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| Open AccessHabitability and sub glacial liquid water on planets of M-dwarf stars
A long-standing issue in astrobiology is whether planets orbiting the most abundant type of stars, M-dwarfs, can support liquid water and eventually life. A new study shows that subglacial melting may provide an answer, significantly extending the habitability region, in particular around M-dwarf stars, which are also the most promising for biosignature detection with the present and near-future technology.
- Amri Wandel
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Article
| Open AccessUltra-high-resolution observations of persistent null-point reconnection in the solar corona
Magnetic reconnection is a fundamental energy release mechanism in space and laboratory plasmas. Here, the authors show persistent magnetic null-point reconnection in the solar corona at a scale of about 390 km.
- X. Cheng
- , E. R. Priest
- & S. Parenti
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Article
| Open AccessParticle-sounding of the spatial structure of kinetic Alfvén waves
Kinetic Alfven Waves (KAWs) are ubiquitous in space plasmas. Here, the authors show that application of particle sounding technique to Magnetospheric Multiscale Mission data enables measuring perpendicular wavelength of KAWs.
- Z.-Y. Liu
- , Q.-G. Zong
- & G. Le
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| Open AccessUracil in the carbonaceous asteroid (162173) Ryugu
Uracil was identified in the sample returned from the asteroid Ryugu. Having been provided to the early Earth as a component in such asteroidal materials, these molecules might have played a role for prebiotic chemical evolution on the early Earth
- Yasuhiro Oba
- , Toshiki Koga
- & Yuichi Tsuda
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Article
| Open AccessGas phase synthesis of the C40 nano bowl C40H10
Nanobowls represent building blocks of fullerenes and nanotubes as detected in combustion systems and deep space, but their formation mechanisms in these environments have remained elusive. Here, the authors explore the gas-phase formation of benzocorannulene and beyond to the C40 nanobowl.
- Lotefa B. Tuli
- , Shane J. Goettl
- & Ralf I. Kaiser
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| Open AccessInsights into the formation and evolution of extraterrestrial amino acids from the asteroid Ryugu
Amino acid concentrations from 2 particles returned from different touchdown sites on the surface of Ryugu are reported. Differences in chemistry suggest different levels of aqueous alteration are recorded at the 2 sampled locations.
- Christian Potiszil
- , Tsutomu Ota
- & Eizo Nakamura
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| Open AccessPlanetary defense with the Double Asteroid Redirection Test (DART) mission and prospects
NASA’s Double Asteroid Redirection Test (DART) mission intentionally impacted the asteroid Dimorphos on September 26, 2022, and this kinetic impact changed Dimorphos’ orbit around its binary companion Didymos. This first planetary defense test explored technological readiness for this method of asteroid deflection.
- Andrew S. Rivkin
- & Andrew F. Cheng
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| Open AccessMagnesium oxide-water compounds at megabar pressure and implications on planetary interiors
Magnesium Oxide and water are abundant in the interior of planets. Here, the authors predict three new MgO-H2O compounds: Mg2O3H2, MgO3H4 and MgO4H6, and they exhibit superionic behavior in planetary interior conditions.
- Shuning Pan
- , Tianheng Huang
- & Jian Sun
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Article
| Open AccessThermodynamics of diamond formation from hydrocarbon mixtures in planets
This study combines computational chemistry and machine learning to provide insight on whether diamonds can form inside ice giants. This can help explain the dichotomy of Uranus and Neptune.
- Bingqing Cheng
- , Sebastien Hamel
- & Mandy Bethkenhagen
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| Open AccessLife on Mars, can we detect it?
Searching for evidence of life on Mars is a major impetus for exploration. A new study published in Nature Communications finds that current Mars mission instruments lack the essential sensitivity to identify life traces in Chilean desert samples that strongly resemble the martian area currently under study by NASA’s Perseverance rover.
