Results 1 to 10 of about 19,004,069 (305)

Metal-rich stars are less suitable for the evolution of life on their planets

Nature Communications, 2023
Atmospheric ozone and oxygen protect the terrestrial biosphere against harmful ultraviolet (UV) radiation. Here, we model atmospheres of Earth-like planets hosted by stars with near-solar effective temperatures (5300 to 6300 K) and a broad range of ...
Anna V. Shapiro, Christoph Brühl, Klaus Klingmüller, Benedikt Steil, Alexander I. Shapiro, Veronika Witzke, Nadiia Kostogryz, Laurent Gizon, Sami K. Solanki, Jos Lelieveld   +9 more
doaj   +1 more source

Simplified Relations for the Martian Night-Time OH* Suitable for the Interpretation of Observations

Remote Sensing, 2022
Observations of excited hydroxyl (OH*) emissions are broadly used for inferring information about atmospheric dynamics and composition. We present several analytical approximations for characterizing the excited hydroxyl layer in the Martian atmosphere ...
Mykhaylo Grygalashvyly, Dmitry S. Shaposhnikov, Alexander S. Medvedev, Gerd Reinhold Sonnemann, Paul Hartogh   +4 more
doaj   +1 more source

Determination of Spatial Scale in Martian Landscape Images Acquired by the Curiosity Rover, and Viewing Image Scale and Target Chemistry Using the ASIC Website

Earth and Space Science, 2023
In this paper we describe a method to compute spatial scales for images acquired by NASA's Mars Curiosity rover (Mars Science Laboratory, MSL). The method is based on the assumption that the rover stands on an infinite plane that may have any orientation
Walter Goetz, Michael Bruns, Stephan Thoma, Iancu Pardowitz, Thomas C. Stein   +4 more
doaj   +1 more source

Brine residues and organics in the Urvara basin on Ceres

Nature Communications, 2022
The authors report the discovery of salts and fresh organic-rich exposures in the Urvara basin, possibly linked to a late resurfacing of the crater floor. These results are consistent with a deep-seated brine/salt reservoir in the crust of Ceres.
A. Nathues, M. Hoffmann, N. Schmedemann, R. Sarkar, G. Thangjam, K. Mengel, J. Hernandez, H. Hiesinger, J. H. Pasckert   +8 more
doaj   +1 more source

Development of Synthesis and Fabrication Process for Mn-CeO₂ Foam via Two-Step Water-Splitting Cycle Hydrogen Production

Energies, 2021
The effects of doping manganese ions into a cerium oxide lattice for a thermochemical two-step water-splitting cycle to produce oxygen and hydrogen and new synthesis methods were experimentally investigated.
Hyun-Seok Cho, Tatsuya Kodama, Nobuyuki Gokon, Selvan Bellan, Jong-Kyu Kim   +4 more
doaj   +1 more source

Small-scale impulsive extreme-UV emission enhancements along network loops

Astronomy & Astrophysics
Context. Network loops are a common feature in the quiet Sun. The physical processes sustaining their energy budget are still discussed. Aims. We relied on a multi-instrumental (Solar Orbiter/EUI, Solar Orbiter/PHI, and IRIS) observation of a six-hour ...
Dolliou A., Peter H., Mandal S., Chitta L. P., Teriaca L., Chen Y., Calchetti D.   +6 more
doaj   +1 more source

Simulations of facular magnetic fields on cool stars

Astronomy & Astrophysics
Context. Stellar convection in the presence of magnetic field affects the emergent intensity, as well as the structure and evolution of cool main-sequence dwarfs. Aims.
Singh Bhatia Tanayveer, Cameron Robert H., Solanki Sami K., Przybylski Damien F., Witzke Veronika, Shapiro Alexander, Kostogryz Nadiia   +6 more
doaj   +1 more source

High-resolution observations of small-scale activity in coronal hole plumes

Astronomy & Astrophysics
Context. Largely radial ray-like structures, termed plumes, are often observed in coronal holes. Plumes have been proposed to channel magnetohydrodynamic (MHD) waves and the solar wind into the heliosphere.
Huang Ziwen, Chitta L. P., Teriaca L., Aznar Cuadrado R., Peter H., Solanki S. K., Wiegelmann T., Plaschke F.   +7 more
doaj   +1 more source

In Situ Optimized Substrate Witness Plates: Ground Truth for Key Processes on the Moon and Other Planets

Earth and Space Science, 2023
Future exploration efforts of the Moon, Mars, and other bodies are poised to focus heavily on persistent and sustainable survey and research efforts, especially given the recent interest in a long‐term sustainable human presence at the Moon. Key to these
Prabal Saxena, Liam S. Morrissey, Rosemary M. Killen, Jason L. McLain, Li Hsia Yeo, Natalie M. Curran, Nithin S. Abraham, Heather V. Graham, Orenthal J. Tucker, Menelaos Sarantos, Aaron B. Regberg, Diane E. Pugel, Andrew W. Needham, Mark Hasegawa, Alfred J. Wong   +14 more
doaj   +1 more source

Ca II λ854.2 nm in an enhanced network region simulated with MURaM-ChE

Astronomy & Astrophysics
Context. The Ca IIλ854.2 nm line is widely used to study the chromosphere of the Sun. In the quiet Sun, the spatially averaged line profile shows a red asymmetry and a redshift of the line center. It is known that the effect of isotopic splitting must be
Ondratschek P. A., Przybylski D., Smitha H. N., Cameron R. H., Solanki S. K.   +4 more
doaj   +1 more source