Sterrekunde

Die opblaas van 'n asteroïde / komeet is regtig erger?

Die opblaas van 'n asteroïde / komeet is regtig erger?


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Dikwels in televisieprogramme en in artikels sien ek dat dit altyd sleg sal wees om 'n asteroïde of komeet op te blaas, want dan sal die energie net versprei word en nog meer skade berokken.

Volgens sommige beramings het ek elke dag ongeveer 100 ton (of meer) meteoroïede op die aarde sien tref. As dit alles saamgevoeg word tot 'n enkele asteroïde, kan dit 'n hele, groot stad vernietig.

Gegewe dit alleen, laat dit my voorkom asof dit logieser is om die kans te waag en 'n asteroïde op te blaas en sodoende sy gewig af te sny, wat veroorsaak dat baie meer makliker by die binnekant verbrand word, sodat wanneer dit raak , sou dit minder skade veroorsaak.

Is dit hoegenaamd logies? As my wetenskap / wiskunde / fisika nie korrek is nie, wil ek verstaan ​​waarom meer verbranding deur verspreiding slegter is as om dit meer gekonsentreerd en gevaarliker te hê.


Daar is wel 'n paar dinge om te oorweeg. Aanvanklik as u kon seker maak dat u, nadat u 'n asteroïde opgeblaas het, met baie, maar klein genoeg stukke sal eindig, sodat dit óf: een, opbrand in die atmosfeer of twee, van die aarde af sal lei (en ons nie vyf slaan nie) jare later) dan is ons in orde, en die asteroïde opblaas met 'n missiel sou 'n regverdige oplossing wees.

Die probleem hier lê in die feit dat ons min weet van die interne samestelling van asteroïdes in die algemeen, en vermoedelik nog minder van 'n spesifieke een, dus dit is baie moeilik om presies te voorspel waar die stukke van die asteroïde wat deur 'n impak gegenereer word, is of nie Dit gaan nie eindig of op sy grootte wees nie.

'N Ander scenario kan wees dat as u die asteroïde effektief in klein stukkies stukkend slaan wat dan in die atmosfeer kan inbrand, en as die stukke toevallig deur die aarde se atmosfeer verteer word, sal dit natuurlik verhit, wat natuurlik 'n onaangename dag op aarde sal veroorsaak. afhangende van die massa van die voorwerp.

Maar daar is 'n baie beter oplossing as die Armageddon-Hollywood-geïnspireerde oplossing. Dit is gravitasie-tethering. Daar is iets wat ons weet, en ons weet baie goed oor asteroïdes, en dit sou hul trajekte of wentelbane wees. Selfs wanneer 'n nuwe asteroïde ontdek word, kan die baan redelik vinnig en met groot akkuraatheid bereken word (omdat ons die swaartekrag van die sonnestelsel baie goed ken). As 'n asteroïde dus 'n impak op die aarde sal hê, sal ons waarskynlik met jare, waarskynlik dekades vooruit, weet. En so kan ons net 'n ruimtetuig (genaamd gravitasietrekker) stuur, met genoeg massa en tyd vooruit, en dit net langs die asteroïde plaas, sodat ons die baan met 'n klein bietjie kan kantel as gevolg van die swaartekrag tussen die twee voorwerpe. As u nou die effek van die klein hoeveelheid op die langtermyn in ag neem, lei dit die pad van die gegewe asteroïde effektief van die aarde af sodat dit ons nie 20 of 30 jaar later sal tref nie.

En dit is iets waaroor ons beheer het, en iets wat ons met groot akkuraatheid kan voorspel. Dit is die (veilige) manier om te gaan.

As u steeds nie tevrede is met my antwoord nie, kan u luister na Neil de Grasse Tyson wat dit in hierdie video van 5 minute verduidelik.

Kyk ook na hierdie toespraak van die American Museum of Natural History oor 'Verdediging van die aarde teen asteroïdes'

Verdere verwysing hier.


Die OP is uiteraard korrek. As u geweet het dat 'n asteroïde op pad was na die aarde en die keuse gehad het om niks te doen nie (en te laat toeslaan) of dit in die helfte te sny en albei helftes te laat slaan, sou u dit verdeel. Deur dit in 'n miljoen stukke te stoot, sou die impak versprei word, wat die botsing minder gevaarlik sou maak. Wil u eerder met 'n koeël of 100 BB's in die bors geskiet word?


Dit is van Phil Plait se "Bad Astronomy" -blad waarin hy sommige tonele uit die film "Deep Impact" dissekteer. In die belang van die wetenskap en solank as wat ek hom behoorlik erken, is ek seker dat hy nie daarvan hou om hom aan te haal nie. Hier is die skakel as u self die hele ding wil lees: http://www.badastronomy.com/bad/movies/di2.html

Sleg: Minute voor die finale impak blaas die ruimtevaarders die tweede komeet op, en ons word getrakteer op 'n skouspelagtige ligskou. Goed: Aaaaarrgg! Dit was die grootste slegste sterrekunde in die film. Om 'n komeet op te blaas, doen niks goed nie en kan sake selfs vererger. Net omdat die stukke kleiner is, beteken dit nie dat u iets verander het nie. As elke stuk nog steeds die aarde beïnvloed (dit wil sê, dit word eintlik deur die aarde of sy atmosfeer gestuit), stort u steeds al die kinetiese energie van die komeet in die aarde se atmosfeer! Dit is 'n GROOT hoeveelheid energie wat feitlik tegelykertyd gestort word. Dit sal steeds 'n massiewe ontploffing skep, wat al ons kernbomme gesamentlik verdwerg. Al sou u die slag op een of ander manier kon versag, sou al die hitte ons weer verwoes. Sommige mense dink eintlik dat dit beter kan wees om 'n groot een bloot te laat slaan eerder as om dit op te blaas, want die Aarde self kan die impaksie-energie beter absorbeer as wat die atmosfeer kan doen. Dit word egter steeds beredeneer. Ek verkies om geen eksperimente te probeer nie!


Die asteroïde wat die dinosourusse vernietig het, was gelykstaande aan ongeveer 'n miljard hiroshima-bomme of 'n miljoen 'tsaarbomme' (grootste atoombomme). Die teenkrag van energie om die kinetiese energie te ontlont, is 'n ingewikkelde dinamiese, wetenskaplik ontwerpte en ge-emuleerde aspek: afbuiging, disintegrasie en vermindering van die impaksnelheid.

Die gevaarlikste ding vir die aarde is 'n gekonsentreerde kort ontploffing op die aardkors wat kernwintere en weghol vulkaniese aktiwiteit veroorsaak en minerale wolke die lug in stuur in teenstelling met die ys wat deur die atmosfeer gekom het, en dit is moeilik om te sê na watter punt dit is beter om die aardoppervlak te skroei as om dit te skok.

Dit is 'n baie tegniese studie. Die energie word vrygestel as hitte of as 'n skokgolf of albei, dus as u die skade aan die aarde wil verminder, moet u weer meet, sal dit 'n massiewe skokgolf beter weerstaan ​​as massiewe hitte.

Uiteindelik sal die huidige SENTRY-asteroïde-moniteringstelsel en toekomstige asteroïde-voorsorgmaatreëls genoeg tyd gee sodat dit meer 'n keuse is om die asteroïde heeltemal af te buig as om dit op so 'n manier te breek dat dit nog steeds op koers met die planeet sal wees.

'N Stofkorrel is genoeg om 'n biljartbal met 'n groot span af te buig, gegewe genoeg afstand, dus die doeltreffendste gebruik van energie is die buiging.


Wil u 'n asteroïde opblaas? Dit is moeiliker as wat jy dink

Asteroïdes kan 'n beduidende bedreiging vir die aarde inhou, maar om een ​​op te blaas is nie so maklik soos dit mag lyk nie. Voorheen het sterrekundiges en ingenieurs geglo dat groter asteroïdes - diegene wat die grootste bedreiging vir die aarde inhou - redelik maklik sou wees om in kleiner stukke uitmekaar te breek. Splete en skeure binne hul liggame sou 'n 'beginpunt' wees as u probeer om die liggaam te breek - of so het die denke verloop. Dit lyk asof hierdie idee verkeerd is, aangesien 'n nuwe studie toon dat asteroïdes harder en taaier is as wat voorheen geglo is.

