Results 81 to 90 of about 33,632 (191)

Climate Emergency and Different Ways to Fail? The Fermi Paradox, the Simulation Hypothesis, Agency and Hope

Journal for the Theory of Social Behaviour, Volume 55, Issue 4, December 2025.
ABSTRACT Humanity seems stuck on different ways to fail to meet the challenge posed by a declared climate emergency and manifest problems of ecological breakdown. Rather than reprise these failures, we use the Fermi Paradox and simulation hypothesis to make a simple point about agency. The argument unfolds in two sections.
Jamie Morgan
wiley   +1 more source

Helium in the Extended Atmosphere of the Warm Superpuff TOI-1420b

The Astronomical Journal
Superpuffs are planets with exceptionally low densities ( ρ ≲ 0.1 g cm ^−3 ) and core masses ( M _c ≲ 5 M _⊕ ). Many lower-mass ( M _p ≲ 10 M _⊕ ) superpuffs are expected to be unstable to catastrophic mass loss via photoevaporation and/or boil-off ...
Shreyas Vissapragada, Michael Greklek-McKeon, Dion Linssen, Morgan MacLeod, Daniel P. Thorngren, Peter Gao, Heather A. Knutson, David W. Latham, Mercedes López-Morales, Antonija Oklopčić, Jorge Pérez González, Morgan Saidel, Abigail Tumborang, Stephanie Yoshida   +13 more
doaj   +1 more source

Neuromorphic Computing with Memcapacitors: Advancements, Challenges, and Future Directions

Advanced Electronic Materials, Volume 11, Issue 18, November 4, 2025.
Neuromorphic computing reduces energy costs by integrating memory and processing in event‐driven architectures, achieving energy usage as low as 10–30 pJ per operation for memcapacitor‐based synapses. Memcapacitors are reviewed as strong contenders for neuromorphic computing, enhancing AI acceleration through charge‐based computations, high resistance,
Nada AbuHamra, Muhammad Umair Khan, Eman Hassan, Mahmoud Al Qutayri, Baker Mohammad   +4 more
wiley   +1 more source

A Multispecies Atmospheric Escape Model with Excited Hydrogen and Helium: Application to HD209458b

The Astrophysical Journal
Atmospheric escape shapes exoplanet evolution and star–planet interactions, with He I 10830 Å absorption serving as a key tracer of mass loss in hot gas giants.
Anna Ruth Taylor, Tommi T. Koskinen, Luca Argenti, Nicholas Lewis, Chenliang Huang, Anthony Arfaux, Panayotis Lavvas   +6 more
doaj   +1 more source

Mercury's Altered Magnetosphere During a Sub‐Alfvénic ICME Event: MESSENGER Observations and Inferred Asymmetric Alfvén Wing Formation From Global MHD Simulations

Journal of Geophysical Research: Space Physics, Volume 130, Issue 11, November 2025.
Abstract We present observations of a rare configuration of Mercury's magnetosphere in response to sub‐Alfvénic upstream conditions, driven by an interplanetary coronal mass ejection (ICME) that impacted the planet on 1 May 2013. Using data from the Mercury Surface, Space Environment, Geochemistry, and Ranging (MESSENGER) spacecraft, supported by a ...
Charles F. Bowers, Caitríona M. Jackman, Xianzhe Jia, Lina Z. Hadid, Weijie Sun, Laura A. Hayes, Ryan M. Dewey, Brandon Burkholder, Daragh M. Hollman, Sebastian Cervantes, Hans L. F. Huybrighs, Matthew J. Rutala   +11 more
wiley   +1 more source

UV transit observations of EUV-heated expanded thermospheres of Earth-like exoplanets around M-stars: testing atmosphere evolution scenarios

Astrophysics and Space Science, 2011
The detection and investigation of EUV heated, extended and non-hydrostatic upper atmospheres around terrestrial exoplanets would provide important insights into the interaction of the host stars plasma environment as well as the evolution of Earth-type planets their atmospheres and possible magnetic environments.
Lammer, H., Eybl, Vera Theresa, Kislyakova, K. G., Weingrill, J., Holmstrom, M., Khodachenko, M. L., Kulikov, Yu N., Reiners, Ansgar, Leitzinger, M., Odert, P., Gruess, M. Xiang, Dorner, B. G., Guedel, M., Hanslmeier, A.   +13 more
openaire   +2 more sources

Evolutionary and functional relationships between plant and microbial C1 metabolism in terrestrial ecosystems

New Phytologist, Volume 248, Issue 3, Page 1132-1153, November 2025.
Summary One‐carbon (C1) metabolism, centered on the universal methyl donor S‐adenosyl methionine (SAM), plays critical roles in biosynthesis, redox regulation, and stress responses across plants and microbes. A recently proposed photosynthetic C1 pathway links SAM methyl groups directly to RuBisCO‐mediated CO2 assimilation and integrates with nitrogen ...
Kolby J. Jardine, Linnea K. Honeker, Zhaoxin Zhang, Steve Kwatcho Kengdo, Yuguo Yang, Joseph Roscioli, William J. Riley   +6 more
wiley   +1 more source

Where Are the Water Worlds? Identifying Exo-water-worlds Using Models of Planet Formation and Atmospheric Evolution

The Astrophysical Journal
Planet formation models suggest that the small exoplanets that migrate from beyond the snowline of the protoplanetary disk likely contain water-ice-rich cores (∼50% by mass), also known as water worlds.
Aritra Chakrabarty, Gijs D. Mulders
doaj   +1 more source

The Cosmic Shoreline Revisited: A Metric for Atmospheric Retention Informed by Hydrodynamic Escape

The Astrophysical Journal
The “cosmic shoreline,” a semi-empirical relation that separates airless worlds from worlds with atmospheres as proposed by K. J. Zahnle & D. C. Catling, is now guiding large-scale JWST surveys aimed at detecting rocky exoplanet atmospheres.
Xuan Ji, Richard D. Chatterjee, Brandon Park Coy, Edwin Kite   +3 more
doaj   +1 more source

JWST/NIRISS Reveals the Water-rich “Steam World” Atmosphere of GJ 9827 d

The Astrophysical Journal Letters
With sizable volatile envelopes but smaller radii than the solar system ice giants, sub-Neptunes have been revealed as one of the most common types of planet in the galaxy. While the spectroscopic characterization of larger sub-Neptunes (2.5–4 R _⊕ ) has
Caroline Piaulet-Ghorayeb, Björn Benneke, Michael Radica, Eshan Raul, Louis-Philippe Coulombe, Eva-Maria Ahrer, Daria Kubyshkina, Ward S. Howard, Joshua Krissansen-Totton, Ryan J. MacDonald, Pierre-Alexis Roy, Amy Louca, Duncan Christie, Marylou Fournier-Tondreau, Romain Allart, Yamila Miguel, Hilke E. Schlichting, Luis Welbanks, Charles Cadieux, Caroline Dorn, Thomas M. Evans-Soma, Jonathan J. Fortney, Raymond Pierrehumbert, David Lafrenière, Lorena Acuña, Thaddeus Komacek, Hamish Innes, Thomas G. Beatty, Ryan Cloutier, René Doyon, Anna Gagnebin, Cyril Gapp, Heather A. Knutson   +32 more
doaj   +1 more source