Pub Date : 2025-12-17DOI: 10.1038/s41550-025-02718-0
S. M. Levin, Z. Zhang, S. J. Bolton, S. Brown, A. I. Ermakov, J. Feng, K. Hand, S. Misra, M. Siegler, D. Stevenson, W. McKinnon, R. Akiba
Jupiter’s moon Europa is thought to harbour a saltwater ocean beneath a variously disrupted ice shell, and it is, thus, one of the highest priority astrobiology targets in the Solar System. Estimates of the ice-shell thickness range from 3 km to over 30 km, and observations by the Galileo spacecraft indicated widespread regions of ice disruption (chaotic terrain) leading to speculation that the ice shell may contain subsurface cracks, faults, pores or bubbles. If persistent, subsurface cracks could provide pathways for habitability by facilitating the transport of oxygen and nutrients between the surface and the ocean. Here we report on observations of Europa’s subsurface ice shell obtained by the Juno microwave radiometer in 2022. For the idealized case of pure water ice, the data are consistent with the existence of a thermally conductive ice shell with a thickness of 29 ± 10 km and with the presence of cracks, pores or other scatterers extending to depths of hundreds of metres below the surface with a characteristic size smaller than a few centimetres in radius. An ice-shell salinity of 15 mg kg−1, as indicated by models based on terrestrial marine ice, would reduce our estimate of the thickness of the ice shell by about 5 km, substantially less than our 10 km uncertainty. The low volume fraction, small size and shallow depth of the scatterers indicate that the fracture interfaces observed at Europa’s surface are alone unlikely to be capable of carrying nutrients between the surface and the ocean. Microwave observations of Jupiter’s moon Europa reveal subsurface properties of the ice shell covering a purported global ocean. The shell is 29 ± 10 km thick, with fractures or pores a few centimetres across that extend hundreds of metres deep.
木星的卫星木卫二被认为在被各种破坏的冰壳下有一个咸水海洋，因此它是太阳系中最优先考虑的天体生物学目标之一。对冰壳厚度的估计范围从3公里到超过30公里，伽利略号航天器的观测表明，冰破坏的广泛区域（混乱的地形）导致推测冰壳可能包含地下裂缝、断层、孔隙或气泡。如果持续存在，地下裂缝可以通过促进氧气和营养物质在地表和海洋之间的运输，为宜居性提供途径。在这里，我们报告了2022年朱诺微波辐射计对木卫二地下冰壳的观测结果。对于纯水冰的理想情况，数据与存在导热冰壳一致，厚度为29±10公里，存在裂缝、孔隙或其他散射体，延伸到地表以下数百米深处，其特征尺寸小于几厘米半径。基于陆地海洋冰的模型表明，冰壳盐度为15 mg kg - 1，将使我们对冰壳厚度的估计减少约5公里，大大小于我们的10公里不确定性。散射体的低体积分数、小尺寸和浅深度表明，在木卫二表面观察到的裂缝界面本身不太可能在表面和海洋之间携带营养物质。
{"title":"Europa’s ice thickness and subsurface structure characterized by the Juno microwave radiometer","authors":"S. M. Levin, Z. Zhang, S. J. Bolton, S. Brown, A. I. Ermakov, J. Feng, K. Hand, S. Misra, M. Siegler, D. Stevenson, W. McKinnon, R. Akiba","doi":"10.1038/s41550-025-02718-0","DOIUrl":"10.1038/s41550-025-02718-0","url":null,"abstract":"Jupiter’s moon Europa is thought to harbour a saltwater ocean beneath a variously disrupted ice shell, and it is, thus, one of the highest priority astrobiology targets in the Solar System. Estimates of the ice-shell thickness range from 3 km to over 30 km, and observations by the Galileo spacecraft indicated widespread regions of ice disruption (chaotic terrain) leading to speculation that the ice shell may contain subsurface cracks, faults, pores or bubbles. If persistent, subsurface cracks could provide pathways for habitability by facilitating the transport of oxygen and nutrients between the surface and the ocean. Here we report on observations of Europa’s subsurface ice shell obtained by the Juno microwave radiometer in 2022. For the idealized case of pure water ice, the data are consistent with the existence of a thermally conductive ice shell with a thickness of 29 ± 10 km and with the presence of cracks, pores or other scatterers extending to depths of hundreds of metres below the surface with a characteristic size smaller than a few centimetres in radius. An ice-shell salinity of 15 mg kg−1, as indicated by models based on terrestrial marine ice, would reduce our estimate of the thickness of the ice shell by about 5 km, substantially less than our 10 km uncertainty. The low volume fraction, small size and shallow depth of the scatterers indicate that the fracture interfaces observed at Europa’s surface are alone unlikely to be capable of carrying nutrients between the surface and the ocean. Microwave observations of Jupiter’s moon Europa reveal subsurface properties of the ice shell covering a purported global ocean. The shell is 29 ± 10 km thick, with fractures or pores a few centimetres across that extend hundreds of metres deep.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"10 1","pages":"84-91"},"PeriodicalIF":14.3,"publicationDate":"2025-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41550-025-02718-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145765581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-16DOI: 10.1038/s41550-025-02758-6
