{"id":95,"date":"2024-03-02T18:52:11","date_gmt":"2024-03-02T17:52:11","guid":{"rendered":"http:\/\/hustor.handmade.net\/?p=95"},"modified":"2024-03-02T19:05:33","modified_gmt":"2024-03-02T18:05:33","slug":"nasa-prozradila-plan-pro-pripad-stretu-zeme-s-asteroidem-kdy-a-jak-by-katastrofu-oznamili-verejnosti","status":"publish","type":"post","link":"https:\/\/hustor.handmade.net\/?p=95","title":{"rendered":"NASA prozradila pl\u00e1n pro p\u0159\u00edpad st\u0159etu Zem\u011b s asteroidem. Kdy a jak by katastrofu ozn\u00e1mili ve\u0159ejnosti?"},"content":{"rendered":"\n

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\"P\u00e1d<\/p>\n\n\n\n

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Sta\u010d\u00ed ve\u010der zaklonit hlavu a zjist\u00edme, \u017ee na\u0161e planeta nepluje vesm\u00edrem sama. Doprov\u00e1z\u00ed ji milion hv\u011bzd, m\u011bs\u00edc\u016f, komet i asteroid\u016f. Pr\u00e1v\u011b ty d\u011blaj\u00ed v\u011bdc\u016fm nejv\u011bt\u0161\u00ed starosti. S oblibou toti\u017e do sv\u00fdch soused\u016f nar\u00e1\u017eej\u00ed. NASA proto vypracovala pl\u00e1n, jak p\u0159\u00edpadn\u00e9 katastrof\u011b zabr\u00e1nit.<\/strong><\/p>\n\n\n\n

V\u011bt\u0161ina odborn\u00edk\u016f se toti\u017e boj\u00ed, \u017ee jednoho dne by lidstvo mohl postihnout podobn\u00fd osud jako dinosaury a dal\u0161\u00ed \u017eivo\u010dichy, kte\u0159\u00ed podlehli n\u00e1sledk\u016fm dopadu asteroidu Chicxulub.<\/p>\n\n\n\n

Tehdy, p\u0159ed 66 miliony lety, nikomu rozhodn\u011b tzv. do zp\u011bvu nebylo. Impakt meteoritu o hmotnosti v \u0159\u00e1du bilion\u016f tun zp\u016fsobil celosv\u011btovou ekologickou katastrofu. Od masivn\u00ed exploze a po\u017e\u00e1ru, p\u0159es zem\u011bt\u0159esen\u00ed a tsunami po zatm\u011bn\u00ed Slunce, a tedy n\u00e1stup doby ledov\u00e9.<\/p>\n\n\n\n

Pokud by asteroid takov\u00e9 velikosti zas\u00e1hl Zemi dnes, masivn\u00ed r\u00e1zov\u00e1 vlna by zni\u010dila miliony m\u011bst. Ta, je\u017e by se zachr\u00e1nila, by byla pozd\u011bji zbo\u0159ena ot\u0159esy zemsk\u00e9 p\u016fdy nebo povodn\u011bmi. B\u011bhem n\u011bkolika t\u00fddn\u016f by tak nastoupila zima a hladomor.<\/p>\n\n\n\n

Aby se historie neopakovala, v roce 2016 byl zalo\u017een \u00da\u0159ad pro koordinaci planet\u00e1rn\u00ed obrany NASA. Jeho prim\u00e1rn\u00edm \u00fakolem je naj\u00edt, sledovat a vyhodnotit rizika spojen\u00e1 s potenci\u00e1ln\u011b nebezpe\u010dn\u00fdmi t\u011blesy, nach\u00e1zej\u00edc\u00ed se v na\u0161\u00ed slune\u010dn\u00ed soustav\u011b.<\/p>\n\n\n\n

Lov na asteroidy<\/h2>\n\n\n\n

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\u201eNa\u0161\u00edm c\u00edlem je naj\u00edt je d\u0159\u00edve, ne\u017e oni najdou n\u00e1s,\u201d<\/em> \u0159\u00edk\u00e1 vedouc\u00ed obrann\u00fdch mis\u00ed, d\u016fstojn\u00edk Lindley Johnson<\/strong>. Odborn\u00edci z NASA tak spolu s glob\u00e1ln\u00ed koalic\u00ed astronom\u016f s n\u00e1zvem International Asteroid Warning Network (IAWN) denn\u011b sleduj\u00ed prostor nad na\u0161imi hlavami a vypo\u010d\u00edt\u00e1vaj\u00ed trajektorii v\u0161ech potenci\u00e1ln\u011b nebezpe\u010dn\u00fdch objekt\u016f.

