Unsaturated nitriles are significant in prebiotic and astrochemistry. Dicyanoacetylene, in particular, is a possible precursor of uracil and was previously detected in Titan’s atmosphere. Its null dipole moment hindered detection through rotational spectroscopy in interstellar clouds, and it escaped identification until recently, when its protonated form NC4NH+ was finally detected toward the Taurus molecular cloud (TMC-1) (Agúndez et al., Astronom. Astrophys. 2023, 669, L1).
We conduct a statistical analysis of multiple bow shock (BS) crossings at Mars. Data from the magnetometer (MAG) and Solar Wind Ion Analyzer (SWIA) onboard the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft from its first 2 years in orbit is used to identify flapping events. These are interpreted as the bow shock moving toward and away from Mars. 9% of all MAVEN passes occur when the BS is flapping.
Aims. This paper focuses on how insolation affects the nucleus of comet 67P/Churyumov-Gerasimenko over its current orbit. We aim to better understand the thermal environment of the nucleus, in particular its surface temperature variations, erosion, relationship with topography, and how insolation affects the interior temperature for the location of volatile species (H2O and CO2). Methods.
Context. We investigate the behavior of the plasma in eruptive prominences and coronal mass ejections in characteristic physical conditions. Aims. We aim to demonstrate various relations between the plasma parameters and radiation properties relevant to Solar Orbiter and Metis observations. Methods. Our method is based on 2D non-local thermodynamic equilibrium (non-LTE) modeling of moving structures that are externally illuminated from the solar disk.
During Forbush decreases (FDs), the fluxes of high‐energy galactic cosmic rays (GCRs) are suppressed. As a consequence, the ionization profile of the atmosphere is affected and the global electric circuit system is perturbed. Recently, using cosmic ray measurements from the Alpha Magnetic Spectrometer (AMS‐02) onboard the International Space Station to classify FDs, Tacza et al.
Low, marine clouds cool the Earth system, reflecting sunlight back to space. Low cloud response to environmental change is a key uncertainty in future climate projections. It is especially uncertain how much warming amplification will occur due to tropical cumulus feedback. A potentially important feedback modulator is the ability for cumulus to cluster through mesoscale circulations. Janssens et al.
The ionosphere-thermosphere (IT) is a convergence point of energy and processes that interconnect Earth’s atmosphere with space. Processes generated by terrestrial weather in the lower atmosphere (i.e., troposphere and stratosphere, altitudes less than ~ 50 km) are recognized by the scientific community as sources of variability in both the structure and composition of the IT.
We analyze the deviations from local thermodynamic equilibrium (LTE) of the ion velocity distribution function (iVDF) in collisionless plasma turbulence. Using data from the magnetospheric multiscale (MMS) mission, we examine the non-Maxwellianity of 439 685 iVDFs in the Earth’s magnetosheath. We find that the iVDFs’ anisotropies and the high-order non-bi-Maxwellian features are widespread and can be significant.
We examine the applicability of homogeneous, negligible cross-helicity magnetohydrodynamic (MHD) turbulence models incorporating “critical balance” (CB) and “scale-dependent dynamic alignment” (SDDA) to Parker Solar Probe observations of a highly Alfvénic, high cross-helicity solar wind stream. At energy-injection scales, both Alfvénic modes satisfy χλ±≡τA±/τnl±≪1 , where τA± and τnl± denote the linear and nonlinear timescales.