The inclusion of neurodivergent astronomers in the community is often overlooked, perhaps because neurodiversity is inherently difficult to generalize. In this issue, six neurodivergent researchers recount their experiences and suggest how astronomy could be made more accessible to everyone.
{"title":"Drawing on the full diversity of mind","authors":"","doi":"10.1038/s41550-025-02758-6","DOIUrl":"10.1038/s41550-025-02758-6","url":null,"abstract":"The inclusion of neurodivergent astronomers in the community is often overlooked, perhaps because neurodiversity is inherently difficult to generalize. In this issue, six neurodivergent researchers recount their experiences and suggest how astronomy could be made more accessible to everyone.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"9 12","pages":"1747-1747"},"PeriodicalIF":14.3,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41550-025-02758-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145761517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-16DOI: 10.1038/s41550-025-02742-0
Ryan Dungee, Olivia Greene, Jessica Schonhut-Stasik, Lindsay Oldham
Three early-career researchers discuss their experiences in astronomy in the context of their neurodivergence.
三位早期的研究人员在神经分化的背景下讨论了他们在天文学方面的经历。
{"title":"Neurodivergent in astronomy: the early-career researcher edition","authors":"Ryan Dungee, Olivia Greene, Jessica Schonhut-Stasik, Lindsay Oldham","doi":"10.1038/s41550-025-02742-0","DOIUrl":"10.1038/s41550-025-02742-0","url":null,"abstract":"Three early-career researchers discuss their experiences in astronomy in the context of their neurodivergence.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"9 12","pages":"1754-1757"},"PeriodicalIF":14.3,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145761518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-16DOI: 10.1038/s41550-025-02716-2
Guillermo Blázquez-Calero, Guillem Anglada, Sylvie Cabrit, Mayra Osorio, Alejandro C. Raga, Gary A. Fuller, José F. Gómez, Robert Estalella, Ana K. Diaz-Rodriguez, José M. Torrelles, Luis F. Rodríguez, Enrique Macías, Itziar de Gregorio-Monsalvo, S. Thomas Megeath, Luis Zapata, Paul T. P. Ho
Outflows play a key role in the star and planet formation processes. Some outflows show discrete clumps of cold molecular gas moving at extremely high velocities (EHVs) of ~100 km s−1, known as ‘molecular bullets’, that are likely closely associated with their primary driving agent. Here we present ALMA CO (J = 3–2) observations of a bright EHV molecular bullet that reveal its morphology in detail down to scales of 30 au and its kinematic structure across the entire intermediate velocity range (~30–100 km s−1). These provide important insights into how outflows transfer mass and momentum to the surrounding medium. The observed channel maps display several sequences of ring-like features whose velocity increases and size decreases with projected distance from the driving source, each sequence tracing a thin, bow-shaped shell culminating on axis in a bright EHV head. The shape, kinematics and mass of each shell all agree remarkably well with the simplest textbook models of momentum-conserving bowshocks produced by a time-variable EHV jet. The dynamical timescale between consecutive shells is of a few decades, with the latest ejection event coinciding with the protostar optical/infrared outburst observed in ~1990. The very strong evidence for bowshock-driven entrainment induced by jet variability revealed by this work suggests that accretion bursts, and therefore variations in the disk snowlines, should occur on decade timescales, which could substantially impact grain growth and planet formation. ALMA has captured exquisitely detailed images of bowshock shells in the outflow of an outbursting protostar. These provide important insights into the variable nature of the ejections from protostars, which play a key role in star and planet formation.
