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in this article, we summarize the work of the nasa outer planets assessment group (opag) roadmaps to ocean worlds (row) group. the aim of this group is to assemble the scientific framework that will guide the exploration of ocean worlds, and to identify and prioritize science objectives for ocean worlds over the next s... | the nasa roadmap to ocean worlds |
the dynamical influence of binary companions is expected to profoundly influence planetary systems. however, the difficulty of identifying planets in binary systems has left the magnitude of this effect uncertain; despite numerous theoretical hurdles to their formation and survival, at least some binary systems clearly... | the impact of stellar multiplicity on planetary systems. i. the ruinous influence of close binary companions |
the typically dark surface of the dwarf planet ceres is punctuated by areas of much higher albedo, most prominently in the occator crater. these small bright areas have been tentatively interpreted as containing a large amount of hydrated magnesium sulfate, in contrast to the average surface, which is a mixture of low-... | bright carbonate deposits as evidence of aqueous alteration on (1) ceres |
fresh water—the bloodstream of the biosphere—is at the center of the planetary drama of the anthropocene. water fluxes and stores regulate the earth's climate and are essential for thriving aquatic and terrestrial ecosystems, as well as water, food, and energy security. but the water cycle is also being modified by hum... | illuminating water cycle modifications and earth system resilience in the anthropocene |
we present measurements of methane (ch4) taken aboard a noaa wp-3d research aircraft in 2013 over the haynesville shale region in eastern texas/northwestern louisiana, the fayetteville shale region in arkansas, and the northeastern pennsylvania portion of the marcellus shale region, which accounted for the majority of ... | quantifying atmospheric methane emissions from the haynesville, fayetteville, and northeastern marcellus shale gas production regions |
there has been an incredibly large investment in obtaining high-resolution stellar spectra for determining chemical abundances of stars. this information is crucial to answer fundamental questions in astronomy by constraining the formation and evolution scenarios of the milky way as well as the stars and planets residi... | accuracy and precision of industrial stellar abundances |
the ability to launch small secondary payloads to mars on future science missions present an exciting opportunity for demonstration of advanced technologies for planetary exploration such as aerocapture. over the years, several aerocapture technology demonstration missions have been proposed but none could be realized,... | a low cost mars aerocapture technology demonstrator |
the study of planetary atmospheres is critical to our understanding of the origin and evolution of the solar system. the combined effect of various physical and chemical processes over billions of years have resulted in a variety of planetary atmospheres across the solar system. this paper performs a comparative study ... | comparative study of planetary atmospheres and implications for atmospheric entry missions |
this study presents a general outline of the qitai radio telescope (qtt) project. qitai, the site of the telescope, is a county of xinjiang uygur autonomous region of china, located in the east tianshan mountains at an elevation of about 1800 m. the qtt is a fully steerable, gregorian-type telescope with a standard par... | the qitai radio telescope |
the amount of ultraviolet irradiation and ablation experienced by a planet depends strongly on the temperature of its host star. of the thousands of extrasolar planets now known, only six have been found that transit hot, a-type stars (with temperatures of 7,300-10,000 kelvin), and no planets are known to transit the e... | a giant planet undergoing extreme-ultraviolet irradiation by its hot massive-star host |
early results from jwst-miri programs on low- and high-mass protostars and disks show significant diversity in their mid-infrared spectra, most notably for co2, h2o and c2h2. benzene is detected in disks around very low mass stars. early results from the james webb space telescope-mid-infrared instrument (jwst-miri) gu... | the diverse chemistry of protoplanetary disks as revealed by jwst |
chemical composition of mafic magmas is a critical indicator of physicochemical conditions, such as pressure, temperature, and fluid availability, accompanying melt production in the mantle and its evolution in the continental or oceanic lithosphere. recovering this information has fundamental implications in constrain... | primary magmas and mantle temperatures through time |
turbulence is a fundamental parameter in models of grain growth during the early stages of planet formation. as such, observational constraints on its magnitude are crucial. here we self-consistently analyze alma co(2-1), sma co(3-2), and sma co(6-5) observations of the disk around tw hya and find an upper limit on the... | turbulence in the tw hya disk |
