Space Probes to Map Planetary Resources Using Raman Spectroscopy

A new NASA proposal explores the development of a class of reconnaissance spacecraft capable of mapping minerals from orbit using Raman spectroscopy. The concept relies on high-speed flybys, eliminating the need for landings, sample returns, or extended stays. This methodology would allow the space agency to evaluate the composition of key resources on nearby celestial bodies, such as ice and ilmenite on the Moon, ore content on asteroids, and volatile-bearing minerals on Mars' moons. Raman spectroscopy is an analytical technique that uses the interaction of light with matter to identify the chemical composition and molecular structure of a material. By illuminating a sample with a laser, photons are scattered, most of which scatter elastically (Rayleigh scattering). However, a small fraction undergoes inelastic scattering (Raman scattering), where photons gain or lose energy by interacting with the molecular vibrations of the material. Analyzing the spectrum of these inelastically scattered photons provides a unique molecular "fingerprint" for each compound. The feasibility of this "Interworld Slingshot" concept represents a significant advance in space exploration. By enabling rapid and efficient resource mapping without the complexity and cost associated with landing or sample return missions, it could accelerate the characterization of targets of interest for future crewed missions or resource extraction. The ability to accurately identify the location and abundance of ice, metals, and other volatiles is crucial for establishing a sustainable human presence beyond Earth and for the development of the space economy.

Plasma and Dark Matter Modify Shadows of Bardeen Black Holes

A recent study has explored how the presence of a plasma medium and perfect fluid dark matter (PFDM) affects the optical appearance of a rotating Bardeen black hole. Researchers analyzed three plasma models: homogeneous, radially varying, and with both radial and angular dependence. The results indicate that both plasma and PFDM induce measurable modifications to the black hole's shadow morphology, suggesting that observing these shadows could offer valuable insights into the cosmic environment, in addition to the intrinsic properties of regular black holes. To assess the astrophysical viability of these effects, the plasma and PFDM parameters were constrained using observations from the Event Horizon Telescope (EHT). Specifically, the limits imposed by the EHT on shadow circularity and fractional diameter deviation were employed. These restrictions allowed for the determination of realistic ranges for the environmental parameters, ensuring that the predicted modifications were consistent with current observational data. This work highlights the importance of considering environmental effects when interpreting black hole images. The modifications in the shadow, induced by plasma and dark matter, not only complicate the determination of the black hole's properties itself but also open a new avenue for characterizing its surrounding medium. The ability to discern these environmental influences through the shadow image transforms black holes into natural probes for studying the distribution of matter and energy in their vicinity.

Shared Cloud Interactions Unveil Candidate Binary Supernova Pair

A new study has identified a binary supernova system with unique characteristics, never before observed. This discovery, based on the observation of shared cloud interactions, suggests a stellar explosion mechanism and binary evolution that challenge current models. The uniqueness of this pair lies in the evidence that both supernovae interacted with a common envelope of material, implying a very specific proximity and sequence of events in their life cycle. The finding is significant because most binary supernova models predict that explosions should be separated by much longer periods, or that interactions with shared material would be less pronounced or asymmetrical. The observation of this system, on the contrary, points to a more intimate co-evolution and a possible mechanism of mass transfer or common envelope ejection preceding both explosions. This opens new avenues for understanding the dynamics of massive stellar systems and how their interactions can influence their ultimate fates. To reach these conclusions, researchers analyzed the spectral and photometric signatures of the supernovae, looking for indications of interaction with the surrounding medium. The presence of specific emission lines and the evolution of the light curve provided evidence that both explosions occurred within a shared gas and dust envelope. This method of "stellar archaeology" allows for the reconstruction of pre-supernova conditions and the evolutionary history of complex binary systems. The implications of this discovery are profound for stellar astrophysics. It could force a revision of models for the evolution of massive stars in binary systems and the formation of Type II supernovae. Furthermore, it provides a natural laboratory for studying the physics of common envelope interactions and mass ejection processes in the final stages of stellar life. Future observations and numerical simulations are expected to help confirm and refine the understanding of this unprecedented phenomenon.

Gravitational Wave Echoes Constrain Maximum Mass of Strange Stars

A recent study explores how gravitational wave echoes, potentially observed after neutron star mergers like GW170817, can reveal properties of exotic compact stars. These echoes, with a significance of 4.2σ and a dominant frequency near 72 Hz, could originate from ultracompact remnants possessing photon spheres that partially trap gravitational perturbations. While standard General Relativity imposes strict limits on stellar compactness for photon sphere formation, this work investigates the possibility within the framework of quadratic curvature gravity coupled to matter. The researchers employed a modified gravity model, considering strange stars described by the MIT bag model equation of state. By solving the modified Tolman-Oppenheimer-Volkoff equations, they obtained mass-radius relations and identified configurations capable of supporting photon spheres and, consequently, producing gravitational wave echoes. The proposed framework allows for more compact stellar solutions than the Buchdahl limit of General Relativity, although photon sphere constraints limit the viable parameter space. Results indicate that increasing the bag constant decreases the maximum mass and echo time, shifting the echo frequency towards the kHz regime. The constraints imposed by gravitational wave echoes are found to be more stringent for the maximum mass and radius of strange stars than those derived from hydrostatic equilibrium. This suggests a revision of the maximum mass bounds for these stars. The study highlights the potential of post-merger strange stars as sources of gravitational wave echoes and demonstrates the role of these echoes as probes of modified gravity and high-frequency gravitational waves.

NASA to Preview Roman Space Telescope Before Launch

NASA has scheduled a virtual press conference for July 29 at 2 p.m. EDT to provide a preview of the Nancy Grace Roman Space Telescope mission. The event will be streamed live across various agency platforms and precedes the telescope's launch, which is set for August 30 from the Kennedy Space Center in Florida. The Roman Space Telescope, formerly known as WFIRST (Wide Field Infrared Survey Telescope), is a next-generation space observatory designed to address fundamental questions in astrophysics, including the nature of dark energy, the distribution of dark matter, and the search for exoplanets. Its key feature is a field of view 100 times larger than that of the Hubble Space Telescope in infrared wavelengths, enabling it to efficiently map vast areas of the sky and conduct large-scale surveys with unprecedented resolution.

Viking 1: The First Image of Mars' Surface in 1976

On July 20, 1976, NASA's Viking 1 probe successfully landed on Mars, marking a milestone in planetary exploration. Forty minutes after touchdown, the lander began transmitting the first images of the Martian surface, revealing a desert-like, rocky landscape. This event represented the first time humanity obtained a direct and detailed view of another planet, overcoming the technical challenges of atmospheric entry and descent. The Viking mission, comprising two orbiters and two landers (Viking 1 and Viking 2), was designed to search for signs of life on Mars and study its atmosphere and geology. Viking 1's success not only demonstrated NASA's capability to operate complex missions over vast distances but also provided crucial data that shaped our initial understanding of the Red Planet. The images and scientific data sent by Viking 1 laid the groundwork for future missions, including current rovers and landers. The landing and image transmission of Viking 1 were the culmination of years of technological development and planning. The probe's ability to survive descent through the thin Martian atmosphere and operate in a hostile environment was a testament to the engineering of the era. Data collected by Viking 1, along with that from Viking 2, allowed scientists to characterize soil composition, meteorology, and the absence of microbial life at the landing sites, although this last conclusion remains a subject of debate and ongoing research.

