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Related papers: The hazard from fragmenting comets

200 papers

High energy cosmic ray jets from nearby mergers or accretion induced collapse (AIC) of neutron stars (NS) that hit the atmosphere can produce lethal fluxes of atmospheric muons at ground level, underground and underwater, destroy the ozone…

Astrophysics · Physics 2008-11-26 Arnon Dar , Ari Laor , Nir J. Shaviv

The modestly eccentric and non-coplanar orbits of the giant planets pose a challenge to solar system formation theories which generally indicate that the giant planets emerged from the protoplanetary disk in nearly perfectly circular and…

Earth and Planetary Astrophysics · Physics 2025-11-06 Garett Brown , Renu Malhotra , Hanno Rein

All cometary nuclei that formed in the early Solar System incorporated radionuclides and therefore were subject to internal radiogenic heating. Previous work predicts that if comets have a pebble-pile structure internal temperature build-up…

Earth and Planetary Astrophysics · Physics 2024-07-12 James E. Robinson , Uri Malamud , Cyrielle Opitom , Hagai Perets , Jürgen Blum

A fragmented landscape reduces the impact of interspecies connectivity, leading to higher diversity levels than otherwise possible in a connected landscape. Reconnecting a previously fragmented landscape initiates an extinction event,…

Populations and Evolution · Quantitative Biology 2026-04-14 Russell K. Standish

The large number of exoplanets found to orbit their host stars in very close orbits have significantly advanced our understanding of the planetary formation process. It is now widely accepted that such short-period planets cannot have…

Earth and Planetary Astrophysics · Physics 2011-12-07 Jianghui Ji , Sheng Jin , C. G. Tinney

The galactic environment has been suspected to influence planetary habitability in many ways. Very metal-poor regions of the Galaxy, or those largely devoid of atoms more massive than H and He, are thought to be unable to form habitable…

Earth and Planetary Astrophysics · Physics 2018-12-05 Nathan A. Kaib

We consider the dynamical evolution of small-scale substructure in clusters within two extreme alternate scenarios for their possible origin: 1) the accretion of groups (or small clusters) on quasi-radial orbits, and 2) the merger of…

Astrophysics · Physics 2009-10-22 Guillermo González-Casado , Gary A. Mamon , Eduard Salvador-Solé

We investigate the outcome of collisions of Ceres-sized planetesimals composed of a rocky core and a shell of water ice. These collisions are not only relevant for explaining the formation of planetary embryos in early planetary systems,…

Earth and Planetary Astrophysics · Physics 2015-05-28 Thomas I. Maindl , Rudolf Dvorak , Christoph Schäfer , Roland Speith

In this chapter, we review the processes involved in the formation of planetesimals and comets. We will start with a description of the physics of dust grain growth and how this is mediated by gas-dust interactions in planet-forming disks.…

Earth and Planetary Astrophysics · Physics 2022-12-12 Jacob B. Simon , Jürgen Blum , Til Birnstiel , David Nesvorný

Ejection of large boulder-like debris is a vigorous form of cometary activity that is unlikely induced by water ice out-gassing alone but rather associated with the sublimation of super-volatile ices. Though perceived on several comets,…

Earth and Planetary Astrophysics · Physics 2024-01-31 Xian Shi , Xuanyu Hu , Jessica Agarwal , Carsten Güttler , Martin Rose , Horst Uwe Keller , Marco Fulle , Jakob Deller , Holger Sierks

Comets are pristine remnants of the Solar system, composed of dust and ice. They remain inactive and undetectable for most of their orbit due to low temperatures. However, as they approach the Sun, volatile materials sublimate, expelling…

Earth and Planetary Astrophysics · Physics 2023-11-20 K. Aravind , Shashikiran Ganesh

Questions regarding how primordial or pristine the comets of the solar system are have been an ongoing controversy. In this review, we describe comets' physical evolution from dust and ice grains in the solar nebula to the contemporary…

Earth and Planetary Astrophysics · Physics 2022-07-27 Jürgen Blum , Dorothea Bischoff , Bastian Gundlach

Global scale impacts modify the physical or thermal state of a substantial fraction of a target asteroid. Specific effects include accretion, family formation, reshaping, mixing and layering, shock and frictional heating, fragmentation,…

Earth and Planetary Astrophysics · Physics 2016-08-31 Erik Asphaug , Gareth Collins , Martin Jutzi

The practical distinctions between asteroids and comets, viewed as products of accretion on either side of the snow line, are less clear-cut than previously understood. In this chapter, we discuss the numerous solar system populations which…

Earth and Planetary Astrophysics · Physics 2022-12-06 David Jewitt , Henry H. Hsieh

The rapid collapse of a polymer, due to external forces or changes in solvent, yields a long-lived `crumpled globule.' The conjectured fractal structure shaped by hierarchical collapse dynamics has proved difficult to establish, even with…

Soft Condensed Matter · Physics 2015-10-07 Guy Bunin , Mehran Kardar

The recent publication by Siraj & Loeb (2021; Nature Scientific Reports 11, 3803) attempts to revive the debate over whether the Chicxulub impactor was a comet or an asteroid. They calculate that ~20% of long-period comets impacting Earth…

Earth and Planetary Astrophysics · Physics 2021-06-04 Steven J. Desch , Alan P Jackson , Jessica L. Noviello , Ariel D. Anbar

The origin of the Chicxulub impactor, which is attributed as the cause of the K/T mass extinction event, is an unsolved puzzle. The background impact rates of main-belt asteroids and long-period comets have been previously dismissed as…

Earth and Planetary Astrophysics · Physics 2021-02-16 Amir Siraj , Abraham Loeb

The physical composition and structure of meteoroids gives us insight into the formation processes of their parent asteroids and comets. The strength of and fundamental grain sizes in meteoroids tell us about the environment in which small…

Earth and Planetary Astrophysics · Physics 2019-04-10 Margaret D. Campbell-Brown

Our current understanding of split, Jupiter-family comets is reviewed. The focus is on what recent studies of comets have told us about the nature of the splitting phenomenon. The goal is to not repeat the information given in recent…

Earth and Planetary Astrophysics · Physics 2009-07-29 Y. R. Fernandez

Meteor showers on the Earth occur at well known times, and are associated with the decay of comets or other minor bodies whose orbital paths pass close to the Earth's trajectory. On the surface, determining the closest proximity of two…

Space Physics · Physics 2007-05-23 Shane L. Larson