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83-450: Deep Impact may refer to: Deep Impact (film) , a 1998 disaster film Deep Impact (horse) , a Japanese racehorse Deep Impact (spacecraft) , a NASA spacecraft launched in 2005 "Deep Impact" ( Dream Corp, LLC episode) "Deep Impact", a song by Dragon Ash DeepImpact, a learned sparse retrieval algorithm See also [ edit ] Impact event Topics referred to by

166-513: A misnomer , as their energy comes from the nucleus of the atom, just as it does with fusion weapons. In fission weapons, a mass of fissile material ( enriched uranium or plutonium ) is forced into supercriticality —allowing an exponential growth of nuclear chain reactions —either by shooting one piece of sub-critical material into another (the "gun" method) or by compression of a sub-critical sphere or cylinder of fissile material using chemically fueled explosive lenses . The latter approach,

249-651: A policy of deliberate ambiguity , it does not acknowledge having them. Germany , Italy , Turkey , Belgium , the Netherlands , and Belarus are nuclear weapons sharing states. South Africa is the only country to have independently developed and then renounced and dismantled its nuclear weapons. The Treaty on the Non-Proliferation of Nuclear Weapons aims to reduce the spread of nuclear weapons, but there are different views of its effectiveness. There are two basic types of nuclear weapons: those that derive

332-552: A car crash while racing to raise the alarm. A year later, MSNBC journalist Jenny Lerner investigates Secretary of the Treasury Alan Rittenhouse over his connection with "Ellie", whom she assumes to be a mistress; she is confused when she finds him and his family loading a boat with large amounts of food and other survival gear. She is apprehended by the FBI and taken to meet President Tom Beck, who persuades her not to share

415-717: A colleague and her young daughter, instead traveling to a beach where she reconciles with her estranged father. The Biederman fragment hits the Atlantic Ocean near Cape Hatteras , North Carolina , creating a megatsunami that destroys much of the East Coast of the United States , reaching the Ohio River Valley , and also hitting Europe and Africa . Millions are killed, including Sarah’s parents, Lerner, and her father. Leo, Sarah, and her baby brother survive after making it to

498-678: A conference—called for in the manifesto—in Pugwash, Nova Scotia , Eaton's birthplace. This conference was to be the first of the Pugwash Conferences on Science and World Affairs , held in July 1957. By the 1960s, steps were taken to limit both the proliferation of nuclear weapons to other countries and the environmental effects of nuclear testing . The Partial Nuclear Test Ban Treaty (1963) restricted all nuclear testing to underground nuclear testing , to prevent contamination from nuclear fallout, whereas

581-458: A faster and less vulnerable attack, the development of long-range intercontinental ballistic missiles (ICBMs) and submarine-launched ballistic missiles (SLBMs) has given some nations the ability to plausibly deliver missiles anywhere on the globe with a high likelihood of success. More advanced systems, such as multiple independently targetable reentry vehicles (MIRVs), can launch multiple warheads at different targets from one missile, reducing

664-594: A few nations possess such weapons or are suspected of seeking them. The only countries known to have detonated nuclear weapons—and acknowledge possessing them—are (chronologically by date of first test) the United States , the Soviet Union (succeeded as a nuclear power by Russia ), the United Kingdom , France , China , India , Pakistan , and North Korea . Israel is believed to possess nuclear weapons, though, in

747-482: A fission bomb to initiate them. Such a device might provide a simpler path to thermonuclear weapons than one that required the development of fission weapons first, and pure fusion weapons would create significantly less nuclear fallout than other thermonuclear weapons because they would not disperse fission products. In 1998, the United States Department of Energy divulged that the United States had, "...made

830-421: A fusion weapon as of January 2016 , though this claim is disputed. Thermonuclear weapons are considered much more difficult to successfully design and execute than primitive fission weapons. Almost all of the nuclear weapons deployed today use the thermonuclear design because it results in an explosion hundreds of times stronger than that of a fission bomb of similar weight. Thermonuclear bombs work by using

913-599: A lack of tension. 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 ). The film was also nominated for Best Science Fiction Film at the Saturn Awards but lost to both Dark City and another asteroid film, Armageddon . Nuclear weapon A nuclear weapon