$f(R,T)$ Gravity Models Consistent with Standard Cosmological Model

A new analysis of modified $f(R,T)$ gravity models, which consider an arbitrary function of the Ricci curvature ($R$) and the trace of the energy-momentum tensor ($T$), has found these models to be consistent with the standard cosmological model ($\Lambda$CDM). Researchers examined the specific form $f(R,T) = R + \lambda T^\epsilon$, fitting its parameters to a variety of observational cosmological data. This approach seeks to explore alternatives to dark energy for explaining the accelerated expansion of the universe, without the need to introduce a cosmological constant or additional fields. The study utilized a combination of key cosmological datasets: the cosmic microwave background (CMB), baryon acoustic oscillations (BAO), cosmic chronometers, and Type Ia supernovae. Unlike previous work, this research explicitly incorporated correlations between the different datasets and radiation effects, allowing for a more robust characterization of the model parameters. The inclusion of these factors is crucial for obtaining precise and reliable fits in the context of current precision cosmology. The results of the analysis show that the best fit for the parameter $\epsilon$ is $0.010^{+0.013}_{-0.021}$. This value is remarkably close to $\epsilon = 0$, which corresponds to the standard cosmological model. The compatibility of this range with $\epsilon = 0$ suggests that, while $f(R,T)$ models offer a broader theoretical framework, current observations do not require a significant deviation from Einstein's gravity in the matter sector. This implies that dark energy remains the simplest and most consistent explanation with current data, although the door to subtle gravitational modifications remains open for future, higher-precision observations.

Primordial Gravitational Waves to Probe Non-Gaussianity and Parity

A new study explores the capability of third-generation gravitational-wave detectors, such as the Einstein Telescope and Cosmic Explorer, to detect scalar-induced gravitational waves (SIGWs). These waves, generated in the primordial universe, could offer a unique pathway to investigate primordial non-Gaussianity and parity violation. Researchers have developed a framework that considers contributions to the energy density spectrum of stochastic gravitational waves (SGWB) arising from scalar non-Gaussianity, quantified by the primordial bispectrum and trispectrum. The particularity of this approach lies in the fact that the parity-odd component of the primordial scalar trispectrum induces circular polarization in the stochastic gravitational-wave background. This circular polarization would act as a direct signature of parity violation in the early universe. The analysis, based on simulated data from future interferometers, suggests that these instruments will be able to place competitive constraints on both the bispectrum and the scalar trispectrum (both its parity-even and parity-odd components). Furthermore, the study has taken into account the contribution from astrophysical sources of gravitational waves, which could act as a "foreground" for the primordial signals. Despite the presence of this astrophysical foreground, the results indicate that future detectors will be able to effectively constrain cosmological parameters related to SIGWs, as well as astrophysical parameters. This highlights the potential of primordial gravitational waves as a cosmological tool to unravel fundamental properties of the early universe, such as the distribution of density fluctuations and parity symmetry.

Gravitational Waves Interact Non-Linearly in Expanding Universe

A new study has explored the nonlinear interactions between gravitational waves in an expanding universe. Through numerical simulations of random ensembles of gravitational waves, researchers have observed how the spectra of these waves evolve, redistributing their energy from the initial predominant wavelengths towards both shorter and longer wavelengths. This phenomenon, known as energy cascade, is crucial for understanding the dynamics of gravitational waves on cosmological scales and could have implications for the detection of background gravitational signals. The simulations were performed in cosmological models where the spatial volume expanded significantly, by more than an order of magnitude, during the course of the evolutions. This allowed for the observation of gravitational wave behavior under conditions that mimic the actual expansion of the universe. A key finding is that the observed energy cascades scale with the amplitude of the gravitational waves in a manner consistent with four-wave scattering models of gravitational-wave turbulence. This agreement validates existing theoretical frameworks for describing these complex interactions. Understanding these nonlinear interactions is fundamental for interpreting gravitational wave observations. As the universe expands, gravitational waves are diluted, and their spectrum can be altered due to these interactions. This work provides a basis for predicting how primordial or astrophysically originated gravitational waves evolve over billions of years, potentially affecting the signal we detect today. The results suggest that gravitational wave turbulence is a relevant process in the cosmological evolution of these spacetime perturbations.

New Swift-BAT Software Localizes Gamma-Ray Bursts During Slew Maneuvers

Scientists have developed BAT-GLIMPSE, a new open-source software tool that enables the Burst Alert Telescope (BAT) aboard the Swift observatory to localize gamma-ray bursts (GRBs) even when the spacecraft is performing slew maneuvers. Previously, Swift-BAT's onboard triggering system was disabled during these movements, preventing autonomous detection and localization of transients during these intervals. BAT-GLIMPSE employs coded-mask imaging and mosaic techniques, automatically selecting the appropriate analysis based on spacecraft attitude, thereby enabling searches for transient sources during both pointing observations and spacecraft slews. The performance of BAT-GLIMPSE was validated on a sample of 66 previously reported GRBs. The software successfully recovered arcminute positions for 43 of these events, with typical offsets of approximately 5 arcminutes, consistent with published localizations. Notably, approximately 88% of the GRBs that occurred during spacecraft slews were recovered through BAT-GLIMPSE's imaging or mosaic analyses. This demonstrates the new system's ability to fill a critical gap in GRB detection. BAT-GLIMPSE played a crucial role during the fourth LIGO-Virgo-KAGRA observing run (O4) in the search for gamma-ray counterparts to gravitational waves, particularly in response to pre-merger alerts that triggered Swift spacecraft slews with extremely low latency. Operating synergistically with NITRATES, another analysis tool, BAT-GLIMPSE is estimated to double Swift-BAT's onboard arcminute-localization rate, unlocking the full potential of the Swift mission for time-domain and multi-messenger astrophysics.

Near-Earth Asteroid Is Actually a Comet

New research led by scientists at NASA's Jet Propulsion Laboratory (JPL) has revealed the true nature of a puzzling near-Earth object (NEO). By precisely tracking its motion through space and utilizing powerful observatories capable of imaging faint celestial objects, it has been determined that the object, previously classified as an asteroid, exhibits cometary characteristics. This duality had confused astronomers, as previous images did not show typical cometary activity, such as the presence of a tail or coma. The study focused on object 2023 FW13, which was discovered in March 2023. Detailed observations of its orbital trajectory and behavior have allowed for its reclassification. Comets are distinguished from asteroids by their icy composition and the emission of gas and dust when approaching the Sun, forming a coma and often a tail. The the absence of these visible features in the initial observations of 2023 FW13 made its initial identification difficult. The ability to distinguish between asteroids and comets is crucial for understanding the composition and evolution of the solar system, as well as for planning space missions and assessing impact risks. This finding underscores the importance of follow-up observations and advanced characterization techniques to correctly classify celestial objects, especially those exhibiting atypical behaviors or located in Earth's vicinity.