- Carol R. Stoker
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Article
| Open AccessAsymmetric eROSITA bubbles as the evidence of a circumgalactic medium wind
The origins of the pair of X-ray bubbles, called eROSITA bubbles (eRBs), detected in the halo of Milky Way are debated. Here, the authors show hydrodynamical simulations suggesting circumgalactic medium wind model can explain asymmetric eRBs.
- Guobin Mou
- , Dongze Sun
- & Zhicheng He
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Article
| Open AccessDiffuse auroral precipitation driven by lower-band chorus second harmonics
Scattering by the upper- and lower-band chorus waves are the dominant cause of diffuse auroral precipitation. Here, the authors show that the lower-band chorus alone satisfies the preferred condition for the generation of second harmonics to trigger the diffuse auroral electron precipitation.
- Xiongdong Yu
- , Zhigang Yuan
- & H. O. Funsten
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Article
| Open AccessEfficient stabilization of cyanonaphthalene by fast radiative cooling and implications for the resilience of small PAHs in interstellar clouds
The abundances of small Polycyclic Aromatic Hydrocarbons (PAHs) observed in interstellar clouds has surprised astronomers and confounded astrochemical models. Here, the authors show that fast radiative cooling by Recurrent Fluorescence efficiently stabilizes the small PAH cation 1-cyanonaphthalene.
- Mark H. Stockett
- , James N. Bull
- & Boxing Zhu
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Article
| Open AccessEquilibrium selection via current sheet relaxation and guide field amplification
Magnetized plasmas display continuous spectra of current-sheet equilibria. How they select a particular equilibrium is not well understood. Now, equilibrium selection in magnetized plasmas is studied by analytical theory, particle-in-cell simulations and spacecraft observations, highlighting the role of current-sheet relaxation processes.
- Young Dae Yoon
- , Deirdre E. Wendel
- & Gunsu S. Yun
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Article
| Open AccessEvidence of structural discontinuities in the inner core of red-giant stars
Red giant stars enter the clump phase as the helium in the cores start fusing. Here, the authors show evidence for large core structural discontinuities in 7% of Kepler satellite clump star data implying that the mixing region beyond the convective core boundary has a radiative thermal stratification.
- Mathieu Vrard
- , Margarida S. Cunha
- & Benoît Mosser
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Article
| Open AccessBepiColombo mission confirms stagnation region of Venus and reveals its large extent
BepiColombo mission had two Venus flybys on its way to Mercury. Here, the authors show that during its second flyby of Venus BepiColombo has crossed the stagnation region, which was predicted by the models.
- M. Persson
- , S. Aizawa
- & G. Murakami
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Article
| Open AccessBa+2 ion trapping using organic submonolayer for ultra-low background neutrinoless double beta detector
One of the possible events signaling a neutrinoless double beta decay is a Xe atom decaying into a Ba ion and two electrons. Aiming at the realisation of a detector for such a process, the authors show that Ba ions can be efficiently trapped (chelated) in vacuum by an organic molecule layer on a surface.
- P. Herrero-Gómez
- , J. P. Calupitan
- & J. T. White
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| Open AccessThe sound of a Martian dust devil
Dust devils are common on Mars and understanding their dynamics is important to gain insights about the meteorology of the planet. Here, the authors show characteristics of a Martian dust devil and its sound from Perseverance rover multi-sensor data combined with modelling.
- N. Murdoch
- , A. E. Stott
- & D. Mimoun
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Article
| Open AccessMicrowave imaging of quasi-periodic pulsations at flare current sheet
Quasi-periodic pulsations (QPPs) are frequently detected in solar and stellar flares, but the underlying physical mechanisms are still to be ascertained. Here, the authors show microwave QPPs during a solar flare originating from quasi-periodic magnetic reconnection at the flare current sheet.
- Yuankun Kou
- , Xin Cheng
- & Mingde Ding
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Article
| Open AccessRossby wave second harmonic generation observed in the middle atmosphere
Rossby waves occur in rotating fluids. Here, the authors show observation of a Rossby wave second harmonic generation event in the middle atmosphere and confirm theoretically anticipated Rossby wave nonlinearity.