In wetenskapsfiksiefilms word ruimtevaarders gereeld asteroïdes opgeblaas terwyl hulle na ons planeet op pad is. In die werklike lewe kan klein fragmente egter 'n groter gevaar vir die aarde inhou as 'n enkele impak, wat 'n koeël in 'n haelgeweer ontploffing maak. Sterrekundiges bestudeer nog steeds die probleem en bied opsies in die geval dat hulle 'n potensieel gevaarlike asteroïde raaksien.

'Dit klink miskien na wetenskapfiksie, maar baie navorsing oorweeg botsings met asteroïdes. As daar byvoorbeeld 'n asteroïde op aarde aankom, is dit beter om dit in klein stukkies te breek of om dit na 'n ander rigting te skuif? En as laasgenoemde, met hoeveel krag moet ons dit tref om dit weg te skuif sonder om dit te laat breek? Dit is werklike vrae wat oorweeg word, ”het Charles El Mir, 'n onlangse doktorsgraad aan die Johns Hopkins Universiteit, gesê.

Asteroïde-botsings is gesimuleer deur die gebruik van rekenaarmodelle in 'n poging om optimale strategieë te bepaal om hierdie voorwerpe te buig of te vernietig. Vroeër rekenaarmodelle het voorspel dat asteroïdes maklik verpletter kon word in 'n botsing met 'n aansienlik groter liggaam. Hierdie modelle het egter nie ten volle rekening gehou met die beperkte spoedkrake wat in asteroïdes groei nie. Die nuwe Tonge-Ramesh-model wat deur navorsers van Johns Hopkins gebruik word, gebruik 'n meer gedetailleerde voorkoms van die strukture van asteroïdes as wat voorheen beskikbaar was.

Die nuwe rekenaarmodel stel voor dat krake vinnig rondom die liggaam van die teiken onmiddellik na 'n impak tussen twee asteroïdes ontstaan ​​en 'n krater sou ontstaan. Alhoewel die voorwerp binne die kern daarvan skade sou ly, sal die asteroïed waarskynlik nie breek nie. Binne enkele ure sou swaartekrag weer rommel bymekaarbring en oor die verswakte, maar nogtans ongeskonde kern saamsmelt.

'Ons ontwikkel baie tegnologieë om met presisie rondom hierdie soort liggame te werk, en teiken na plekke op hul oppervlaktes, asook om hul algemene fisiese en chemiese eienskappe te kenmerk. U sou hierdie inligting nodig hê as u 'n asteroïde-buigingsmissie wil ontwerp, 'het Dante Lauretta, hoofondersoeker vir die OSIRIS-REx-sending, aan die Universiteit van Arizona in Tucson, gesê.

Die aarde word gereeld deur kleiner asteroïdes beïnvloed en word soms deur 'n groter liggaam besoek, soos dié wat in 2013 oor Chelyabinsk, Rusland, ontplof het en 1100 mense beseer het. Tot dusver het waarnemers nog nie 'n asteroïde of komeet gevind wat op pad was na ons tuiswêreld nie, maar dit is waarskynlik net 'n kwessie van tyd totdat so 'n bedreiging gevind word. Hierdie navorsing, en sulke programme, kan ondersoekers help om metodes te ontwikkel om so 'n bedreiging die hoof te bied as dit na ons kant toe gesien word.

Benewens die voorbereiding van navorsers vir 'n inkomende asteroïde, kan hierdie nuwe studie ook insig gee in die vorming van die sonnestelsel en metodes bied vir die ontginning van asteroïdes.


Asteroïde Wetenskap: Hoe 'Armageddon' verkeerd is

WAIMEA, Hawaii - In die 1998-film & quotArmageddon, & quot, dreig 'n asteroïde van die grootte van Texas binne 18 dae met die aarde te bots. Om die planeet van vernietiging te red, is 'n ragtag-span diepsee-olieboorwerkers vrywillig om die massiewe ruimterots af te lei deur 'n kernbom onder die oppervlak te begrawe en dit in twee stukke te slaan wat verby die aarde sal vlieg.

Maar ondanks sy vermaaklikheidswaarde, is die film fantasties onakkuraat, het die sterrekundige Phil Plait gesê, wat die & quotBad Astronomy & quot -blog op Slate.com skryf.

& quot; Gaan nie na Hollywood vir raad oor hoe om 'n asteroïde te hanteer nie, & rdquo; Plait het Saterdag (13 September) 'n klein, maar stampvol gehoor op HawaiiCon, 'n wetenskap-, wetenskap- en fantasiekonvensie op die eiland Hawaii, vertel. Die driedaagse byeenkoms bevat gesprekke en geleenthede met bekendes uit die gewilde wetenskaplike TV-reeks, sowel as kundiges oor ruimte en sterrekunde. [Top 10 maniere om die aarde te vernietig]

Plait het tydens sy toespraak 'n clip van & quotArmageddon & quot getoon waarin Bruce Willis se karakter sukkel om die bom met die hand te laat ontplof voordat die asteroïde die aarde binnedring en alle lewe vernietig.

& quot; Daar is meer foute in die clip as videorame, & quot; het Plait gesê. Om 'n asteroïde so groot soos die een in die film op te blaas, moet die bom met dieselfde hoeveelheid energie ontplof as wat die son produseer, het hy gesê.

Al sou u so 'n wapen kon maak, sou & quotit gevaarliker wees as die asteroïde self. & Quot; Wat meer is, nou het u nie net 'n asteroïde nie; u het 'n radioaktiewe asteroïde, het hy gesê.

Maar hoewel die werklike wetenskap in & quotArmageddon & quot klaaglik misluk, kan u baie meer akkurate wetenskap vind in die soortgelyke film & quotDeep Impact, & quot wat ook in 1998 vrygestel is, het Plait gesê. In die film ontdek 'n tiener-amateur-sterrekundige 'n 7 km-wye (11 kilometer) komeet op 'n pad wat oor twee jaar in die aarde sal val.

Soos in & quotArmageddon, stuur die mensdom 'n span mense na die ruimterots om dit met 'n kernwapen te vernietig, maar hierdie keer is die ontploffing baie kleiner, en die fragmente wat deur die ontploffing voortgebring is, beland steeds op aarde. Een van die stukke dompel in die Atlantiese Oseaan, wat 'n mega-tsoenami oplewer wat Manhattan en baie belangrike kuslyne oorstroom, 'n scenario wat eintlik redelik akkuraat is, het Plait gesê.

Maar selfs & quotDeep Impact & quot kry sommige dinge verkeerd. Die asteroïdesending stuur 'n ruimteskip om die ander komeetklomp op te blaas en fragmente te produseer wat skadeloos opbrand in die aarde se atmosfeer in plaas daarvan om dodelike gevolge te veroorsaak - nie 'n baie waarskynlike scenario nie, het Plait gesê.

In die werklike lewe hou asteroïdes en komete wat die Aarde kan tref - sogenaamde & aarde-voorwerpe & quot - 'n bedreiging in vir die lewe op die planeet.

Gelukkig hou NASA en ander organisasies, soos die B612-stigting in Menlo Park, Kalifornië, die lug dop vir hierdie bedreigings. Ongelukkig is nie al die gevare waarneembaar nie. In werklikheid ontdek wetenskaplikes soms slegs sommige van hierdie nabygeleë ruimtestene nadat die voorwerpe reeds deur die planeet geswaai en gemis het.

Groter teleskope is nodig om meer van hierdie onwelkome besoekers op te spoor, en hoe vroeër dit opgespoor kan word, hoe makliker sal dit wees om hulle af te buig, het Plait gesê.

Redakteur & # 39 s opmerking: Hierdie verhaal is genereer tydens 'n reis wat deur die Hawaii Tourism Bureau betaal is.

Copyright 2014 LiveScience, 'n TechMediaNetwork-onderneming. Alle regte voorbehou. Hierdie materiaal mag nie gepubliseer, uitgesaai, herskryf of versprei word nie.


Opblaas van gevaarlike asteroïdes? Waarskynlik nie 'n goeie idee nie.

As u baie films kyk, sal u ongetwyfeld op een afgekom het oor 'n fiktiewe en 'n wêreldse scenario wat 'n groot asteroïde-impak het. Soos met die meeste Hollywood-films, vind die mensdom gewoonlik 'n manier om sulke apokalips af te weer, dikwels deur plofstof te stuur om die dreigende ruimterots te neutraliseer. Maar sou hierdie benadering eerlik in die regte wêreld werk?

