Results 21 to 30 of about 2,536 (230)

Strongly Depleted Methanol and Hypervolatiles in Comet C/2021 A1 (Leonard): Signatures of Interstellar Chemistry?

The Planetary Science Journal, 2023
We measured the chemical composition of comet C/2021 A1 (Leonard) using the long-slit echelle grating spectrograph iSHELL/IRTF on 2021 December 20 and on 2022 January 8 and 9.
Sara Faggi, Manuela Lippi, Michael J. Mumma, Geronimo L. Villanueva   +3 more
doaj   +1 more source

Anisotropy of long-period comets explained by their formation process [PDF]

The Astronomical Journal, 2020
Long-period comets coming from the Oort cloud are thought to be planetesimals formed in the planetary region on the ecliptic plane. We have investigated the orbital evolution of these bodies due to the Galactic tide. We extended Higuchi et al.
openaire   +2 more sources

COSINE (Cometary Object Study Investigating Their Nature and Evolution). I. Project Overview and General Characteristics of Detected Comets

The Astrophysical Journal Supplement Series
We present the first results from the Cometary Object Study Investigating their Nature and Evolution (COSINE) project, based on a uniformly processed data set of 484 comets observed over the full 15 yr duration of the Wide-field Infrared Survey Explorer (
Yuna G. Kwon, Dar W. Dahlen, Joseph R. Masiero, James M. Bauer, Yanga R. Fernández, Adeline Gicquel, Yoonyoung Kim, Jana Pittichová, Frank Masci, Roc M. Cutri, Amy K. Mainzer   +10 more
doaj   +1 more source

Recent Advances in Ferrite‐Based Materials for Biomedical Applications: A Comprehensive Review

Advanced Materials, EarlyView.
Ferrite nanoplatforms are presented as tunable biomedical materials in which synthesis control, cation engineering, defect/morphology regulation, and surface functionalization govern structure–property–bioactivity relationships. These design strategies enable multifunctional applications including MRI contrast, magnetic hyperthermia, targeted drug ...
Pramod D. Mhase, Varsha C. Pujari, Akash V. Fulari, Sunil M. Patange, Sean Li, Danyang Wang, Sagar E. Shirsath   +6 more
wiley   +1 more source

Photocatalytic Water Splitting on the Lunar Surface: Prospects for In Situ Resource Utilization

Advanced Materials Interfaces, EarlyView.
Water has been found in craters on the moon nearby locations which are illuminated >80% of the time. Photocatalysis uses energy from sunlight to drive chemical reactions such as water splitting to produce oxygen and hydrogen. It is a scalable technology that requires lighter equipment and utilizes resources available on the moon. ABSTRACT The discovery
Ranjani Kalyan, Thomas D. Small, Gregory F. Metha, Mahmoud Adel Hamza, Thomas J. O'Dea, Yideng Shen, Cameron J. Shearer   +6 more
wiley   +1 more source

β‐Elemene Rescues Radiation‐Induced Enteritis by Orchestrating a Host‐Microbiome Circuit That Fuels Epigenetic DNA Repair

Advanced Science, EarlyView.
This study elucidates that β‐elemene promotes cellular uptake of L. gasseri‐derived lactate by enhancing the membrane translocation of MCT1 in a CD147‐dependent manner. Intracellular lactate, through the lactylation of RBBP4 at the K26 site, recruits EP300 to the promoter regions of downstream genes (POLD1/POLD3), catalyzing H3K27ac modification.
Jiancheng He, Jiapeng Bao, Shukang Deng, Weijie Zang, Haoming Yan, Zihao Zhao, Guangze Zhang, Ruiqing Liu, Junjie Chen, Yilin Hu, Wanjiang Xue   +10 more
wiley   +1 more source

Disintegration of Long-period Comet C/2019 Y4 (ATLAS). II. Postperihelion Remnant Recovery

The Astronomical Journal
We present an investigation into the fate of disrupting near-Sun comet C/2019 Y4 (ATLAS). Imaging observations with the Lowell Discovery Telescope, obtained 3–5 months after the reported disruption and the last sighting, constrained the primary component
Salvatore A. Cordova Quijano, Quanzhi Ye, Michael S. P. Kelley   +2 more
doaj   +1 more source

On the role of collisions with meteoroids in splitting and acceleration of heliocentric velocity of comets

Open Astronomy, 2020
The hypothesis on the role of the meteoroid impacts in the comet nuclei splitting as well as acceleration of their heliocentric velocity are considered.
Guliyev Ayyub, Guliyev Rustam
doaj   +1 more source

Characteristics of Single Encounters of Long-Periodic Comets With Jupiter [PDF]

Symposium - International Astronomical Union, 1979
Original nearly parabolic orbits of comets are known to be evolved toward short-periodic elliptic orbits as statistical results of hundreds of encounters with Jupiter. There seems to be two methods to handle the process, namely, the method by exact numerical integrations for each orbit (Everhart, 1972) and random walk approach by using probability ...
openaire   +1 more source

Long Dust Trails of Short Period Comets [PDF]

International Astronomical Union Colloquium, 1991
Comets constitute an important source for the zodiacal dust cloud. Mainly large particles are contributed because the smaller particles are emitted into hyperbolic orbits relative to the sun. Radiation pressure force reduces the effective solar gravitational attraction. Information about large cometary particles can be derived from a variety of sources
H. U. Keller, K. Richter
openaire   +1 more source