- Maosheng He
- & Jeffrey M. Forbes
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| Open AccessLiquid water on cold exo-Earths via basal melting of ice sheets
Liquid water is key for life as we know it. Here, the authors show even with a modest geothermal heat flow, subglacial oceans of liquid water can form at the base of and within the ice sheets on exo-Earths, which may provide habitable conditions for an extended period.
- Lujendra Ojha
- , Bryce Troncone
- & George McDonald
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| Open AccessInner southern magnetosphere observation of Mercury via SERENA ion sensors in BepiColombo mission
BepiColombo mission had already two flybys of Mercury, over the total of six, as planned before entering the planet’s orbit in 2025. Here, the authors show the first ion measurements of Mercury’s inner southern magnetosphere during BepiColombo mission’s first Mercury flyby.
- S. Orsini
- , A. Milillo
- & A. Vorburger
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| Open AccessConstraining surface properties of asteroid (162173) Ryugu from numerical simulations of Hayabusa2 mission impact experiment
Hayabusa2 mission impact experiment on asteroid Ryugu formed a crater larger than expected. Here, the authors show numerical impact simulations and find that the target cohesion may be very low, indicating the Hayabusa2 impact experiment probably occurred in the transitional cratering regime.
- Martin Jutzi
- , Sabina D. Raducan
- & Masahiko Arakawa
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Article
| Open AccessUnraveling sulfur chemistry in interstellar carbon oxide ices
The authors report photolytic H atom transfer reactions of HOSO• in astronomical CO & CO2 ices, forming reactive acyl radicals & molecular complexes with SO & SO2. Connecting the photochemistry of S oxides & C oxides in cold molecular clouds in the interstellar medium.
- Xiaolong Li
- , Bo Lu
- & Xiaoqing Zeng
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Article
| Open AccessAlternate oscillations of Martian hydrogen and oxygen upper atmospheres during a major dust storm
Dust storms on Mars drive water escape to space. Here, the authors show the impact Martian dust storms have on the abundance of atmospheric hydrogen and oxygen, and how this helps to overall oxidize the Martian atmosphere.
- Kei Masunaga
- , Naoki Terada
- & Ichiro Yoshikawa
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| Open AccessDirect observations of energy transfer from resonant electrons to whistler-mode waves in magnetosheath of Earth
Excitation of whistler-mode waves by cyclotron instability is considered as the likely generation process of the waves. Here, the authors show direct observational evidence for locally ongoing secular energy transfer from the resonant electrons to the whistler-mode waves in Earth’s magnetosheath.
- N. Kitamura
- , T. Amano
- & J. L. Burch
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Article
| Open AccessLaboratory evidence of magnetic reconnection hampered in obliquely interacting flux tubes
Magnetic reconnection acts as energy transfer process in plasma and induces processes like plasma heating, particle acceleration. Here the authors demonstrate the variation of magnetic reconnection between two flux tubes in the presence of external magnetic field.
- Simon Bolaños
- , Andrey Sladkov
- & Julien Fuchs
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Article
| Open AccessSpectral interpretation of late-stage mare basalt mineralogy unveiled by Chang’E-5 samples
Laboratory spectroscopic and X-ray diffraction analyses on the Chang’E-5 lunar soil samples have demonstrated that the spectral features of lunar late-stage mare basalts are representative of iron-rich high-Ca pyroxene rather than olivine.
- Dawei Liu
- , Xing Wang
- & Chunlai Li
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Article
| Open AccessA wind environment and Lorentz factors of tens explain gamma-ray bursts X-ray plateau
The origin of the plateau observed in the early X-ray light curves of gamma ray bursts (GRBs) is debated. Here, the authors show that the observed plateau can be explained within the classical GRB model by considering expanding shell with initial Lorentz factor of a few tens.