Soos dit wil voorkom, is daar 'n aantal aanwysers wat daarop dui dat dit nie sou wou gaan nie, en 'n artikel wat pas hierdie week in die tydskrif gepubliseer is. Ikarus blyk dit verder te bevorder, selfs al is dit indirek.

Die navorsers het na bewering rekenaarmodelle saamgestel om vas te stel wat kan gebeur as 'n kleiner asteroïde wat net 'n paar duisend meter oor is, in 'n baie massiewe asteroïde val wat meer as 'n dosyn kilometer breed is. Terwyl sommige die volledige ruimterots volkome en algehele vernietiging sou verwag, was dit nie wat die navorsers in hul modellering gesien het nie.

Terwyl die kleiner asteroïde wel daarin geslaag het om die groter een groot skade aan te rig, was laasgenoemde se kern nog heel ongeskonde en net so gevaarlik soos altyd. Nog verbasender, die asteroïde-skerwe wat net ná die impak in elke rigting gaan vlieg het, het op die beskadigde asteroïde en rsquos se swaartekrag getrek en stadig saamgeval om weer 'n enkele voorwerp te vorm.

& ldquo Hulle breek nie die manier waarop ons gedink het nie, en KT Ramesh, 'n medeskrywer van die koerant, het toegelig. & ldquoEn die eindresultaat is dat hierdie liggame aansienlik kan beskadig, maar nie opgebreek kan word nie. & rdquo

Die bevindings handel miskien nie spesifiek oor of plofstof nuttige instrumente teen potensieel gevaarlike asteroïde-impak sal wees nie, maar volgens die hoofskrywer Charles El Mir van die studie kan dit geïnterpreteer word as 'n argument teen 'n asteroïde as 'n verdedigingsstrategie. & Rdquo

& ldquoJy wil beslis nie probeer wat die films doen en hierdie dinge opblaas nie, & rdquo Ramesh het bygevoeg. & ldquoDit & rsquos gaan nie baie help nie. Wat u regtig wil doen, is om die asteroïde uit die pad te skuif. & Rdquo

Dit is nie die eerste keer dat navorsers rekenaarmodelle gebruik om die uitkoms van een asteroïde in 'n ander te voorspel nie, maar dit was miskien een van die mees gedetailleerde modelle tot nog toe. Daar is weliswaar nie rekening gehou met die veranderlikes wat verskillende asteroïdes kan hê nie; die faktore sluit in rotasie, bestaande krake en samestelling, en elkeen kan die uitkoms heeltemal verander.

Daar is nog baie om oor asteroïdes en hul fisiese eienskappe te leer, maar ruimteagentskappe van regoor die wêreld ondersoek aktiewe asteroïdes in die sonnestelsel in 'n poging om meer insig daaroor te kry. Wat ons uit hierdie missies leer, kan bydra tot die onderskeidende lewensvatbare maniere om die aarde teen gevolge te beskerm, maar net die tyd sal leer.


Die opblaas van 'n asteroïde / komeet is regtig erger? - Sterrekunde

Koop my goed

Hou slegte sterrekunde na aan u hart, en help my om vuil te word. Haai, dit is of een van die regtig irriterende PayPal-donasie-knoppies hier.

Die (disfunksionele) Family Channel se weergawe van Chicken Little

Om die een of ander rede is daar meer TV-programme oor asteroïdes uitgesaai as wat daar eintlik asteroïdes is. As hulle by dokumentêre films hou, was die vertonings oor die algemeen redelik goed. NBC het egter besluit om 'n fiktiewe weergawe te maak van 'n asteroïde-aanval in hul aaklige, aaklige TV-film "Asteroid", waaroor ek nie genoeg slegte dinge kan sê nie. Nadat ek "Doomsday Rock" gekyk het, kan ek eerlikwaar sê dit laat "Asteroid" soos 'n werk van genie lyk.

Voordat ek regtig hier begin, kyk gerus na my webblad waar ek die NBC se sterrekunde ondersoek. Baie van die punte wat ek hier stel, sal soortgelyk wees aan (indien nie presies gelyk aan) punte wat daar gestel word nie. As ek verwys na iets wat ek op daardie bladsy gesê het, skakel ek eenvoudig daarna en laat u die verwysing vind.

Eerstens 'n kort oorsig van die plot: Connie Sellecca vertolk 'n sterrekundige wie se vader, Dr. Sorensen (gespeel deur William Devane), voorspel dat 'n asteroïde die aarde sal tref deur brande te veroorsaak en suur te maak. reën, die beskawing uitwis, ensovoorts, ensovoorts. Niemand glo hom nie, en hy neem natuurlik 'n kernmissiel-silo in Colorado oor, waarvandaan hy 'n paar kern-ICBM's by die inkomende asteroïde kan oplaai en opblaas. Die rede waarom mense hom nie glo nie, is omdat al die berekeninge om die baan wys dat die asteroïde die aarde sal mis. Die rede waarom hy glo dit is as gevolg van 'n Australiese inheemse legende dat die aarde aan die einde van die 20ste eeu via 'n 'Demon Rock' sal eindig. Reg. Volg my nog steeds? Op die laaste oomblik blyk dit dat hy reg is, kernmissiele word gelanseer, die asteroïde verdamp sekondes voor die impak, en almal is gelukkig.

Almal behalwe ek dit is. Uit my beskrywing is hierdie film natuurlik nie heeltemal akkuraat bedoel nie, en was hulle, net soos die film "Asteroid", bereid om 'n bietjie wetenskaplike geloofwaardigheid vir die intrige op te offer. Maar net soos 'Asteroïde', was elke bietjie sterrekunde wat hulle ingesit het verkeerd, en die intrige was selfs erger as 'Asteroïde'. Ek het opgemerk dat hulle 'n wetenskaplike adviseur vir die film gehad het, maar weereens, om redes wat slegs bekend was vir The Powers That Be at the Family Channel, het hulle sy advies uiteraard heeltemal geïgnoreer. Laat ons dus sonder meer nadink oor die slegte sterrekunde wat die film afgekondig het (in die volgende lys sal ek 'Doomsday Rock' as 'DR' noem vir die eenvoud):

Sleg:
In 'n vroeë toneelstuk van 'DR' doseer Connie Sellecca studente oor sterrekunde, en een van hulle vra haar die verskil tussen 'n swart gat en 'n neutronster. Sy sê (geparafraseer) "Neem Cygnus X-1. Dit produseer gammastrale. Neutronsterre het 'n magneetveld wat so intens is dat gammastrale nie kan ontsnap nie. Dit is hoe ons weet dat dit 'n swart gat was."

Goed:
Dit is moeilik om te weet waar om met hierdie een te begin. Eerstens die regte dinge: Cygnus X-1 word inderdaad as 'n swart gat beskou, gammastrale is daaruit opgespoor en neutronsterre het intense magnetiese velde. Hierna het die skrywers egter verskriklik verward geraak. Gammastrale is basies weergawes van sigbare lig met baie energie: albei is vorme van wat ons 'elektromagnetiese straling' noem. Die belangrikste verskil tussen gammastrale en sigbare lig is dat gammastrale baie meer energie per foton het. Magneetvelde kan egter geen lig stop nie. Hulle beïnvloed dit wel op baie maniere, maar dit is nie moontlik om te stop nie. Ek dink die skrywers het magnetisme met swaartekrag verwar. 'N Sterk genoeg swaartekrag kan inderdaad voorkom dat selfs lig ontsnap. Wat lewer 'n swaartekragveld so sterk op? 'N Swart gat. Ironies genoeg het die skrywers dit presies agteruit gekry. 'N Swart gat kan gammastralings stop, maar 'n neutronster nie!

Die rede waarom ons gammastrale (en alle ander vorme van elektromagnetiese straling) van swart gate sien, is omdat die groot swaartekrag van die swart gat die straling net baie naby stop. Die swaartekrag-effekte strek egter ver en kan beïnvloed materie rondom dit, trek dit in. Terwyl die materie in die swart gat draai, verhit plaaslike effekte die saak tot ongelooflike temperature, wat op sy beurt weer allerhande straling laat uitstraal. Daarom dink ons ​​Cygnus X-1 is 'n swart gat. In die toneel probeer hulle om Sellecca as 'n briljante sterrekundige te vestig, maar eintlik het hulle presies die teendeel bereik.

