Small Asteroid  Society Collapse

Small impactor cause mass death, ecological catastrophe, and has geopolitical impacts

Even though smaller, more frequent impactors do not create large tsunamis or long preserved impact craters, they are far from harmless. On June 30, 1908 a near-Earth object, some 50 to 70 meters in diameter, exploded 8 km above the Stony Tunguska River, in Siberia. Whether it was an asteroid or comet is still in dispute, but the resulting air blast devastated an area of some 2150 square kilometers. In the hot central epicenter the forest flashed into a huge ascending column of flame that was visible for several hundred kilometers. Fires burned for weeks destroying 1 000 square kilometers of forest. Ash and powdered fragments of tundra were drawn skywards by the fiery vortex and carried around the world by the global air circulation (Gallant n.d.). The blast felled trees outwards in a radial pattern over an area half the size of Rhode Island. The mass of the object involved was probably about 100 000 tons and the explosion’s force some 40 megatons of TNT, that is 2000 times the energy of the Hiroshima atomic bomb. St. Petersburg seismograph station, 4000 kilometers to the west recorded tremors associated with the blast. Fortunately, the Tunguska region was a very sparsely inhabited. Nevertheless, the event instantly incinerated a local herdsman, Vasily Dzhenkoul, together with his hunting dogs, and 600 to 700 reindeer (Gallant n.d.). Despite the extraterrestrial object’s relatively small size, as Chapman (1998) has pointed out, its associated destruction covered an area larger than either New York City or Washington, D.C. Had such a cosmic body exploded over a densely populated area of Europe instead of the desolate region of Siberia, the number of human victims would have been 500 000 or more, not to mention the ensuing ecological catastrophe and geopolitical ramifications (Galland 2004).

COMETS

Asteroid Deflection Key to Comet Deflection

Asteroid deflection key to learn how to deflect comets

But when it comes to killer comets, you’ll just have to lose sleep over the possibility of their approach; there are no proposals for what to do about them. Comets are easy to see when they are near the sun and glowing but are difficult to detect at other times. Many have “eccentric” orbits, spending centuries at tremendous distances from the sun, then falling toward the inner solar system, then slingshotting away again. If you were to add comets to one of those classroom models of the solar system, many would need to come from other floors of the building, or from another school district, in order to be to scale. Advanced telescopes will probably do a good job of detecting most asteroids that pass near Earth, but an unknown comet suddenly headed our way would be a nasty surprise. And because many comets change course when the sun heats their sides and causes their frozen gases to expand, deflecting or destroying them poses technical problems to which there are no ready solutions. The logical first step, then, seems to be to determine how to prevent an asteroid from striking Earth and hope that some future advance, perhaps one building on the asteroid work, proves useful against comets.

1AC Comet Impact

Oort Cloud comets cause mass extinction

Marusek ‘7 (James, nuclear physicist & engineer, American Institute of Aeronautics and Astronautics, “Comet and Asteroid Threat Impact Analysis,” http://www.aero.org/conferences/planetarydefense/2007papers/P4-3--Marusek-Paper.pdf)

The great majority of asteroid and comet impacts will produce only limited regions of great devastation. The effects from these impacts can be quantitatively assessed by comparing the effects from equivalent air and/or surface nuclear explosion. In my assessment, global mass extinction events are extremely rare and are caused by deep impactors, those that penetrate the Earth’s crust. In general, these massive impacts are caused by inward falling comets from the Oort Cloud. The energy released by a deep impactor is split between surface effects and interior effects. The surface effects can be modeled a surface nuclear burst. The interior effects can be modeled by an equivalent underground nuclear explosions, the main component is a directional ground shock. A deep impact produces two zones of destruction: one at the point-of-impact and the other on the opposite side of the globe. The destruction at the point-of-impact produces a regional area of great devastation that wrecks havoc for several days. The shock wave from the impacts traveled through the Earth fracturing the Earth’s crust on the opposite side of the planet, producing a jumbled debris field and triggering massive mantle plume volcanism. The area of devastation on the opposite side of the Earth is significantly greater and the devastation is long-term extending thousands of years. It is this component that produces global devastation by releasing massive quantities of volcanic magma, which in turn generates acidic and poisonous gases. The gases combine with moisture to form acids that are primarily responsible for extinguishing life across the entire planet.4 The gas generation is also responsible for the drawdown of oxygen levels below minimally acceptable levels. These deep impacts are not random. Rather they occur with regularity in geological time.5