Perseverance Captures Sweeping View of Jezero Crater Rim on Mars

NASA's Perseverance rover has captured a detailed image of the outer rim of Jezero Crater on Mars. The photograph, taken by the Mastcam-Z instrument on May 15, 2025 (sol 1505 of the mission), shows a 150-meter-tall elevated section known as Broom Point. This panoramic view offers a crucial perspective for understanding the geology and water history of the region. The image reveals light-colored rocks exposed along the slope, extending from the middle-left to the middle-right of the view. These rock formations are of particular interest to scientists, as they could contain clues about ancient aquatic environments and, potentially, past microbial life. The analysis of these rock layers is fundamental to the Perseverance mission's objectives, which include searching for signs of ancient life and collecting samples for future return to Earth. Perseverance's ability to accurately document these geological features from different angles and distances is key for planning future routes and selecting sampling sites. These observations not only contribute to understanding the evolution of Jezero Crater, an ancient lake, but also provide valuable data for future crewed missions to Mars, helping to identify potential resources and hazards in the Martian terrain.

NASA's Anil Menon Launches to International Space Station

NASA astronaut Anil Menon has successfully launched to the International Space Station (ISS) aboard a Soyuz spacecraft. The launch took place on Tuesday, July 14, 2026, from the Baikonur Cosmodrome in Kazakhstan, at 7:47 p.m. local time. Menon is accompanied by Roscosmos cosmonauts Pyotr Dubrov and Anna Kikina, forming the crew of the Soyuz MS-29 mission. This launch marks a new milestone in international space collaboration, bringing a diverse team of astronauts and cosmonauts to the ISS. The MS-29 mission contributes to the ongoing research and maintenance efforts of the orbital platform, which serves as a unique laboratory for scientific experiments in microgravity and as a testing ground for future space exploration missions.

Artemis III Mission to Test Crewed Lunar Landing in 2027

NASA has announced that the Artemis III mission, scheduled for 2027, will serve as a key demonstration for future crewed lunar landing operations. This mission, while not carrying astronauts to the lunar surface, will allow teams on Earth and in orbit to practice rendezvous and docking maneuvers between commercial human landing systems and the Orion spacecraft. The primary objective is to validate procedures and technology before astronauts land on the Moon in 2028. Data gathered from this demonstration mission, along with future uncrewed missions to the Moon, will be crucial for refining protocols and ensuring crew safety. This phased approach underscores the complexity of lunar operations and the need to thoroughly test each component and phase of the mission. Preparation for Artemis III is a fundamental step in NASA's program to return to the Moon, which seeks to establish a sustainable human presence on our natural satellite.

Faintest planet ever imaged from Earth discovered

A team of astronomers has discovered a third planet orbiting the star Beta Pictoris, named Beta Pictoris d. This new exoplanet is one hundred times fainter than Beta Pictoris b, the first planet detected in the same system, and is among the lightest exoplanets ever directly imaged from ground-based observatories. The discovery was made using the European Southern Observatory's (ESO) Very Large Telescope (VLT). Most notably, after its initial identification with the VLT, the research team found that Beta Pictoris d had been hiding in archived observations spanning more than a decade. This fact underscores the difficulty of detecting such faint objects and the importance of advanced data processing techniques to unveil latent information in existing datasets. The ability to discern such a weak object in an already known system opens new avenues for exoplanet searches. This discovery expands our understanding of planetary diversity and stellar system formation. The detection of a third planet in Beta Pictoris, a relatively young and nearby system, provides a natural laboratory for studying planetary evolution. Characterizing low-mass exoplanets through direct imaging is crucial for refining planetary formation models and for better understanding the distribution of Earth-like planets in our galaxy.

Pristine Meteorite Reveals Clues About Water and Primitive Asteroid Chemistry

NASA scientists are uncovering new clues about ancient water, the chemical evolution of primitive asteroids, and the ingredients that may have helped make life possible in the early solar system. This has been made possible by the analysis of a meteorite recovered immediately upon its fall to Earth on July 16, 2024. The rapid recovery of the specimen, still in a pristine state, is crucial to ensure that its components have not been altered by prolonged exposure to Earth's atmosphere or environmental contamination. The study of this meteorite offers a unique window into the conditions and chemical processes prevalent in the early stages of our solar system. By examining its composition, researchers hope to reconstruct the history of water in primordial celestial bodies and understand how asteroids may have acted as vehicles for the transport of essential organic compounds. These findings could shed light on the origin of the basic building blocks of life on Earth and elsewhere in the cosmos.

Supernova Neutrinos Could Explain the Origin of Biomolecular Homochirality

A new study proposes that interactions of supernova neutrinos with chiral molecules in nearby interstellar molecular clouds could be the source of biomolecular homochirality. Homochirality, the preference of biological systems for one of two mirror-image forms (L or D enantiomers) of organic molecules, is a fundamental mystery in the origin of life. Researchers have introduced neutrino interactions into autocatalytic chemical reactions, demonstrating how these interactions could create a directional bias that is then amplified. The proposed mechanism relies on the weak interaction of neutrinos with chiral molecules. Although this interaction is intrinsically weak, the model suggests it can generate a considerable enantiomeric excess, exceeding 10%. This value is consistent with recent chemical analyses of meteorites, which often contain a slight excess of one enantiomer. The process is amplified by autocatalysis and stochastic fluctuations in a far-from-equilibrium system, allowing a small initial bias to propagate and become fixed. The authors solved the stochastic equations using the Ito sense to describe the dynamics of the probability distribution of enantiomeric excesses. This framework provides a plausible astrophysical scenario for the delivery of homochirality seeds to Earth via meteorites. Furthermore, they scanned the model's parameter space, inferring values from observational data to explore the window of opportunity for generating initial homochiral states in interstellar molecular clouds. This work opens a window into understanding how particle physics might have influenced the earliest steps of life.

Hubble Captures Stellar Nursery with Massive and Low-Mass Stars

The Hubble Space Telescope has captured a detailed image of LH 95, a stellar nursery located in the Large Magellanic Cloud, a dwarf galaxy orbiting the Milky Way. The image, taken on July 3, 2026, reveals a vibrant contrast between blue and white stars and a crimson background of glowing gas. This region is notable for hosting a coexistence of low-mass infant stars alongside massive blue giant stars. The Large Magellanic Cloud serves as a natural laboratory for studying star formation in environments different from our own galaxy. The simultaneous presence of stars of various masses in LH 95 offers a unique opportunity to investigate the processes governing star formation at different scales and how different types of stars interact in their early life stages. The glowing gas, visible in crimson hues, is an indicator of the ionization and heating activity caused by radiation from young, massive stars. Hubble's observations in LH 95 contribute to a better understanding of star formation mechanisms in dwarf galaxies and how these processes may differ from those observed in larger spiral galaxies. The study of these regions allows astronomers to refine theoretical models of stellar and galactic evolution, providing clues about the history of star formation in the early universe, where dwarf galaxies were more common.

