Results 61 to 70 of about 2,103,717 (319)

Unraveling the Water Sources in Comet 103P/Hartley 2 from Deep Impact Flyby Observations

The Planetary Science Journal
The Deep Impact eXtended Mission flyby of comet 103P/Hartley 2 offered a rare opportunity to study a hyperactive comet with high-cadence and high-resolution observations from a fixed vantage point.
L. M. Feaga, J. M. Sunshine
doaj   +1 more source

COMETARY VOLATILES AND THE ORIGIN OF COMETS [PDF]

The Astrophysical Journal, 2012
We describe recent results on the CO/CO2/H2O composition of comets together with a survey of older literature (primarily for CO/H2O) and compare these with models of the protoplanetary disk. Even with the currently small sample, there is a wide dispersion in abundance ratios and little if any systematic difference between Jupiter-family comets (JFCs ...
A'Hearn, Michael F., Feaga, Lori M., Keller, H. Uwe, Kawakita, Hideyo, Hampton, Donald L., Kissel, Jochen, Klaasen, Kenneth P., Mcfadden, Lucy A., Meech, Karen J., Schultz, Peter H., Sunshine, Jessica M., Thomas, Peter C., Veverka, Joseph, Yeomans, Donald K., Besse, Sebastien, Bodewits, Dennis, Farnham, Tony L., Groussin, Olivier, Kelley, Michael S., Lisse, Carey M., Merlin, Frederic, Protopapa, Silvia, Wellnitz, Dennis D.   +22 more
openaire   +3 more sources

Selenium Nanomaterials for Wound Healing: Synergistic Strategies from Anti‐Infection to Tissue Regeneration

Advanced NanoBiomed Research, EarlyView.
Selenium nanoparticles (SeNPs) are emerging as multifunctional platforms for wound healing, integrating antimicrobial, anti‐inflammatory, and proregenerative activities. This review summarises key mechanisms and recent advances in SeNP‐enabled composite dressings, immunomodulatory nanocomposites, microenvironment‐responsive hydrogels, photothermal and ...
Yangxia Chen, Xiaoshuang Liang, Sirui Li, Shuoshan Li, Wei Liu, Yingping Lin, Siqi Li, Zehang Zhang, Judun Zheng, Tianfeng Chen, Rongyi Chen   +10 more
wiley   +1 more source

CO and N2 Produced from H2O, CO2, and NH3 Cometary Ice Analogs

The Astrophysical Journal
Hypervolatile species such as carbon monoxide (CO) and molecular nitrogen (N _2 ) have been detected in comets, and could be used to constrain comet formation temperature conditions if their presence is due to freeze-out and/or entrapment.
Alexandra McKinnon, Alexia Simon, Michelle R. Brann, Elettra L. Piacentino, Karin I. Öberg, Mahesh Rajappan   +5 more
doaj   +1 more source

Origin and Evolution of Short-period Comets [PDF]

The Astrophysical Journal, 2017
Abstract Comets are icy objects that orbitally evolve from the trans-Neptunian region into the inner solar system, where they are heated by solar radiation and become active due to the sublimation of water ice. Here we perform simulations in which cometary reservoirs are formed in the early solar system and evolved over 4.5 Gyr.
Nesvorny, D., Vokrouhlicky, D., Dones, L., Levison, H. F., Kaib, N., Morbidelli, A.   +5 more
openaire   +2 more sources

Contributions from Accreted Organics to Titan’s Atmosphere: New Insights from Cometary and Chondritic Data

Astrophysical Journal, 2019
Since its discovery in the first half of the 20th century, scientists have puzzled over the origins of Titan’s atmosphere. Current models suggest that atmospheric N2 on Titan may have originated from NH3-bearing ice with N-isotopic ratios similar to ...
Kelly E. Miller, C. Glein, J. Waite
semanticscholar   +1 more source

Trabecular bone ontogeny of the human talus

The Anatomical Record, EarlyView.
Abstract Studies of trabecular ontogeny may provide insight into the factors that drive healthy bone development. There is a growing understanding of how the juvenile skeleton responds to these influences; however, gaps in our knowledge remain. This study aims to identify ontogenetic trabecular patterns and regional changes during development within ...
Rebecca A. G. Reid, Catriona Davies, Craig Cunningham   +2 more
wiley   +1 more source

Migration of Jupiter-family comets and resonant asteroids to near-Earth space

, 2003
We estimated the rate of comet and asteroid collisions with the terrestrial planets by calculating the orbits of 13000 Jupiter-crossing objects (JCOs) and 1300 resonant asteroids and computing the probabilities of collisions based on random-phase ...
Asher, Binzel, Bottke, Bulirsh, Chyba, Delsemme, Duncan, Fernandez, Fernandez, Ipatov, Ipatov, Ipatov, Ipatov, Ipatov, Ipatov, Ipatov, J C MATHER, Jedicke, Jewitt, Jewitt, Jewitt, Kuchner, Levison, Levison, Levison, Lupishko, Morbidelli, Ozernoy, Pavlov, Rickman, S I IPATOV, Valsecchi   +31 more
core   +3 more sources

About origin of comet 55P [PDF]

Astronomical School’s Report, 2014
55P is a periodic comet with an orbital period of 33 years. It fits the classical definition of a Halley-type comet. The comet is the parent body of the Leonid meteor shower. Orbital simulation of the comet’s 55P/Tempel-Tuttle orbit for 5000 years before its discovery by a variety of integrators is provided in this work.
openaire   +2 more sources

Skeletal pathologies in extant crocodilians as a window into the paleopathology of fossil archosaurs

The Anatomical Record, EarlyView.
Abstract Crocodilians, together with birds, are the only extant relatives to many extinct archosaur groups, making them highly important for interpreting paleopathological conditions in a phylogenetic disease bracketing model. Despite this, comprehensive data on osteopathologies in crocodilians remain scarce.
Alexis Cornille, Kyla Beguesse, Ewan Wolff, Clemens Zinner, Patrick Asbach, François Clarac, Florian Witzmann   +6 more
wiley   +1 more source