Frontiers in Astronomy and Space Sciences | New and Recent Articles

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…

This study investigates variability in ionospheric Total Electron Content (TEC) associated with the 28 March 2025 moment magnitude (Mw) 7.7 Sagaing (Myanmar) earthquake within the low-latitude environment of Southeast Asia. A primary challenge in this region is identifying seismogenic perturbations during the residual recovery phase of two successive geomagnetic storms (25–26 March), which produc…

IntroductionTo investigate the impact of surface sampling operations on the physical and mechanical properties of lunar soil—defined as the granular, sub-centimeter-sized fraction of the lunar regolith—and to mitigate design errors in sampling missions that arise from neglecting such disturbance, we conducted sampling disturbance experiments using the CUG-1A lunar soil simulant.MethodsThe degree …

The search for life signatures beyond Earth is one of the main objectives of space exploration. Studies of analogous terrestrial ecosystems have shed light on the limits of life and on the adaptations of microbial communities to thrive in these extreme environments resembling Icy Moons. However, their findings tend to be compartmentalized, which hinders the drawing of broad conclusions about the …

Real-Time Kinematic (RTK) positioning technique, with centimeter-level accuracy, is widely used in landslide deformation and building structural health monitoring. However, in large-height-difference scenarios where the height difference between the base and rover station is generally over 100 m, RTK positioning performance experiences a significant decline, mainly due to the deficiency in tropos…

The establishment of sustainable agriculture on extraterrestrial bodies (the Moon, Mars, etc.) depends on transforming regolith, an unconsolidated, microbiota-free, mineral substrate, into a functional soil-like material with numerous beneficial properties including as a growth substrate for plants. Lunar and Martian regolith present physicochemical challenges, including alkaline pH, high concent…

IntroductionRecent studies have demonstrated that temporal filtering can successfully identify local acoustic source wavefronts in radiative magnetohydrodynamic simulations of the solar photosphere. Extending this capability to observations promises new insight into the stochastic excitation of solar p-modes, the source depth distribution below the photosphere, and the dominant physical processes…

The Kelvin–Helmholtz instability (KHI), in its nonlinear phase, plays a significant role in transporting solar-wind plasma into Earth’s magnetosphere. This study investigates the turbulence properties and reconnection signatures observed at the edges of Kelvin–Helmholtz vortices during a geomagnetic storm. Temporal spectra of the magnetic field, electric field, and bulk ion velocity exhibit power…

This work introduces a statistical framework to obtain Bayesian constraints on planet formation parameters, which offers a probabilistic interpretation of uncertainties and degeneracies contained within planet formation models. The model likelihood, or the probability distribution of observations conditioned on a set of formation parameters, is intractable for planet formation theories due to the…

The electron heat flux plays a important role in the expansion of the solar corona and solar wind. The electron heat flux of the solar wind is fully described by the electron velocity distribution function as it evolves with heliocentric distance. We investigate the characteristics of the radial evolution of the electron heat flux in the inner heliosphere from 0.2 to 2.2 au. The electron Fokker-P…

Abstract Introduction: The high-precision numerical ephemeris of Mars is important for its mission planning, spacecraft navigation, and solar system dynamics studies. Methods: This study systematically compares the dynamical models employed in the DE441, EPM2021, INPOP21a, and PETREL19 ephemerides and evaluates the contributions of the principal perturbation forces to Mars orbit. Results: Over a …

Abstract From 2000 to 2001, ground-based geocoronal hydrogen Balmer- 1 Introduction Hydrogen distribution is key to understanding the chemistry and dynamics of the middle and upper atmosphere (Bishop, 2001). Atomic hydrogen in the mesosphere is a byproduct of photolysis reactions of Brasseur and Solomon, 2005). Furthermore, as a minor species in the lower thermosphere, atomic hydrogen becomes inc…

Abstract To estimate the effects of magnetic holes on the magnitude of B magnetic power spectral density, a 2-day interval of fast coronal-hole-origin plasma at 1 AU is examined. The magnetic holes are identified and removed from the magnetic time series, and the power spectral density of the hole-free time series is compared with the power spectral density of the original time series. The magnet…

Abstract We present simultaneous multi-point observation of local-time asymmetry in keV ion and electron fluxes during the interplanetary (IP) shock impact on 19 April 2014 under geomagnetically quiet conditions. During this event, Van Allen Probe-A and Probe-B were simultaneously located in the afternoon and morning sectors, respectively, for ∼20 min (18:38-18:58 UT), while sampling nearly ident…

1 Background and motivation Molecular abundances are crucial for obtaining information about astronomical objects, spanning from molecular clouds to star-forming regions and planetary atmospheres (Herbst and van Dishoeck, 2009; Tielens, 2013). In this context, the importance of tracers and proxy species is unquestionable. For example, the study of species with distinct isotopic composition (also …