喷流在恒星和行星形成过程中起着关键作用。一些流出物显示出离散的冷分子气体团块，以~100 km / s−1的极高速度（EHVs）移动，被称为“分子子弹”，这可能与它们的主要驱动因子密切相关。在这里，我们展示了ALMA CO （J = 3-2）对一颗明亮的EHV分子子弹的观测结果，详细揭示了它的形态，小至30 au的尺度，以及它在整个中速范围（~30 - 100 km s - 1）的运动学结构。这为研究流出物如何向周围介质传递质量和动量提供了重要的见解。观察到的通道图显示了几个环状特征序列，其速度随距离驱动源的投影距离而增加，大小随距离的增加而减小，每个序列都跟踪一个薄的弓形壳，在一个明亮的超高压头部的轴线上达到顶点。每个弹壳的形状、运动学和质量都与教科书上关于时变超高压射流产生的保动量弓形激波的最简单模型非常吻合。连续壳层之间的动力学时间尺度为几十年，最近的喷射事件与1990年观测到的原恒星光学/红外爆发相吻合。这项工作揭示的由喷流变化引起的弓形激波驱动的夹带的非常有力的证据表明，吸积爆发，因此圆盘雪线的变化，应该在十年的时间尺度上发生，这可能会实质性地影响颗粒生长和行星形成。ALMA捕捉到了一颗爆发的原恒星流出物中弓形激波壳的精细图像。这为了解原恒星抛射的可变性质提供了重要的见解，而原恒星抛射在恒星和行星的形成中起着关键作用。
{"title":"Bowshocks driven by the pole-on molecular jet of outbursting protostar SVS 13","authors":"Guillermo Blázquez-Calero, Guillem Anglada, Sylvie Cabrit, Mayra Osorio, Alejandro C. Raga, Gary A. Fuller, José F. Gómez, Robert Estalella, Ana K. Diaz-Rodriguez, José M. Torrelles, Luis F. Rodríguez, Enrique Macías, Itziar de Gregorio-Monsalvo, S. Thomas Megeath, Luis Zapata, Paul T. P. Ho","doi":"10.1038/s41550-025-02716-2","DOIUrl":"10.1038/s41550-025-02716-2","url":null,"abstract":"Outflows play a key role in the star and planet formation processes. Some outflows show discrete clumps of cold molecular gas moving at extremely high velocities (EHVs) of ~100 km s−1, known as ‘molecular bullets’, that are likely closely associated with their primary driving agent. Here we present ALMA CO (J = 3–2) observations of a bright EHV molecular bullet that reveal its morphology in detail down to scales of 30 au and its kinematic structure across the entire intermediate velocity range (~30–100 km s−1). These provide important insights into how outflows transfer mass and momentum to the surrounding medium. The observed channel maps display several sequences of ring-like features whose velocity increases and size decreases with projected distance from the driving source, each sequence tracing a thin, bow-shaped shell culminating on axis in a bright EHV head. The shape, kinematics and mass of each shell all agree remarkably well with the simplest textbook models of momentum-conserving bowshocks produced by a time-variable EHV jet. The dynamical timescale between consecutive shells is of a few decades, with the latest ejection event coinciding with the protostar optical/infrared outburst observed in ~1990. The very strong evidence for bowshock-driven entrainment induced by jet variability revealed by this work suggests that accretion bursts, and therefore variations in the disk snowlines, should occur on decade timescales, which could substantially impact grain growth and planet formation. ALMA has captured exquisitely detailed images of bowshock shells in the outflow of an outbursting protostar. These provide important insights into the variable nature of the ejections from protostars, which play a key role in star and planet formation.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"10 1","pages":"105-123"},"PeriodicalIF":14.3,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145770602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-16DOI: 10.1038/s41550-025-02730-4
Luis Welbanks, Matthew C. Nixon, Peter McGill, Lana J. Tilke, Lindsey S. Wiser, Yoav Rotman, Sagnick Mukherjee, Adina D. Feinstein, Michael R. Line, Björn Benneke, Sara Seager, Thomas G. Beatty, Darryl Z. Seligman, Vivien Parmentier, David K. Sing