Anil Menon and Cosmonauts Arrive at International Space Station

NASA astronaut Anil Menon, along with Roscosmos cosmonauts Pyotr Dubrov and Anna Kikina, have successfully arrived at the International Space Station (ISS). Their arrival temporarily increases the station's crew to ten individuals for approximately the next two weeks. This event marks a new milestone in international collaboration for space exploration. The trio launched aboard the Soyuz MS-29 spacecraft. The liftoff occurred at 10:47 a.m. EDT (7:47 p.m. local time) from the Baikonur Cosmodrome. This successful launch and docking underscore the reliability of current space transport systems and the continuity of crewed missions to the ISS.

LISA could detect low-mass dark matter halos via gravitational lensing

A new study proposes that the future space-based gravitational wave observatory LISA (Laser Interferometer Space Antenna) could detect low-mass dark matter halos, with masses between 10 and 10,000 solar masses (M☉). These halos, predicted by cold dark matter models, are sensitive to the fundamental nature of dark matter and the primordial power spectrum, but have remained undetected until now. The proposal is based on the wave-optics lensing effect that multiple dark matter halos would produce on gravitational waves. The method focuses on the statistical properties of stochastic diffraction, a phenomenon that would imprint correlated fluctuations on the amplitude and phase of the original gravitational waveforms. These stochastic distortions can be described by an orthogonal basis that captures the dominant "tones" associated with dark matter properties, a concept termed "dark timbre." This timbre is not degenerate with binary gravitational wave source parameters, allowing for their distinction. LISA would be particularly sensitive to dark matter halos in this mass range. Although the per-event signal would be very weak, on the order of 10⁻³ in the cold dark matter model, the study suggests that stacking the signals from 50 to 500 loud binaries (gravitational wave sources) could confirm the existence of these halos with a statistical significance of 2 to 5 standard deviations (σ). This would require major advances in waveform accuracy and data analysis techniques. Even without reaching this direct detection threshold, stochastic diffraction would allow for stringent bounds on models that enhance small-scale structure, such as axion miniclusters or primordial black holes.

NASA Astronaut Anil Menon Prepares for ISS Mission

NASA astronaut Anil Menon posed for a portrait in his spacesuit at NASA's Johnson Space Center in Houston, Texas, on January 8, 2026. This event marks another step in his preparations for an upcoming mission to the International Space Station (ISS). Menon is scheduled to launch aboard the Roscosmos Soyuz MS-29 spacecraft. The launch is expected on Tuesday, July 14. For this mission, Menon will be accompanied by cosmonauts Pyotr Dubrov and Anna Kikina. Once at the ISS, they will join the Expedition crew.

Boson Stars Emit More Gravitational Waves Than Black Holes

A numerical relativity study has investigated head-on collisions of boson stars, employing an initial data method inspired by the Bowen-York approach, commonly used to model binary black hole systems. This method allows for the incorporation of information from the early, post-Newtonian inspiral phase in binary coalescences, simplifying the modeling of these cosmic events. The research included testing the method on a single boson star with linear momentum, as well as simulations of head-on collisions between two boson stars and encounters between boson stars and black holes. The results of this study are consistent with previous investigations, validating the effectiveness of the proposed initial data method. A key finding is that head-on collisions between boson stars emit a greater amount of energy in the form of gravitational waves compared to equivalent binary black hole collisions. This contrast suggests fundamental differences in the dynamics of gravitational wave emission between these compact objects. Conversely, head-on collisions between a boson star and a black hole showed less gravitational radiation emission than their binary black hole counterparts. These differences in gravitational wave emission provide valuable insights for gravitational wave astrophysics and the characterization of exotic compact objects such as boson stars, which are candidates for dark matter.

Protocell formation on micrometeorites

Scientists have demonstrated that micrometeorites, tiny particles of space dust continuously falling on Earth, could have acted as "micro-laboratories" for the formation of the first protocells. These findings suggest a new mechanism for the origin of life on Earth, where micrometeorites not only transported organic materials but also provided the necessary physicochemical conditions for their assembly into prebiotic structures. This study adds to the growing evidence that outer space may have played a crucial role in abiogenesis. The research team simulated the conditions experienced by micrometeorites upon entering Earth's atmosphere and interacting with aquatic environments. They found that the porous structure and mineral composition of micrometeorites, combined with the wetting and drying cycles that occur in shallow pools, facilitate the concentration and assembly of simple organic molecules into lipid vesicles. These vesicles, considered protocells, are membranous structures that can encapsulate genetic and metabolic material, a fundamental step towards life. Experiments showed that micrometeorites can catalyze the polymerization of monomers into more complex polymers, and that these reactions are favored by the presence of certain minerals and alternating dry and wet conditions. The ability of micrometeorites to concentrate molecules and protect them within their pores, along with their abundance on early Earth, makes them plausible candidates for sites of life's origin. This work opens new avenues for understanding how the basic components of life could have organized into the first biological structures on a young planet.

SACRA-K: New Numerical Relativity Code for Astrophysical Simulations

Researchers have developed SACRA-K, a new numerical relativity code designed to simulate extreme astrophysical events such as the merger of black holes and neutron stars. This code, an adaptation to C++ with the Kokkos library from the previous Fortran code SACRA-MPI, retains the original physics and numerical methods, including BSSN spacetime evolution with Z4c constraint propagation and Berger-Oliger adaptive mesh refinement. The main novelty of SACRA-K is its "performance portability" across different hardware architectures, allowing it to leverage the power of graphics processing units (GPUs) and accelerated processing units (APUs). SACRA-K was validated by comparing it against SACRA-MPI across various configurations, such as binary black hole systems, black hole-neutron star systems, and binary neutron star systems. The results show that discrepancies in the generated gravitational waveforms are well below the variability observed among independent codes and resolution-dependent variations within a given code. Furthermore, these differences remain at or below the distinguishability threshold of current gravitational-wave detectors. The code also preserves π symmetry at the bitwise level and exhibits second-order convergence in the gravitational wave phase during neutron star mergers. In the smallest test configurations, SACRA-K proved to be approximately an order of magnitude faster on NVIDIA A100 GPU clusters or AMD MI300A APU clusters than Fortran SACRA-MPI on CPU clusters. The team has successfully scaled SACRA-K's performance up to 256 accelerator devices, highlighting its ability to exploit the massive parallelism of modern architectures. This advancement is crucial for numerical astrophysics, enabling faster and more efficient simulations of gravitational-wave-generating phenomena, thus facilitating a better interpretation of observational data from detectors like LIGO and Virgo.

Tilted Accretion Disks Modeled in Full Kerr Spacetime

Researchers have developed an equation to describe the dynamics of thin, viscous accretion disks around compact objects within the full Kerr spacetime. This formulation is valid for all values of the Kerr parameter $a$, enabling the study of both Kerr black holes ($0 < a \le 1$) and Kerr naked singularities ($a > 1$). The model incorporates exact Keplerian and Lense-Thirring precession frequencies, analytically deriving radial disk tilt profiles without recourse to slow-spin or weak-field approximations. Numerical solutions of these equations, obtained under realistic boundary conditions, reveal significant deviations from slow-spin approximations, particularly in the inner disk where relativistic effects dominate. In the diffusive regime, the study finds that for Kerr naked singularities, the tilt profile exhibits distinct inner hump(s) near the radius where the specific angular momentum vanishes—a feature absent in Kerr black holes. Considering the tilt in the inner disk could significantly influence the interpretation of observed X-ray spectral, timing, and polarization features. These observations are crucial for probing the strong gravity regime and inferring the spin of the central object. While the distinct hump feature alone does not uniquely distinguish Kerr black holes from Kerr naked singularities, its interpretation in conjunction with disk regime constraints may provide an observational handle on the nature of the accreting collapsed object.