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996-472: A nation's economic electronics-based infrastructure. Because the effect is most effectively produced by high altitude nuclear detonations (by military weapons delivered by air, though ground bursts also produce EMP effects over a localized area), it can produce damage to electronics over a wide, even continental, geographical area. Research has been done into the possibility of pure fusion bombs : nuclear weapons that consist of fusion reactions without requiring

1079-532: A new nuclear strategy, one that is distinct from that which gave relative stability during the Cold War. Since 1996, the United States has had a policy of allowing the targeting of its nuclear weapons at terrorists armed with weapons of mass destruction . Robert Gallucci argues that although traditional deterrence is not an effective approach toward terrorist groups bent on causing a nuclear catastrophe, Gallucci believes that "the United States should instead consider

1162-425: A nuclear war between two nations would result in mutual annihilation. From this point of view, the significance of nuclear weapons is to deter war because any nuclear war would escalate out of mutual distrust and fear, resulting in mutually assured destruction . This threat of national, if not global, destruction has been a strong motivation for anti-nuclear weapons activism. Critics from the peace movement and within

1245-411: A nuclear weapon from another country by threatening nuclear retaliation is known as the strategy of nuclear deterrence . The goal in deterrence is to always maintain a second strike capability (the ability of a country to respond to a nuclear attack with one of its own) and potentially to strive for first strike status (the ability to destroy an enemy's nuclear forces before they could retaliate). During

1328-465: A nuclear weapon is a gravity bomb dropped from aircraft ; this was the method used by the United States against Japan in 1945. This method places few restrictions on the size of the weapon. It does, however, limit attack range, response time to an impending attack, and the number of weapons that a country can field at the same time. With miniaturization, nuclear bombs can be delivered by both strategic bombers and tactical fighter-bombers . This method

1411-409: A nuclear weapon to its target is an important factor affecting both nuclear weapon design and nuclear strategy . The design, development, and maintenance of delivery systems are among the most expensive parts of a nuclear weapons program; they account, for example, for 57% of the financial resources spent by the United States on nuclear weapons projects since 1940. The simplest method for delivering

1494-433: A nuclear weapon with suitable materials (such as cobalt or gold ) creates a weapon known as a salted bomb . This device can produce exceptionally large quantities of long-lived radioactive contamination . It has been conjectured that such a device could serve as a "doomsday weapon" because such a large quantity of radioactivities with half-lives of decades, lifted into the stratosphere where winds would distribute it around

1577-421: A policy of expanded deterrence, which focuses not solely on the would-be nuclear terrorists but on those states that may deliberately transfer or inadvertently leak nuclear weapons and materials to them. By threatening retaliation against those states, the United States may be able to deter that which it cannot physically prevent.". Graham Allison makes a similar case, arguing that the key to expanded deterrence

1660-447: A significant portion of their energy from fission reactions used to "trigger" fusion reactions, and fusion reactions can themselves trigger additional fission reactions. Only six countries—the United States , Russia , the United Kingdom , China , France , and India —have conducted thermonuclear weapon tests. Whether India has detonated a "true" multi-staged thermonuclear weapon is controversial. North Korea claims to have tested

1743-477: 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 . In 1995, the forthcoming film was announced in industry publications as "Screenplay by Bruce Joel Rubin, based on

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1826-438: A strict filming schedule and a comparatively low budget, the idea was scratched. Visual effects supervisor Scott Farrar felt that coverage of worldwide events would have distracted and detracted from the main characters' stories. 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

1909-547: A substantial investment" in the past to develop pure fusion weapons, but that, "The U.S. does not have and is not developing a pure fusion weapon", and that, "No credible design for a pure fusion weapon resulted from the DOE investment". Nuclear isomers provide a possible pathway to fissionless fusion bombs. These are naturally occurring isotopes ( Hf being a prominent example) which exist in an elevated energy state. Mechanisms to release this energy as bursts of gamma radiation (as in

1992-526: A total gross of $ 349 million. 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. Deep Impact had a mixed critical reception. Based on 98 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

2075-420: Is a thermonuclear weapon that yields a relatively small explosion but a relatively large amount of neutron radiation . Such a weapon could, according to tacticians, be used to cause massive biological casualties while leaving inanimate infrastructure mostly intact and creating minimal fallout. Because high energy neutrons are capable of penetrating dense matter, such as tank armor, neutron warheads were procured in