{"title":"Challenges in the detection of gases in exoplanet atmospheres","authors":"Luis Welbanks, Matthew C. Nixon, Peter McGill, Lana J. Tilke, Lindsey S. Wiser, Yoav Rotman, Sagnick Mukherjee, Adina D. Feinstein, Michael R. Line, Björn Benneke, Sara Seager, Thomas G. Beatty, Darryl Z. Seligman, Vivien Parmentier, David K. Sing","doi":"10.1038/s41550-025-02730-4","DOIUrl":"https://doi.org/10.1038/s41550-025-02730-4","url":null,"abstract":"","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"5 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145770601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-16DOI: 10.1038/s41550-025-02739-9
Dan Burger, Scott Gaudi, Meridith Joyce, Jessica Schonhut-Stasik, Lindsay Oldham
Three advanced-career researchers discuss their experiences in astronomy in the context of their neurodivergence.
三位高级职业研究人员在神经分化的背景下讨论了他们在天文学方面的经历。
{"title":"Neurodivergent in astronomy: the advanced-career researcher edition","authors":"Dan Burger, Scott Gaudi, Meridith Joyce, Jessica Schonhut-Stasik, Lindsay Oldham","doi":"10.1038/s41550-025-02739-9","DOIUrl":"10.1038/s41550-025-02739-9","url":null,"abstract":"Three advanced-career researchers discuss their experiences in astronomy in the context of their neurodivergence.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"9 12","pages":"1750-1753"},"PeriodicalIF":14.3,"publicationDate":"2025-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145761519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-12DOI: 10.1038/s41550-025-02723-3
Pierre-Alexis Roy, Björn Benneke, Marylou Fournier-Tondreau, Louis-Philippe Coulombe, Caroline Piaulet-Ghorayeb, David Lafrenière, Romain Allart, Nicolas B. Cowan, Lisa Dang, Doug Johnstone, Adam B. Langeveld, Stefan Pelletier, Michael Radica, Jake Taylor, Loïc Albert, René Doyon, Laura Flagg, Ray Jayawardhana, Ryan J. MacDonald, Jake D. Turner
Recent transit observations of K2-18 b and TOI-270 d revealed strong molecular absorption signatures, lending credence to the idea that temperate sub-Neptunes (equilibrium temperature Teq = 250–400 K) have upper atmospheres mostly free of aerosols. These observations also indicated higher-than-expected CO2 abundances on both planets, implying bulk compositions with high water mass fractions. However, it remains unclear whether these findings hold true for all temperate sub-Neptunes. Here we present the JWST NIRSpec/PRISM 0.7–5.4-μm transmission spectrum of a third temperate sub-Neptune, the 2.4 R⊕ planet LP 791-18 c (Teq = 355 K), which is even more favourable for atmospheric characterization thanks to its small M6 host star. Intriguingly, despite the radius, mass and equilibrium temperature of LP 791-18 c being between those of K2-18 b and TOI-270 d, we find a drastically different transmission spectrum. Although we also detect methane on LP 791-18 c, its transit spectrum is dominated by strong haze scattering and there is no discernible CO2 absorption. Overall, we infer a deep metal-enriched atmosphere (246–415 times solar) for LP 791-18 c, with a CO2-to-CH4 ratio smaller than 0.07 (at 2σ), indicating less H2O in the deep envelope of LP 791-18 c and implying a relatively dry formation inside the water-ice line. These results show that sub-Neptunes that are near analogues in density and temperature can show drastically different aerosols and envelope chemistry and are intrinsically diverse beyond a simple temperature dependence.