Constraints on dark matter in rotating black hole halos

Researchers have explored how the presence of a Hernquist-type dark matter halo affects the optical properties of a rotating Kerr black hole. The study focused on the spacetime geometry generated by this configuration, deriving the null geodesic equations and effective potentials. This approach allowed for the analysis of three-dimensional photon trajectories around the event horizon and ergoregion, as well as the calculation of critical impact parameters for unstable spherical photon orbits. The team constructed the black hole shadow contours for a distant observer, finding that the rotation parameter primarily shifts and distorts the shadow. However, the presence of the Hernquist dark matter halo significantly increases the photon capture region and, consequently, the apparent size of the shadow. By comparing the area-equivalent shadow diameter with Event Horizon Telescope (EHT) measurements for Sgr A* and M87*, they were able to establish constraints on the dimensionless halo parameter, $\hat{\rho}=M^2\rho$. The strongest restrictions come from Sgr A*, with values of $\hat{\rho}\sim(2.7-3.8)\times10^{-3}$ at $1\sigma$ and $\hat{\rho}\sim(4.1-5.2)\times10^{-3}$ at $2\sigma$. In addition to the shadow analysis, the study examined gravitational lensing in both the strong-field and weak-field regimes. In the strong-field regime, the halo shifts the unstable photon orbit and critical impact parameter, influencing the logarithmic deflection angle and the position of relativistic images. In the weak-field regime, the halo contributes to the leading bending angle and amplifies deviations from the Kerr metric as $\rho$ increases. Using the Einstein ring of ESO325-G004, further constraints were obtained for the parameter $\hat{\rho}$: $0\leq\hat{\rho}\lesssim0.00939$ at $1\sigma$ and $0\leq\hat{\rho}\lesssim0.01963$ at $2\sigma$.

NASA's Curiosity Detects Sulfur Crystals on Mars

NASA's Curiosity rover has made a significant discovery on Mars, observing sulfur crystals on the planet's surface for the first time. This finding occurred serendipitously on May 30, 2024, when the rover accidentally crushed a rock while traversing, revealing the underlying crystalline fragments. Days later, Curiosity used its robotic arm camera to capture detailed images of these crystals, confirming their sulfurous nature. The identification of pure sulfur crystals is relevant for understanding the geological and geochemical processes on Mars. Sulfur is a common element in the solar system, and its presence in various forms on Mars was already known, often associated with sulfates or sulfides. However, the detection of elemental sulfur crystals suggests specific formation conditions that could imply past volcanic activity, hydrothermal processes, or the alteration of pre-existing minerals in a particular oxidizing or reducing environment. This type of discovery helps scientists reconstruct the Red Planet's environmental history and assess its past or present habitability potential.

IXPE Measures Pulsar Magnetic Fields for the First Time

For the first time, scientists have used NASA’s Imaging X-ray Polarimetry Explorer (IXPE) to directly measure the magnetic fields of PSR J1101−6101, a pulsar located within the Lighthouse Nebula. This breakthrough provides new insight into the structure of some of the most extreme objects in the cosmos. X-ray polarimetry allows researchers to infer the orientation of the magnetic field in the pulsar's environment, offering crucial data on how these fields are generated and evolve under extreme gravity and density conditions. Pulsars are rapidly rotating neutron stars that emit beams of electromagnetic radiation. Their magnetic fields are the strongest known in the universe, with intensities that can exceed 10^12 Gauss, trillions of times stronger than Earth's magnetic field. Understanding the configuration and strength of these fields is fundamental to unraveling the emission mechanisms of pulsars, their interaction with the interstellar medium, and the fundamental physics of matter under extreme conditions. The IXPE mission, launched in 2021, is specifically designed to measure the polarization of X-rays from cosmic sources. By analyzing the direction and degree of polarization of the X-ray light emitted by PSR J1101−6101, researchers have been able to map the magnetic field structure in the pulsar's magnetosphere. These results not only validate IXPE's unique capabilities but also open a new window for the detailed study of pulsars and other compact objects, such as black holes and supernova remnants.

Unification of polynomial and exponential cosmological attractors in inflation

A new cosmological model has successfully unified two types of inflationary attractors, exponential and polynomial, within a single formulation. This advance allows interpolation between both behaviors through a continuous parameter, offering a more flexible tool to describe the early cosmic inflation phase. The unification is based on a family of $\alpha$-attractor models, which are known for their robustness and for predicting values of the spectral index $n_s$ and the tensor-to-scalar ratio $r$ compatible with cosmic microwave background (CMB) observations. Traditionally, inflationary models have been classified into distinct categories according to the shape of their scalar potential, leading to different predictions for cosmological observables. Exponential and polynomial attractors represent two important classes that have been studied separately. The ability to transition between them with a single parameter $\mu$ simplifies the theoretical framework and allows for the exploration of a wider range of inflationary scenarios in a coherent manner. The study demonstrates that, by varying this interpolation parameter $\mu$, the model can generate a wide range of values for the spectral index $n_s$. This is crucial, as it allows the model's predictions to be adjusted to match current and future observations of the cosmic microwave background radiation and data from large galaxy surveys, such as those provided by the Dark Energy Spectroscopic Instrument (DESI). This flexibility is fundamental for the confrontation between inflationary theory and precision cosmological data.

Artemis II Crew Dedicates Second-Generation "Moon Tree"

The crew of the Artemis II mission, a crewed lunar flyby, participated on June 25, 2026, in the dedication of a second-generation "Moon tree" at the Lunar Receiving Park at NASA's Johnson Space Center. This tree, a loblolly pine, is a descendant of the original Moon trees, whose seeds traveled aboard the Apollo 14 mission in 1971. The original "Moon trees" were seeds carried by astronaut Stuart Roosa on the Apollo 14 mission. Roosa, who served as the command module pilot, kept the seeds in his personal kit during the journey to the Moon. After their return to Earth, the seeds were germinated, and the resulting seedlings were planted in various locations across the United States and worldwide, as a symbol of space exploration and international cooperation. The dedication of this second-generation tree by the Artemis II crew symbolizes the continuity of NASA's lunar exploration program. Artemis II, expected to be the first crewed mission to orbit the Moon since the Apollo program, will lay the groundwork for future Artemis missions that aim to establish a sustainable human presence on the lunar surface and in orbit, including the eventual sending of the first woman and first person of color to the Moon.

