Results 41 to 50 of about 207,371 (176)

Sulfidation Reaction Mechanisms of Olivine and Diopside at Mercury's Reducing Conditions

Journal of Geophysical Research: Planets, Volume 131, Issue 11, November 2026.
Abstract The surface of Mercury contains elevated amounts of sulfur of up to 4 wt.%. Volcanic degassing of S from the interior of the planet could have initiated sulfidation reactions between the degassed S and surface materials in the planet's past, leading to the observed surface S enrichment.
Rody C. Erftemeijer, Thomas Müller, Christian J. Renggli   +2 more
wiley   +1 more source

A Preferred Orientation Angle for Bipolar Planetary Nebulae

Galaxies, 2020
We present preliminary results from measuring Galactic orientation angles of 766 elliptical and bipolar Planetary Nebulae (PNe) in the Hong Kong/Australian Astronomical Observatory/Strasbourg Observatory H-alpha Planetary Nebula research platform and ...
Andreas Ritter, Quentin A. Parker
doaj   +1 more source

A tipping point for tipping points

Oikos, Volume 2026, Issue 10, October 2026.
Tipping points (TPs) – often understood as abrupt changes to a system – have become a popular framework for ecology and environmental science across spatial and temporal scales. The underlying, quantitative foundation of TP theory is built on mathematical models from catastrophe and predator–prey theories.
David G. Jenkins, Alexandria G. Lacoursière   +1 more
wiley   +1 more source

Ancient ‘ghost’ planetary nebulae discovered with amateur telescopes

Astronomy & Astrophysics
As planetary nebulae evolve, they fade and dissipate into the surrounding interstellar medium, which makes them harder to detect. Modern, advanced amateur equipment can help to uncover this hidden population of ancient ‘ghost’ planetary nebulae.
Manuel J. A., Jones D., Santander-García M., Reindl N.   +3 more
doaj   +1 more source

From Flybys to Sample Return: A Review of Space Probes and Robotic Sampling Technologies for Small Bodies

Journal of Field Robotics, Volume 43, Issue 7, Page 4475-4514, October 2026.
ABSTRACT As a crucial puzzle piece of deep space exploration, exploring small bodies can provide significant scientific insights and valuable mineral resources. Unlike missions to the Moon and Mars, small‐body missions pose distinct technical challenges, including communication delays, weak gravity, and uncertain environments. This paper reviews a full
Xin Zhang, Hao Zhou, Dalin Zhou, Zhaojie Ju   +3 more
wiley   +1 more source

Europa's Neutral Sodium Exosphere Is Quasi‐Stable Over Decades

Journal of Geophysical Research: Space Physics, Volume 131, Issue 10, October 2026.
Abstract Europa's sodium cloud is thought to be modified by its orbital longitude and by its plasma environment, which modulates with Jovian magnetic geometry. To explore and quantify sodium cloud variability, seven sets of Keck I/HIRES measurements are compared providing comprehensive coverage of orbital and magnetic geometry.
Emma L. Lovett, Carl A. Schmidt, Zachariah Milby, Sean P. Ellis, Jamey R. Szalay   +4 more
wiley   +1 more source

Oxygen isotope thermometry and composition of aqueous fluids within the parent body of asteroid (101955) Bennu

Meteoritics &Planetary Science, Volume 61, Issue 10, Page 2567-2591, October 2026.
Abstract We report on the petrography and oxygen isotopic compositions from in situ analyses of carbonates (Ca‐carbonate, dolomite, and Fe‐rich magnesite), magnetite, and apatite in particles from asteroid Bennu. Using oxygen isotope thermometry of Ca‐carbonate, dolomite, and magnetite, we estimated crystallization temperatures and the oxygen isotopic ...
Gary R. Huss, Kazuhide Nagashima, Elena Dobrică, Alexander N. Krot, Gregory Cane, Zoe E. Wilbur, Timothy J. McCoy, Catherine M. Corrigan, Sara S. Russell, Jessica J. Barnes, Ann N. Nguyen, Harold C. Connolly Jr., Dante S. Lauretta   +12 more
wiley   +1 more source

Pattern Formation in Rocks

Geochemistry, Geophysics, Geosystems, Volume 27, Issue 9, September 2026.
Abstract This commentary concerns a two‐part paper by Regenauer‐Lieb et al. (2026a, 2026b) on pattern formation in deforming porous rocks. The theory developed in part I (https://doi.org/10.1029/2025GC012710) uses the general idea of Turing's reaction‐diffusion model of morphogenesis based on interactions between two types of diffusible chemical ...
Jibamitra Ganguly
wiley   +1 more source

M31 Planetary nebulae as seen by the Panchromatic Hubble Andromeda Treasury [PDF]

, 2012
We present a preliminary analysis of known planetary nebulae (PNe) in M31 that were observed in the first year of the Panchromatic Hubble Andromeda Treasury HST Multi-cycle program.
Johnson, L. Clifton, Gordon, Karl, Caldwell, Nelson, Seth, Anil C., Williams, Benjamin F., Lan, Dustin, Girardi, Léo, Bianchi, Luciana, ROSENFIELD, PHILIP, MARIGO, PAOLA, Dalcanton, Julianne J.   +10 more
core   +1 more source

Molecular Hydrogen Microstructures in Planetary Nebulae

Galaxies, 2020
Molecular hydrogen (H 2 ) emission is commonly detected in planetary nebulae (PNe), specially in objects with bipolar morphologies. New studies showed that H 2 gas is also packed in microstructures embedded in PNe of any morphological type.
Stavros Akras, Denise R. Gonçalves, Gerardo Ramos-Larios, Isabel Aleman   +3 more
doaj   +1 more source