{"title":"Diversity in the haziness and chemistry of temperate sub-Neptunes","authors":"Pierre-Alexis Roy, Björn Benneke, Marylou Fournier-Tondreau, Louis-Philippe Coulombe, Caroline Piaulet-Ghorayeb, David Lafrenière, Romain Allart, Nicolas B. Cowan, Lisa Dang, Doug Johnstone, Adam B. Langeveld, Stefan Pelletier, Michael Radica, Jake Taylor, Loïc Albert, René Doyon, Laura Flagg, Ray Jayawardhana, Ryan J. MacDonald, Jake D. Turner","doi":"10.1038/s41550-025-02723-3","DOIUrl":"https://doi.org/10.1038/s41550-025-02723-3","url":null,"abstract":"Recent transit observations of K2-18 b and TOI-270 d revealed strong molecular absorption signatures, lending credence to the idea that temperate sub-Neptunes (equilibrium temperature Teq = 250–400 K) have upper atmospheres mostly free of aerosols. These observations also indicated higher-than-expected CO2 abundances on both planets, implying bulk compositions with high water mass fractions. However, it remains unclear whether these findings hold true for all temperate sub-Neptunes. Here we present the JWST NIRSpec/PRISM 0.7–5.4-μm transmission spectrum of a third temperate sub-Neptune, the 2.4 R⊕ planet LP 791-18 c (Teq = 355 K), which is even more favourable for atmospheric characterization thanks to its small M6 host star. Intriguingly, despite the radius, mass and equilibrium temperature of LP 791-18 c being between those of K2-18 b and TOI-270 d, we find a drastically different transmission spectrum. Although we also detect methane on LP 791-18 c, its transit spectrum is dominated by strong haze scattering and there is no discernible CO2 absorption. Overall, we infer a deep metal-enriched atmosphere (246–415 times solar) for LP 791-18 c, with a CO2-to-CH4 ratio smaller than 0.07 (at 2σ), indicating less H2O in the deep envelope of LP 791-18 c and implying a relatively dry formation inside the water-ice line. These results show that sub-Neptunes that are near analogues in density and temperature can show drastically different aerosols and envelope chemistry and are intrinsically diverse beyond a simple temperature dependence.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"50 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145746792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-12DOI: 10.1038/s41550-025-02737-x
Karsten Jedamzik, Levon Pogosian, Tom Abel
Primordial magnetic fields (PMFs), long studied as relics of the early Universe, accelerate recombination and have been proposed as a way to relieve the Hubble tension. However, previous studies relied on simplified toy models. Here we use recent evaluations of recombination with PMFs, incorporating full magnetohydrodynamic simulations and detailed Lyman-α radiative transfer, to test PMF-enhanced recombination (bΛCDM) against observational data for the cosmic microwave background, baryon acoustic oscillations and type Ia supernovae. Focusing on non-helical PMFs with a Batchelor spectrum, we find a preference for present-day total field strengths of approximately 5–10 pG. Depending on the dataset combination, this preference ranges from mild (~1.8σ with Planck+DESI) to moderate (~3σ with Planck+DESI+SH0ES-calibrated supernovae) significance. The bΛCDM has Planck+DESI χ2 values equal to or better than those for ΛCDM while predicting a higher Hubble constant. Future high-resolution cosmic microwave background temperature and polarization measurements will be crucial for confirming or further constraining PMFs at recombination. Field strengths of 5–10 pG align closely with those required for cluster magnetic fields to originate entirely from primordial sources, without the need for extra dynamo amplification.
