Frontiers in Astronomy and Space Sciences | New and Recent Articles

We report a Kelvin–Helmholtz vortex (KHV) event observed at the duskside magnetopause boundary layer by the magnetospheric multiscale (MMS) satellites in conjunction with auroral beads detected in the high-latitude ionosphere by the Defense Meteorological Satellite Program (DMSP) on 27 September 2016. During the KHV event, the MMS spacecraft were located in the low-latitude boundary layer and wer…

In this pilot study, we investigate the known PN population in M 33, a nearby spiral galaxy, at a distance of ≈840 kpc, using data from the DR3 of the Javalambre-Photometric Local Universe Survey (J-PLUS), a 12-band photometric dataset extensively used to identify Hα line emitters. From the 143 known PNe of M 33, the photometry of only 13 is present in the J-PLUS catalog, as available on the J-PL…

In December 2023 an interplanetary coronal mass ejection impacted Mars and left the magnetosphere in a highly disturbed state that was observed by NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. One consequence of this space weather impact was the driving of large amplitude (∼50 nT) steepened magnetic structures that propagated into the dayside ionosphere. Here we focus on electrom…

Natural impulsive events such as earthquakes, volcanic eruptions, and thunderstorms, as well as anthropogenic events such as rocket launches and atmospheric re-entries, can generate acoustic-gravity waves (AGWs) that propagate in the upper-atmosphere and produce traveling ionospheric disturbances (TIDs) observable with GNSS total electron content (TEC) measurements. We developed an algorithm for …

The Mars Sample Return (MSR) mission is a major but prohibitively expensive goal of planetary exploration. This article presents a conceptual single-launch integrated mission architecture that consolidates entry, descent, and landing (EDL), surface sample retrieval, Mars ascent, and Earth-return functions (traditionally distributed across three separate spacecraft) into one capsule-class vehicle …

The problem of understanding how a newly forming solar system manages to lose angular momentum from the stage of collapsing core to the final main sequence phase is a long-standing one. This is especially pertinent regarding the evolution of the accretion disks. Both theoretical studies and recent observational surveys have questioned the paradigm of viscosity-driven disk evolution, while at the …

Recent developments in AI capabilities have seen significant advances in our ability to rapidly gather and summarise information, using big data repositories. In some applications, this has been realised, using Large Language Models (LLMs) to compile rapid responses to enquiries, although this output can be contaminated by spurious content, such as disinformation. Nevertheless, Machine learning a…

IntroductionWe present the results from the observations of the galaxy NGC 628 with the Planetary Nebulae Spectrograph (PN.S) equipped with the Hα arm. With the third PN.S arm, the Hα arm, we measure the Hα fluxes, in addition to fluxes and line-of-sight velocities (LOSV) of monochromatic, spatially unresolved [OIII] 5007Å sources, in the nearly face-on disc of NGC 628.MethodsThe narrow band colo…

IntroductionGeomagnetic storms are typical solar eruption activities. When high-speed solar wind or coronal mass ejections from solar eruptions strike the Earth, they trigger rapid severe geomagnetic disturbances and further induce ionospheric variations. For low-frequency time-code signals that depend on the ionosphere as a reflective propagation medium for long-distance transmission, geomagneti…

Understanding how dust evolves in protoplanetary disks is crucial to constraining the initial conditions of planet formation. The apparent “mass budget problem”, which stems from the comparison of the observed disk masses to the ones inferred for exoplanets, remains debated, as it is unclear whether the discrepancy arises from limitations in interpreting disk observations, from evolutionary proce…

Biosignature detection is at the forefront of modern astrobiology and paleobiology research. Previous studies have demonstrated that machine learning models trained on data from pyrolysis–gas chromatography–mass spectrometry (py–GC–MS) can distinguish purely biotic and abiotic specimens from one another, as well as identify differences among contemporary biotic and ancient biotic samples. However…

TeV blazars emit very high-energy gamma rays that interact with the extragalactic background light, producing relativistic electron–positron pair beams. These beams are expected to initiate electromagnetic cascades that give observable GeV-scale emission. Yet, for many blazars, this cascade component is absent in the observed spectra. One possible explanation attributes this suppression to weak i…

The rapid increase in space debris poses a major threat to sustainable space operations and underscores the importance of understanding long-term drivers of orbital decay. Because debris objects do not perform station-keeping maneuvers, their orbital evolution directly reflects variations in thermospheric density, unlike that of operational satellites. This makes space debris an effective natural…

The identification of exoplanets within habitable zones remains a central objective in modern astrophysics, particularly with the availability of large-scale photometric datasets from space-based missions such as the Transiting Exoplanet Survey Satellite (TESS). This study investigates the effectiveness of unsupervised machine learning techniques–specifically k-means and k-medians clustering–for …

Enhanced Loran (eLoran) provides resilient, wide-area positioning, navigation, and timing (PNT) services in the low-frequency band. However, receiver acquisition remains computationally demanding because of the long group repetition intervals (GRIs) and high sampling rates required for signal processing. Although the uniform partitioned overlap-save (UPOLS) algorithm has potential for matched fil…

The plasmasphere contains rich small-scale structure that plays a key role in regulating wave propagation and mass transport in the inner magnetosphere, yet the evolution of plasmaspheric density ducts remains poorly understood. We use joint observations from the Van Allen Probes to investigate how density structures change over time by identifying matched structures observed by both spacecraft d…