. The abundance of ammonia in Europa's building blocks is
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Libby-Roberts, Jessica E., Zachory K. Berta-Thompson, Hannah Diamond-Lowe, et al. "The Featureless HST/WFC3 Transmission Spectrum of the Rocky Exoplanet GJ 1132b: No Evidence for a Cloud-free Primordial Atmosphere and Constraints on Starspot Contamination." Astronomical Journal 164, no. 2 (2022): 59. http://dx.doi.org/10.3847/1538-3881/ac75de.

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Abstract Orbiting an M dwarf 12 pc away, the transiting exoplanet GJ 1132b is a prime target for transmission spectroscopy. With a mass of 1.7 M ⊕ and radius of 1.1 R ⊕, GJ 1132b’s bulk density indicates that this planet is rocky. Yet with an equilibrium temperature of 580 K, GJ 1132b may still retain some semblance of an atmosphere. Understanding whether this atmosphere exists and its composition will be vital for understanding how the atmospheres of terrestrial planets orbiting M dwarfs evolve. We observe five transits of GJ 1132b with the Wide Field Camera 3 (WFC3) on the Hubble Space Teles
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Cannon, Kevin M., Stephen W. Parman, and John F. Mustard. "Primordial clays on Mars formed beneath a steam or supercritical atmosphere." Nature 552, no. 7683 (2017): 88–91. http://dx.doi.org/10.1038/nature24657.

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27

Haq, Ehsan ul, Farwah Waseem, and Abdul Baqi. "Appraisal of Temporal Variations in Atmospheric Compositions over South Asia by Addition of Various Pollutant’s in Recent Decade." Vol 3 Issue 1 3, no. 1 (2021): 1–15. http://dx.doi.org/10.33411/ijist/2021030101.

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Atmosphere is an envelope of gasses and aerosols around the planet, 99% of the total mass of atmospheric gases resides within 32km from Earth’s surface in vertical column. From primordial era to current scenario composition of earth endured numerous drastic modifications. In last decade atmosphere had undergone a vigorous change by the addition of many pollutants in both natural and anthropogenic aspects. South Asia is a densely populated; masses here are in a transition state, this developing nation in this region considerably done enough damage to the atmosphere of south Asia by inserting mu
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Yalinewich, Almog, and Matthew E. Caplan. "Crater morphology of primordial black hole impacts." Monthly Notices of the Royal Astronomical Society: Letters 505, no. 1 (2021): L115—L119. http://dx.doi.org/10.1093/mnrasl/slab063.

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ABSTRACT In this work, we propose a novel campaign for constraining relativistically compact massive compact halo object (MACHO) dark matter, such as primordial black holes (PBHs), using the Moon as a detector. PBHs of about 1019 to 1022 g may be sufficiently abundant to have collided with the Moon in the history of the Solar system. We show that the crater profiles of a PBH collision differ from traditional impactors and may be detectable in high-resolution lunar surface scans now available. Any candidates may serve as sites for in situ measurements to identify high-pressure phases of matter
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29

Mizuno, Hiroshi, and Kiyoshi Nakazawa. "Chapter 22. Primordial Atmosphere Surrounding a Protoplanet and Formation of Jovian Planets." Progress of Theoretical Physics Supplement 96 (1988): 266–73. http://dx.doi.org/10.1143/ptps.96.266.

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30

Davenport, Brian, Eliza M. R. Kempton, Matthew C. Nixon, et al. "TOI-421 b: A Hot Sub-Neptune with a Haze-free, Low Mean Molecular Weight Atmosphere." Astrophysical Journal Letters 984, no. 2 (2025): L44. https://doi.org/10.3847/2041-8213/adcd76.

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Abstract Common features of sub-Neptune atmospheres observed to date include signatures of aerosols at moderate equilibrium temperatures (∼500–800 K) and a prevalence of high mean molecular weight atmospheres, perhaps indicating novel classes of planets such as water worlds. Here we present a 0.83–5 μm JWST transmission spectrum of the sub-Neptune TOI-421 b. This planet is unique among previously observed counterparts in its high equilibrium temperature (T eq ≈ 920 K) and its Sun-like host star. We find marked differences between the atmosphere of TOI-421 b and those of sub-Neptunes previously
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Modirrousta-Galian, D., B. Stelzer, E. Magaudda, et al. "GJ 357 b." Astronomy & Astrophysics 641 (September 2020): A113. http://dx.doi.org/10.1051/0004-6361/202038280.