'N Ander punt: as die FBI haar gebraai het, sê 'n agent dat sy te gekwalifiseer is om sterrekunde op hoërskool te leer. Ek het dit persoonlik 'n bietjie beledigend gevind. Onderrig is een van die belangrikste aspekte van sterrekunde. U het miskien nie 'n doktorsgraad nodig om hoërskool te gee nie, maar hulle het geïmpliseer dat dit onder haar was. Ek is van mening dat die onderrig van sterrekunde redelik edel is, en elkeen wat dit vir hoërskoolleerlinge probeer leer, verdien 'n medalje en geen bespotting nie.

Sleg:
Dr Sorensen, nadat hy die kernmissiel silo oorgeneem het, eis (van die Minister van Verdediging!) Die onmiddellike gebruik van die Hubble-ruimteteleskoop (HST). Hy sê hy het die koördinate en dit sal slegs 'n paar minute neem om dit te wys. Nadat aan sy eis voldoen is, kry hy dadelik live video-invoer van die asteroïde van HST, wat die draaiende asteroïde duidelik wys.

Goed:
Nog 'n digte voorbeeld van Bad Astronomy. Eerstens neem dit minstens twee weke om HST op 'n gegewe voorwerp te wys. Tyd is baie kosbaar en baie oordeelkundig op HST afgestaan, so die omvang is geskeduleer maande is vooraf. Dit is moontlik om die skedule met 'n prioriteitswaarneming te onderbreek, maar dit neem ongeveer twee weke in. Dit is letterlik onmoontlik om binne 'n paar minute die omvang aan te dui sonder om dit af te sluit.

Tweedens, HST kan nie video neem nie. U kan 'n reeks waarnemings neem as u wil en dit dan in 'n film verander, maar dit neem dae, weke of selfs maande om dit te doen.

Derdens, en wat verband hou met die tweede punt, neem dit lank om HST-data te ontleed. Selfs 'n span mense kan maande neem om die data behoorlik in 'n vorm te kry waar dit ontleed kan word, en die ontleding kan jare duur. Om 'n regstreekse videostroom te hê, is belaglik.

Vierdens, aangesien die impak ure ver was, sou die asteroïde heeltemal te vinnig beweeg om HST dit op te spoor. HST kan bewegende voorwerpe soos planete, komete, asteroïdes, ens. Opspoor, maar net tot op 'n punt. Iets wat 50 000 myl per uur beweeg en minder as 'n dag verder sou beweeg om vinnig op te spoor, tensy dit reguit op ons af is. In die film word egter verskeie kere gesê dat die asteroïde ons met 'n halfmiljoen kilometer sal mis. Daarom was dit nie reguit vir ons nie en HST kon dit nie opspoor nie.

Vyfde (vyfde! In een toneel!), Waarom gebruik jy HST? Hubble is op baie maniere 'n uitstekende teleskoop, maar dit is nie baie groot nie. 'N Groter, grondgebaseerde omvang sou die asteroïde baie vinniger kon voorstel, en hulle hoef nie twee weke te wag om die waarneming geskeduleer te kry nie! Maar almal het natuurlik van Hubble gehoor, en dit was baie dramaties om hom te eis. Dit was ook sleg.

Terloops, later in die film gebruik Sellecca 'n baie klein omvang en kry so goeie data soos Sorensen van HST. Gaan figuur.

Sleg:
In een toneel moet Sellecca die baan van die asteroïde self nagaan. Sy vlieg na die Space Scan Observatory in Virginia om 'n teleskoop daar te gebruik. Die teleskoop is in 'n verligte kamer geleë, omring deur rekenaarmonitors.

Goed:
Natuurlik is daar geen "Space Scan" sterrewag daar nie, maar dit is 'n bietjie lisensie wat ek sal vergewe (net soos die "National Observatory" in "Asteroid"). Maar soos 'n veteraan van Virginia waarneem, sal niemand daar wil bou nie. Die weer in Virginia, sowel as baie Oosterse state, is net te bewolk en wazig om enige waarnemingsprogram goed te laat werk. U is baie beter daaraan toe in die weste, waar dit dikwels duidelik is. Ook het 'DR' dieselfde fout gemaak om 'n teleskoop in 'n verligte kamer te plaas wat Asteroid gemaak het.

Sleg:
Later gaan Sellecca na Puerto Rico om die Arecibo-radioteleskoop te gebruik. Sy noem dit die 'beste radioteleskoop ter wêreld', en gebruik dit om meer bevestiging van die baan van die asteroïde te kry.

Goed:
Arecibo is die grootste enkele radioteleskoop ter wêreld, maar 'beste' is 'n subjektiewe term. U kry wel 'n hoër resolusie (dit wil sê die vermoë om twee uiters naby voorwerpe te verdeel) met groter omvang, maar die hoogste resolusie wat verkry word, word eintlik met behulp van 'n verskeidenheid teleskope gedoen. In die film (en boek) 'Contact' is die sein van die vreemdelinge opgespoor met behulp van die VLA, oftewel Very Large Array, wat 'n versameling is van 27 radioteleskope wat in harmonie optree. Baie ander teleskope neem deel aan Very Long Baseline Interferometry (VLBI), waar teleskope van regoor die wêreld dieselfde voorwerp waarneem. As u dit op hierdie manier vasmaak, is dit asof u 'n enkele omvang het met die deursnee van die aarde!

Nog 'n probleem is met die manier waarop Arecibo werk. Dit is ingebou in grond in plaas van 'n losstaande skottel. Dit bied 'n meer rigiede ontwerp, wat 'n maklike manier is om dit groter te maak. Hierdie ontwerp beperk egter die hoeveelheid lug wat die omvang kan sien. Eintlik (die laaste wat ek gehoor het), was dit beperk tot ongeveer +/- 30 grade van regop. Die asteroïde moet gemaklik vanuit daardie gebied binnekom en op daardie spesifieke tyd in die lug wees. Nog 'n lawwigheid van die skrywers. Maar hoekom dan hoegenaamd 'n radioteleskoop gebruik? 'N Optiese teleskoop sal beter werk verrig en makliker wees om te gebruik. Weereens wou die skrywers net 'n "gee-whiz" -toneel hê, ondanks enige grondslag in die werklikheid.

Sleg:
Kom ons kyk na die asteroïde self: dit is ongeveer 10 by 5 by 3 kilometer groot, byna geheel en al van yster gemaak en beweeg ongeveer 50.000 myl per uur in. Daar word gesê dat die impak sal wees soos die gelyktydige ontploffing van 30 atoombomme. Sellecca vergelyk dit met 'om 'n kantaloep van tien meter af te skiet met 'n 44 Magnum'.

Goed:
Eerstens gebruik sterrekundiges nooit kilometers nie. Ons is metries. Soveel getalle in die film het egter nie-metrieke getalle gebruik dat ek dit ook sal gebruik as ek 'n vergelyking tref. Tweedens, 'n impak van 'n grootte van 'n voorwerp, wat so vinnig beweeg, sal 'n bietjie meer energiek wees as 30 atoombomme. Daardie lyn het my hardop laat lag. Die volume, gegewe die digtheid van yster, het 'n massa van 10 18 gram, of ongeveer triljoen ton (dit is 'n miljoen miljoen ton).

(Nota bygevoeg 9 Maart 2003: Wel, hoe simpel. Ek het oorspronklik twee foute in hierdie bladsy gemaak. Ek het gesê die massa was 10 triljoen ton, as dit regtig een triljoen is. Ek het ook gesê dat die kinetiese energie 5 x 10 30 erge is, as dit regtig 2,5 x 10 30 ergs is. Ek het hierdie getalle reggestel en die foute hier aangedui om my eerlik te hou! My dank aan Bad Reader John Owens wat my daarop gewys het.)

