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    Default NEO 2004 MN4 - Asteriod 99942 Apophis - Impact with Earth

    Supercomputer Takes on a Cosmic Threat

    By Leonard David
    Senior Space Writer
    posted: 14 June 2006
    06:50 am ET




    A super-powerful computer has simulated what it might take to keep Earth safe from a menacing asteroid.

    Researchers have utilized the number-crunching brainpower of Red Storm—a supercomputer at Sandia National Laboratories in Albuquerque, New Mexico. Red Storm, a Cray XT3 supercomputer, is the first computer to surpass the 1 terabyte-per-second performance mark—a measure that indicates the capacity of a network of processors to communicate with each other when dealing with the most complex situations—in both classified and unclassified realms.

    The massively parallel computing simulations have modeled how much explosive power it would take to destroy or sidetrack an asteroid that’s got Earth in its cross-hairs.

    Radar measurements

    For the computer runs, asteroid 6489 Golevka was chosen. Golevka isn’t going to hit the Earth, explained Mark Boslough, a Sandia scientist and asteroid threat analyst. This particular asteroid was used as a "proxy" because solid geometry data about the object existed, he said.

    Since its discovery in May 1991 by astronomer Eleanor Helin, asteroid Golevka has been repeatedly radar-scanned. It is roughly .33 mile (one half-kilometer) across, but tips the scales at about 460 billion pounds (210 billion kilograms), according to asteroid experts at the Jet Propulsion Laboratory in Pasadena, California.

    The Golevka asteroid has been a particular object of interest since 2003. That’s when NASA scientists discovered its course had changed.

    Keeping tabs on Golevka has helped pin down the Yarkovsky Effect—a miniscule amount of force produced as the asteroid absorbs energy from the Sun and re-radiates it into space as heat. Over time—lots of it—that force can have a big effect on an asteroid’s orbit.

    Deflection and disruption

    Boslough said the actual geometry from radar measurements of asteroid Golevka were used in the computer simulations.

    "Of course we don’t know the internal structure so we had to assume something," Boslough said. He and his colleagues tried both heterogeneous and homogenous simulations, but selected the uniform strength and density for the high-resolution demonstration mainly for simplicity.

    The researchers applied the Keep It Simple Stupid (KISS) principle of avoiding unnecessary complications—don’t try the hardest thing first, Boslough added.

    In general terms, several findings stood out in Red Storm computations that might be useful for future planetary defense systems.

    Boslough first noted that there are two "end-member strategies" in the Golevka work:

    Deflection: Keeping the asteroid in one piece and changing its trajectory to miss the Earth; and
    Disruption: Blowing it to smithereens and making sure all the bits miss the Earth.
    "There are a range of in-between options," Boslough told SPACE.com, "but the deflection end of the spectrum is much more realistic." On a kiloton-per-kiloton basis, small, shallow explosions are much more effective for moving the asteroid than large, deep ones.

    Bruce Willis: encore coring

    One demonstration simulation—10 megatons at the center of mass of the object—is the most spectacular "end member" of the range that the research team explored—but is also the least likely scenario, Boslough explained. "It also neglects a fundamental problem of how you would get the device inside an asteroid."

    Unlike Bruce Willis and his team drilling into the core of an asteroid in the 1998 movie Armageddon and planting a nuclear bomb, that scenario just doesn’t seem likely, Boslough said.

    Playing out Golevka’s hypothetical demise even on a super-fast computer took longer than the movie. Sandia’s half- second, billion-cell simulation of a 10-megaton explosion at Golevka's center took 12 hours to run on 7,200 processors of Red Storm.

    The supercomputer is a product of a partnership between Cray Computers Inc. and Sandia National Laboratories, developed for the Advanced Simulation and Computing program of the Department of Energy’s National Nuclear Security Administration (NNSA) laboratory.

    Low-yield, high payoff

    The Red Storm computational output provided useful insights.

    In particular, Boslough said, was the realization that using multiple, low-yield, deflecting explosions is much better than using one high-yield device.

    "There are many advantages" to this approach, Boslough observed. "For one, you don’t need to rendezvous with the asteroid and drill a hole or otherwise place a devise. You can set it off as a surface burst. Contrast the time it takes to ‘land’ something on the surface of an asteroid—like NASA’s Near Earth Asteroid Rendezvous (NEAR) spacecraft—to how long it takes just to get there, like NASA’s Deep Impact," he said.