Low-scale cosmological phase transitions and gravitational waves

A new study has investigated low-scale cosmological phase transitions within a dark Abelian Higgs sector, a gauge theory model describing spontaneous symmetry breaking. The work was motivated by recent evidence for a stochastic gravitational-wave (GW) background reported by pulsar timing array (PTA) collaborations. Researchers quantified the impact of thermal resummation, higher-order matching corrections, and higher-dimensional operators on the phase-transition thermodynamics and the resulting gravitational wave signal. Their analysis reveals that the parameter region favored by current PTA observations lies close to the boundary of validity of the effective field theory. In this regime, higher-dimensional operators become increasingly important. Despite substantial shifts induced by higher-order thermal corrections, the predicted signal from the model remains disfavored by PTA data, even within the controlled region of the theory. Furthermore, the study delineated parameter regions where the dark and visible sectors are thermally and hydrodynamically coupled or decoupled. It also revisited dark matter phenomenology, identifying asymmetric freeze-out as naturally compatible with both the observed relic abundance and the gauge couplings favored by strong phase transitions. These results underscore the importance of systematically controlled finite-temperature calculations for reliable GW predictions from low-scale cosmological phase transitions.

Black Hole Merger 'Direct Wave' Not a Reliable Horizon Probe

A recent study on ArXiv challenges the reliability of the so-called "direct wave," a component of gravitational radiation emitted after black hole mergers, as an indicator of the event horizon properties of the remnant black hole. Previous research had associated the frequency and damping time of this wave with horizon characteristics, and it had even been used to test Hawking's area law. However, the new analysis, based on numerical relativity strain data, demonstrates that the direct wave frequency is not correlated with the horizon frequency or surface gravity, except for an incidental crossing around a remnant spin $\chi_f \approx 0.7$, which coincides with the spin of the GW250114 event. Furthermore, it is observed that, although the instantaneous frequency of the direct wave is quasi-stable, its damping time shows significant evolution, invalidating models that assume a single damped sinusoid with a fixed damping time. The authors also point out that evolving frequency models based on horizon properties fail to adequately describe the direct wave component for systems with large remnant spins. They conclude that attempting to verify Hawking's area law using a horizon frequency derived from the direct wave interpretation could lead to apparent violations of the law, even when no actual violation occurs. These findings suggest that the direct wave is not a reliable probe for investigating the horizon properties of black holes resulting from mergers.

Opacity in Black Hole Models and its Impact on Astrophysics

A recent analysis addresses the "epistemic opacity" in computer simulations and machine learning methods used in black hole imaging. This opacity refers to the difficulty in fully understanding how these models arrive at their conclusions. The study argues that, while the inherent opacity of techniques such as machine learning does not always compromise the reliability of an inference, especially when integrated into a broader inferential framework, there are certain forms of opacity that are problematic and limit our current understanding of astrophysical sources. The researchers propose conditions under which opaque methods can be useful, highlighting their potential in the context of the Event Horizon Telescope (EHT) and its next generation. However, they point out that a particular problematic form of opacity is currently present in black hole imaging: the GRMHD (general relativistic magnetohydrodynamics) models of Sagittarius A* are intrinsically opaque. This opacity in the GRMHD models of Sagittarius A* indicates limitations in our understanding of this astrophysical source and restricts the potential use of machine learning models in future observations. The main implication is that, although machine learning offers powerful tools for processing and analyzing the vast datasets generated by telescopes like the EHT, the lack of transparency in certain underlying models can hinder a complete and reliable interpretation of the results. Understanding and addressing this opacity is crucial for advancing our ability to accurately image and comprehend the fundamental physics of black holes, as well as for guiding the development of future observation and modeling techniques.

SKA to Enhance Precision in Gravity Tests with Binary Pulsars

The future Square Kilometre Array (SKA) telescope promises to revolutionize our ability to test Einstein's General Relativity in the strong-field regime. Binary pulsar systems, acting as natural space laboratories, have so far enabled some of the most precise gravity tests, including those of the strong equivalence principle and the radiative properties of gravity. SKA, with its high sensitivity, will drastically improve the timing precision of recycled pulsars, allowing for an unprecedentedly sensitive search for deviations from General Relativity in currently known systems. In addition to refining measurements in existing systems, a Galactic pulsar census with SKA will discover dozens of new relativistic systems. Among these, pulsar-black hole binaries are expected, offering unique opportunities to test fundamental hypotheses such as cosmic censorship and the no-hair theorem for black holes. These systems will allow exploration of gravitational aspects like strong equivalence principles, gravitational dipole radiation, the existence of extra field components of gravity, gravitomagnetism, and spacetime symmetries. SKA's ability to contribute to this science will depend on its specific features and capabilities, which are being designed to maximize discovery potential in this field. The improvement in timing precision and the detection of new exotic systems will open a new window for understanding the fundamental nature of gravity, allowing scientists to search for subtle deviations that could point towards a more complete theory.

Neutron stars with 'scalar hair' challenge General Relativity

A new study explores the existence of neutron stars with an exotic feature called "primary scalar hair" within a subfamily of Degenerate-Higher-Order-Scalar-Tensor (DHOST) theories of gravity. These theories, which modify Einstein's General Relativity, predict that neutron stars could possess a fundamental scalar field extending beyond their surface, significantly altering their gravitational and structural properties. The research focuses on static and spherically symmetric solutions for these stellar configurations. The researchers solved modified Tolman-Oppenheimer-Volkoff (TOV) equations to construct equilibrium configurations, using both polytropic and realistic equations of state. This approach allowed them to analyze the impact of scalar hair on the internal structure of the stars. The resulting scalar field and spacetime metric profiles, as well as the mass-radius relation of these exotic stars, were examined. The results show notable deviations from the predictions of standard General Relativity. Specifically, the presence of positive scalar charges leads to more compact stars than would be expected under General Relativity. Furthermore, it was found that above a critical threshold of these scalar charges, the solutions lead to singularities. These theoretical predictions open a crucial avenue for observational physics, as future observations of neutron stars, such as precise measurements of their masses and radii, could place stringent constraints on the parameters characterizing beyond-General Relativity effects in these theories and the potential existence of their scalar hair.

XMM-Newton and Chandra Recalibrate Distance to Outer Spiral Arms

The European Space Agency's (ESA) XMM-Newton and NASA's Chandra X-ray space telescopes have detected the echoes of three bright explosions propagating through the outer spiral arms of the Milky Way. By measuring the distance to these echoes, astronomers have determined that the outer arms are up to 10% further away than previously estimated. This finding suggests a revision in the mapping of our own galaxy. These observations are based on the detection of X-ray light emitted by the explosions, which interacts with interstellar gas and dust in the spiral arms. The way this light scatters and attenuates allows for the inference of the distance to galactic structures. The ability of XMM-Newton and Chandra to capture these faint echoes has been crucial for obtaining precise measurements in such distant regions of the Milky Way. The recalibration of the distance to the outer spiral arms has significant implications for our understanding of the Milky Way's structure and evolution. A greater distance implies a slightly different galactic scale, which could affect models of mass distribution, galactic rotation, and star formation in these regions. This type of precise measurement is fundamental for constructing a more accurate three-dimensional map of our galaxy.

Webb Telescope Challenges Models on Early Black Holes and Galaxies

Observations from the James Webb Space Telescope (JWST) are posing a significant challenge to standard cosmological models. The JWST has detected the presence of black holes and galaxies in the early universe that were not expected to exist at such primordial stages of their evolution. These findings suggest that the formation and growth processes of these cosmic structures might be much faster or different than current theories predict, forcing astrophysicists to revise their conceptual frameworks on universe formation. The existence of massive black holes and well-developed galaxies in epochs so close to the Big Bang raises fundamental questions about the initial mechanisms of nucleation and matter accretion. Previous models indicated insufficient time for these structures to reach the observed size and complexity. This discrepancy has prompted the scientific community to propose a variety of new theories to explain these unexpected observations, opening a fertile field of research to determine which of these hypotheses best fit cosmic reality.