As jy ongeveer 2 miljoen sentimeter per sekonde beweeg, beteken dit dat dit 'n kinetiese energie van 2,5 x 10 30 erge het. 'N Erg is tienerige eenheid van energie: een megaton is ongeveer 4 x 10 22 ergs. Maar wag! Daar is baie erge in die asteroïde. Die kinetiese energie van die asteroïde is ongeveer honderd miljoen megatons! As ons in ag neem dat 'n groot waterstofbom slegs 'n paar tien megatons is (die grootste wat ooit ontplof het, was minder as 60), sien ons dat die skrywers die energie van die asteroïde ongelukkig onderskat het. Nou gaan nie alle kinetiese energie van die asteroïde in die impak nie, maar as selfs 1% daarvan wel het, het ons nog steeds iets wat die kernvermoë van elke nasie op aarde saamdwerg.

Dit is egter nie naastenby genoeg om die aarde werklik te verpletter nie. Eintlik is dit net genoeg om 'n groot krater te verlaat, maar selfs die krater sou net 'n paar kilometer diep wees. Met gravitasie-argumente kan aangetoon word dat dit ongeveer 10 40 erge sal neem om die Aarde te verpletter. Dus het die asteroïde minder as 1 tien miljard die energie om dit te doen. Die fliek het beslis vinnig en los gespeel met hul getalle!

Sleg:
Die asteroïde is na verneem word 19 minute vanaf die impak op 50 000 mph. Die volgende afbeelding toon die asteroïde oor die maanoppervlak, kompleet met skaduwee.

Goed:
Die maan is 250,000 myl weg, of vyf uur teen 50,000 mph. Op 19 minute na inslag moes die asteroïde net ongeveer 17 000 kilometer ver gewees het. Dit is nader as geosinchrone satelliete!

Sleg:
Kort voor impak bots die asteroïde met 'n komeet, wat die gang van die asteroïde verander en dit na die aarde rig.

Goed:
Puh-huurkontrak! Ek het dit alles bespreek op my bladsy oor "Asteroïde". Eintlik is die kans dat dit so groot is dat u met veiligheid kan sê dat dit nooit sal gebeur nie. 'N Komeet het ook nie die energie om die koers van 'n asteroïde dramaties te verander nie. * *. Aangesien hulle die asteroïde opgeblaas het, was die voorspelling terloops verkeerd. Sellecca het gesê die tydlyn van die toekoms wat deur die stam geskryf is, eindig in die 20ste eeu. Ek dink ons ​​het nog drie jaar om deur 'n ander asteroïde getref te word. Noudat ek daaraan dink, sou dit 'n semi-koel einde gewees het: hulle besef almal dat die profesie hierdie keer nie waar geword het nie, dus daar moet 'n ander asteroïde wees. ->

Sleg:
Twee kernmissiele blaas die asteroïde op.

Goed:
Die volume van die asteroïde is 1,5 x 10 17 kubieke sentimeter. Rofweg, Mt. Everest is dieselfde grootte. Stel jou nou voor dat jy twee atoombomme op die berg laat val. Everest. Dit sou seergemaak word, maar nie heeltemal vernietig word nie. Daardie asteroïde was van soliede yster gemaak. Twee atoombomme sal nie baie skade berokken nie. Hulle sal dit beslis nie verdamp nie. Hoe dit ook al sy, met die massa van die asteroïde na die ontploffing? Die ding het sekondes voor die impak opgeblaas, wat dit feitlik in die aarde se atmosfeer sou plaas. Selfs verdamp, sou al die massa steeds na die Aarde toe gelei word, wat weer beteken dat al die energie nog op die aarde gestort sou word. Hulle het die asteroïde vernietig, maar niks verander nie. As u soveel energie in die aarde se atmosfeer stort, kan dit net soveel skade berokken. Sommige mense dink nog meer, want daar is geen impak op die grond nie, maar die energie word versprei en rig meer skade aan oor 'n groter gebied.

Ek het ook baie klein pikkewyne:

Hulle stuur vroeg 'n missiel as 'n bluf. Die hoogtemeter toon dat dit op sy beste ongeveer 100 voet per sekonde styg. Dit is ongeveer 100 kilometer per uur, of so vinnig soos 'n motor op die snelweg. Op daardie spoed sou dit tien minute neem om net uit die onderste atmosfeer te kom! Dit sou ure geneem het om in 'n baan te beland.

Hulle sê die Pentagon is in Washington DC. Dit is nie. It's in Arlington, Virginia.

An astronomer mentioned Halley's comet, but pronounced it "Hay-lee". Every astronomer I know pronounces it "Hal-lee", since Halley was British. Also, comets are referred to as "Comet such and such", not "such and such Comet".

Over and over again, Sellecca says that the comet will "split". The astronomy term for that is "calving". Why didn't she ever use it, even when talking to another astronomer?

The Russians launch a missile to help our missile destroy the asteroid. However, the asteroid was so close by then that the Russian missile would never have had time to get all the way over to it, let alone at the same time as the U.S. missile.

During this whole thing, the President never gets involved. The Defense Secretary calls all the shots, including one where she orders an atomic bomb raid on a missile silo inside U.S. boundary. Where was the President?

Yegads. A military advisor to the President pronounced "NASA" as "Nassau". I'd think someone of his authority would know the difference between a multi-billion dollar agency and the capital city of the Commonweath of the Bahamas. At least I never heard the word "nuc-you-ler" during the movie.

Lastly, they keep calling it the "Demon Rock" or "Doomsday Rock". However, it's made of metal. Even the title of the movie is wrong!

All in all, this movie was actually worse than "Asteroid", which I would have thought impossible. They even stole the idea of the comet collision! How low can you stoop? I won't even bother commenting on the quality of the writing (besides the science), the acting, the special effects and the direction. The Family Channel, being a supporter of family values, should also want our families to get an education. I sure did, watching this. I'll never believe there is a lower limit to the quality of made-for-TV movies again.


REVEALED: How Nasa is developing a GUN to DEFLECT asteroids…but is it too late?

Skakel gekopieer

A computer image of the proposed gun

As u inteken, sal ons die inligting wat u verskaf gebruik om hierdie nuusbriewe aan u te stuur. Soms bevat dit aanbevelings vir ander verwante nuusbriewe of dienste wat ons aanbied. Ons privaatheidskennisgewing verduidelik meer oor hoe ons u data en u regte gebruik. U kan te eniger tyd uitteken.

New York-based engineers Honeybee Robotics &ndash an interplanetary exploration specialist - has been commissioned to develop the concept for the Nasa Asteroid Redirect Mission (ARM).

The idea behind it is not to blow up an asteroid, as this could potentially make things worse sending hundreds of smaller meteorites crashing into the planet.

It would, instead be to hit one with enough force to steer it away so it passed as a safe distance.

Currently, there is next to nothing that could be done to prevent a significant asteroid on a collision course with us from crash to earth.

If it was a rock of a size significant enough to threaten life on earth (500 metres and upwards), the change of direction would probably have to take place about 100 years before it got here.

The shotgun could also be used to get samples from asteroids and test the strength of them as they are in orbit.

Kris Zacny, vice president at Honeybee Robotics, said the concept will also be "key" to sending sending humans to Mars in the future.

Verwante artikels

Verwante artikels

If a ball is fired at an asteroid and it cracks open on the surface, then we&rsquoll know the asteroid is likely sturdy enough to land on with a probe

Honeybee Robotics spokesman

If the gun is developed, chunks of asteroids will be dislodged out of orbit and sent closer to the moon, where they would be more accessible to experts.

A Honeybee Robotics spokesman said one risk with collecting samples from asteroids is &ldquothe unknown geotechnical properties and strength of the asteroid regolith.&rdquo

The space shotgun helps lower this risk because the balls it fires at the asteroid can help scientists estimate its surface strength.

He said: "If a ball is fired at an asteroid and it cracks open on the surface, then we&rsquoll know the asteroid is likely sturdy enough to land on with a probe.

"Or if the balls bounce back off the asteroid&rsquos surface, they should bounce back at a velocity that correlates with the rock&rsquos overall strength.

"The gun could even fire balls designed to make craters in the asteroid to give researchers an estimate of how hard the surface of the asteroid might be."

Many will be hoping the technology is finished sooner, rather than later, as online doom mongers continue to claim an asteroid will strike in Puerto Rico, any time between now and September 28, when the Blood Moon rare lunar eclipse takes place.


In a NASA exercise of an asteroid impact, scientists couldn't stop the space rock and Europe (target of the simulation) gets hit

Can loft 200 tons to the moon, send 5 expendable Starships. Send 10,000 tons of nuclear warheads. The resulting small and short mini sun or timed explosion should push the asteroid away while burning small debris.