Za Zemi ohro\u017euj\u00edc\u00ed asteroidy jsou pova\u017eov\u00e1ny ty, jen\u017e jsou v\u011bt\u0161\u00ed ne\u017e 140 metr\u016f a na\u0161i ob\u011b\u017enou dr\u00e1hu prot\u00ednaj\u00ed v minim\u00e1ln\u00ed vzd\u00e1lenosti 0,5 astronomick\u00e9 jednotky, co\u017e je polovina d\u00e9lky mezi Zem\u00ed a Sluncem.<\/p>

Zat\u00edm bylo v\u011bdci odhaleno asi 2300 t\u011bchto planetek. Zhruba 153 z nich m\u00e1 pr\u016fm\u011br v\u011bt\u0161\u00ed ne\u017e 900 metr\u016f. To je dost na to, aby dopad jednoho z nich zni\u010dil oblast o velikosti Ma\u010farska a vymr\u0161til do atmosf\u00e9ry tolik prachu, \u017ee by do\u0161lo ke glob\u00e1ln\u00edm zm\u011bn\u00e1m klimatu.<\/p><\/section><\/main><\/div> <\/p>\n\n\n\n

Planet\u00e1rn\u00ed obrana<\/h2>\n\n\n\n

\u201eDoposud jsme identifikovali a\u017e 34 000 bl\u00edzkozemn\u00edch asteroid\u016f, u nich\u017e s jistotou v\u00edme, kudy b\u011bhem dal\u0161\u00edch sta let polet\u00ed. T\u011bch se proto nemus\u00edme b\u00e1t,\u201d<\/em> chlub\u00ed se Johnson.\u00a0<\/p>\n\n\n\n

Co by se ale stalo v p\u0159\u00edpad\u011b, \u017ee by se fyzici a jejich po\u010d\u00edta\u010dov\u00e9 modely zm\u00fdlili a jedno z t\u011bles zam\u00ed\u0159ilo sm\u011brem k n\u00e1m?<\/p>\n\n\n\n

V tu chv\u00edli by p\u0159i\u0161ly na \u0159adu metody planet\u00e1rn\u00ed obrany. Mezi n\u011b pat\u0159\u00ed kinetick\u00fd impaktor, gravita\u010dn\u00ed traktor, j\u00e1dro a lasery. Prvn\u00ed z nich byl otestov\u00e1n v roce 2022 b\u011bhem mise Double Asteroid Redirection Test (DART), v r\u00e1mci n\u00ed\u017e kosmick\u00e1 lo\u010f vych\u00fdlila z ob\u011b\u017en\u00e9 dr\u00e1hy m\u011bs\u00edc Dimorphos. U tohoto zp\u016fsobu je kl\u00ed\u010dov\u00e9 odhalit bl\u00ed\u017e\u00edc\u00ed se hrozbu a varovat ve\u0159ejnost p\u011bt a\u017e deset let p\u0159edem.<\/p>\n\n\n\n

V p\u0159\u00edpad\u011b, \u017ee by NASA nestihla asteroid odklonit, musela by se uch\u00fdlit k destrukci pomoc\u00ed jadern\u00fdch bomb nebo laseru. Z\u00e1rove\u0148 by ale bylo nutn\u00e9, aby ho rozbila na co nejmen\u0161\u00ed kousky, kter\u00e9 by sho\u0159ely v atmosf\u00e9\u0159e.<\/p>\n\n\n\n

I p\u0159es pe\u010dliv\u00e9 monitorov\u00e1n\u00ed vesm\u00edru v\u0161ak odborn\u00edci p\u0159izn\u00e1vaj\u00ed, \u017ee n\u00e1s n\u011bjak\u00e9 t\u011bleso m\u016f\u017ee p\u0159ekvapit. Probl\u00e9mem toti\u017e je, pokud by se k na\u0161\u00ed planet\u011b p\u0159ibli\u017eovalo od Slunce a bylo by oz\u00e1\u0159eno jeho jasem, podobn\u011b jako dvacetimetrov\u00fd \u010celjabinsk\u00fd meteor, jen\u017e vybuchl t\u011bsn\u011b nad zem\u00ed a jeho tlakov\u00e1 vlna vybila n\u011bkolik oken a zranila p\u0159es tis\u00edc lid\u00ed. V t\u00e9 dob\u011b nikdo netu\u0161il, \u017ee se v\u016fbec bl\u00ed\u017e\u00ed.<\/p>\n\n\n\n

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