Webb reveals how an exoplanet survived its star's death

NASA’s James Webb Space Telescope (JWST) has provided new observations of an exoplanet, designated HIP 65426 b, which has survived the final phase of its star's life. This discovery offers a crucial perspective on the fate of planetary systems, including our own, when their stars exhaust their nuclear fuel and expand into red giants, potentially engulfing their inner planets. HIP 65426 b is a gas giant with a mass of approximately six to twelve times that of Jupiter, orbiting at a considerable distance from its host star, HIP 65426. The star, which is about twice as massive as our Sun, has passed through the red giant phase, an event that typically drastically alters nearby planetary systems. The exoplanet's ability to persist after this stellar event provides valuable data to validate and refine theoretical models of stellar and planetary evolution. JWST observations, utilizing its infrared capabilities, allowed astronomers to characterize the planet's atmosphere and orbit with unprecedented precision. The distance of HIP 65426 b from its star (approximately 92 astronomical units) is considered a key factor in its survival. This separation allowed it to escape the star's expanded envelope during its red giant phase, a fate that likely awaits planets like Earth when the Sun expands in billions of years. This study underscores the importance of direct exoplanet observations for understanding long-term astrophysical processes. Webb's data not only confirms the existence of planets that can survive the death of their stars but also opens new avenues for investigating the conditions and mechanisms that enable such survival. Future observations of similar systems with JWST promise to shed more light on the long-term habitability of exoplanets and the evolution of stellar systems.

NASA Seeks Volunteers for Yearlong Simulated Moon, Mars Mission

NASA is recruiting participants for its next simulated deep space mission. Starting no earlier than August 2027, volunteers will live and work for one year in environments replicating the interplanetary conditions expected on future crewed missions to the Moon or Mars. This initiative will take place at the agency's Johnson Space Center in Houston, under isolated conditions simulating deep space. The primary goal of these analog missions is to gather crucial data on the physical and mental challenges astronauts will face during long-duration space travel. The information obtained will help NASA develop countermeasures and strategies to ensure crew health and well-being. The agency is looking for candidates who meet astronaut requirements, including a master's degree in a STEM field (science, technology, engineering, or mathematics) or equivalent experience, and a relevant professional background. These studies are essential for understanding how isolation, confinement, and the stress of a prolonged space mission affect human performance and team dynamics. The collected data will allow for the optimization of training protocols, habitat design, and life support systems for future lunar and Martian explorations, thus paving the way for sustained human presence beyond Earth's orbit.

Webb detects atmosphere of exoplanet that survived its star's death

An international team of astronomers has used the James Webb Space Telescope (JWST) to observe the exoplanet WD 1856 b as it transited its host star, a white dwarf. They have successfully measured the planet's mass and temperature, and for the first time, detected its atmosphere. This finding provides the first direct insight into the fate of gas giant planets, similar to Jupiter, after their host star exhausts its nuclear fuel and becomes a white dwarf, a scenario awaiting our own solar system billions of years from now. The researchers found that WD 1856 b is significantly warmer than anticipated. In addition to the atmospheric detection, the study has allowed for the determination of the most probable mechanism by which the planet reached its current, extremely close orbit around the white dwarf. This discovery is crucial for understanding planetary dynamics in post-main-sequence stellar systems and offers clues about the potential habitability of such worlds in the distant future of the universe.

Chandra Reveals More Extended Spiral Arms in the Milky Way

New observations from NASA’s Chandra X-ray Observatory suggest that the outer spiral arms of the Milky Way extend further than previously thought. This finding could modify our current understanding of our galaxy's structure, challenging existing models of its morphology and size. A team of astronomers made this discovery by precisely measuring the distances to dust clouds, using Chandra data. The observatory's ability to detect X-ray emissions from these distant regions has been crucial for determining their location with unprecedented accuracy. These measurements have allowed for mapping the outermost regions of the spiral arms, revealing a greater extension than expected. The main implication of this research is that the Milky Way might be a larger barred spiral galaxy than previously believed. This not only affects theoretical models of galactic formation and evolution but could also influence the estimation of dark matter distribution and stellar dynamics in peripheral regions. Future research will focus on corroborating these results with other observational techniques and refining galactic structure models.

Euclid reveals millions of stars and thousands of hidden exoplanets in the Milky Way

The ESA's Euclid space telescope has captured an unprecedented view of the Milky Way's center, revealing a mosaic of tens of millions of stars in extraordinary detail. This observation, completed in just 26 hours, not only provides a detailed image of the region but also serves as a map of stellar evolution, from dark clouds where stars are born to ancient populations packed into the galactic bulge. Beyond the visible stars, this dense field of light conceals thousands of exoplanets that cannot be directly observed. Astronomers identify them through gravitational microlensing, a technique that measures tiny, temporary changes in light as one star passes in front of another. This method allows for the detection of planets and even the estimation of their masses based solely on their gravitational effects. Although Euclid was primarily designed to investigate dark matter and dark energy, its capabilities are opening a new window into exploring our own galaxy and the unseen worlds within it. This ability to detect exoplanets via gravitational microlensing in such a dense stellar region underscores the telescope's versatility and its potential to significantly contribute to exoplanetology, in addition to its primary cosmological objectives.

Notable Astronomical Events in July 2026

July 2026 will offer a series of notable astronomical events for skywatchers. Among the highlights are a predawn meetup between the Moon and several planets, the return of a comet, an excellent opportunity to observe the Milky Way, and a new perspective on Saturn's rings. The month will begin with a planetary conjunction visible before dawn, where the Moon will align with several planets, creating a visual spectacle in the eastern sky. Additionally, a returning comet will be visible near Earth, offering an opportunity for amateur astronomers to track its trajectory. July nights will also be ideal for observing the Milky Way, especially in locations with low light pollution, due to Earth's orbital position. Finally, Saturn's rings will present a different viewing angle than usual. This change in the rings' inclination relative to Earth will allow terrestrial and space telescopes to obtain new perspectives and potentially reveal details not visible in other configurations, contributing to the understanding of the dynamics and composition of this ring system.

Propagating slow-mode shocks discovered in solar flare loops

A research team has discovered the propagation of slow-mode shock waves within dynamic solar flare loops. This finding, made through detailed observations, provides a new perspective on the energy release and heating mechanisms in the solar atmosphere. Slow-mode shock waves are a type of magnetohydrodynamic (MHD) wave that propagates at a speed slower than the sound speed in plasma, and their detection in this context is crucial for understanding the complex dynamics of flares. Solar flares are massive energy explosions occurring on the Sun's surface, releasing radiation and charged particles. While these flares are known to heat the solar corona to millions of degrees, the exact mechanisms of how this energy is transferred and dissipated remain an active area of research. The observation of these slow-mode shock waves suggests a possible channel for energy dissipation and coronal plasma heating, complementing other processes such as magnetic reconnection. The discovery was achieved by analyzing high-resolution temporal and spatial data from solar flares. Researchers were able to identify the characteristic signature of slow-mode shock waves, including abrupt changes in plasma density and temperature as the wave propagated along the magnetic loops of the flare. These results open new avenues for modeling and simulating the physics of solar flares, as well as for predicting their effects on Earth's space environment.

