{"id":344,"date":"2022-02-11T18:30:52","date_gmt":"2022-02-11T18:30:52","guid":{"rendered":"https:\/\/pressbooks.ccconline.org\/astronomy\/?post_type=chapter&p=344"},"modified":"2022-02-11T18:30:52","modified_gmt":"2022-02-11T18:30:52","slug":"key-terms-5","status":"publish","type":"chapter","link":"https:\/\/pressbooks.ccconline.org\/astronomy\/chapter\/key-terms-5\/","title":{"raw":"Key Terms","rendered":"Key Terms"},"content":{"raw":"
\r\n \t
asteroid<\/dt>\r\n \t
a stony or metallic object orbiting the Sun that is smaller than a major planet but that shows no evidence of an atmosphere or of other types of activity associated with comets<\/dd>\r\n<\/dl>\r\n
\r\n \t
comet<\/dt>\r\n \t
a small body of icy and dusty matter that revolves about the Sun; when a comet comes near the Sun, some of its material vaporizes, forming a large head of tenuous gas and often a tail<\/dd>\r\n<\/dl>\r\n
\r\n \t
differentiation<\/dt>\r\n \t
gravitational separation of materials of different density into layers in the interior of a planet or moon<\/dd>\r\n<\/dl>\r\n
\r\n \t
giant planet<\/dt>\r\n \t
any of the planets Jupiter, Saturn, Uranus, and Neptune in our solar system, or planets of roughly that mass and composition in other planetary systems<\/dd>\r\n<\/dl>\r\n
\r\n \t
half-life<\/dt>\r\n \t
time required for half of the radioactive atoms in a sample to disintegrate<\/dd>\r\n<\/dl>\r\n
\r\n \t
meteor<\/dt>\r\n \t
a small piece of solid matter that enters Earth\u2019s atmosphere and burns up, popularly called a\u00a0shooting<\/em>\u00a0star<\/em>\u00a0because it is seen as a small flash of light<\/dd>\r\n<\/dl>\r\n
\r\n \t
meteorite<\/dt>\r\n \t
a portion of a meteor that survives passage through an atmosphere and strikes the ground<\/dd>\r\n<\/dl>\r\n
\r\n \t
planetesimals<\/dt>\r\n \t
objects, from tens to hundreds of kilometers in diameter, that formed in the solar nebula as an intermediate step between tiny grains and the larger planetary objects we see today; the comets and some asteroids may be leftover planetesimals<\/dd>\r\n<\/dl>\r\n
\r\n \t
radioactivity<\/dt>\r\n \t
process by which certain kinds of atomic nuclei decay naturally, with the spontaneous emission of subatomic particles and gamma rays<\/dd>\r\n<\/dl>\r\n
\r\n \t
solar nebula<\/dt>\r\n \t
the cloud of gas and dust from which the solar system formed<\/dd>\r\n<\/dl>\r\n
\r\n \t
terrestrial planet<\/dt>\r\n \t
any of the planets Mercury, Venus, Earth, or Mars; sometimes the Moon is included in the list<\/dd>\r\n<\/dl>\r\n
This book was adapted from the following: Fraknoi, A., Morrison, D., & Wolff, S. C. (2016). Key Terms. In Astronomy<\/i>. OpenStax. https:\/\/openstax.org\/books\/astronomy\/pages\/7-key-terms under a Creative Commons Attribution License 4.0<\/a><\/div>\r\n
Access the entire book for free at https:\/\/openstax.org\/books\/astronomy\/pages\/1-introduction<\/a><\/div>","rendered":"
\n
asteroid<\/dt>\n
a stony or metallic object orbiting the Sun that is smaller than a major planet but that shows no evidence of an atmosphere or of other types of activity associated with comets<\/dd>\n<\/dl>\n
\n
comet<\/dt>\n
a small body of icy and dusty matter that revolves about the Sun; when a comet comes near the Sun, some of its material vaporizes, forming a large head of tenuous gas and often a tail<\/dd>\n<\/dl>\n
\n
differentiation<\/dt>\n
gravitational separation of materials of different density into layers in the interior of a planet or moon<\/dd>\n<\/dl>\n
