Results 61 to 70 of about 789,439 (256)

Earth's Mesosphere During Possible Encounters With Massive Interstellar Clouds 2 and 7 Million Years Ago

Geophysical Research Letters
Our solar system's path has recently been shown to potentially intersect dense interstellar clouds 2 and 7 million years ago: the Local Lynx of Cold Cloud and the edge of the Local Bubble.
Jesse A. Miller, Merav Opher, Maria Hatzaki, Kyriakoula Papachristopoulou, Brian C. Thomas   +4 more
doaj   +1 more source

JWST Imaging of the Closest Globular Clusters—VI. The Lowest‐Mass Objects in M 4 and the Galactic Bulge

Astronomische Nachrichten, Volume 346, Issue 9, November 2025.
ABSTRACT We present James Webb Space Telescope observations of M 4—the closest globular cluster—that probe the lower Main Sequence down to the hydrogen‐burning limit. The unveiled stellar sequence reaches much fainter luminosities than previously possible, revealing a few extremely red objects that are consistent with brown dwarfs as cool as Teff∼1000K$
L. R. Bedin, R. Gerasimov, A. Calamida, M. Libralato, M. Scalco, D. Nardiello, M. Griggio, D. Apai, J. Anderson, A. Bellini, A. Burgasser   +10 more
wiley   +1 more source

Interstellar Migration, the Population ‘Problem’ and the Climate Emergency

Critical Quarterly, EarlyView.
Anna Hartnell
wiley   +1 more source

Correlation Patterns of Muon Flux With Vertical Atmospheric Profiles: Insights From Monte Carlo Simulations

Journal of Geophysical Research: Space Physics, Volume 130, Issue 11, November 2025.
Abstract The production, attenuation, and absorption of secondary cosmic rays (SCR) are influenced by atmospheric parameters such as air pressure and temperature. To reliably correlate SCR flux measurements with atmospheric ionization driven by energetic particle precipitation, these dependencies must be quantified.
A. Al‐Qaaod, V. Pierrard, A. Winant, U. Stolzenberg, I. Ambrozova, M. Sommer, J. Slegl, J. Solc, A. Gkikoudi, A. G. Georgakilas, A. Papayannis, F. S. Krasniqi   +11 more
wiley   +1 more source

Physicochemical Constraints on the Abiotic Polymerization of Nucleotides Into RNA

Journal of Geophysical Research: Biogeosciences, Volume 130, Issue 11, November 2025.
Abstract One of the key steps in the origin of life is the polymerization of nucleotides into nucleic acids like RNA. We have quantified the energetic impact of temperature, pressure, and composition on the polymerization of nucleotides into RNA using the Gibbs function. These Gibbs energies have been used to calculate the probability that a nucleotide
D. E. LaRowe, J. M. Dick
wiley   +1 more source

From Anti‐Van't Hoff Le Bel Molecules of C6NH to Astronomically Relevant and Experimentally Known and Unknown Carbenes

ChemPhysChem, Volume 26, Issue 20, October 15, 2025.
Molecules with a planar tetracoordinate carbon atom serve as reactive intermediates for carbenes. While isomer 2 has been identified in the laboratory, isomer 5 remains elusive to date. Here, four stationary points with a planar tetracoordinate carbon (ptC) atom that are considered as anti‐van't Hoff Le Bel molecules have been computationally ...
Shilpa Shajan, Devipriya Sivadasan, Krishnan Thirumoorthy, Venkatesan S. Thimmakondu   +3 more
wiley   +1 more source

Formation of All Three C2H4O Isomers—Ethylene Oxide (c-C2H4O), Acetaldehyde (CH3CHO), and Vinyl Alcohol (CH2CHOH)—in Ethanol-containing Interstellar Analog Ices

The Astrophysical Journal
Oxygen-containing complex organic molecules are key precursors to biorelevant compounds fundamental for the origins of life. However, the untangling of their interstellar formation mechanisms has just scratched the surface, especially for oxygen ...
Jia Wang, Chaojiang Zhang, Joshua H. Marks, Ralf I. Kaiser   +3 more
doaj   +1 more source

UV–Vis Spectra of Carbonic Acid: Rationalizing Experimental Redshifts between Monomer and Bulk based on (H2CO3)n Calculations

ChemPhysChem, Volume 26, Issue 18, September 19, 2025.
In bulk carbonic acid (e.g., in interstellar icy dust grains) cluster formation produces two distinct UV‐Vis spectral features redshifted by ≈2 eV (25 nm) and by ≈5 eV (80 nm) compared to gas phase single molecule carbonic acid 's adiabatic ionization energy. Theory and experiment were used to investigate the origin of these shifts.
Dennis F. Dinu, Bastian Klein, Chaojiang Zhang, Radu A. Talmazan, Thomas Loerting, Hinrich Grothe, Ralf I. Kaiser, Maren Podewitz   +7 more
wiley   +1 more source

Overlapping Open Clusters NGC 1750 and NGC 1758 behind the Taurus Dark Clouds. II. CCD Photometry in the Vilnius System

Open Astronomy, 2003
Seven-color photometry in the Vilnius system has been obtained for 420 stars down to V = 16 mag in the area containing the overlapping open clusters NGC 1750 and NGC 1758 in Taurus.
Straižys V., Kazlauskas A., Černiauskas A., Boyle R. P., Vrba F. J., Philip A. G. Davis, Laugalys V., Černis K., Smriglio F.   +8 more
doaj   +1 more source

Plasma Production by Laser Ablation of Heavy Metals

Contributions to Plasma Physics, Volume 65, Issue 7, August 2025.
ABSTRACT An Nd:YAG focused laser operating at 1064 nm, 3 ns pulse width, 360 mJ pulse energy, is employed to irradiate heavy metals, such as Ta, W, Pt, Au, and Pb. The in‐vacuum irradiation produces an expanding plasma at the target surface which has high density, temperature, and kinetic energy of emitted ions. Ions have a velocity of the order of 104 
L. Torrisi, M. Cutroneo, A. Torrisi
wiley   +1 more source