La Luna è un pezzetto della Terra, strappato in modo violentissimo dall’impatto di un altro corpo celeste con il nostro pianeta che fu polverizzato e vaporizzato mentre si stava formando. La conferma definitiva arriva da analisi chimiche più raffinate di quelle finora possibili, effettuate da un gruppo di ricercatori dell'università di Harvard.
Le analisi mostrano che Terra e Luna hanno composizione identica. Gli scienziati hanno riesaminato 7 campioni di roccia lunare confrontandoli con 8 prelevati dal mantello terreste, lo strato che si trova tra la crosta e il nucleo. Tutti presentano gli stessi elementi chimici. Ma soprattutto quelli lunari contengono un isotopo molto pesante del potassio che potrebbe essere nato solo ad altissime temperature, come quelle che accompagnarono lo scontro avvenuto qualcosa più di 4 miliardi di anni fa.
''I nostri risultati forniscono la prima prova concreta che l'impatto ha fatto letteralmente vaporizzare gran parte della Terra'', ha detto il coordinatore della ricerca Kun Wang.
Diem/ATS
%20--%3e%3csvg%20version='1.1'%20id='Layer_1'%20xmlns='http://www.w3.org/2000/svg'%20xmlns:xlink='http://www.w3.org/1999/xlink'%20x='0px'%20y='0px'%20viewBox='0%200%20138.2%2048'%20style='enable-background:new%200%200%20138.2%2048;'%20xml:space='preserve'%3e%3cstyle%20type='text/css'%3e%20.st0{fill-rule:evenodd;clip-rule:evenodd;fill:%23AF001E;}%20.st1{fill-rule:evenodd;clip-rule:evenodd;fill:%23FFFFFF;}%20%3c/style%3e%3cpath%20class='st0'%20d='M0,48h138V0H0V48z'/%3e%3cpath%20class='st1'%20d='M9.3,31.7l-0.4,2.7C8.8,35,9,35.2,9.5,35.3c2,0.2,4,0.3,6.1,0.3c5.6,0,9.7-1.8,9.7-7.1c0-3.1-1.3-5.4-6-6.6%20l-2.6-0.7c-1.8-0.5-2.6-1-2.6-2.3c0-1.9,1.7-2.2,3.3-2.2c2.2,0,4.4,0.2,5.3,0.2c0.9,0.1,1.2,0,1.3-0.8l0.4-2.6c0-0.1,0-0.2,0-0.3%20c0-0.1-0.1-0.2-0.1-0.3s-0.1-0.1-0.2-0.2c-0.1,0-0.2-0.1-0.3-0.1c-2-0.2-4.1-0.3-6.1-0.3C11.8,12.4,9,14.9,9,19c0,3.6,2,5.8,5.4,6.7%20l2.6,0.7c2.1,0.6,3,1.2,3,2.5c0,2-1.3,2.3-4.6,2.3c-1.5,0-4-0.2-4.9-0.3C9.6,30.9,9.4,31,9.3,31.7'/%3e%3cpath%20class='st1'%20d='M36.4,23.6l-0.3,1.5C36,25.4,36,25.6,36,25.9c0,0.4,0.1,0.8,0.4,1.1l4.2,7.6c0.1,0.3,0.3,0.5,0.