Oliver James

HStallion

Once spacex finishes Starship we should be ok. Expendable Starship (I know, Elon said he would never do it but there is a asteroid coming)

Can loft 200 tons to the moon, send 5 expendable Starships. Send 10,000 tons of nuclear warheads. The resulting small and short mini sun or timed explosion should push the asteroid away while burning small debris.

Thewienke

Mantidor

I wonder how consecutive nuclear blasts would do. Like if you just had a train (not close enough to set eachother off) of nukes set to detonate over and over on the "bottom" (southern relative to us) side so it would go above us past the north pole.

I can't imagine that would take more than a month to plan and with thousands of those things we could do that for months over and over. Wonder if it would generate enough force/thrust to move it to another uninhabitable area like the north pole or just miss completely.

Liam Allen-Miller

they had 6 months and their conclusion was to give up? lmaooo

not even an asspull solution?

Burly

Dreams-Visions

Killerrin

Better to blow up an asteroid and doom a couple cities than wipe out all life except for the deep sea microbes.

Anyhow, It depends on how small the debris field is. At a certain point the atmosphere can handle it in its own. And the Earth is bathed in much worse forms of radiation every second of its existence.

The debris will just burn off in the atmosphere and the magnetic field will take care of the rest. The solar winds will burn off the radiation on the asteroid in transit and the debris won't stay in the field long enough to become coated since newton's laws of motion would shoot the radiation off into space rather than stick around in a given area.

SigSig

Something Creative

HStallion

Better to blow up an asteroid and doom a couple cities than wipe out all life except for the deep sea microbes.

Anyhow, It depends on how small the debris field is. At a certain point the atmosphere can handle it in its own. And the Earth is bathed in much worse forms of radiation every second of its existence.

The debris will just burn off in the atmosphere and the magnetic field will take care of the rest. The solar winds will burn off the radiation on the asteroid in transit and the debris won't stay in the field long enough to become coated since newton's laws of motion would shoot the radiation off into space rather than stick around in a given area.

Fat4all

Community Retriever

Entremet

TheBaldwin

DarthWoo

Killerrin

Yes, which is why when people propose nukes it comes in the context of multiple nukes and multiple missions to mop up the debris field. It's not just going to be one and done. That would be idiotic.

Anyhow, even if you split an asteroid, you are going to change its orbit and trajectory. And that split may be substantial enough to avert the worst of the scenario. Especially if it was found with enough advance. In which case you can focus on the remaining debris which now being smaller, you have more options available like high frequency lasers, solar sails, or even towing it elsewhere.

Anyhow when it comes down to it. Nukes aren't even the best way. You'd really want rail guns here if the plan is to split asteroids and their debris up to the point they vaporize in the atmosphere. And it'd be more practical to launch and keep maintained and stocked since you could do it with satellites in Earth Orbit, and kept restocked with standard rockets that we have in abundance. Just make the rods/shells made of Tungstein, maybe with an explosive tip. Add a massive solar array to charge it quickly for rapid fire. Then sit back and watch as you rain havok down upon all the threating asteroids.


Thread: Blowing up asteroid

I often hear on SGU that blowing up a large asteroid that is heading towards us would not work as a means of defence.

I understand it would result in the same mass hitting us at the same speed (minus whatever bits get blown off in other directions), but surely 20 tonnes of gravel would be different than a 20 tonne rock.

So, why would it not work as a viable technique if we only had short notice of an impending impact.

There are at least a couple of major issues with a large asteroid:

(1) It might not all be gravel. Some of the pieces could be quite large, so instead of one large asteroid you might now have half a dozen somewhat smaller, but still large chunks.

(2) Even if you do end up with gravel, you are still dealing with a lot of gravel hitting the atmosphere. A lot of gravel hitting the atmosphere in a short time is going to produce a lot of heat, and could flash burn anything exposed. Then there's the nitric oxide that could be produced. A lot of that would be bad.

With both of those, breaking up a large asteroid could make things worse.

"The problem with quotes on the Internet is that it is hard to verify their authenticity." Abraham Lincoln

I say there is an invisible elf in my backyard. How do you prove that I am wrong?

My understanding is that a large part of the effects of an asteroid striking the Earth is the heat transfered into the atmosphere. As a first order approximation, that is only dependent upon the mass of the material and the speed it hits. Breaking up the asteroid into smaller pieces changes neither.

IIRC, in some ways smaller pieces are worse for one, if they disintergrate in the atmosphere, all their energy gets put into the atmosphere. Large pieces striking the ground transfer some of their energy into the ground, where it does less significant heating.

At night the stars put on a show for free (Carole King)

Also, if the asteroid is blown up with nuclear weapons, not only do you have a few thousand high velocity impacts, but a few thousand high velocity, radioactive impacts. This may be an exaggerated danger, but it will depend very much on the details of the warhead design.

As vaguely related aside, would there be any kind of electro-magnetic pulse from a few thousand tons of gravel whacking into the atmosphere?

Inligting oor Amerikaanse Engelsgebruik hier. Kwessies oor drywende punte? Lees dit asseblief voordat u dit plaas.

Hoe vlieg dinge? Dit verklaar dit alles.

Eintlik kan hulle nie: & quot; Swaarder as vliegtuigmasjiene is onmoontlik nie & quot & - Lord Kelvin, president, Royal Society, 1895.

My understanding is that a large part of the effects of an asteroid striking the Earth is the heat transfered into the atmosphere. As a first order approximation, that is only dependent upon the mass of the material and the speed it hits. Breaking up the asteroid into smaller pieces changes neither.

IIRC, in some ways smaller pieces are worse for one, if they disintergrate in the atmosphere, all their energy gets put into the atmosphere. Large pieces striking the ground transfer some of their energy into the ground, where it does less significant heating.

"The problem with quotes on the Internet is that it is hard to verify their authenticity." Abraham Lincoln

I say there is an invisible elf in my backyard. How do you prove that I am wrong?

When I have personally used explosives, we can use one tonne of conventional explosive to lift 1 acre to a depth of 6 feet. That's using drills, and very efficiently placed explosive.
So I see getting enough explosive delivered to the right spot as very expensive and something you couldn't do at short notice.

But hypothically, if we were given 3 months notice today of a 1km object coming straight at us, I guess we would try to steer it off course by detonating bomb after bomb on one side of the object?? Pushing would be a far more efficient use of the explosive's enerygy than cracking.

I'm not so sure a meteor that size would be likely to burn up.
I used a very simple calculator, which assumes among other
things that the meteoroid does not explode or break apart as
it enters.

Initial mass: 20,000 kg
Initial speed: 40 km/s
Entry angle: 45 degrees
Entry height: 120 km
Density: 2.2 g/cm^3

Original diameter: 2.589 m
Final diameter at impact: 1.512 m
Final mass at impact: 3,981 kg
Speed at impact:1.967 km/s
Time in atmosphere: 6.31 s
Impact energy: 7,700 MJ

Inligting oor Amerikaanse Engelsgebruik hier. Kwessies oor drywende punte? Lees dit asseblief voordat u dit plaas.

Hoe vlieg dinge? Dit verklaar dit alles.

Eintlik kan hulle nie: & quot; Swaarder as vliegtuigmasjiene is onmoontlik nie & quot & - Lord Kelvin, president, Royal Society, 1895.

My point is that it's not "just one bomb". A shattered meteor with several large destructive pieces is several bombs.
And maybe the radiation won't be an issue, but the shockwave can be.

Let's say a large shattered asteroid produces dozens (or even hundreds if it's large enough) destructive pieces. What you may get is dozens of Tunguskas over a period of minutes spread across a large area of the Earth.

My point is that it's not "just one bomb". A shattered meteor with several large destructive pieces is several bombs.
And maybe the radiation won't be an issue, but the shockwave can be.

Let's say a large shattered asteroid produces dozens (or even hundreds if it's large enough) destructive pieces. What you may get is dozens of Tunguskas over a period of minutes spread across a large area of the Earth.

There is another way of explaining it. An asteroid impact is comparable to an explosion of a nuclear weapon.