a group of kurtosis-guided-grams, such as kurtogram, protrugram and skrgram, is designed to detect the resonance band excited by faults based on the sparsity index. however, a common issue associated with these methods is that they tend to choose the frequency band with individual impulses rather than the desired fault... | improvement of kurtosis-guided-grams via gini index for bearing fault feature identification |
a fault diagnosis approach based on multi-sensor data fusion is a promising tool to deal with complicated damage detection problems of mechanical systems. nevertheless, this approach suffers from two challenges, which are (1) the feature extraction from various types of sensory data and (2) the selection of a suitable ... | an adaptive multi-sensor data fusion method based on deep convolutional neural networks for fault diagnosis of planetary gearbox |
we present a multiplicity study of all known protostars (94) in the perseus molecular cloud from a karl g. jansky very large array survey at ka-band (8 mm and 1 cm) and c-band (4 and 6.6 cm). the observed sample has a bolometric luminosity range between 0.1 l⊙ and ∼33 l⊙, with a median of 0.7 l⊙. this multiplicity stud... | the vla nascent disk and multiplicity survey of perseus protostars (vandam). ii. multiplicity of protostars in the perseus molecular cloud |
increasing our understanding of earth's biodiversity and responsibly stewarding its resources are among the most crucial scientific and social challenges of the new millennium. these challenges require fundamental new knowledge of the organization, evolution, functions, and interactions among millions of the planet's o... | earth biogenome project: sequencing life for the future of life |
current desalination technologies provide solutions to the increasing water demands of the planet but require substantial electric energy, limiting their sustainable use where conventional power infrastructure may be unavailable. here, we report a direct solar method for desalination that utilizes nanoparticle-assisted... | nanophotonics-enabled solar membrane distillation for off-grid water purification |
the hobby-eberly telescope (het) dark energy experiment (hetdex) is undertaking a blind wide-field low-resolution spectroscopic survey of 540 deg2 of sky to identify and derive redshifts for a million lyα-emitting galaxies in the redshift range 1.9 < z < 3.5. the ultimate goal is to measure the expansion rate of ... | the hetdex instrumentation: hobby-eberly telescope wide-field upgrade and virus |
the timeline of the lunar bombardment in the first gy of solar system history remains unclear. basin-forming impacts (e.g. imbrium, orientale), occurred 3.9-3.7 gy ago, i.e. 600-800 my after the formation of the moon itself. many other basins formed before imbrium, but their exact ages are not precisely known. there is... | the timeline of the lunar bombardment: revisited |
the detection1 of a dust disk around the white dwarf star g29-38 and transits from debris orbiting the white dwarf wd 1145+017 (ref. 2) confirmed that the photospheric trace metals found in many white dwarfs3 arise from the accretion of tidally disrupted planetesimals4. the composition of these planetesimals is similar... | accretion of a giant planet onto a white dwarf star |
ultra-hot jupiters orbit very close to their host star and consequently receive strong irradiation, causing their atmospheric chemistry to be different from the common gas giants. here, we have studied the atmosphere of one of these particular hot planets, mascara-2b/kelt-20b, using four transit observations with high ... | atmospheric characterization of the ultra-hot jupiter mascara-2b/kelt-20b. detection of caii, feii, nai, and the balmer series of h (hα, hβ, and hγ) with high-dispersion transit spectroscopy |
it has been suggested that the gaps and cavities recently discovered in transitional disks are opened by planets. to explore this scenario, we combine two-dimensional two fluid (gas + particle) hydrodynamical calculations with three-dimensional monte carlo radiative transfer simulations and study the observational sign... | observational signatures of planets in protoplanetary disks i. gaps opened by single and multiple young planets in disks |
the molecules with alma at planet-forming scales (maps) large program provides a unique opportunity to study the vertical distribution of gas, chemistry, and temperature in the protoplanetary disks around im lup, gm aur, as 209, hd 163296, and mwc 480. by using the asymmetry of molecular line emission relative to the d... | molecules with alma at planet-forming scales (maps). iv. emission surfaces and vertical distribution of molecules |
we report the results of the statistical analysis of planetary signals discovered in moa-ii microlensing survey alert system events from 2007 to 2012. we determine the survey sensitivity as a function of planet-star mass ratio, q, and projected planet-star separation, s, in einstein radius units. we find that the mass-... | the exoplanet mass-ratio function from the moa-ii survey: discovery of a break and likely peak at a neptune mass |