2158-718: Is an explosive device that derives its destructive force from nuclear reactions , either fission (fission bomb) or a combination of fission and fusion reactions ( thermonuclear bomb ), producing a nuclear explosion . Both bomb types release large quantities of energy from relatively small amounts of matter . The first test of a fission ("atomic") bomb released an amount of energy approximately equal to 20,000 tons of TNT (84  TJ ). The first thermonuclear ("hydrogen") bomb test released energy approximately equal to 10 million tons of TNT (42 PJ). Nuclear bombs have had yields between 10 tons TNT (the W54 ) and 50 megatons for

2241-451: Is analogous to identifying a criminal by fingerprints. "The goal would be twofold: first, to deter leaders of nuclear states from selling weapons to terrorists by holding them accountable for any use of their weapons; second, to give leaders every incentive to tightly secure their nuclear weapons and materials." According to the Pentagon's June 2019 " Doctrine for Joint Nuclear Operations " of

2324-403: Is coming up with ways of tracing nuclear material to the country that forged the fissile material. "After a nuclear bomb detonates, nuclear forensics cops would collect debris samples and send them to a laboratory for radiological analysis. By identifying unique attributes of the fissile material, including its impurities and contaminants, one could trace the path back to its origin." The process

2407-552: Is different from Wikidata All article disambiguation pages All disambiguation pages Deep Impact (film) Deep Impact was released in the same summer as the similarly themed Armageddon , which fared better at the box office, while astronomers described Deep Impact as being more accurate. Both films were similarly received by critics, with Armageddon scoring 43% and Deep Impact scoring 45% on Rotten Tomatoes . Deep Impact grossed over $ 349.5 million worldwide on an $ 80 million production budget , becoming

2490-481: Is for the purpose of achieving different yields for different situations , and in manipulating design elements to attempt to minimize weapon size, radiation hardness or requirements for special materials, especially fissile fuel or tritium. Some nuclear weapons are designed for special purposes; most of these are for non-strategic (decisively war-winning) purposes and are referred to as tactical nuclear weapons . The neutron bomb purportedly conceived by Sam Cohen

2573-498: Is no evidence that it is feasible beyond the military domain. However, the U.S. Air Force funded studies of the physics of antimatter in the Cold War , and began considering its possible use in weapons, not just as a trigger, but as the explosive itself. A fourth generation nuclear weapon design is related to, and relies upon, the same principle as antimatter-catalyzed nuclear pulse propulsion . Most variation in nuclear weapon design

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2656-409: Is not a fusion bomb. In the boosted bomb, the neutrons produced by the fusion reactions serve primarily to increase the efficiency of the fission bomb. There are two types of boosted fission bomb: internally boosted, in which a deuterium-tritium mixture is injected into the bomb core, and externally boosted, in which concentric shells of lithium-deuteride and depleted uranium are layered on the outside of

2739-490: Is not clear that this has ever been implemented, and their plausible use in nuclear weapons is a matter of dispute. The other basic type of nuclear weapon produces a large proportion of its energy in nuclear fusion reactions. Such fusion weapons are generally referred to as thermonuclear weapons or more colloquially as hydrogen bombs (abbreviated as H-bombs ), as they rely on fusion reactions between isotopes of hydrogen ( deuterium and tritium ). All such weapons derive

2822-451: Is the primary means of nuclear weapons delivery; the majority of U.S. nuclear warheads, for example, are free-fall gravity bombs, namely the B61 , which is being improved upon to this day. Preferable from a strategic point of view is a nuclear weapon mounted on a missile , which can use a ballistic trajectory to deliver the warhead over the horizon. Although even short-range missiles allow for

2905-530: The Messiah in orbit, a spacecraft to transport a team to alter the comet's path with nuclear bombs . The Messiah launches a short time later with a crew of five American astronauts and one Russian cosmonaut. They land on the comet's outer-most layer and drill the nuclear bombs deep beneath its surface, but the comet shifts into the sunlight. Consequently, one astronaut is blinded and another propelled into space by an explosive release of gas. The remaining crew escape