    You want to solve the problem quickly, Boslough said, "even if we know about an impact decades in advance—the public perception will be that time is of the essence."

    If asteroid deflection is the game plan, there’s need to avoid accidental breakage.

    A low yield blast lessens the volume of material that is subjected to the highest tensile and shear stress, reducing the likelihood that the object will come apart.

    "If you do break the asteroid, you want to make sure none of the big pieces hit the Earth," Boslough said. "Multiple low-yield bursts over an entire hemisphere [of the asteroid] would reduce the likelihood that anything big would get left behind on the impact trajectory."

    Backup plan

    The fact that you can get a low-yield device to a menacing object fast also means that you are more likely to have a second chance, Boslough noted. That equates to a viable "backup plan", he added, for other, more elaborate, expensive, and time-consuming methods.

    "When you are saving the Earth, it’s good to have a plan B. I suspect that if a Near Earth Object (NEO) were confirmed to be on an impact trajectory, public opinion would demand fast action and this would become plan A, if it wasn’t already," Boslough said.

    Boslough said that follow-on work regarding defending Earth from NEOs is slated. Specifically on tap is delving into momentum transfer for a variety of assumed asteroidal and cometary materials and structures.
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    Default Re: Supercomputer Takes on a Cosmic Threat

    NASA to Look into NEO Threat Response Proposals
    By Leonard David
    Senior Space Writer
    posted: 16 May 2006
    06:26 am ET



    NASA is on the lookout for ways to fend off Earth-threatening Near-Earth Objects. The space agency has issued a call for papers May 15 that, among a range of topics, would help sort out possible alternatives to divert an object if found to be on a likely collision course with Earth.

    A U.S. Congress go-ahead on the matter is tied to the NASA Authorization Act of 2005 passed by Congress late last year, and subsequently signed by the President.

    "The U.S. Congress has declared that the general welfare and security of the United States require that the unique competence of NASA be directed to detecting, tracking, cataloguing, and characterizing near-Earth asteroids and comets in order to provide warning and mitigation of the potential hazard of such near-Earth objects to the Earth," the Act states.

    The Act directs the NASA Administrator to plan, develop, and implement a Near-Earth Object Survey program to detect, track, catalogue, and characterize the physical characteristics of near-Earth objects (NEOs) equal to or greater than 460 feet (140 meters) in diameter in order to assess the threat of such near-Earth objects to the Earth.

    Engaging the experts

    NASA’s call for papers and selection of best ideas will lead to a NEO Detection, Characterization and Threat Mitigation workshop, to be held in a few months time. This workshop is being organized in support of NASA’s Office of Program Analysis & Evaluation study in response to the congressional direction.

    The four-day workshop is to engage experts from the NEO scientific and technical communities to identify the fullest possible set of alternatives for meeting congressional direction. Three focus areas of the workshop are:

    * Detection, Tracking and Cataloging NEOs
    * Characterization of NEOs, and
    * Deflection or other forms of NEO Threat Mitigation

    An objective of the workshop is to wrestle with a number of issues, such as what are current U.S. and international capabilities to discover and track NEOs? How does warning time vary with object size for an object on a likely collision course?

    Additionally, the workshop would delve into possible need for space-based systems—do they provide advantages over ground-based detection and tracking systems? Furthermore, can amateur or other astronomers assist with discovery and tracking? How can they be encouraged to do so…perhaps using cash awards for spotting new objects?

    Deflection options

    In the area of deflection and threat Mitigation of NEOs, the workshop would scope out key options.

    For one, what is the ability of a proposed concept to characterize, either remotely or on-the-spot, a NEO for factors related to mitigation, including the size, composition and structure? Also, how best to mitigate the impact effects of a Near-Earth Object found to be on a likely collision course with Earth during a determined time period in the future?