there is a renewed awareness of the finite nature of the world's soil resources, growing concern about soil security and significant uncertainties about the carrying capacity of the planet. regular assessments of soil conditions from local through to global scales are requested, and there is a clear demand for accurate... | imaging spectroscopy for soil mapping and monitoring |
the interior structure of saturn, the depth of its winds, and the mass and age of its rings constrain its formation and evolution. in the final phase of the cassini mission, the spacecraft dived between the planet and its innermost ring, at altitudes of 2600 to 3900 kilometers above the cloud tops. during six of these ... | measurement and implications of saturn's gravity field and ring mass |
as planetary boundaries are rapidly being approached, humanity has little room for additional expansion and conventional intensification of agriculture, while a growing world population further spreads the food gap. ample evidence exists that improved on-farm water management can close water-related yield gaps to a con... | integrated crop water management might sustainably halve the global food gap |
discovery of the earth's van allen radiation belts by instruments flown on explorer 1 in 1958 was the first major discovery of the space age. the observation of distinct inner and outer zones of trapped megaelectron volt (mev) particles, primarily protons at low altitude and electrons at high altitude, led to early mod... | earth's van allen radiation belts: from discovery to the van allen probes era |
a prominent signal of the anthropocene is the extinction and population reduction of the megabiota—the largest animals and plants on the planet. however, we lack a predictive framework for the sensitivity of megabiota during times of rapid global change and how they impact the functioning of ecosystems and the biospher... | the megabiota are disproportionately important for biosphere functioning |
there are no planets intermediate in size between earth and neptune in our solar system, yet these objects are found around a substantial fraction of other stars1. population statistics show that close-in planets in this size range bifurcate into two classes on the basis of their radii2,3. it is proposed that the group... | a reflective, metal-rich atmosphere for gj 1214b from its jwst phase curve |
airborne observations over the amazon basin showed high aerosol particle concentrations in the upper troposphere (ut) between 8 and 15 km altitude, with number densities (normalized to standard temperature and pressure) often exceeding those in the planetary boundary layer (pbl) by 1 or 2 orders of magnitude. the measu... | aerosol characteristics and particle production in the upper troposphere over the amazon basin |
over the duration of the kepler mission, kic 8462852 was observed to undergo irregularly shaped, aperiodic dips in flux of up to ∼20 per cent. the dipping activity can last for between 5 and 80 d. we characterize the object with high-resolution spectroscopy, spectral energy distribution fitting, radial velocity measure... | planet hunters ix. kic 8462852 - where's the flux? |
we present a kinematic analysis of 152 low surface gravity m7-l8 dwarfs by adding 18 new parallaxes (including 10 for comparative field objects), 38 new radial velocities, and 19 new proper motions. we also add low- or moderate-resolution near-infrared spectra for 43 sources confirming their low surface gravity feature... | population properties of brown dwarf analogs to exoplanets |
cheops (characterising exoplanet satellite) is an esa s-class mission that observes bright stars at high cadence from low-earth orbit. the main aim of the mission is to characterize exoplanets that transit nearby stars using ultrahigh precision photometry. here, we report the analysis of transits observed by cheops dur... | analysis of early science observations with the characterising exoplanets satellite (cheops) using pycheops |
cultivation-independent surveys have shown that the desert soils of antarctica harbour surprisingly rich microbial communities. given that phototroph abundance varies across these antarctic soils, an enduring question is what supports life in those communities with low photosynthetic capacity. here we provide evidence ... | atmospheric trace gases support primary production in antarctic desert surface soil |
we present hubble space telescope (hst) near-ultraviolet (nuv) transits of the hot jupiter wasp-121b, acquired as part of the pancet program. time-series spectra during two transit events were used to measure the transmission spectra between 2280 and 3070 å at a resolution of 30,000. using hst data from 61 space telesc... | the hubble space telescope pancet program: exospheric mg ii and fe ii in the near-ultraviolet transmission spectrum of wasp-121b using jitter decorrelation |
context. ultra-hot jupiters are excellent laboratories for the study of exoplanetary atmospheres. wasp-121b is one of the most studied; many recent analyses of its atmosphere report interesting features at different wavelength ranges.aims: in this paper we analyze one transit of wasp-121b acquired with the high-resolut... | atmospheric rossiter-mclaughlin effect and transmission spectroscopy of wasp-121b with espresso |