2988-688: The Starfish Prime high-altitude nuclear test in 1962, an unexpected effect was produced which is called a nuclear electromagnetic pulse . This is an intense flash of electromagnetic energy produced by a rain of high-energy electrons which in turn are produced by a nuclear bomb's gamma rays. This flash of energy can permanently destroy or disrupt electronic equipment if insufficiently shielded. It has been proposed to use this effect to disable an enemy's military and civilian infrastructure as an adjunct to other nuclear or conventional military operations. By itself it could as well be useful to terrorists for crippling

3071-548: The Tsar Bomba (see TNT equivalent ). A thermonuclear weapon weighing as little as 600 pounds (270 kg) can release energy equal to more than 1.2 megatonnes of TNT (5.0 PJ). A nuclear device no larger than a conventional bomb can devastate an entire city by blast, fire, and radiation . Since they are weapons of mass destruction , the proliferation of nuclear weapons is a focus of international relations policy. Nuclear weapons have been deployed twice in war , both by

3154-663: The Tsar Bomba of the USSR, which released an energy equivalent of over 50 megatons of TNT (210 PJ), was a three-stage weapon. Most thermonuclear weapons are considerably smaller than this, due to practical constraints from missile warhead space and weight requirements. In the early 1950s the Livermore Laboratory in the United States had plans for the testing of two massive bombs, Gnomon and Sundial , 1 gigaton of TNT and 10 gigatons of TNT respectively. Fusion reactions do not create fission products, and thus contribute far less to

3237-424: The hafnium controversy ) have been proposed as possible triggers for conventional thermonuclear reactions. Antimatter , which consists of particles resembling ordinary matter particles in most of their properties but having opposite electric charge , has been considered as a trigger mechanism for nuclear weapons. A major obstacle is the difficulty of producing antimatter in large enough quantities, and there

3320-599: The head of government or head of state . Despite controls and regulations governing nuclear weapons, there is an inherent danger of "accidents, mistakes, false alarms, blackmail, theft, and sabotage". In the late 1940s, lack of mutual trust prevented the United States and the Soviet Union from making progress on arms control agreements. The Russell–Einstein Manifesto was issued in London on July 9, 1955, by Bertrand Russell in

3403-456: The sixth highest-grossing film of 1998 . It was the final film by cinematographer Dietrich Lohmann , who died before the film's release. In May 1998, at a star party in Virginia, teenage amateur astronomer Leo Biederman observes an unidentified 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

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3486-436: The tropopause into the stratosphere , where the calm non-turbulent winds permit the debris to travel great distances from the burst, eventually settling and unpredictably contaminating areas far removed from the target of the explosion. There are other types of nuclear weapons as well. For example, a boosted fission weapon is a fission bomb that increases its explosive yield through a small number of fusion reactions, but it

3569-537: The "implosion" method, is more sophisticated and more efficient (smaller, less massive, and requiring less of the expensive fissile fuel) than the former. A major challenge in all nuclear weapon designs is to ensure that a significant fraction of the fuel is consumed before the weapon destroys itself. The amount of energy released by fission bombs can range from the equivalent of just under a ton to upwards of 500,000 tons (500 kilotons ) of TNT (4.2 to 2.1 × 10  GJ). All fission reactions generate fission products ,

3652-578: The 1980s (though not deployed in Europe) for use as tactical payloads for US Army artillery shells (200 mm W79 and 155 mm W82 ) and short range missile forces. Soviet authorities announced similar intentions for neutron warhead deployment in Europe; indeed, they claimed to have originally invented the neutron bomb, but their deployment on USSR tactical nuclear forces is unverifiable. A type of nuclear explosive most suitable for use by ground special forces

3735-425: The Cold War, policy and military theorists considered the sorts of policies that might prevent a nuclear attack, and they developed game theory models that could lead to stable deterrence conditions. Different forms of nuclear weapons delivery (see above) allow for different types of nuclear strategies. The goals of any strategy are generally to make it difficult for an enemy to launch a pre-emptive strike against

3818-484: The Earth's atmosphere, averting further catastrophe. After the waters recede, President Beck speaks to a large crowd at an under-construction replacement United States Capitol . The origins of Deep Impact started in the late 1970s when producers Richard D. Zanuck and David Brown approached Paramount Pictures proposing a remake of the 1951 film When Worlds Collide . Although several screenplay drafts were completed,