\n
giant planet<\/dt>\n
any of the planets Jupiter, Saturn, Uranus, and Neptune in our solar system, or planets of roughly that mass and composition in other planetary systems<\/dd>\n<\/dl>\n
\n
half-life<\/dt>\n
time required for half of the radioactive atoms in a sample to disintegrate<\/dd>\n<\/dl>\n
\n
meteor<\/dt>\n
a small piece of solid matter that enters Earth\u2019s atmosphere and burns up, popularly called a\u00a0shooting<\/em>\u00a0star<\/em>\u00a0because it is seen as a small flash of light<\/dd>\n<\/dl>\n
\n
meteorite<\/dt>\n
a portion of a meteor that survives passage through an atmosphere and strikes the ground<\/dd>\n<\/dl>\n
\n
planetesimals<\/dt>\n
objects, from tens to hundreds of kilometers in diameter, that formed in the solar nebula as an intermediate step between tiny grains and the larger planetary objects we see today; the comets and some asteroids may be leftover planetesimals<\/dd>\n<\/dl>\n
\n
radioactivity<\/dt>\n
process by which certain kinds of atomic nuclei decay naturally, with the spontaneous emission of subatomic particles and gamma rays<\/dd>\n<\/dl>\n
\n
solar nebula<\/dt>\n
the cloud of gas and dust from which the solar system formed<\/dd>\n<\/dl>\n
\n
terrestrial planet<\/dt>\n
any of the planets Mercury, Venus, Earth, or Mars; sometimes the Moon is included in the list<\/dd>\n<\/dl>\n
This book was adapted from the following: Fraknoi, A., Morrison, D., & Wolff, S. C. (2016). Key Terms. In Astronomy<\/i>. OpenStax. https:\/\/openstax.org\/books\/astronomy\/pages\/7-key-terms under a Creative Commons Attribution License 4.0<\/a><\/div>\n
Access the entire book for free at https:\/\/openstax.org\/books\/astronomy\/pages\/1-introduction<\/a><\/div>\n","protected":false},"author":33,"menu_order":11,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[48],"contributor":[],"license":[],"class_list":["post-344","chapter","type-chapter","status-publish","hentry","chapter-type-numberless"],"part":323,"_links":{"self":[{"href":"https:\/\/pressbooks.ccconline.org\/astronomy\/wp-json\/pressbooks\/v2\/chapters\/344","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.ccconline.org\/astronomy\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.ccconline.org\/astronomy\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.ccconline.org\/astronomy\/wp-json\/wp\/v2\/users\/33"}],"version-history":[{"count":1,"href":"https:\/\/pressbooks.ccconline.org\/astronomy\/wp-json\/pressbooks\/v2\/chapters\/344\/revisions"}],"predecessor-version":[{"id":345,"href":"https:\/\/pressbooks.ccconline.org\/astronomy\/wp-json\/pressbooks\/v2\/chapters\/344\/revisions\/345"}],"part":[{"href":"https:\/\/pressbooks.ccconline.org\/astronomy\/wp-json\/pressbooks\/v2\/parts\/323"}],"metadata":[{"href":"https:\/\/pressbooks.ccconline.org\/astronomy\/wp-json\/pressbooks\/v2\/chapters\/344\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.ccconline.org\/astronomy\/wp-json\/wp\/v2\/media?parent=344"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.ccconline.org\/astronomy\/wp-json\/pressbooks\/v2\/chapter-type?post=344"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.ccconline.org\/astronomy\/wp-json\/wp\/v2\/contributor?post=344"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.ccconline.org\/astronomy\/wp-json\/wp\/v2\/license?post=344"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}