{"title":"Hints of primordial magnetic fields at recombination and implications for the Hubble tension","authors":"Karsten Jedamzik, Levon Pogosian, Tom Abel","doi":"10.1038/s41550-025-02737-x","DOIUrl":"https://doi.org/10.1038/s41550-025-02737-x","url":null,"abstract":"Primordial magnetic fields (PMFs), long studied as relics of the early Universe, accelerate recombination and have been proposed as a way to relieve the Hubble tension. However, previous studies relied on simplified toy models. Here we use recent evaluations of recombination with PMFs, incorporating full magnetohydrodynamic simulations and detailed Lyman-α radiative transfer, to test PMF-enhanced recombination (bΛCDM) against observational data for the cosmic microwave background, baryon acoustic oscillations and type Ia supernovae. Focusing on non-helical PMFs with a Batchelor spectrum, we find a preference for present-day total field strengths of approximately 5–10 pG. Depending on the dataset combination, this preference ranges from mild (~1.8σ with Planck+DESI) to moderate (~3σ with Planck+DESI+SH0ES-calibrated supernovae) significance. The bΛCDM has Planck+DESI χ2 values equal to or better than those for ΛCDM while predicting a higher Hubble constant. Future high-resolution cosmic microwave background temperature and polarization measurements will be crucial for confirming or further constraining PMFs at recombination. Field strengths of 5–10 pG align closely with those required for cluster magnetic fields to originate entirely from primordial sources, without the need for extra dynamo amplification.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"168 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145746847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-10DOI: 10.1038/s41550-025-02724-2
When icy ocean worlds in the outer Solar System experience episodes of heating, their ice shells thin. Modelling shows that this thinning can lead to boiling of the ocean beneath the ice shell, or to compressional faulting — and that the outcome is determined by the size of the moon.
{"title":"Small moons boil, large moons break","authors":"","doi":"10.1038/s41550-025-02724-2","DOIUrl":"10.1038/s41550-025-02724-2","url":null,"abstract":"When icy ocean worlds in the outer Solar System experience episodes of heating, their ice shells thin. Modelling shows that this thinning can lead to boiling of the ocean beneath the ice shell, or to compressional faulting — and that the outcome is determined by the size of the moon.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"10 1","pages":"20-21"},"PeriodicalIF":14.3,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146016474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-09DOI: 10.1038/s41550-025-02741-1
Amanda M. Cook, Alice P. Curtin
This year, the latest in an annual series of Fast Radio Burst conferences was held as a fully hybrid experience from 7–11 July at McGill University in Montreal, Quebec, Canada. Marking ten years since the first repeating fast radio burst was discovered, more than 200 scientists at FRB 2025 discussed the latest results in the field and charted a course for future experiments.
{"title":"Fast Radio Bursts 2025","authors":"Amanda M. Cook, Alice P. Curtin","doi":"10.1038/s41550-025-02741-1","DOIUrl":"10.1038/s41550-025-02741-1","url":null,"abstract":"This year, the latest in an annual series of Fast Radio Burst conferences was held as a fully hybrid experience from 7–11 July at McGill University in Montreal, Quebec, Canada. Marking ten years since the first repeating fast radio burst was discovered, more than 200 scientists at FRB 2025 discussed the latest results in the field and charted a course for future experiments.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"9 12","pages":"1760-1761"},"PeriodicalIF":14.3,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145761520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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