    NASA’s call for ideas in abstract submission form is open until May 26. Those selected will be required to submit a full white paper by June 25. The workshop location and dates are yet to be determined, but penciled in for the late June-July time frame.
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    Default Re: Supercomputer Takes on a Cosmic Threat

    Earth-Hitting Asteroids: Katrina From Space
    By Leonard David

    National Space Society
    posted: 06 May 2006
    11:22 am ET



    LOS ANGELES, California – Natural events such as hurricanes, tsunamis and earthquakes rock this planet from time to time. But when the Earth gets stoned by an asteroid, consider it akin to a Katrina from outer space.

    When Hurricane Katrina slammed into the United States in August of last year, it became a deadly, destructive, and costly episode—one that has also become a metaphor for lack of government action, both pre- and post strike.

    At the current time there is no agency of the U.S. government—nor of any government in the world—with the explicit responsibility to develop and demonstrate the technology necessary to protect the planet from near-Earth object (NEO) impacts.

    The U.S. Congress needs to be encouraged to take a step in demonstrating the ability to deflect a menacing NEOs believes former NASA astronaut, Russell Schweickart, Chairman of the B612 Foundation. He presented an update today on dealing with troublesome asteroids here at the 25th International Space Development Conference.

    Key capabilities

    The goal of B612, a confab of scientists, technologists, astronomers, astronauts, and other specialists is to significantly alter the orbit of an asteroid in a controlled manner by 2015.

    In detailing today’s NEO situation, Schweickart said there are several givens: That the Earth is infrequently hit by asteroids which cross our orbit while circling the Sun; the consequence of such impacts ranges from the equivalent of a 15 megaton (TNT) explosion to a civilization ending gigaton event; and for the first time in the history of humankind we have the technology which, if we are properly prepared, we can use to prevent such occurrences from happening in the future.

    “Remember, we’re dealing here with a less frequent, but far more devastating Katrina … a Katrina of the Cosmos,” Schweickart reported. “NEOs happen so infrequently that even though they are orders of magnitude more devastating, people don’t naturally make that match,” he told SPACE.com, “but you don’t want to be caught with your pants down.”

    There are key capabilities, Schweickart said, which will enable humanity to avoid devastating cosmic collisions: Early warning; a demonstrated deflection capability; and an established international decision making process.

    While some progress is being made, there remains significant work ahead in all these areas, Schweickart emphasized.

    Sky-sweeping surveys

    Given sky-sweeping surveys and extrapolating into the future, by 2018 on the order of 10,000 NEOs with some risk of impact over the next 100 years are likely to be cataloged, Schweickart forecast - but there is better than an even chance that none of these 10,000 will actually hit the Earth in those 100 years.

    “The important fact however, is that a substantial number of them will appear as though they may be headed for impact,” Schweickart advised. Today, of the 104 currently on impact listings, “two have an elevated risk and we are watching them closely,” he said.

    At present, the two asteroids on that “keep an eye on them roster” are 2004 VD17 and Apophis, formerly listed as 2004 MN4.

    “Extrapolating to 2018 we may have as many as 200 in a similarly elevated attention category and of growing concern to the general public,” Schweickart reported today. “Therefore, it is certainly possible, if not likely, that in the timeframe of the next 12 years we—the world—may well be in a position where we need to take action to insure that we will be able to carry out a deflection mission if needed,” he said.

    The U.S. Congress amended the Space Act in 2005 to charge NASA with responsibility to “detect, track, catalogue, and characterize” NEOs greater than some 460 feet (140 meters) in diameter. However, it has, thus far, come up short on actually assigning the responsibility to take action should one of these objects be discovered headed for a collision, Schweickart pointed out.

    There is a bit of good news forthcoming, Schweickart explained. The Congress did require NASA to provide by the end of 2006 an analysis of possible alternatives that could be employed to divert an object on a likely collision course with Earth. In response to this Congressional directive, NASA is about to announce a process for carrying out this mandate.

    Global threat … global response

    Schweickart told the ISDC audience here, that a third leg of the triad for protecting the Earth from NEO impacts is probably the most challenging, albeit subtle.

    “It is complicated by two related facts,” he said, that NEO impacts are a global threat, not a national one, and the only decision making body representing, essentially, the whole planet is the United Nations—a body not known for timely, crisp decision making, he added.

    Still, in this area, steps forward are being made.

    The Association of Space Explorers (ASE)—the professional organization of astronauts and cosmonauts—has formed a committee on NEOs which Schweickart chairs. Earlier this year, a technical presentation at a UN meeting in Vienna apprised them that this issue was coming at them.