- Hüsne Dereli-Bégué
- , Asaf Pe’er
- & Maria G. Dainotti
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Article
| Open AccessRepeating fast radio burst 20201124A originates from a magnetar/Be star binary
Fast radio bursts (FRBs) are bright millisecond or shorter duration transient events. Here, the authors propose that FRB 20201124A comes from a binary system of a magnetar and a Be star with a decretion disk.
- F. Y. Wang
- , G. Q. Zhang
- & K. S. Cheng
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Article
| Open AccessThe imprint of star formation on stellar pulsations
The classical stellar evolution concept assumes that when the stars arrive on the main sequence, there is no traceable mark remains about their early evolutionary history. Here, the authors show that the accretion history leaves an imprint on the interior structure of the stars that are potentially detectable via asteroseismology.
- Thomas Steindl
- , Konstanze Zwintz
- & Eduard Vorobyov
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Article
| Open AccessJuno spacecraft gravity measurements provide evidence for normal modes of Jupiter
Juno spacecraft experienced unknown accelerations near the closest approach to Jupiter. Here, the authors show that Jupiter’s axially symmetric, north-south asymmetric gravity field measured by Juno is perturbed by a time-variable component, associated to internal oscillations.
- Daniele Durante
- , Tristan Guillot
- & Scott J. Bolton
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Article
| Open AccessThe supernova remnant SN 1006 as a Galactic particle accelerator
It is known that cosmic rays could be accelerated by shock waves in supernova (SN) remnants. Here, the authors show that SN 1006 remnant is an efficient source of cosmic rays, providing observational support for the quasi-parallel acceleration mechanism.
- Roberta Giuffrida
- , Marco Miceli
- & Giovanni Peres
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Article
| Open AccessWidespread impact-generated porosity in early planetary crusts
Large impacts can create deep lying porosity far away from the crater. This result explains GRAIL’s findings and suggests impacts could support widespread fluid circulation, which has implications for habitable environments on early Earth and Mars.
- Sean E. Wiggins
- , Brandon C. Johnson
- & Simone Marchi
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Article
| Open AccessEndogenically sourced volatiles on Charon and other Kuiper belt objects
We show cryovolcanic eruptions released sufficient methane to source volatile products on Charon. Irradiated methane products are found on other Kuiper belt objects, so endogenically sourced volatiles could be important across the Kuiper belt.
- Stephanie M. Menten
- , Michael M. Sori
- & Ali M. Bramson
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Article
| Open AccessInferring interiors and structural history of top-shaped asteroids from external properties of asteroid (101955) Bennu
Asteroid interiors are key to understand their formation and evolution. Here, the authors show that numerically simulated low-cohesion and low-friction structures with several high-cohesion internal zones can explain asteroid Bennu’s geophysical characteristics and the absence of the moons.
- Yun Zhang
- , Patrick Michel
- & Dante S. Lauretta
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Article
| Open AccessDetection of companion galaxies around hot dust-obscured hyper-luminous galaxy W0410-0913
Lyman-alpha emission is one of the observational probes for the high-redshift universe. Here, the authors show several Lyman-alpha emitting companion galaxies around the hot dust-obscured galaxy W0410-091 suggesting that the galaxy evolves in a very dense environment.
- M. Ginolfi
- , E. Piconcelli
- & A. Verhamme
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| Open AccessPhotochemical and thermochemical pathways to S2 and polysulfur formation in the atmosphere of Venus
Polysulfur compounds have been ascribed as the unknown near-UV absorbers in Venusian atmosphere and play a key role in the sulfur chemical cycle of this planet. Here, authors establish their production from (SO)2 on the grounds of quantifications of photochemical and thermal pathways involved in the sulfur chemical cycle of the planet.
- Antonio Francés-Monerris
- , Javier Carmona-García
- & Daniel Roca-Sanjuán
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Article
| Open AccessNGC1818 unveils the origin of the extended main-sequence turn-off in young Magellanic Clouds clusters
The nature of young star clusters in the Magellanic Clouds is debated. Here, the authors show an alternative approach that exploits data to exclude the presence of age differences greater than a few million years among cluster stars in a very young cluster.