we present research results on the rayleigh-taylor (rt) instability at an unstable interface under high-energy density conditions using the national ignition facility at lawrence livermore national laboratory. we can reach pressures in the 100-tpa regime on the hugoniot, or ∼500-gpa regime along a quasi-isentrope, allo... | rayleigh-taylor instabilities in high-energy density settings on the national ignition facility |
for the last few decades the northern hemisphere midlatitudes have seen an increasing number of temperature extreme events. it has been suggested that some of these extremes are related to planetary wave activity. in this study we identify wave propagation regions at 300 hpa using the era-interim dataset from 1980 to 2... | midlatitude winter extreme temperature events and connections with anomalies in the arctic and tropics |
we present the discovery of a spatially unresolved source of submillimeter continuum emission (λ = 855 μm) associated with a young planet, pds 70 c, recently detected in hα emission around the 5 myr old t tauri star pds 70. we interpret the emission as originating from a dusty circumplanetary disk with a dust mass betw... | detection of continuum submillimeter emission associated with candidate protoplanets |
solar and stellar flares are the most intense emitters of x-rays and extreme ultraviolet radiation in planetary systems1,2. on the sun, strong flares are usually found in newly emerging sunspot regions3. the emergence of these magnetic sunspot groups leads to the accumulation of magnetic energy in the corona. when the ... | a comprehensive three-dimensional radiative magnetohydrodynamic simulation of a solar flare |
the maven solar wind electron analyzer (swea) is a symmetric hemispheric electrostatic analyzer with deflectors that is designed to measure the energy and angular distributions of 3-4600-ev electrons in the mars environment. this energy range is important for impact ionization of planetary atmospheric species, and enco... | the maven solar wind electron analyzer |
we report the latest view of kepler solar-type (g-type main-sequence) superflare stars, including recent updates with apache point observatory (apo) 3.5 m telescope spectroscopic observations and gaia-dr2 data. first, we newly conducted apo 3.5 m spectroscopic observations of 18 superflare stars found from kepler 1-min... | do kepler superflare stars really include slowly rotating sun-like stars?—results using apo 3.5 m telescope spectroscopic observations and gaia-dr2 data |
the deep ocean is the largest and least-explored ecosystem on earth, and a uniquely energy-poor environment. the distribution, drivers and origins of deep-sea biodiversity remain unknown at global scales. here we analyse a database of more than 165,000 distribution records of ophiuroidea (brittle stars), a dominant com... | deep-sea diversity patterns are shaped by energy availability |
beijing has been experiencing serious air pollution in recent years, resulting in serious impacts on the local environment and climate and on human health. in addition to individual pollution sources and weather systems, feedback between aerosols and downwelling solar radiation (dsr) and between aerosols and winds also... | intensification of aerosol pollution associated with its feedback with surface solar radiation and winds in beijing |
hematite is a canted antiferromagnet with reddish color that occurs widely on earth and mars. identification and quantification of hematite is conveniently achieved through its magnetic and color properties. hematite characteristics and content are indispensable ingredients in studies of the iron cycle, paleoenvironmen... | the magnetic and color reflectance properties of hematite: from earth to mars |
aims: the shine program is a high-contrast near-infrared survey of 600 young, nearby stars aimed at searching for and characterizing new planetary systems using vlt/sphere's unprecedented high-contrast and high-angular-resolution imaging capabilities. it is also intended to place statistical constraints on the rate, ma... | discovery of a warm, dusty giant planet around hip 65426 |
trappist-1 is a nearby system of seven earth-sized, temperate, rocky exoplanets transiting a jupiter-sized m8.5v star, ideally suited for in-depth atmospheric studies. each trappist-1 planet has been observed in transmission both from space and from the ground, confidently rejecting cloud-free, hydrogen-rich atmosphere... | atmospheric reconnaissance of trappist-1 b with jwst/niriss: evidence for strong stellar contamination in the transmission spectra |
the extratropical atmosphere is characterized by robust circulations which have time scales longer than that associated with developing baroclinic systems but shorter than a season. such low-frequency variability is governed to a large extent by nonlinear dynamics and, hence, is chaotic. a useful aspect of this low-fre... | low-frequency nonlinearity and regime behavior in the northern hemisphere extratropical atmosphere |