3901-488: The Joint Chiefs of Staffs website Publication, "Integration of nuclear weapons employment with conventional and special operations forces is essential to the success of any mission or operation." Because they are weapons of mass destruction, the proliferation and possible use of nuclear weapons are important issues in international relations and diplomacy. In most countries, the use of nuclear force can only be authorized by

3984-512: The North American box office with $ 41 million in ticket sales. It managed to cross over Twister , scoring the tenth-highest opening weekend of all time. For a decade, the film held the record for having the biggest opening weekend for a female-directed film until it was taken by Twilight in 2008. The film grossed $ 140 million in North America and an additional $ 209 million worldwide for

4067-497: The Nuclear Age (1961) that mere possession of a nuclear arsenal was enough to ensure deterrence, and thus concluded that the spread of nuclear weapons could increase international stability . Some prominent neo-realist scholars, such as Kenneth Waltz and John Mearsheimer , have argued, along the lines of Gallois, that some forms of nuclear proliferation would decrease the likelihood of total war , especially in troubled regions of

4150-651: The USAAF detonated a plutonium implosion-type fission bomb nicknamed " Fat Man " over the Japanese city of Nagasaki . These bombings caused injuries that resulted in the deaths of approximately 200,000 civilians and military personnel . The ethics of these bombings and their role in Japan's surrender are to this day, still subjects of debate . Since the atomic bombings of Hiroshima and Nagasaki , nuclear weapons have been detonated over 2,000 times for testing and demonstration. Only

4233-753: The USAF AIR-2 Genie , the AIM-26 Falcon and US Army Nike Hercules . Missile interceptors such as the Sprint and the Spartan also used small nuclear warheads (optimized to produce neutron or X-ray flux) but were for use against enemy strategic warheads. Other small, or tactical, nuclear weapons were deployed by naval forces for use primarily as antisubmarine weapons. These included nuclear depth bombs or nuclear armed torpedoes. Nuclear mines for use on land or at sea are also possibilities. The system used to deliver

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4316-515: The United States against the Japanese cities of Hiroshima and Nagasaki in 1945 during World War II . Nuclear weapons have only twice been used in warfare, both times by the United States against Japan at the end of World War II . On August 6, 1945, the United States Army Air Forces (USAAF) detonated a uranium gun-type fission bomb nicknamed " Little Boy " over the Japanese city of Hiroshima ; three days later, on August 9,

4399-512: The United States. Small, two-man portable tactical weapons (somewhat misleadingly referred to as suitcase bombs ), such as the Special Atomic Demolition Munition , have been developed, although the difficulty of combining sufficient yield with portability limits their military utility. Nuclear warfare strategy is a set of policies that deal with preventing or fighting a nuclear war. The policy of trying to prevent an attack by

4482-485: The chance of a successful missile defense . Today, missiles are most common among systems designed for delivery of nuclear weapons. Making a warhead small enough to fit onto a missile, though, can be difficult. Tactical weapons have involved the most variety of delivery types, including not only gravity bombs and missiles but also artillery shells, land mines , and nuclear depth charges and torpedoes for anti-submarine warfare . An atomic mortar has been tested by

4565-478: The comet and detonate the bombs. However, rather than deflect 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 Biederman—are still headed for Earth. Wolf is on a collision course with western Canada , and its impact is expected to fill the atmosphere with dust, blocking all sunlight for two years and creating an impact winter that will kill all life on

4648-435: The creation of nuclear fallout than fission reactions, but because all thermonuclear weapons contain at least one fission stage, and many high-yield thermonuclear devices have a final fission stage, thermonuclear weapons can generate at least as much nuclear fallout as fission-only weapons. Furthermore, high yield thermonuclear explosions (most dangerously ground bursts) have the force to lift radioactive debris upwards past

4731-450: The decision process. The prospect of mutually assured destruction might not deter an enemy who expects to die in the confrontation. Further, if the initial act is from a stateless terrorist instead of a sovereign nation, there might not be a nation or specific target to retaliate against. It has been argued, especially after the September 11, 2001, attacks , that this complication calls for

4814-463: The energy of a fission bomb to compress and heat fusion fuel. In the Teller-Ulam design , which accounts for all multi-megaton yield hydrogen bombs, this is accomplished by placing a fission bomb and fusion fuel ( tritium , deuterium , or lithium deuteride ) in proximity within a special, radiation-reflecting container. When the fission bomb is detonated, gamma rays and X-rays emitted first compress