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Aims. In this paper we present a deep X-ray observation of the nearby M dwarf GJ 357 and use it to put constraints on the atmospheric evolution of its planet, GJ 357 b. We also analyse the systematic errors in the stellar parameters of GJ 357 in order to see how they affect the perceived planetary properties. Methods. By comparing the observed X-ray luminosity of its host star, we estimate the age of GJ 357 b as derived from a recent XMM-Newton observation (log Lx [erg s−1] = 25.73), with Lx− age relations for M dwarfs. We find that GJ 357 presents one of the lowest X-ray activity levels ever
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32

Micca Longo, Gaia, and Savino Longo. "The role of primordial atmosphere composition in organic matter delivery to early Earth." Rendiconti Lincei. Scienze Fisiche e Naturali 31, no. 1 (2020): 53–64. http://dx.doi.org/10.1007/s12210-020-00878-x.

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Molaverdikhani, K., Ch Helling, B. W. P. Lew, et al. "Understanding the atmospheric properties and chemical composition of the ultra-hot Jupiter HAT-P-7b." Astronomy & Astrophysics 635 (March 2020): A31. http://dx.doi.org/10.1051/0004-6361/201937044.

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Aims. The atmospheres of ultra-hot Jupiters (UHJs) are commonly considered to be at thermochemical equilibrium. We aim to provide disequilibrium chemistry maps for a global understanding of the chemistry in the atmosphere of HAT-P-7b and assess the importance of disequilibrium chemistry on UHJs. Methods. We applied a hierarchical modeling approach using 97 1D atmospheric profiles from a 3D general circulation model of HAT-P-7b. For each atmospheric 1D profile, we evaluated our kinetic cloud formation model consistently with the local gas-phase composition in chemical equilibrium. This served a
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Schroeder I, Isaac R. H. G., Kathrin Altwegg, Hans Balsiger, et al. "16O/18O ratio in water in the coma of comet 67P/Churyumov-Gerasimenko measured with the Rosetta/ROSINA double-focusing mass spectrometer." Astronomy & Astrophysics 630 (September 20, 2019): A29. http://dx.doi.org/10.1051/0004-6361/201833806.

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The European Space Agency spacecraft Rosetta accompanied the Jupiter-family comet 67P/Churyumov-Gerasimenko for over 2 yr along its trajectory through the inner solar system. Between 2014 and 2016, it performed almost continuous in situ measurements of the comet’s gaseous atmosphere in close proximity to its nucleus. In this study, the 16O/18O ratio of H2O in the coma of 67P/Churyumov-Gerasimenko, as measured by the ROSINA DFMS mass spectrometer onboard Rosetta, was determined from the ratio of H216O/H218O and 16OH/18OH. The value of 445 ± 35 represents an ~11% enrichment of 18O compared with
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Jaupart, Etienne, Sebatien Charnoz, and Manuel Moreira. "Primordial atmosphere incorporation in planetary embryos and the origin of Neon in terrestrial planets." Icarus 293 (September 2017): 199–205. http://dx.doi.org/10.1016/j.icarus.2017.04.022.

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36

Afshordi, N., R. B. Mann, and R. Pourhasan. "A holographic big bang?" International Journal of Modern Physics D 24, no. 12 (2015): 1544029. http://dx.doi.org/10.1142/s0218271815440290.

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We present a cosmological model in which the Universe emerges out of the collapse of a five-dimensional (5D) star as a spherical three-brane. The initial singularity of the big bang becomes hidden behind a causal horizon. Near scale-invariant primordial curvature perturbations can be induced on the brane via a thermal atmosphere that is in equilibrium with the brane, circumventing the need for a separate inflationary process and providing an important test of the model.
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Zhang, Michael, Jacob L. Bean, David Wilson, et al. "Constraining Atmospheric Composition from the Outflow: Helium Observations Reveal the Fundamental Properties of Two Planets Straddling the Radius Gap." Astronomical Journal 169, no. 4 (2025): 204. https://doi.org/10.3847/1538-3881/adb490.

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Abstract TOI-836 is a ∼2–3 Gyr K dwarf with an inner super Earth (R = 1.7 R ⊕, P = 3.8 days) and an outer mini-Neptune (R = 2.6 R ⊕, P = 8.6 days). JWST/NIRSpec 2.8–5.2 μm transmission spectra are flat for both planets. We present Keck/NIRSPEC observations of escaping helium for super-Earth b, which shows no excess absorption in the 1083 nm triplet to deep limits (<0.2%), and mini-Neptune c, which shows strong (0.7%) excess absorption in both visits. These results demonstrate that planet c retains at least some primordial atmosphere, while planet b is consistent with having lost its entire
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Ferus, Martin, Fabio Pietrucci, Antonino Marco Saitta, et al. "Formation of nucleobases in a Miller–Urey reducing atmosphere." Proceedings of the National Academy of Sciences 114, no. 17 (2017): 4306–11. http://dx.doi.org/10.1073/pnas.1700010114.

