Results 1 to 10 of about 2,128 (236)

Sodium Brightening of (3200) Phaethon near Perihelion

open access: yesThe Planetary Science Journal, 2023
Sunskirting asteroid (3200) Phaethon has been repeatedly observed in Solar Terrestrial Relations Observatory (STEREO) Heliospheric Imager 1 (HI1) imagery to anomalously brighten and produce an antisunward tail for a few days near each perihelion passage,
Qicheng Zhang   +4 more
doaj   +1 more source

Impact Rates in the Outer Solar System

open access: yesThe Planetary Science Journal, 2023
Previous studies of cometary impacts in the outer solar system used the spatial distribution of ecliptic comets (ECs) from dynamical models that assumed ECs began on low-inclination orbits (≲5°) in the Kuiper Belt.
David Nesvorný   +4 more
doaj   +1 more source

FUV Observations of the Inner Coma of 46P/Wirtanen

open access: yesThe Planetary Science Journal, 2021
Far-ultraviolet observations of comets yield information about the energetic processes that dissociate the sublimated gases from their primitive surfaces.
John W. Noonan   +8 more
doaj   +1 more source

Comparative Analysis of Aristolochic Acids in Aristolochia Medicinal Herbs and Evaluation of Their Toxicities

open access: yesToxins, 2022
Aristolochic acids (AAs) are a group of nitrophenanthrene carboxylic acids present in many medicinal herbs of the Aristolochia genus that may cause irreversible hepatotoxicity, nephrotoxicity, genotoxicity and carcinogenicity.
Shu-Han Zhang   +8 more
doaj   +1 more source

Dust Properties of Comets Observed by Spitzer

open access: yesThe Planetary Science Journal, 2023
As comets journey into the inner solar system, they deliver particulates and volatile gases into their comae that reveal the most primitive materials in the solar system.
David E. Harker   +3 more
doaj   +1 more source

Recombinant Forms of HIV-1 in the Last Decade of the Epidemic in the Russian Federation

open access: yesViruses, 2023
Currently, HIV-1 displays a substantial level of genetic diversity on a global scale, partly attributed to its recombinant variants. This study seeks to identify and analyze HIV-1 recombinants in Russia during the last decade of the epidemic.
Anastasiia Antonova   +6 more
doaj   +1 more source

The Collisional Evolution of the Primordial Kuiper Belt, Its Destabilized Population, and the Trojan Asteroids

open access: yesThe Planetary Science Journal, 2023
The tumultuous early era of outer solar system evolution culminated when Neptune migrated across the primordial Kuiper Belt (PKB) and triggered a dynamical instability among the giant planets.
William F. Bottke   +8 more
doaj   +1 more source

Origin of comets [PDF]

open access: yesAstronomical School’s Report, 2003
Three basic conceptions of origin of comets are under discussion. The first one belongs to Laplace who supposed that comets are becoming the members of the Solar system being captured by a giant planet, e.g. Jupiter. It is the hypothesis of capture. Oort supposed that there is a giant cloud of cometary nuclei at the heliocentric distance ∼105 AU.
openaire   +2 more sources

ON THE ORIGIN OF COMETS

open access: yesChinese Journal of Space Science, 1982
Abstract The fact that comets are rich in volatile material shows that they were formed and kept for a long time in the outer, low-temperature regions of the solar system. In this paper we analyse the structure in the outer edge of the solar nebula and show that no formation zone of comets can exist there. Our view is that the comets evolved from the
null Hu Zhong-wei, null Yang Ke-zhong
openaire   +1 more source

The Origin of Comets [PDF]

open access: yesSymposium - International Astronomical Union, 1972
The evolution of the solar system is surveyed, it being presumed that the Sun, Jupiter, and Saturn formed rather quickly and essentially with the composition of the original collapsing cloud of dust and gas. Just as the refractory material of the cloud is considered to have formed into planetesimals, from which the terrestrial planets collected, so is ...
openaire   +1 more source

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