在弗吉尼亚里奇蒙天文实验室里,14岁的里奥.贝德曼无意中发现了一颗不知名的彗星，后来经过科学家证实这竟是一颗能给予地球毁灭性打击的彗星。这颗彗星重约500兆吨，面积相当于纽约市大小。目前它正受太阳的引力而围绕太阳运行，如果按照它所运行的轨道，大约一年后便会与地球相撞。为了拯救地球，政府决定派遣由前宇航员坦纳船长率领的小组驾驶由美、俄联合制造的飞船“弥塞亚”号登陆彗星，试图用核装置引爆彗星或使彗星偏离原来的轨道以阻止这颗灾难之星。然而由于对彗星结构分析的不够，爆炸使彗星分成大小两块仍继续飞向地球，“弥塞亚”号则在行动失败后与地球失去了联系。随着彗星与地球的距离越来越近，人类已经无法阻止其前进，地球虽然不会因为撞击而消失，但撞击所产生的海啸与尘埃将会给地球所有的生命以致命的打击。为了能够使人类生存下去，政府不得不实行了最后的“方舟”计划，即建立一处秘密庇护所，里面存有种子、植物、动物和少数人类的精英以便在两年后尘埃落定再出来完成自己的重任。撞击的日子终于到来了，第一块小彗星以超过光的速度撞进了大西洋，倾刻之间纽约、波士顿、费城等地被海啸吞没。幸运的是，“弥赛亚”号几经波折又与地球取得了联系，宇航员们毅然启动核装置，义无返顾地冲向随后而来的大彗星块……苍穹划过一片壮丽的流星雨，人类终于得救了。AstronomyLaboratoryinRichmond,Virginia,the14-year-oldRio.inadvertentlydiscoveredanunknowncomet,afterscientistsconfirmedthatthiswasadevastatingblowtotheEarthcanbegiventothecomet.Thecomet,weighingabout500trilliontons,coveringanareaequivalenttothesizeofNewYorkCity.Atpresent,itisbythesun'sgravityandrunningaroundthesun,accordingtoitsorbitaroundtheEarthwillbeoneyearafterthecollision.Inordertosaveourplanet,theGovernment'sdecisiontosendastronautsfromtheformercaptainoftheteamheadedbyTannerdrivingfromtheUnitedStates,Russiaspacecraftmanufacture"Messiah,"acometlanding,triedtodetonateanucleardeviceorcometsbeyondtheorbitofthecometinordertopreventthisStarofstarsdisaster.However,duetostructuralanalysisofthecomet'snotenough,theexplosionsothatthesizeoftwopiecesofthecometintotheEarthwillcontinuetofly,"Messiah"initsoperationsafterthefailureoflostcontactwithEarth.AsthedistancebetweenthecometandtheEarthgettingcloserandclosertomankindhasbeenunabletopreventitfromadvancing,theEarthwillnotdisappearbecauseoftheimpact,buttheimpactofthetsunamigeneratedbytheearthandthedustwillbethelivesofallthefatalblow.Inordertoenablemankindtosurvive,wehavecarriedoutthefinal"Ark"program,namelytheestablishmentofasecretsanctuary,whichhaveseeds,plants,animalsandasmallnumberofhumanbeingstotheeliteagainaftertwoyearsoutofthedusthassettledcompleteitstask.Theimpactofthedayhasfinallyarrived,thefirstsmallpieceofthecometoverthespeedoflightcrashedintotheAtlanticOcean,betweenthedumpingengravedNewYork,Boston,Philadelphiaandotherplacesbythetsunamiengulfed.Fortunately,the"Messiah"afteritstwistsandturnsandmadecontactwiththeEarth,theastronautsdecidedtostartanucleardevice,thentocomeintothegreatcometacrosstheskypiecesof......amagnificentmeteorshower,mankindhasfinallysavedddd