Comet strike will puncture the earth causing extinction

Marusek ‘7 (James, nuclear physicist & engineer, American Institute of Aeronautics and Astronautics, “Comet and Asteroid Threat Impact Analysis,” http://www.aero.org/conferences/planetarydefense/2007papers/P4-3--Marusek-Paper.pdf)

In general, a comet or asteroid impact will only create a regional zone of devastation (defined as the area within the blast wave 1-psi peak overpressure). This zone of destruction is caused primarily by the shock wave with a contributing component from thermal radiation, debris and electromagnetic effects. On rare occasions a massive comet can deeply penetrate the Earth’s crust. Deep penetrations can be modeled by underground nuclear explosions; with the major effect being focused ground shock. The impact shock wave can pass through the Earth rupturing the crust on the opposite side of the planet. Vast flows of volcanic magma would be released. The gases generated from this magma release are the prime culprits of global mass extinctions.4,5

Long Period Comet – Link

Long period comet could come at any time

Task Force ‘2k (British National Space Centre, Report of the Task Force on Potentially Hazardous Near Earth Objects, http://www.spacecentre.co.uk/neo/report.html)

Long period comets present new dimensions of difficulty. By definition, such comets have never been seen before. They come unpredictably at all angles from the outer reaches of the Solar System, but can usually only be seen when at a distance of about 5 AU from Earth. Warning of the approach of such a body could well be less than a year. Urgent measures and even more powerful rockets and explosives would then be essential.

Long Period Comet  Extinction

Impact by long period comet causes extinction

Marusek ‘5 (James, nuclear physicist & engineer, American Institute of Aeronautics and Astronautics, The Cosmic Clock, The Cycle of Terrestrial Mass Extinctions, http://www.lpi.usra.edu/meetings/lpsc2005/pdf/1009.pdf)

These unexpected results led to a reevaluation of the impact hypothesis. The estimate of impactor size was derived from equations comparing impactor crater size to that of a comparable nuclear surface burst. But if the impactor was larger, such as a long period comet (LPC), it would have sufficient energy to penetrate the Earth’s crust (especially an ocean impact where the crust is thin) and this assumption would begin to fall apart. Deep impacts produce smaller craters because most of the energy is released within the interior of the planet. The impact energy can be thought of as the sum of the energy released at the surface and the en-ergy released deep within the Earth’s mantle. The surface component can be approximated to the blast and thermal radiation effects from a comparably-sized nuclear explosion. The effects of the impact energy released in the mantle are obscure and are only observ-able in massive flood basalt eruptions, the creation of a deep magma hot spot, kimberlite pipes and interior structure anomalies, such as magnetic pole reversals. This analysis was expanded to the end-Permian extinction, which shared distinct similarities with the end-Cretaceous. In both extinctions, massive volcanic flood basalt eruptions took place and a significant drawdown of oxygen levels in the atmosphere and oceans occurred. From this study, a hypothesis took shape describing a cluster of comet impacts over a short geological timeframe (5-8 million years) as the cause of the end-Permian extinction. Several impacts were of sufficient size to rupture through the Earth’s crust, producing deep impact effects. The impacts focused shock destruction on the opposite side of the Earth creating fractures at continent/ocean seams. The resulting Emeishan & Siberian Traps generated pro-longed periods of surface flood basalt eruptions induc-ing extensive acid rainfall. Acidification targeted evo-lutionary weaknesses within marine and terrestrial life forms, culminating in a massive die-off at the end of the Permian Period [2]. In summary, one mechanism capable of producing a global extinction event is deep impact from a LPC. It is theorized these massive, high velocity comets can drive through the Earth’s crust and deep into the Earth’s interior producing episodes of massive flood basalt eruptions on the other side of the globe.