A nuclear weapon is described by its yield (Y). However, a more important parameter is called effective yield, which describes surface area destroyed in a blast: Y_eff = Y^2/3. Effective yield increases with 2/3 power of device yield, because explosion energy is dissipated in THREE dimensions, while the target surface flat. Or, imagine that you explode a warhead on the ground. In the first approximation, it will excavate a spherical crater with the same dimensions as the fireball. Since fireball volume is proportional to Y, its diameter is proportional to Y^1/3. So the destroyed area is proportional to the square of its diameter, i.e. Y^2/3. You do not care how deep the crater is, only what is its horizontal extent.

So, a 10MT warhead has an effective yield of 10^(2/3)=4.6MT. But, two warheads 5MT each are equivalent to a single 2*5^(2/3)=5.8MT warhead in terms of surface damage. That's 26% more damage just by splitting the charge! Effective yield of 10 1MT warheads is 10*1^(2/3)=10MT. Now, it gets really interesting. 100 devices 0.1MT each give you an effective yield of 21.5MT, out of combined device yield of 10MT! (Coincidentally, this is why largest nuclear weapons currently in service are 1.2MT, despite designs as big as 50MT being successfully tested).


Contents

In May 1998, at a star party, teenage amateur astronomer Leo Beiderman observes an unidentifiable object in the night sky. He sends a picture to astronomer Dr. Marcus Wolf, who realizes it is a comet on collision course with Earth. Wolf dies in a car crash while racing to raise the alarm.

A year later, journalist Jenny Lerner investigates Secretary of the Treasury Alan Rittenhouse over his connection with "Ellie", whom she supposes to be a mistress. She is apprehended by the FBI and taken to meet President Tom Beck, who persuades her not to share the story for 48 hours in return for a prominent role in the press conference he will arrange. She subsequently discovers that "Ellie" is actually an acronym — ELE — which stands for "extinction-level event". Two days later, Beck announces that the comet Wolf–Beiderman is on course to impact the Earth in roughly one year and could cause humanity's extinction. He reveals that the United States and Russia have been constructing the Messiah in orbit, a spacecraft to transport a team to alter the comet's path with nuclear bombs.

Die Messiah launches a short time later with a crew of five American astronauts and one Russian cosmonaut. They land on the comet's surface and drill the nuclear bombs deep beneath its surface.

Rigging the bombs takes longer than anticipated and the crew are still on the surface when the comet's rotation moves them into the sunlight. One astronaut is blinded and another propelled into space by an explosive release of gas. The remaining crew of six escape the comet and detonate the bombs.

Rather than destroy the comet, the bombs split it in two. Beck announces the mission's failure in a television address, and that both pieces — the larger now named Wolf and the smaller named Beiderman — are both still headed for Earth. Martial law is imposed and a lottery selects 800,000 Americans to join 200,000 pre-selected individuals in underground shelters. Lerner is pre-selected as a trusted national journalist, as are the Beiderman family as gratitude for discovering the comet. Leo's girlfriend Sarah and her family are not, so Leo marries Sarah in a vain attempt to save her family, and Sarah refuses to go to the shelter without them.

A last-ditch effort to deflect the comets with ICBMs fails. Upon arrival at the shelter, Leo eschews his safety and leaves to find Sarah. He reaches her on the freeway and takes her and her baby brother to high ground. Lerner gives up her seat on the evacuation helicopter to her friend Beth and her young daughter, and instead travels to the beach where she reconciles with her estranged father.

The smaller comet, Beiderman, hits the Atlantic ocean, creating a megatsunami that destroys much of the East Coast of the United States and also hits Europe and Africa, resulting in millions of fatalities. Leo, Sarah, and her baby brother survive in the Appalachian Mountains.

The crew of Messiah decide to sacrifice themselves to destroy the larger comet by flying deep inside it and detonating their remaining nuclear bombs. They say goodbye to their loved ones and execute their plan. Wolf is blown into smaller pieces which burn up harmlessly in the Earth's atmosphere.

After the waters from the megatsunami recede, President Beck speaks to a large crowd at the damaged United States Capitol, encouraging them to remember those lost as they begin to rebuild.

    as Captain Spurgeon "Fish" Tanner, a veteran astronaut who becomes the rendezvous pilot of the Messiah as Jenny Lerner, an MSNBC journalist as Leo Beiderman, a teenage astronomer who discovers the Wolf–Beiderman comet as Robin Lerner, the mother of Jenny as Jason Lerner, the estranged father of Jenny as Tom Beck, the President of the United States as Alan Rittenhouse, the Secretary of the Treasury who resigns in light of the Wolf–Beiderman comet threat as Commander Oren Monash, the Mission Commander for the Messiah as Dr. Gus Partenza, the medical officer of the Messiah as Beth Stanley, the co-worker of Jenny as Stuart Caley, Jenny's boss at MSNBC as Andrea "Andy" Baker, the pilot of the Messiah as Don Beiderman, the father of Leo as Ellen Beiderman, the mother of Leo as Sarah Hotchner, the girlfriend of Leo as Mark Simon, the navigator of the Messiah as Eric Vennekor, the co-worker of Jenny as Tim Urbanski, another co-worker of Jenny as Colonel Michail Tulchinsky, a nuclear specialist from Russia and crew member of the Messiah as Mike Perry, Leo's teacher as General Scott as Otis "Mitch" Hefter, a NASA worker as Morten Entriken, advisor to the President as Wendy Mogel, engaged to Mark Simon as Vicky Hotchner, the mother of Sarah

The origins of Deep Impact started in the late 1970s when producers Richard Zanuck and David Brown approached Paramount Studios proposing a remake of the 1951 film When Worlds Collide. [7] Although several screenplay drafts were completed, the producers were not completely happy with any of them and the project remained in "development hell" for many years. In the mid-1990s, they approached director Steven Spielberg, with whom they had made the 1975 blockbuster Kake, to discuss their long-planned project. [7] However, Spielberg had already bought the film rights to the 1993 novel The Hammer of God by Arthur C. Clarke, which dealt with a similar theme of an asteroid on a collision course for Earth and humanity's attempts to prevent its own extinction. Spielberg planned to produce and direct The Hammer of God himself for his then-fledgling DreamWorks studio, but opted to merge the two projects with Zanuck and Brown, and they commissioned a screenplay for what would become Deep Impact. [7] In 1995, the forthcoming film was announced in industry publications as "Screenplay by Bruce Joel Rubin, based on the film When Worlds Collide en The Hammer of God by Arthur C Clarke" [8] though ultimately, following a subsequent redraft by Michael Tolkin, neither source work would be credited in the final film. Spielberg still planned to direct Deep Impact himself, but commitments to his 1997 film Amistad prevented him from doing so in time, particularly as Touchstone Pictures had just announced their own similarly-themed film Armageddon, also to be released in summer 1998. [7] Not wanting to wait, the producers opted to hire Mimi Leder to direct Deep Impact, with Spielberg acting as executive producer. [7] Leder was unaware of the other film being made. “I couldn’t believe it. And the press was trying to pit us against each other. That didn’t feel good. Both films have great value and, fortunately, they both succeeded tremendously." Clarke's novel was used as part of the film's publicity campaign both before and after the film's release [9] [10] [11] [12] and he was disgruntled about not being credited on the film. [13] [14]

Jenny Lerner, the character played by Téa Leoni, was originally intended to work for CNN. CNN rejected this because it would be "inappropriate". MSNBC agreed to be featured in the movie instead, seeing it as a way to gain exposure for the then newly created network. [15]

Director Mimi Leder later explained that she would have liked to travel to other countries to incorporate additional perspectives, but due to a strict filming schedule and a comparatively low budget, the idea was scratched. [16] Visual effects supervisor Scott Farrar felt that coverage of worldwide events would have distracted and detracted from the main characters' stories. [16]

A number of scientists worked as science consultants for the film including astronomers Gene Shoemaker, Carolyn Shoemaker, Josh Colwell and Chris Luchini, former astronaut David Walker, and the former director of the NASA's Lyndon B. Johnson Space Center Gerry Griffin. [17]

The music for the film was composed and conducted by James Horner.