4897-503: The film When Worlds Collide and The Hammer of God by Arthur C Clarke" 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. Not wanting to wait,

4980-501: The film's release and he was disgruntled about not being credited on the film. 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. Director Mimi Leder later explained that she would have liked to travel to other countries to incorporate additional perspectives, but due to

5063-451: The fission bomb core. The external method of boosting enabled the USSR to field the first partially thermonuclear weapons, but it is now obsolete because it demands a spherical bomb geometry, which was adequate during the 1950s arms race when bomber aircraft were the only available delivery vehicles. The detonation of any nuclear weapon is accompanied by a blast of neutron radiation . Surrounding

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5146-478: The foothills of the Appalachian Mountains . The crew of Messiah , now dangerously low on both life-support and remaining propellant fuel, decide to sacrifice themselves to destroy the larger Wolf fragment by flying deep inside it and detonating their remaining nuclear bombs. They say goodbye to their loved ones by video call and execute their plan. Wolf is blown into smaller pieces which burn up harmlessly in

5229-474: The former director of the NASA 's Lyndon B. Johnson Space Center Gerry Griffin . The music for the film was composed and conducted by James Horner . Deep Impact was released by Paramount Pictures in the United States and DreamWorks Pictures internationally on May 8, 1998. Deep Impact was released on VHS on October 20, 1998, LaserDisc on November 3 and DVD on December 15. Deep Impact debuted at

5312-420: The fusion fuel, then heat it to thermonuclear temperatures. The ensuing fusion reaction creates enormous numbers of high-speed neutrons , which can then induce fission in materials not normally prone to it, such as depleted uranium . Each of these components is known as a "stage", with the fission bomb as the "primary" and the fusion capsule as the "secondary". In large, megaton-range hydrogen bombs, about half of

5395-520: The globe, would make all life on the planet extinct. In connection with the Strategic Defense Initiative , research into the nuclear pumped laser was conducted under the DOD program Project Excalibur but this did not result in a working weapon. The concept involves the tapping of the energy of an exploding nuclear bomb to power a single-shot laser that is directed at a distant target. During

5478-491: The lottery, commits ritual suicide. Leo marries Sarah in a vain attempt to save her family; while this saves Sarah, her family are still not selected, and she refuses to go 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 higher ground while her parents remain. Lerner gives up her seat on an evacuation helicopter to

5561-496: The majority of their energy from nuclear fission reactions alone, and those that use fission reactions to begin nuclear fusion reactions that produce a large amount of the total energy output. All existing nuclear weapons derive some of their explosive energy from nuclear fission reactions. Weapons whose explosive output is exclusively from fission reactions are commonly referred to as atomic bombs or atom bombs (abbreviated as A-bombs ). This has long been noted as something of

5644-509: The memorable disaster flick it aspires to be." Metacritic gave a score of 40 out of 100 based on 20 reviews, indicating "mixed or average reviews". Audiences polled by CinemaScore gave the film an average grade of "B" on an A+ to F scale. Elvis Mitchell of The New York Times said that the film "has a more brooding, thoughtful tone than this genre usually calls for", while Rita Kempley and Michael O'Sullivan of The Washington Post criticized what they saw as unemotional performances and

5727-407: The midst of the Cold War. It highlighted the dangers posed by nuclear weapons and called for world leaders to seek peaceful resolutions to international conflict. The signatories included eleven pre-eminent intellectuals and scientists, including Albert Einstein , who signed it just days before his death on April 18, 1955. A few days after the release, philanthropist Cyrus S. Eaton offered to sponsor

5810-536: The military establishment have questioned the usefulness of such weapons in the current military climate. According to an advisory opinion issued by the International Court of Justice in 1996, the use of (or threat of use of) such weapons would generally be contrary to the rules of international law applicable in armed conflict, but the court did not reach an opinion as to whether or not the threat or use would be lawful in specific extreme circumstances such as if

5893-408: The missiles before they land or implementing civil defense measures using early-warning systems to evacuate citizens to safe areas before an attack. Weapons designed to threaten large populations or to deter attacks are known as strategic weapons . Nuclear weapons for use on a battlefield in military situations are called tactical weapons . Critics of nuclear war strategy often suggest that