the existence of a radius valley in the kepler size distribution stands as one of the most important observational constraints to understand the origin and composition of exoplanets with radii between those of earth and neptune. in this work we provide insights into the existence of the radius valley, first from a pure... | the nature of the radius valley. hints from formation and evolution models |
strongly influenced by thermodynamic stability, the planetary boundary layer (pbl) is key to the exchange of heat, momentum, and moisture between the ground surface and free troposphere. the pbl with different thermodynamic stability across the whole of china, however, is not yet well understood. in this study, the occ... | on the summertime planetary boundary layer with different thermodynamic stability in china: a radiosonde perspective |
while the elevated ambient levels of particulate matters with aerodynamic diameter of 2.5 µm or less (pm2.5) are alleviated largely with the implementation of effective emission control measures, an opposite trend with a rapid increase has been seen in surface ozone (o3) in the north china plain (ncp) region over the p... | rapid increase in summer surface ozone over the north china plain during 2013-2019: a side effect of particulate matter reduction control? |
context. the planet-forming region of protoplanetary disks is cold, dense, and therefore weakly ionized. for this reason, magnetohydrodynamic (mhd) turbulence is thought to be mostly absent, and another mechanism has to be found to explain gas accretion. it has been proposed that magnetized winds, launched from the ion... | global simulations of protoplanetary disks with net magnetic flux. i. non-ideal mhd case |
the asteroid belt contains less than a thousandth of earth's mass and is radially segregated, with s-types dominating the inner belt and c-types the outer belt. it is generally assumed that the belt formed with far more mass and was later strongly depleted. here we show that the present-day asteroid belt is consistent ... | the empty primordial asteroid belt |
materials for extreme environments can help to protect people, structures and the planet. extreme temperatures in aeroplane engines, hypervelocity micrometeoroid impacts on satellites, high-speed machining of ceramics and strong radiation doses in nuclear reactors are just some examples of extreme conditions that mater... | materials for extreme environments |
it is the purpose of this paper to provide a comprehensive documentation of the new ncar (national center for atmospheric research) version of the spectral element (se) dynamical core as part of the community earth system model (cesm2.0) release. this version differs from previous releases of the se dynamical core in s... | ncar release of cam-se in cesm2.0: a reformulation of the spectral element dynamical core in dry-mass vertical coordinates with comprehensive treatment of condensates and energy |
some recently discovered short-period earth- to neptune-sized exoplanets (super-earths) have low observed mean densities that can only be explained by voluminous gaseous atmospheres. here, we study the conditions allowing the accretion and retention of such atmospheres. we self-consistently couple the nebular gas accre... | super-earth atmospheres: self-consistent gas accretion and retention |
polycyclic aromatic hydrocarbon (pah) molecules are abundant and widespread throughout the universe, as revealed by their distinctive set of emission bands at 3.3, 6.2, 7.7, 8.6, 11.3 and 12.7 μm, which are characteristic of their vibrational modes. they are ubiquitously seen in a wide variety of astrophysical regions,... | spitzer's perspective of polycyclic aromatic hydrocarbons in galaxies |
the exomol database (www.exomol.com) provides molecular data for spectroscopic studies of hot atmospheres. while the data are intended for studies of exoplanets and other astronomical bodies, the dataset is widely applicable. the basic form of the database is extensive line lists; these are supplemented with partition ... | the 2020 release of the exomol database: molecular line lists for exoplanet and other hot atmospheres |
exoplanets orbiting pre-main-sequence stars are laboratories for studying planet evolution processes, including atmospheric loss, orbital migration, and radiative cooling. v1298 tau, a young solar analog with an age of 23 ± 4 myr, is one such laboratory. the star is already known to host a jupiter-sized planet on a 24 ... | four newborn planets transiting the young solar analog v1298 tau |
the extreme ultraviolet (euv)/x-ray photoevaporation and core-powered mass-loss models are both capable of reproducing the bimodality in the sizes of small, close-in exoplanets observed by the kepler space mission, often referred to as the 'radius gap'. however, it is unclear which of these two mechanisms dominates the... | photoevaporation versus core-powered mass-loss: model comparison with the 3d radius gap |