Box office Edit

Deep Impact debuted at the North American box office with $41,000,000 in ticket sales. The movie grossed $140,000,000 in North America and an additional $209,000,000 worldwide for a total gross of $349,000,000. Despite competition in the summer of 1998 from the similar Armageddon, both films were widely successful, with Deep Impact being the higher opener of the two, while Armageddon was the most profitable overall. [2]

Critical reception Edit

The film had a mixed critical reception. Based on 86 reviews collected by Rotten Tomatoes, 45% of critics enjoyed the film, with an average rating of 5.8/10. The website's critical consensus reads, "A tidal wave of melodrama sinks Deep Impact ' s chance at being the memorable disaster flick it aspires to be." [18] Metacritic gave a score of 40 out of 100 based on 20 reviews, indicating "mixed or average reviews". [19]

Elvis Mitchell of Die New York Times said that the film "has a more brooding, thoughtful tone than this genre usually calls for", [20] while Rita Kempley and Michael O'Sullivan of Die Washington Post criticized what they saw as unemotional performances and a lack of tension. [21] [22]

At the 1998 Stinkers Bad Movie Awards, the film was nominated for Worst Supporting Actress for Leoni (lost to Lacey Chabert for Lost in Space) and Worst Screenplay For A Film Grossing More Than $100 Million (Using Hollywood Math) (lost to Godzilla). [23]


Asteroids are much tougher than Hollywood movies make them out to be

Researchers previously determined the strength and physical properties of various types of rocks. However, once a space rock reached the size of an asteroid big enough to cause an extinction event, the calculations got unreliable.

To keep things simple, the JHU researchers stuck to a single asteroid impact scenario. They calculated a theoretical space rock with a diameter of 0.62 miles (one kilometer).

In their simulation, the impactor hit a more massive asteroid that measured 15 miles (25 km) across. The impact velocity of the smaller asteroid was 0.6 miles (5 km) per second.

Other researchers investigated this scenario in the past. They reported that the resulting asteroid impact event utterly annihilated the smaller space rock.

However, the JHU team realized that the earlier studies failed to take into account the sluggish rate at which the cracks form within the asteroids. When El Mir and his colleagues added this data to the scenario, they learned that their simulated asteroid collision led to a two-stage process.

During the first stage, numerous cracks appeared and spread throughout the asteroid. The fissures inflicted considerable damage to the core of the rock.

However, instead of breaking apart, the asteroid continued to hold itself together. The damaged but still-sound core retained enough mass to generate gravity.

In the second stage, the asteroid core tugged on the smaller chunks that broke off during the collision, but remained within its gravitational field. The gravity pulled the pieces back toward the core.


Is Earth Ready for the Next Asteroid Strike?

Asteroids permeate the Solar System, and thousands of these bodies are known to pass close to our own planet. Most of these bodies are small, and the Earth is regularly bombarded by 100 tons of material from space every day, burning up harmlessly in the atmosphere. However, the danger from a larger body is real, with an impact potentially wiping out cities, nations, or causing a worldwide extinction.

For two decades, NASA and other space agencies have been scouring the skies, searching for asteroids and comets which may impact the Earth. Now, the American space agency and FEMA are carrying out simulations to determine how prepared we would be if a large asteroid were to impact our world. Between April 29 and May 3, 2019, a tabletop exercise will be conducted at the sixth annual conference on planetary defense, hosted by the International Academy of Astronautics (IAA).

“These exercises have really helped us in the planetary defense community to understand what our colleagues on the disaster management side need to know. This exercise will help us develop more effective communications with each other and with our governments,” Lindley Johnson, NASA’s Planetary Defense Officer, said.

As part of the exercise, the agencies have created data for a fictional asteroid, designated 2019 PDC (even this designation is not valid for a real asteroid). In this fictional scenario, 2019 PDC was discovered March 26, 2019, and the object is deemed to be a Potentially Hazardous Asteroid (PHA).

Computer simulations predict the most likely date for impact is April 29, 2027 — eight years after discovery. The probability of impact is initially deemed to be fairly low — just one in 50,000. As observations continue, the chances of the asteroid hitting Earth rise — reaching one percent on the first day of the real-world meeting. The exercise runs through scenarios of how humans might respond to such a threat, were such an asteroid found heading our way.

This Sounds Like Rock and/or Roll…

Near-Earth Objects (NEO’s) are bodies passing within both 195 million kilometers (121 million miles) of the Sun and 50 million kilometers (30 million miles) of Earth. Fortunately, most of these objects are small enough (less than 20 meters, or 66 feet in diameter) that they would burn up in the atmosphere, were they to encounter Earth. Astronomers currently know of more than 18,000 NEO’s, and are still discovering roughly 40 of these objects every week. Although no such body is currently known to be on a collision course with Earth, a few remain a concern to observers.

“Noteworthy among these is 99942 Apophis, one of the most important near-Earth asteroids ever discovered. This asteroid will pass by Earth on Friday, April 13, 2029, closer than where our weather satellites orbit. It will be bright enough to be visible with an unaided eye for several hours around the closest approach. Apophis, named after the ancient Egyptian spirit of evil, darkness and destruction, is estimated to be around 340 meters in diameter and if it were to hit, it would cause major damage to our planet and likely to our civilization as well,” the IAA reports.

Because asteroids are so small, and usually dark, they are difficult to spot until the object is just a few hours or days away from crossing the orbit of the Earth. Quite often, media outlets drive flurries of reports on these near-misses, which occur on a fairly regular basis.

Sorry… False Alarm

On March 11, 1998, a message was sent to astronomers worldwide who search for asteroids, announcing that a body discovered the previous year, 1997 XF11, might strike the Earth in 2028. That message was soon picked up by the media and the general public, feeding popular stories of a one-kilometer (half-mile) wide object hitting the planet in just a few years. Subsequent observations showed the Earth is in no danger from XF 11, but that idea still remains in the minds of many people.

“To this day we still get queries on the chances of XF11 impacting in 2028. There is simply no chance of XF11 impacting our planet that year, or for the next 200 years,” said Paul Chodas, director of NASA’s Center for Near-Earth Object Studies (CNEOS) at Jet Propulsion Laboratory.

On March 15, 2019, a large asteroid exploded in the air above the Krasnoyarsk region of Russia. As the object heated, it divided into at least two pieces before exploding with a force estimated by some observers to be around 185 times greater than the atomic bomb that destroyed the city of Hiroshima at the end of the Second World War. At least one piece of that body crashed through a meter of ice, landing in the Podkamennaya Tunguska river.

A Game of Interplanetary Dodgeball

In 1998, Congress directed the nation’s space agencies to find and track 90 percent of near-Earth asteroids larger than one kilometer (3,280 feet in diameter) within 10 years. With that goal accomplished, asteroid hunters now have plans to discover and track 90 percent of all such bodies 140 meters (450 feet) across by the year 2020. Asteroids of this size would not cause a worldwide catastrophe were they to strike the planet, but an impact close to a metropolitan area could still result in significant damage and loss of life.

Russia seems to attract more than its fair share of asteroids and cometary impacts, due to the massive size of that nation. In 1908, a large asteroid or comet exploded in the atmosphere near Stony Tunguska River in Yeniseysk Governorate (now Krasnoyarsk Krai), Russia, sending trees down over a wide area, in an event known as the Tunguska event. In February 2013, the country was the victim of another visitor from space, as an asteroid exploded above Chelyabinsk, injuring more than 1,100 people.

As astronomers discover more NEO’s, we gain more knowledge about which bodies pose a risk to our planet. However, the search will not be complete for the foreseeable future, and it only takes a single body to wreak havoc with human populations.

I Love You, You Love… BOOM! Sorry, Barney!

Should we find a dangerous object headed our way, the more time we have, the better it will be for those charged with heading off an impact. Despite what is seen in many science fiction stories, blowing up an asteroid would only turn a bullet into a shotgun blast, distributing the damage over a wider area. Given enough time, the safest course of action would be to alter the orbit of the body, causing it to miss the Earth.

“I don’t want to be the embarrassment of the galaxy to have had the power to deflect an asteroid, and then not and end up going extinct. We’d be the laughingstock of the aliens of the cosmos if that were the case.” — Neil deGrasse Tyson

Roughly 66 million years ago, an asteroid the size of Mount Everest impacted the Earth, setting off a chain of environmental consequences, ending the age of the dinosaurs.

Unlike those unfortunate animals, humans have the ability to see an asteroid headed our way, if we put a determined effort into searching for them. But, we are just starting our search for these bodies, and it remains a daunting challenge to find the next doomsday rock before it finds us.


Kyk die video: How Asteroids Really Killed The Dinosaurs - Part 2. Last Day Of The Dinosaurs (Desember 2022).