5976-517: The planet's surface. Martial law is imposed and a lottery selects 800,000 Americans to join 200,000 pre-selected individuals in underground shelters in Missouri 's limestone bluffs. Lerner is pre-selected, as are the Biederman family as gratitude for discovering the comet, though Leo's girlfriend Sarah and her family are not selected. Lerner's mother, upon learning most senior citizens are ineligible for

6059-427: The producers opted to hire Mimi Leder to direct Deep Impact , with Spielberg acting as executive producer. 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

6142-413: 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 Jaws , to discuss their long-planned project. However, Spielberg had already bought the film rights to the 1993 novel The Hammer of God by Arthur C. Clarke , which dealt with

6225-428: The remains of the split atomic nuclei. Many fission products are either highly radioactive (but short-lived) or moderately radioactive (but long-lived), and as such, they are a serious form of radioactive contamination . Fission products are the principal radioactive component of nuclear fallout . Another source of radioactivity is the burst of free neutrons produced by the weapon. When they collide with other nuclei in

6308-419: The same term [REDACTED] This disambiguation page lists articles associated with the title Deep Impact . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Deep_Impact&oldid=1174641797 " Category : Disambiguation pages Hidden categories: Short description

6391-421: The story in return for a prominent role in the press conference he will arrange. She subsequently discovers that "Ellie" is actually an acronym—E.L.E.—which stands for " extinction-level event ". Two days later, Beck announces that the comet Wolf–Biederman 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

6474-402: The surrounding material, the neutrons transmute those nuclei into other isotopes, altering their stability and making them radioactive. The most commonly used fissile materials for nuclear weapons applications have been uranium-235 and plutonium-239 . Less commonly used has been uranium-233 . Neptunium-237 and some isotopes of americium may be usable for nuclear explosives as well, but it

6557-498: The survival of the state were at stake. Another deterrence position is that nuclear proliferation can be desirable. In this case, it is argued that, unlike conventional weapons, nuclear weapons deter all-out war between states, and they succeeded in doing this during the Cold War between the U.S. and the Soviet Union . In the late 1950s and early 1960s, Gen. Pierre Marie Gallois of France, an adviser to Charles de Gaulle , argued in books like The Balance of Terror: Strategy for

6640-446: The weapon system and difficult to defend against the delivery of the weapon during a potential conflict. This can mean keeping weapon locations hidden, such as deploying them on submarines or land mobile transporter erector launchers whose locations are difficult to track, or it can mean protecting weapons by burying them in hardened missile silo bunkers. Other components of nuclear strategies included using missile defenses to destroy

6723-631: The world where there exists a single nuclear-weapon state. Aside from the public opinion that opposes proliferation in any form, there are two schools of thought on the matter: those, like Mearsheimer, who favored selective proliferation, and Waltz, who was somewhat more non- interventionist . Interest in proliferation and the stability-instability paradox that it generates continues to this day, with ongoing debate about indigenous Japanese and South Korean nuclear deterrent against North Korea . The threat of potentially suicidal terrorists possessing nuclear weapons (a form of nuclear terrorism ) complicates

6806-624: The yield comes from the final fissioning of depleted uranium. Virtually all thermonuclear weapons deployed today use the "two-stage" design described to the right, but it is possible to add additional fusion stages—each stage igniting a larger amount of fusion fuel in the next stage. This technique can be used to construct thermonuclear weapons of arbitrarily large yield. This is in contrast to fission bombs, which are limited in their explosive power due to criticality danger (premature nuclear chain reaction caused by too-large amounts of pre-assembled fissile fuel). The largest nuclear weapon ever detonated,

6889-744: Was the Special Atomic Demolition Munition , or SADM, sometimes popularly known as a suitcase nuke . This is a nuclear bomb that is man-portable, or at least truck-portable, and though of a relatively small yield (one or two kilotons) is sufficient to destroy important tactical targets such as bridges, dams, tunnels, important military or commercial installations, etc. either behind enemy lines or pre-emptively on friendly territory soon to be overtaken by invading enemy forces. These weapons require plutonium fuel and are particularly "dirty". They also demand especially stringent security precautions in their storage and deployment. Small "tactical" nuclear weapons were deployed for use as antiaircraft weapons. Examples include

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