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The Miller–Urey experiments pioneered modern research on the molecular origins of life, but their actual relevance in this field was later questioned because the gas mixture used in their research is considered too reducing with respect to the most accepted hypotheses for the conditions on primordial Earth. In particular, the production of only amino acids has been taken as evidence of the limited relevance of the results. Here, we report an experimental work, combined with state-of-the-art computational methods, in which both electric discharge and laser-driven plasma impact simulations were
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Montoya, David. "Hostilidad perpetua, transformaciones transitorias: Persona, cuerpo y moralidad entre los tsotsiles de Chamula, Chiapas / Perpetual hostility, transitory transformations: Person, body and morality between the tsotsiles of Chamula, Chiapas." Revista Trace, no. 78 (July 31, 2020): 67. http://dx.doi.org/10.22134/trace.78.2020.735.

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El actual estudio etnográfico da cuenta de que lo chon –un aspecto de la persona, generalmente, asociado a lo animal– está relacionado con un estado de permanente hostilidad, presente en el mundo desde tiempos primordiales. Este aspecto, a la vez que potencia la vulnerabilidad entre los humanos, resalta la fortaleza de otros seres, como Dios y el Pukuj. En la búsqueda de lidiar con esa atmósfera de hostilidad y, de mitigar su propia vulnerabilidad, la humanidad experimenta múltiples transformaciones morales-corporales.Abstract: This ethnographic study shows that the chon –an aspect of the pers
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Swindle, T. D., and J. H. Jones. "The xenon isotopic composition of the primordial Martian atmosphere: Contributions from solar and fission components." Journal of Geophysical Research: Planets 102, E1 (1997): 1671–78. http://dx.doi.org/10.1029/96je03110.

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Anderson, Don L. "A model to explain the various paradoxes associated with mantle noble gas geochemistry." Proceedings of the National Academy of Sciences 95, no. 16 (1998): 9087–92. http://dx.doi.org/10.1073/pnas.95.16.9087.

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As a result of an energetic accretion, the Earth is a volatile-poor and strongly differentiated planet. The volatile elements can be accounted for by a late veneer (≈1% of total mass of the Earth). The incompatible elements are strongly concentrated into the exosphere (atmosphere, oceans, sediments, and crust) and upper mantle. Recent geochemical models invoke a large primordial undegassed reservoir with chondritic abundances of uranium and helium, which is clearly at odds with mass and energy balance calculations. The basic assumption behind these models is that excess “primordial” 3He is res
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Chakrabarty, Aritra, and Gijs D. Mulders. "Where Are the Water Worlds? Identifying Exo-water-worlds Using Models of Planet Formation and Atmospheric Evolution." Astrophysical Journal 966, no. 2 (2024): 185. http://dx.doi.org/10.3847/1538-4357/ad3802.

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Abstract Planet formation models suggest that the small exoplanets that migrate from beyond the snowline of the protoplanetary disk likely contain water-ice-rich cores (∼50% by mass), also known as water worlds. While the observed radius valley of the Kepler planets is well explained by the atmospheric dichotomy of the rocky planets, precise measurements of the mass and radius of the transiting planets hint at the existence of these water worlds. However, observations cannot confirm the core compositions of those planets, owing to the degeneracy between the density of a bare water-ice-rich pla
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Atreya, Sushil K., Melissa G. Trainer, Heather B. Franz, et al. "Primordial argon isotope fractionation in the atmosphere of Mars measured by the SAM instrument on Curiosity and implications for atmospheric loss." Geophysical Research Letters 40, no. 21 (2013): 5605–9. http://dx.doi.org/10.1002/2013gl057763.

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Xing, Lei, Dongdong Yan, and Jianheng Guo. "The Mass Fractionation of Helium in the Escaping Atmosphere of HD 209458b*." Astrophysical Journal 953, no. 2 (2023): 166. http://dx.doi.org/10.3847/1538-4357/ace43f.