6,0.7%20c0.3,0.2,0.6,0.2,0.9,0.2h3.8c0.5,0,1.1-0.3,0.5-1.2l-5.1-8.6c1.7-1.1,3.6-2.6,3.6-6.1c0-4.4-2.5-6.9-7.9-6.9h-7.8%20c-0.7,0-0.9,0.2-0.9,1v20.8c0,0.7,0.2,1,0.9,1h3.2c0.7,0,0.9-0.2,0.9-1V16.8h3.3c2.1,0,3.1,0.8,3.1,2.8c0.1,0.6,0,1.2-0.3,1.6%20c-0.3,0.5-0.7,0.9-1.3,1.1C37.1,22.7,36.8,22.3,36.4,23.6z'/%3e%3cpath%20class='st1'%20d='M66.1,34V22.7c0-0.7-0.2-1-0.9-1h-5.8c-0.7,0-0.9,0.2-0.9,1v2.5c0,0.7,0.2,0.9,0.9,0.9h1.7v5%20c-0.6,0.1-1.1,0.1-1.7,0.1c-4.8,0-6-3.1-6-7.4c0-5.4,2-6.8,6.5-6.8c1.3,0,3.1,0.1,4.1,0.2c1,0.1,1.2,0,1.3-0.8l0.4-2.5%20c0.1-0.7,0-1-0.8-1.1c-1.8-0.2-3.6-0.3-5.4-0.2c-8.2,0-11.6,4.3-11.6,11.3s2.7,11.9,11.3,11.9c2,0.1,4,0,6-0.4%20C65.9,35.2,66.2,34.9,66.1,34'/%3e%3cpath%20class='st1'%20d='M74.9,31.7l-0.4,2.7c-0.1,0.5,0.2,0.7,0.6,0.8c2,0.2,4,0.3,6.1,0.3c5.6,0,9.7-1.8,9.7-7.1c0-3.1-1.3-5.4-6-6.6%20l-2.6-0.7c-1.8-0.5-2.6-1-2.6-2.3c0-1.9,1.7-2.2,3.3-2.2c2.2,0,4.4,0.2,5.3,0.2c0.9,0.1,1.2,0,1.3-0.8l0.4-2.6c0-0.1,0-0.2,0-0.3%20c0-0.1-0.1-0.2-0.1-0.3s-0.1-0.1-0.2-0.2c-0.1,0-0.2-0.1-0.3-0.1c-2-0.2-4.1-0.3-6.1-0.3c-5.8,0-8.6,2.6-8.6,6.6%20c0,3.6,2,5.8,5.4,6.7l2.6,0.7c2.1,0.6,3,1.2,3,2.6c0,2-1.3,2.3-4.6,2.3c-1.5,0-4-0.2-4.9-0.3C75.3,30.8,75,30.9,74.9,31.7'/%3e%3cpath%20class='st1'%20d='M93.1,31.7l-0.4,2.7c-0.1,0.5,0.2,0.7,0.6,0.8c2,0.2,4,0.3,6.1,0.3c5.6,0,9.7-1.8,9.7-7.1c0-3.1-1.3-5.4-6-6.6%20l-2.6-0.7c-1.8-0.5-2.6-1-2.6-2.3c0-1.9,1.7-2.2,3.3-2.2c2.2,0,4.4,0.2,5.3,0.2c0.9,0.1,1.2,0,1.3-0.8l0.4-2.6c0-0.1,0-0.2,0-0.3%20c0-0.1-0.1-0.2-0.1-0.3c-0.1-0.1-0.1-0.1-0.2-0.2c-0.1,0-0.2-0.1-0.3-0.1c-2-0.2-4.1-0.3-6.1-0.3c-5.8,0-8.6,2.6-8.6,6.6%20c0,3.6,2,5.8,5.4,6.7l2.6,0.7c2.1,0.6,3,1.2,3,2.6c0,2-1.3,2.3-4.6,2.3c-1.5,0-4-0.2-4.9-0.3S93.1,30.9,93.1,31.7'/%3e%3cpath%20class='st1'%20d='M120.2,23.6l-0.3,1.5c-0.1,0.3-0.1,0.5-0.1,0.8c0,0.4,0.1,0.8,0.3,1.1l4.2,7.6c0.1,0.3,0.3,0.5,0.6,0.7%20c0.3,0.2,0.6,0.2,0.9,0.2h3.8c0.5,0,1.1-0.3,0.5-1.2l-5.1-8.6c1.7-1.1,3.7-2.7,3.7-6.1c0-4.4-2.5-6.9-7.9-6.9H113%20c-0.7,0-0.9,0.2-0.9,1v20.8c0,0.7,0.2,1,0.9,1h3.2c0.7,0,0.9-0.2,0.9-1V16.8h3.3c2.1,0,3.1,0.8,3.1,2.8c0.1,0.6,0,1.2-0.3,1.6%20c-0.3,0.5-0.7,0.9-1.3,1.1C120.9,22.7,120.6,22.3,120.2,23.6'/%3e%3c/svg%3e)