    While the UN has been brought the problem, Schweickart said, the ASE is committed to bringing them a solution. This solution will take the form of a draft United Nations treaty—or protocol—formulated in a series of workshops over the next two years.

    “In these NEO Deflection Policy workshops we will gather together a dozen or so international experts in diplomacy, international law, insurance, and risk management, as well as space expertise to identify and wrestle with these difficult international issues,” Schweickart noted. “Our goal is to return to the UN in 2009 with a draft NEO Deflection Decision Protocol and present it to them for their consideration and deliberation.”

    Facing the challenge

    In wrapping up his ISDC talk, Schweickart said the NEO challenge, in a sense, “is an entry test for humankind to join the cosmic community.” He reasons that, if there is intelligent life elsewhere in the universe “it is virtually certain that it has already faced this challenge to survival … and passed it.”

    “Our choice is to face this infrequent but substantial cosmic test … or pass into history, not as an incapable species like the dinosaurs, but as a fractious and self serving creature with inadequate vision and commitment to continue its evolutionary development,” Schweickart concluded.

    * ISDC 2006: Exploring New Worlds
    * Private Space Companies Forge Ahead Despite Failures
    * Rutan Takes Aim at NASA's CEV Plans, Likens it to 'Archeology'
    * NASA, X Prize Foundation Shoot For the Moon

    Leonard David is a Senior Space Writer for SPACE.com and the former editor of Ad Astra, the official magazine of the National Space Society
    NOTE: The views of this article are the author’s and do not reflect the policies of the National Space Society.

    Visit SPACE.com/Ad Astra Online for more news, views and scientific inquiry from the National Space Society.
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    Default Re: Supercomputer Takes on a Cosmic Threat

    New Asteroid Threat to Earth

    From Nick Greene,

    Impact Potential in 2014 - Updated; No Threat

    Although scientists have basically cleared us from any danger from asteroid 2002 NT7, which originally had been reported as an impact hazard for the year 2019, a newer space rock has been spotted, which may pose a threat even sooner.

    At around 1.2 km in width, 2003 QQ47 is substantially smaller than 2002 NT7 (2km), but has been called "an event meriting careful monitoring" by astronomers. If an impact does occur, it could be on March 21, 2014.

    Discovered on August 24, 2003, by the Lincoln Near Earth Asteroid Research Project (an MIT Lincoln Laboratory program funded by the United States Air Force and NASA) in New Mexico, 2003 QQ47 has been classified as a 1 on the Torino scale of impact hazards.
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    Scientists are urging calm, however, saying the odds of a catastrophic collision are only around 1 in 909,000.

    The orbit of this asteroid has been calculated on only 51 observations during a seven-day period and require further observations to determine if any danger does exist. It will be monitored closely over the next two months. Astronomers expect the risk of impact to decrease significantly as more data is gathered.

    If it does strike Earth, the impact could have the effect of over 20 million Hiroshima style atomic bombs. As Billy Bob Thornton says in Armageddon, “It's what we call a Global Killer....the end of mankind. Half the world will be incinerated by the heat blast.....the rest will freeze to death in a nuclear winter. Basically, the worst part of the Bible!”

    Asteroids are rocks and debris which are the leftovers of the construction of our solar system nearly 5 billions years ago. Most are in a belt, which orbits the sun between Mars and Jupiter. However, the gravitational influence of the gas giant planets, like Jupiter, or an impact by a comet can knock these large rocks out of their safe orbit.

    Needless to say, we will be monitoring this situation very closely.

    Update:
    Once again, the planet can breathe a sigh of relief. After making further observations of asteroid 2003 QQ47, astronomers now say there is no threat from this rock. It has been downgraded to a zero (0) on the Torin scale, which says, "The likelihood of a collision is zero, or well below the chance that a random object of the same size will strike the Earth within the next few decades. This designation also applies to any small object that, in the event of a collision, is unlikely to reach the Earth's surface intact."