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Abstract The absorption signals of metastable He in HD 209458b and several other exoplanets can be explained via an escaping atmosphere model with a subsolar He/H ratio. The low abundance of helium can be a result of planet formation if there is a small amount of helium in their primordial atmosphere. However, another possibility is that the low He/H ratio is caused by the process of mass fractionation of helium in the atmosphere. In order to investigate the effect of fractionation in the hydrogen-helium atmosphere, we developed a self-consistent multi-fluid 1D hydrodynamic model based on the
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Sasaki, Sho, and Kiyoshi Nakazawa. "Origin of isotopic fractionation of terrestrial Xe: hydrodynamic fractionation during escape of the primordial H2He atmosphere." Earth and Planetary Science Letters 89, no. 3-4 (1988): 323–34. http://dx.doi.org/10.1016/0012-821x(88)90120-3.

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Ávila, Patricio Javier, Tommaso Grassi, Stefano Bovino, et al. "Presence of water on exomoons orbiting free-floating planets: a case study." International Journal of Astrobiology 20, no. 4 (2021): 300–311. http://dx.doi.org/10.1017/s1473550421000173.

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AbstractA free-floating planet (FFP) is a planetary-mass object that orbits around a non-stellar massive object (e.g. a brown dwarf) or around the Galactic Centre. The presence of exomoons orbiting FFPs has been theoretically predicted by several models. Under specific conditions, these moons are able to retain an atmosphere capable of ensuring the long-term thermal stability of liquid water on their surface. We model this environment with a one-dimensional radiative-convective code coupled to a gas-phase chemical network including cosmic rays and ion-neutral reactions. We find that, under spe
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Misener, William, Matthäus Schulik, Hilke E. Schlichting, and James E. Owen. "Blowin’ in the Nonisothermal Wind: Core-powered Mass Loss with Hydrodynamic Radiative Transfer." Astrophysical Journal 980, no. 1 (2025): 152. https://doi.org/10.3847/1538-4357/ada777.

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Abstract The mass loss rates of planets undergoing core-powered escape are usually modeled using an isothermal Parker-type wind at the equilibrium temperature, T eq. However, the upper atmospheres of sub-Neptunes may not be isothermal if there are significant differences between the opacity to incident visible and outgoing infrared radiation. We model bolometrically driven escape using AIOLOS, a hydrodynamic radiative-transfer code that incorporates double-gray opacities, to investigate the process’s dependence on the visible-to-infrared opacity ratio, γ. For a value of γ ≈ 1, we find that the
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Gibson, Carl H. "Turbulence in the Ocean, Atmosphere, Galaxy, and Universe." Applied Mechanics Reviews 49, no. 5 (1996): 299–315. http://dx.doi.org/10.1115/1.3101929.

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Flows in natural bodies of fluid often become turbulent, with eddy-like motions dominated by inertial-vortex forces. Buoyancy, Coriolis, viscous, self-gravitational, electromagnetic, and other force constraints produce a complex phase space of wave-like hydrodynamic states that interact with turbulence eddies, masquerade as turbulence, and preserve information about previous hydrodynamic states as fossil turbulence. Evidence from the ocean, atmosphere, galaxy and universe are compared with universal similarity hypotheses of Kolmogorov (1941, 1962) for turbulence velocity u, and extensions to s
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Kubyshkina, D., L. Fossati, A. J. Mustill, et al. "The Kepler-11 system: evolution of the stellar high-energy emission and initial planetary atmospheric mass fractions." Astronomy & Astrophysics 632 (November 29, 2019): A65. http://dx.doi.org/10.1051/0004-6361/201936581.

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The atmospheres of close-in planets are strongly influenced by mass loss driven by the high-energy (X-ray and extreme ultraviolet, EUV) irradiation of the host star, particularly during the early stages of evolution. We recently developed a framework to exploit this connection and enable us to recover the past evolution of the stellar high-energy emission from the present-day properties of its planets, if the latter retain some remnants of their primordial hydrogen-dominated atmospheres. Furthermore, the framework can also provide constraints on planetary initial atmospheric mass fractions. Th
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Orell-Miquel, J., F. Murgas, E. Pallé, et al. "A tentative detection of He I in the atmosphere of GJ 1214 b." Astronomy & Astrophysics 659 (March 2022): A55. http://dx.doi.org/10.1051/0004-6361/202142455.

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The He I λ10833 Å triplet is a powerful tool for characterising the upper atmosphere of exoplanets and tracing possible mass loss. Here, we analysed one transit of GJ 1214 b observed with the CARMENES high-resolution spectrograph to study its atmosphere via transmission spectroscopy around the He I triplet. Although previous studies using lower resolution instruments have reported non-detections of He I in the atmosphere of GJ 1214 b, we report here the first potential detection. We reconcile the conflicting results arguing that previous transit observations did not present good opportunities
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