- Giacomo Cordoni
- , Antonino P. Milone
- & Maria V. Legnardi
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Article
| Open AccessEarly crustal processes revealed by the ejection site of the oldest martian meteorite
A new study pinpoints the ejection site of the 4.5-Ga-old Martian breccia NWA 7034 and paired stones to an area northeast of the Terra 679 Cimmeria–Sirenium province.
- A. Lagain
- , S. Bouley
- & P. A. Bland
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Article
| Open AccessPrimitive noble gases sampled from ocean island basalts cannot be from the Earth’s core
Li et al. established a liquid-liquid partition model based on ab initio calculations to reveal that He and Ne strongly fractionate during core-mantle separation, which concludes the primitive volatiles seen in hotspots cannot be from the core.
- Yunguo Li
- , Lidunka Vočadlo
- & John P. Brodholt
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Article
| Open Access21st-century stagnation in unvegetated sand-sea activity
Earth’s largest dune fields are set to become less dynamic on average over this century due to anthropogenic climate change, with no future action able to mitigate this effect, as predicted by the newest iteration of CMIP models.
- Andrew Gunn
- , Amy East
- & Douglas J. Jerolmack
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Article
| Open AccessIdentification and characterization of a new ensemble of cometary organic molecules
A new analysis of Rosetta mass spectra reveals an ensemble of complex organic molecules with striking similarities to other organic reservoirs in the Solar System, including Saturn’s ring rain material, pointing at a likely joint prestellar history.
- N. Hänni
- , K. Altwegg
- & S. F. Wampfler
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Article
| Open AccessStability of high-temperature salty ice suggests electrolyte permeability in water-rich exoplanet icy mantles
Hot cubic ice is shown to retain dissolved salt in its lattice, suggesting the mantle of water-rich exoplanets is more permeable to electrolytes than assumed, which has implications on its properties and on the element cycles inside such planets.
- Jean-Alexis Hernandez
- , Razvan Caracas
- & Stéphane Labrosse
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Article
| Open AccessEvidence of water on the lunar surface from Chang’E-5 in-situ spectra and returned samples
Laboratory analysis of returned Chang’E-5 samples from the lunar surface show their hydroxyl contents to be on the weak end of lunar hydration features.
- Jianjun Liu
- , Bin Liu
- & Ziyuan Ouyang
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Article
| Open AccessThree-dimensional network of filamentary currents and super-thermal electrons during magnetotail magnetic reconnection
Magnetotail reconnection plays an important role in explosive energy conversion. Here, the authors show direct evidence of super-thermal electrons up to 300 keV within X-line region in Earth’s magnetotail, indicating effective electron acceleration due to turbulence.
- Xinmin Li
- , Rongsheng Wang
- & Shui Wang
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Article
| Open AccessDirect observations of anomalous resistivity and diffusion in collisionless plasma
It is suggested that waves can provide both diffusion and resistivity that can potentially support the reconnection electric field in low-density astrophysical plasmas. Here, the authors show, using direct spacecraft measurements, that the waves contribute to anomalous diffusion but do not contribute to the reconnection electric field.
- D. B. Graham
- , Yu. V. Khotyaintsev
- & K. Dokgo
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Article
| Open AccessAnalogue cosmological particle creation in an ultracold quantum fluid of light
Under certain conditions light can act as a fluid like a Bose-Einstein condensate. Here the authors discuss an analogy of cosmological particle creation using such a quantum fluid of light.
- Jeff Steinhauer
- , Murad Abuzarli
- & Quentin Glorieux
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Article
| Open AccessStructural transition and re-emergence of iron's total electron spin in (Mg,Fe)O at ultrahigh pressure
Iron spin transition occurs at ultrahigh pressure. The total electron spin increases from 0 to 1 as the structural transition of (Mg,Fe)O occurs (~0.6 TPa) and drops back to 0 at higher pressure. Its effects on exoplanet interiors are anticipated.
- Han Hsu
- & Koichiro Umemoto