this study investigates the influences of urban land cover on the extreme rainfall event over the zhengzhou city in central china on 20 july 2021 using the weather research and forecasting model at a convection-permitting scale [1-km resolution in the innermost domain (d3)]. two ensembles of simulation (ctrl, nurb), ea... | on the influences of urbanization on the extreme rainfall over zhengzhou on 20 july 2021: a convection-permitting ensemble modeling study |
from 2019 to 2021, scientific field campaigns have been organised in corsica by the muséum national d'histoire naturelle, the office français de la biodiversité and the collectivité de corse as part of the "our planet reviewed" naturalist exploration programme. this paper presents the context, the state of biogeographi... | our planet reviewed in corsica 2019-2021: a large-scale survey of neglected biodiversity on a mediterranean island |
we report the discovery of 6576 new spectroscopically confirmed white dwarf and subdwarf stars in the sloan digital sky survey data release 12. we obtain teff, log g and mass for hydrogen atmosphere white dwarf stars (das) and helium atmosphere white dwarf stars (dbs), estimate the calcium/helium abundances for the whi... | new white dwarf and subdwarf stars in the sloan digital sky survey data release 12 |
previous studies of planet occurrence rates largely relied on photometric stellar characterizations. in this paper, we present planet occurrence rates for mid-type m dwarfs using spectroscopy, parallaxes, and photometry to determine stellar characteristics. our spectroscopic observations have allowed us to constrain sp... | kepler planet occurrence rates for mid-type m dwarfs as a function of spectral type |
constraining dust properties of planet-forming disks via high-angular-resolution observations is fundamental to understanding how solids are trapped in substructures and how dust growth may be favored or accelerated therein. we use alma dust continuum observations of the molecules with alma at planet-forming scales (ma... | molecules with alma at planet-forming scales (maps). xiv. revealing disk substructures in multiwavelength continuum emission |
critical measurements for understanding accretion and the dust/gas ratio in the solar nebula, where planets were forming 4.5 billion years ago, are being obtained by the giada (grain impact analyser and dust accumulator) experiment on the european space agency’s rosetta spacecraft orbiting comet 67p/churyumov-gerasimen... | dust measurements in the coma of comet 67p/churyumov-gerasimenko inbound to the sun |
we have introduced a fast and versatile computer code, ggchem, to determine the chemical composition of gases in thermo-chemical equilibrium down to 100 k, with or without equilibrium condensation. we have reviewed the data for molecular equilibrium constants, kp(t), from several sources and discussed which functional ... | equilibrium chemistry down to 100 k. impact of silicates and phyllosilicates on the carbon to oxygen ratio |
comets are considered to be some of the most pristine and unprocessed solar system objects accessible to in situ exploration. investigating their molecular and elemental composition takes us on a journey back to the early period of our solar system and possibly even further. in this work, we deduce the bulk abundances ... | elemental and molecular abundances in comet 67p/churyumov-gerasimenko |
context. the formation of planetesimals in protoplanetary disks is not well-understood. streaming instability is a promising mechanism to directly form planetesimals from pebble-sized particles, provided a high enough solids-to-gas ratio. however, local enhancements of the solids-to-gas ratio are difficult to realize i... | planetesimal formation near the snowline: in or out? |
detailed characterization of exoplanets has begun to yield measurements of their atmospheric properties that constrain the planets’ origins and evolution. for example, past observations of the dayside emission spectrum of the hot jupiter wasp-12b indicated that its atmosphere has a high carbon-to-oxygen ratio (c/o >... | a detection of water in the transmission spectrum of the hot jupiter wasp-12b and implications for its atmospheric composition |
in this study, it is shown that cmip5 global climate models (gcms) that convert supercooled water to ice at relatively warm temperatures tend to have a greater mean-state cloud fraction and more negative cloud feedback in the middle and high latitude southern hemisphere. we investigate possible reasons for these relati... | on the relationships among cloud cover, mixed-phase partitioning, and planetary albedo in gcms |
seagrasses colonized the sea on at least three independent occasions to form the basis of one of the most productive and widespread coastal ecosystems on the planet. here we report the genome of zostera marina (l.), the first, to our knowledge, marine angiosperm to be fully sequenced. this reveals unique insights into ... | the genome of the seagrass zostera marina reveals angiosperm adaptation to the sea |
mud volcanism, or sedimentary volcanism, represents one of the most intriguing phenomena of the earth's crust, with important implications in energy resource exploration, seismicity, geo-hazard and atmospheric budget of greenhouse gases. since the first review papers were issued at the beginning of 2000s, a large amoun... | mud volcanism: an updated review |
