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Near-Earth Objects

Harris, A.W. and Drube, Line (2014) Near-Earth Objects. In: Encyclopedia of the Solar System, Third Edition Elsevier. pp. 603-623. ISBN 9780124158450.

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Official URL: http://store.elsevier.com/Encyclopedia-of-the-Solar-System/isbn-9780124158450/

Abstract

A near-Earth object (NEO) is an asteroid or comet orbiting the Sun with a perihelion distance of less than 1.3 AU (1 AU, an “astronomical unit”, is the mean distance between the Earth and the Sun, around 150 million km). If the orbit of an NEO can bring it to within 0.05 AU of the Earth’s orbit, and it is larger than about 120 m, it is termed a potentially hazardous object (PHO); an object of this size is likely to survive passage through the atmosphere and cause extensive damage on impact. (The acronyms NEA and PHA are used when referring specifically to asteroids.) The recognition that a giant asteroid or comet perhaps 5-10 km across most likely caused, or at least contributed to, the extinction of the dinosaurs in a geological episode known as the Cretaceous-Tertiary Event has highlighted the hazard to our civilization presented by NEOs. The energy involved in collisions of NEOs with the Earth can be much larger than that released in the detonation of nuclear weapons or naturally occurring phenomena on Earth (e.g. volcanoes, earthquakes, or tsunamis). Scientists cannot accurately predict what effects a major NEO impact would have on today’s technically sophisticated and highly networked world. Computer simulations of impacts provide some insight but natural phenomena elsewhere in the solar system provide real proof of the destructive potential of collisions between planets and small bodies. The collision of comet Shoemaker-Levy 9 with Jupiter, observed worldwide through telescopes in 1994, created scars in Jupiter’s atmosphere larger than the Earth. Even relatively small impactors can cause considerable damage on Earth. The object that exploded over the Russian city of Chelyabinsk in February 2013 had a diameter of only 17-20 m, yet it produced a blast wave that damaged buildings and injured some 1500 people. The potentially devastating effects on Earth of a collision with a large asteroid or comet are now well recognized by scientists and policy makers.

Item URL in elib:https://elib.dlr.de/89607/
Document Type:Contribution to a Collection
Title:Near-Earth Objects
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Harris, A.W.alan.harris (at) dlr.deUNSPECIFIED
Drube, LineLine.Drube (at) dlr.dehttps://orcid.org/0000-0003-2486-8894
Date:2014
Journal or Publication Title:Encyclopedia of the Solar System, Third Edition
Refereed publication:Yes
Open Access:No
Gold Open Access:No
In SCOPUS:No
In ISI Web of Science:No
Page Range:pp. 603-623
Editors:
EditorsEmail
Spohn, T.Tilman.Spohn@dlr.de
Breuer, D.Doris.Breuer@dlr.de
Johnson, T. V.Jet Propulsion Laboratory, Pasadena, CA
Publisher:Elsevier
ISBN:9780124158450
Status:Published
Keywords:Asteroids; Near-Earth objects; Impact hazard; Meteors; Meteorites; Comets; Space missions
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Space
HGF - Program Themes:Space Science and Exploration
DLR - Research area:Raumfahrt
DLR - Program:R EW - Erforschung des Weltraums
DLR - Research theme (Project):R - Vorhaben Exploration des Sonnensystems
Location: Berlin-Adlershof
Institutes and Institutions:Institute of Planetary Research > Leitungsbereich PF
Deposited By: Harris, Prof. Alan
Deposited On:04 Jul 2014 14:47
Last Modified:26 Apr 2017 12:46

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