*LPC = long period comet

Small Comet Impact

Small comet impact could cause extinction via climate disaster

Binzel & Thomas ‘9 (Richard, prof of planetary science at MIT and author of leading reference book on asteroids, & Cristina, graduate student, “Space Topics: Near Earth Objects, Sizing Up the Threat,” http://www.planetary.org/explore/topics/near_earth_objects/threat.html)

Most estimates suggest that an impacting stony asteroid about 1.5 kilometers (1 mile) across or larger marks the threshold energy for causing a globally devastating event. However, there is much uncertainty associated with making this size estimate, and realistic guesses fall between 0.5 and 5.0 kilometers (0.3 and 3 miles). One part of the uncertainty is the lack of knowledge about how our planet's ecosystem and our society would respond to the sudden and severe stress wrought by an impact. Another area of uncertainty arises from variations in the nature of potential impactors. For example, asteroids in near-Earth space typically encounter our planet with velocities of about 20 kilometers (12 miles) per second. Comets, however, encounter Earth with much higher velocities, typically 30 to 60 kilometers (19 to 37 miles) per second. Because the damaging effects are dependent on the kinetic energy of the impact (equal to half of the mass of the impactor times the square of its velocity), a comet smaller than 1 kilometer (0.6 mile) across could pack a punch with sufficient energy to initiate a global climate disaster.

A2 – Comets Key

Asteroids are 99% of the NEO risk

Morrison ‘7 (David, senior scientist at the NASA Astrobiology Institute, NASA Ames Research Center, Ch. 8: The Impact Hazard: Advanced NEO Surveys and Societal Responses, in Comet/Asteroid Impacts and Human Society: An Interdisciplinary Approach, SpringLink)

Comets as well as asteroids can strike the Earth. We do not know if the impact that killed the dinosaurs, for example, was from a comet or an asteroid. Statistically, however, asteroid hits are more frequent than comet hits. This disparity increases as the size declines, to the point where comets are virtually absent below 1 km diameter (Yeomans 2003). Therefore, the discussions in this paper refer only to asteroids, which account for 99 percent or more of the risk in the sizes of primary interest.

Active comets only represent 1% of the NEO threat

Levasseur-Regourd ‘7 (A. Chantal, prof at Université P. & M. Curie (Paris VI), Aéronomie CNRS-IPSL, Ch. 10: Physical Properties of NEOs and Risks of an Impact: Current Knowledge and Future Challenges, in Comet/Asteroid Impacts and Human Society: An Interdisciplinary Approach, SpringLink)

The near Earth objects (hereafter NEOs) population consists of asteroids (or fragments thereof), which are rocky objects; it also includes cometary nuclei, consisting of ice and dust, which happen to eject gases and dust whenever they are sufficiently heated by the solar radiation, and of so-called defunct or dormant comets, which have lost all their ice or are coated by an insulating dust mantle. Asteroids most likely represent the main population. However, dormant and defunct comets could represent up to 18% of the total population, and active comets about 1% of the total population (Binzel et al. 2004).

A2 – Jupiter Protects: Comets

Jupiter launches comets at Earth

Overbye ‘9 (Dennis, NYT Correspondent, “Jupiter: Our Cosmic Protector?” 7-25, http://www.nytimes.com/2009/07/26/weekinreview/26overbye.html)

But is this warm and fuzzy image of the King of Planets as father-protector really true? “I really question this idea,” said Brian G. Marsden of the Harvard-Smithsonian Center for Astrophysics, referring to Jupiter as our guardian planet. As the former director of the International Astronomical Union’s Central Bureau for Astronomical Telegrams, he has spent his career keeping track of wayward objects, particularly comets, in the solar system.Jupiter is just as much a menace as a savior, he said. The big planet throws a lot of comets out of the solar system, but it also throws them in. Take, for example, Comet Lexell, named after the Swedish astronomer Anders Lexell. In 1770 it whizzed only a million miles from the Earth, missing us by a cosmic whisker, Dr. Marsden said. That comet had come streaking in from the outer solar system three years earlier and passed close to Jupiter, which diverted it into a new orbit and straight toward Earth. The comet made two passes around the Sun and in 1779 again passed very close to Jupiter, which then threw it back out of the solar system. “It was as if Jupiter aimed at us and missed,” said Dr. Marsden, who complained that the comet would never have come anywhere near the Earth if Jupiter hadn’t thrown it at us in the first place. Hal Levison, an astronomer at the Southwest Research Institute, in Boulder, Colo., who studies the evolution of the solar system, said that whether Jupiter was menace or protector depended on where the comets came from. Lexell, like Shoemaker Levy 9 and probably the truck that just hit Jupiter, most likely came from an icy zone of debris known as the Kuiper Belt, which lies just outside the orbit of Neptune, he explained. Jupiter probably does increase our exposure to those comets, he said.

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