circumstellar disks of planetary debris are now known or suspected to closely orbit hundreds of white dwarf stars. to date, both data and theory support disks that are entirely contained within the preceding giant stellar radii, and hence must have been produced during the white dwarf phase. this picture is strengthene... | circumstellar debris and pollution at white dwarf stars |
the detection of exoplanets orbiting other stars has revolutionized our view of the cosmos. first results suggest that it is teeming with a fascinating diversity of rocky planets, including those in the habitable zone. even our closest star, proxima centauri, harbors a small planet in its habitable zone, proxima b. wit... | how to characterize habitable worlds and signs of life |
interpretations of exoplanetary transmission spectra have been undermined by apparent obscuration due to clouds/hazes. debate rages on whether weak h2o features seen in exoplanet spectra are due to clouds or inherently depleted oxygen. assertions of solar h2o abundances have relied on making a priori model assumptions,... | hd 209458b in new light: evidence of nitrogen chemistry, patchy clouds and sub-solar water |
the planet venus is covered by thick clouds of sulfuric acid that move westwards because the entire upper atmosphere rotates much faster than the planet itself. at the cloud tops, about 65 km in altitude, small-scale features are predominantly carried by the background wind at speeds of approximately 100 m s-1. in cont... | large stationary gravity wave in the atmosphere of venus |
the loss of water from mars to space is thought to result from the transport of water to the upper atmosphere, where it is dissociated to hydrogen and escapes the planet. recent observations have suggested large, rapid seasonal intrusions of water into the upper atmosphere, boosting the hydrogen abundance. we use the a... | stormy water on mars: the distribution and saturation of atmospheric water during the dusty season |
the giant impact hypothesis remains the leading theory for lunar origin. however, current models struggle to explain the moon's composition and isotopic similarity with earth. here we present a new lunar origin model. high-energy, high-angular-momentum giant impacts can create a post-impact structure that exceeds the c... | the origin of the moon within a terrestrial synestia |
radial velocity monitoring has found the signature of a msini = 1.3m⊕ planet located within the habitable zone (hz) of proxima centauri. despite a hotter past and an active host star, the planet proxima b could have retained enough volatiles to sustain surface habitability. here we use a 3d global climate model (gcm) t... | the habitability of proxima centauri b. ii. possible climates and observability |
we redetermine the abundances of all iron group nuclei in the sun, based on neutral and singly-ionised lines of sc, ti, v, mn, fe, co and ni in the solar spectrum. we employ a realistic 3d hydrodynamic model solar atmosphere, corrections for departures from local thermodynamic equilibrium (nlte), stringent line selecti... | the elemental composition of the sun. ii. the iron group elements sc to ni |
nucleosynthetic isotope anomalies are powerful tracers to determine the provenance of meteorites and their components, and to identify genetic links between these materials. here we show that chondrules and matrix separated from the allende cv3 chondrite have complementary nucleosynthetic mo isotope anomalies. these an... | molybdenum isotopic evidence for the origin of chondrules and a distinct genetic heritage of carbonaceous and non-carbonaceous meteorites |
earth is the only planet known to have continents, although how they formed and evolved is unclear. here using the oxygen isotope compositions of dated magmatic zircon, we show that the pilbara craton in western australia, earth's best-preserved archaean (4.0-2.5 billion years ago (ga)) continental remnant, was built i... | giant impacts and the origin and evolution of continents |
forests play a key role in humanity's current challenge to mitigate climate change thanks to their capacity to sequester carbon. preserving and expanding forest cover is considered essential to enhance this carbon sink. however, changing the forest cover can further affect the climate system through biophysical effects... | revealing the widespread potential of forests to increase low level cloud cover |
gj 3470b is a warm neptune transiting an m-dwarf star at the edge of the evaporation desert. it offers the possibility of investigating how low-mass, close-in exoplanets evolve under the irradiation from their host stars. we observed three transits of gj 3470b in the lyman-α line with the hubble space telescope (hst) a... | hubble pancet: an extended upper atmosphere of neutral hydrogen around the warm neptune gj 3470b |
