<\/p>
Sometime between 1.5 and 0.5 billion years ago, the Earth\u2019s core began to crystallise into a solid ball, formed mainly of iron and nickel. The core is growing by around one millimetre per year, and at that rate, Earth won\u2019t have time to fully cool and solidify before the Sun<\/a> reaches the end of its life. This will happen in around five billion years\u2019 time when it\u2019ll expand and potentially engulf the planet we live on<\/a>.<\/p>\n If some currently unknown mechanism caused Earth to cool much sooner, it would have serious long-term consequences for most life on the planet. Without the electric dynamo of the molten outer core, Earth\u2019s magnetic field<\/a> would fade to zero, and the stream of charged particles from the Sun, known as solar wind, would begin stripping away the atmosphere, as may have happened to Mars<\/a> long ago.<\/p>\n For Earth to have already cooled by now, it would have to be much smaller. Gravitational compression and friction will heat any planet-sized body, and radioactive decay from elements in the mantle will add to this heat.<\/p>\n The Moon<\/a> is thought to have been formed from the impact of a Mars-sized body called Theia<\/a> with the early Earth, around 4.5 billion years ago. The energy of the collision would have meant that Earth and the Moon would have both started out mostly molten, but the Moon cooled much more rapidly because it was smaller.<\/p>\n A smaller, cold Earth would have lacked the volcanoes and plate tectonics that have recycled carbon and minerals in the crust and added gases to the atmosphere. Without a thick atmosphere, the surface temperature would drop low enough to freeze the ocean. It\u2019s doubtful that life \u2013 at least, complex life \u2013 would have evolved<\/a> in these conditions.<\/p>\n Read more:<\/strong><\/p>\n Asked by: B Kirkby, via email<\/strong><\/p>\n To submit your questions email us at questions@sciencefocus.com (don\u2019t forget to include your name and location)<\/em><\/p> <\/body><\/html>\n By Luis Villazon Published: Friday, 13 January 2023 at 12:00 am Sometime between 1.5 and 0.5 billion years ago, the Earth\u2019s core began to crystallise into a solid ball, formed mainly of iron and nickel. The core is growing by around one millimetre per year, and at that rate, Earth won\u2019t have time to fully […]<\/p>\n","protected":false},"author":24,"featured_media":22915,"template":"","categories":[30],"acf":{"readingTimeMinutes":"2"},"uagb_featured_image_src":{"full":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2023\/01\/how-earths-cooling-molten-core-could-destroy-the-planet.png",1200,511,false],"thumbnail":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2023\/01\/how-earths-cooling-molten-core-could-destroy-the-planet-150x150.png",150,150,true],"medium":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2023\/01\/how-earths-cooling-molten-core-could-destroy-the-planet-300x128.png",300,128,true],"medium_large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2023\/01\/how-earths-cooling-molten-core-could-destroy-the-planet-768x327.png",768,327,true],"large":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2023\/01\/how-earths-cooling-molten-core-could-destroy-the-planet-1024x436.png",800,341,true],"1536x1536":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2023\/01\/how-earths-cooling-molten-core-could-destroy-the-planet.png",1200,511,false],"2048x2048":["https:\/\/c01.purpledshub.com\/uploads\/sites\/42\/2023\/01\/how-earths-cooling-molten-core-could-destroy-the-planet.png",1200,511,false]},"uagb_author_info":{"display_name":"importmanagerhub@sprylab.com","author_link":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/author\/importmanagerhubsprylab-com\/"},"uagb_comment_info":0,"uagb_excerpt":"By Luis Villazon Published: Friday, 13 January 2023 at 12:00 am Sometime between 1.5 and 0.5 billion years ago, the Earth\u2019s core began to crystallise into a solid ball, formed mainly of iron and nickel. The core is growing by around one millimetre per year, and at that rate, Earth won\u2019t have time to fully…","_links":{"self":[{"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/rss_feed\/22914"}],"collection":[{"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/rss_feed"}],"about":[{"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/types\/rss_feed"}],"author":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/users\/24"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/media\/22915"}],"wp:attachment":[{"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/media?parent=22914"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c01.purpledshub.com\/bbcsciencefocus\/wp-json\/wp\/v2\/categories?post=22914"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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