Globular Cluster NGC 6723, a 'Stellar Chandelier' in Sagittarius

The Hubble Space Telescope has captured a new image of the globular cluster NGC 6723, also known as the 'Chandelier Cluster' due to its sparkle. This cluster, located 27,000 light-years from Earth in the constellation Sagittarius, hosts some of the oldest known stars in the universe. Globular clusters are dense groupings of hundreds of thousands of stars gravitationally bound, orbiting the halo of galaxies. Their study is crucial for understanding the formation and evolution of galaxies, including the Milky Way. NGC 6723 is a paradigmatic example of these objects, offering a window into the early universe. Observing its stars allows astrophysicists to analyze the metallicity and age of these stellar populations, providing clues about the primordial conditions of the universe and stellar nucleosynthesis processes. The detailed Hubble image reveals the intricate distribution of stars, from red giants to white dwarfs, all contributing to the cluster's impressive luminosity.

Curvaton and supermassive primordial black holes: a new cosmological scenario

A recent study explores curvaton dynamics beyond standard models, revealing how self-interactions of this field can generate strongly non-Gaussian curvature perturbations after cosmic inflation. These perturbations, deviating from a simple random distribution, have significant implications for the formation of small-scale structures in the early universe. Researchers have developed a formalism that connects the frozen and oscillatory regimes of the curvaton, exposing sources of non-Gaussianity not observed in the purely quadratic case. The team applied this formalism to various potentials (quadratic, monomial, quartic, and cosine), demonstrating that curvaton self-interactions can either enhance or suppress the resulting non-Gaussianity, depending on the potential and initial conditions. This analysis includes non-perturbative aspects in the strongly non-Gaussian regime, showing how strong non-Gaussianity can even suppress the power spectrum of primordial fluctuations. This is crucial for understanding the distribution of matter in the early universe. As a practical application, the study proposes a scenario where strong positive curvaton non-Gaussianity could seed supermassive primordial black holes. These objects, with peak amplitudes of approximately 10^-5, would be compatible with constraints imposed by COBE/FIRAS μ-distortion observations of the cosmic microwave background. This mechanism offers a primordial explanation for the "Little Red Dots" observed by the James Webb Space Telescope (JWST), suggesting that the oldest supermassive black holes might have a cosmological origin rather than forming from stellar collapse. An axion-like curvaton is presented as a natural candidate for this mechanism.

Dark Energy Model with Ghost Condensate and Dark Matter

Scientists have explored the cosmic evolution of a generalized dilatonic ghost condensate field as a dark energy candidate. This model is formulated from a Lagrangian density featuring two dominant kinetic terms—one linear and one of arbitrary integer order $n>2$—combined with an exponential potential. The novelty lies in the field's interaction with dark matter via a source term, allowing for the study of the present universe under different coupling scenarios. The study analyzed three situations: a non-interacting case ($Q=0$) and two specific interaction models ($Q\propto\rho_m\dot\varphi$ and $Q\propto\rho_m H$). For each model, a detailed phase-space analysis was performed to identify critical points and stability conditions. In all scenarios, the system reproduces standard cosmological dynamics, evolving towards late-time dark energy-dominated attractors, exhibiting quintessence or phantom features depending on the sign of the coupling parameter $\alpha$ associated with the standard kinetic term. A joint likelihood analysis was conducted using Cosmic Chronometers, PantheonPlus, and DESI observations for two values of $n$ ($n=3$ and $n=5$). This allowed for the determination of marginalized parameter constraints at 68% and 95% confidence levels for the different $Q$-models. For the interaction term $Q\propto\dot\varphi\rho_m$, the direction of energy flow depends on the sign of $\alpha$. However, for $Q\propto H\rho_m$, the energy flow is consistently negative, indicating an energy transfer from dark matter to dark energy, irrespective of the sign of $\alpha$.

NASA Seeks Industry Input for Lunar Technologies

NASA has initiated a consultation process with industry to accelerate the development of key technologies for the lunar surface. This collaborative effort aims to involve private companies in the design, development, testing, and evaluation of innovative solutions that support U.S. space priorities. The objective is to establish the necessary infrastructure and operations for long-term lunar exploration and mitigate associated risks. The initiative focuses on gathering feedback on a draft solicitation for lunar technologies. This approach underscores the need for close cooperation between the space agency and the private sector to overcome the technical and operational challenges involved in a sustained human presence on the Moon. Long-term lunar exploration demands robust and efficient systems capable of functioning cohesively in such a demanding environment.

Erin Kara seeks to understand the universe's most extreme objects

Astrophysicist Erin Kara is dedicated to the study of black holes, the most extreme objects in the universe. Her research focuses on analyzing X-ray reverberations and other astrophysical data to unravel the mysteries surrounding these enigmatic cosmic structures. This approach allows for obtaining information about matter in the vicinity of the event horizon, a region where gravity is so intense that not even light can escape. Kara's work falls within high-energy astrophysics, utilizing space telescopes that detect X-rays emitted by the extremely hot gas orbiting black holes. By studying how these X-rays reflect and reverberate off the surrounding material, scientists can map the geometry of spacetime and the properties of the accretion disk. These observations provide crucial clues about the black hole's spin, its mass, and the physical processes occurring in its immediate environment.

Cosmological Models Unite Decaying Dark Matter and Dynamic Dark Energy

Researchers have developed a new cosmological framework that integrates decaying dark matter (DDM) with a semi-cosmographic reconstruction of dark energy. This model allows the study of nonlinear structure formation in the universe, where a non-relativistic dark matter component decays into relativistic dark radiation with a decay rate Γ. In parallel, dark energy is modeled directly from the cosmic expansion history, rather than assuming a fixed cosmological constant. This unified approach connects a reconstructed dark energy sector and DDM to the nonlinear formation of cosmic structures, offering a more flexible perspective on the universe's evolution. To constrain this model, the team used data from the Baryon Acoustic Oscillation (BAO) measurements and compressed ShapeFit measurements from DESI DR1. These data were employed to determine the background cosmological evolution, propagating the resulting constraints into the nonlinear regime through spherical collapse and halo abundance calculations. The results indicate that the reconstructed dark energy equation of state can deviate from the standard ΛCDM value (w=-1), while the critical density threshold for structure collapse remains close to its standard prediction. The most significant signatures of this model emerge in the abundance of massive halos, reflecting modifications to the growth of structures driven by both dark matter decay and dynamic dark energy. By combining DESI DR1 clustering constraints with halo mass function measurements from the DESI Legacy Imaging Surveys DR9, joint constraints on the DDM lifetime and dark energy parameters were obtained. This demonstrates that halo abundances provide a powerful complementary probe for investigating non-standard dark sector physics, opening new avenues for understanding the nature of these fundamental components of the universe.