variability in the light curves of spotted, rotating stars is often non-sinusoidal and quasi-periodic - spots move on the stellar surface and have finite lifetimes, causing stellar flux variations to slowly shift in phase. a strictly periodic sinusoid therefore cannot accurately model a rotationally modulated stellar l... | inferring probabilistic stellar rotation periods using gaussian processes |
nitrogen is a critical component of the economy, food security, and planetary health. many of the world's sustainability targets hinge on global nitrogen solutions, which, in turn, contribute lasting benefits for (i) world hunger; (ii) soil, air, and water quality; (iii) climate change mitigation; and (iv) biodiversity... | a world of cobenefits: solving the global nitrogen challenge |
agricultural activities are a major source contributing to nh3 emissions in shanghai and most other regions of china; however, there is a long-standing and ongoing controversy regarding the contributions of vehicle-emitted nh3 to the urban atmosphere. from april 2014 to april 2015, we conducted measurements of a wide r... | the importance of vehicle emissions as a source of atmospheric ammonia in the megacity of shanghai |
the widely accepted paradigm of earth's geochemical evolution states that the successive extraction of melts from the mantle over the past 4.5 billion years formed the continental crust, and produced at least one complementary melt-depleted reservoir that is now recognized as the upper-mantle source of mid-ocean-ridge ... | kimberlites reveal 2.5-billion-year evolution of a deep, isolated mantle reservoir |
turbulence can transport angular momentum in protoplanetary disks and influence the growth and evolution of planets. with spatially and spectrally resolved molecular emission line measurements provided by (sub)millimeter interferometric observations, it is possible to directly measure non-thermal motions in the disk ga... | weak turbulence in the hd 163296 protoplanetary disk revealed by alma co observations |
computing and using opacities is a key part of modeling and interpreting data of exoplanetary atmospheres. since the underlying spectroscopic line lists are constantly expanding and currently include up to ∼1010-1011 transition lines, the opacity calculator codes need to become more powerful. here we present major upgr... | helios-k 2.0 opacity calculator and open-source opacity database for exoplanetary atmospheres |
here we present a publicly available database of opacities for molecules of astrophysical interest named exomolop that has been compiled for over 80 species, and is based on the latest line list data from the exomol, hitemp, and mollist databases. these data are generally suitable for characterising high-temperature ex... | the exomolop database: cross sections and k-tables for molecules of interest in high-temperature exoplanet atmospheres |
advent of satellite altimetry brought into focus the pervasiveness of mesoscale eddies o (100 ) km in size, which are the ocean's analogue of weather systems and are often regarded as the spectral peak of kinetic energy (ke). yet, understanding of the ocean's spatial scales has been derived mostly from fourier analysis... | global energy spectrum of the general oceanic circulation |
we explain the axisymmetric gaps seen in recent long-baseline observations of the hl tau protoplanetary disc with the atacama large millimetre/submillimetre array (alma) as being due to the different response of gas and dust to embedded planets in protoplanetary discs. we perform global, three-dimensional dusty smoothe... | on planet formation in hl tau |
the transit of primordial black holes through a white dwarf causes localized heating around the trajectory of the black hole through dynamical friction. for sufficiently massive black holes, this heat can initiate runaway thermonuclear fusion causing the white dwarf to explode as a supernova. the shape of the observed ... | dark matter triggers of supernovae |
we have developed ultralow-noise electronics in combination with repetitive, nondestructive readout of a thick, fully depleted charge-coupled device (ccd) to achieve an unprecedented noise level of 0.068 e- rms /pixel . this is the first time that discrete subelectron readout noise has been achieved reproducible over m... | single-electron and single-photon sensitivity with a silicon skipper ccd |
we present an open-source python package, orbits from radial velocity, absolute, and/or relative astrometry (orvara), to fit keplerian orbits to any combination of radial velocity, relative astrometry, and absolute astrometry data from the hipparcos-gaia catalog of accelerations. by combining these three data types, on... | orvara: an efficient code to fit orbits using radial velocity, absolute, and/or relative astrometry |
we present a new global model for the earth's lithosphere and upper mantle (lithoref18) obtained through a formal joint inversion of 3-d gravity anomalies, geoid height, satellite-derived gravity gradients and absolute elevation complemented with seismic, thermal and petrological prior information. the model includes c... | a global reference model of the lithosphere and upper mantle from joint inversion and analysis of multiple data sets |
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