    While this particular asteroid appears to not be a threat to Earth at this time, the Near Earth Object Program and other agencies continue to monitor space for other threats. After all, it is a big universe, and there are a lot of asteroids and comets out there.
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    Default Re: Supercomputer Takes on a Cosmic Threat

    NASA Announces Latest Asteroid Threat to Earth

    from JPL Near Earth Objects Program/NASA

    May 4 2005
    Near-Earth Asteroid 2004 MN4 Reaches Highest Score To Date On Hazard Scale
    It may sound like an Urban Legend, but it's not. Urban Legends Guide, David Emory has listed some of the "unlucky numerical omens" associated with this asteroid.

    A recently rediscovered 400-meter Near-Earth Asteroid (NEA) is predicted to pass near the Earth on 13 April 2029. The flyby distance is uncertain and an Earth impact cannot yet be ruled out. The odds of impact, initially around 1 in 300, were unusual enough to merit special monitoring by astronomers, but should not be of public concern.

    As of December 24, 2004, 2004 MN4 is now being tracked very carefully by many astronmers around the world, and we continue to update our risk analysis for this object. New impact monitoring results indicate that the impact probability for April 13, 2029 has risen to about 1.6%, which for an object of this size corresponds to a rating of 4 on the ten-point Torino Scale.

    Nevertheless, the odds against impact are still high, about 60 to 1, meaning that there is a better than 98% chance that new data in the coming days, weeks, and months will rule out any possibility of impact in 2029.

    These odds are likely to change on a day-to-day basis as new data are received. In all likelihood, the possibility of impact will eventually be eliminated as the asteroid continues to be tracked by astronomers around the world.

    This object is the first to reach a level 2 (out of 10) on the Torino Scale. According to the Torino Scale, a rating of 2 indicates "a discovery, which may become routine with expanded searches, of an object making a somewhat close but not highly unusual pass near the Earth. While meriting attention by astronomers, there is no cause for public attention or public concern as an actual collision is very unlikely. New telescopic observations very likely will lead to re-assignment to Level 0 [no hazard]." This asteroid should be easily observable throughout the coming months.
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    Default Re: Supercomputer Takes on a Cosmic Threat

    NASA Announces Latest Asteroid Threat to Earth

    from JPL Near Earth Objects Program/NASA

    May 4 2005
    Is It a Danger?


    The brightness of 2004 MN4 suggests that its diameter is roughly 400 meters (1300 feet) and our current, but very uncertain, best estimate of the flyby distance in 2029 is about twice the distance of the moon, or about 780,000 km (480,000 miles). On average, an asteroid of this size would be expected to pass within 2 lunar distances of Earth every 5 years or so.



    Most of this object's orbit lies within the Earth's orbit, and it approaches the sun almost as close as the orbit of Venus. 2004 MN4's orbital period about the sun is 323 days, placing it within the Aten class of NEAs, which have an orbital period less than one year. It has a low inclination with respect to the Earth's orbit and the asteroid crosses near the Earth's orbit twice on each of its passages about the sun.

    2004 MN4 was discovered on 19 June 2004 by Roy Tucker, David Tholen and Fabrizio Bernardi of the NASA-funded University of Hawaii Asteroid Survey (UHAS), from Kitt Peak, Arizona, and observed over two nights.

    On 18 December, the object was rediscovered from Australia by Gordon Garradd of the Siding Spring Survey, another NASA-funded NEA survey. Further observations from around the globe over the next several days allowed the Minor Planet Center to confirm the connection to the June discovery, at which point the possibility of impact in 2029 was realized by the automatic SENTRY system of NASA's Near-Earth Object Program Office. NEODyS, a similar automatic system at the University of Pisa and the University of Valladolid, Spain also detected the impact possibility and provided similar predictions.




    Update!
    Further observations have helped NASA determine that there will be no threat from this pass of this object.
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    Default Re: NEO 2004 MN4 - Asteriod 99942 Apophis - Impact with Earth

    I've just renamed this thread.

    Here's why. Having been watching some TV shows lately on several of the various science channels, I have come to learn that the asteroid 2004 MN4 was NAMED "Apophis" and is scheduled to make a rendezvous with the Earth again on 13 April 2029.

    It will pass within a few hundred miles of Earth. Give or take an inch or two. The most recent data from JPL is listed below:>>
    99942 Apophis (2004 MN4)
    Earth Impact Risk Summary
    >>
    Torino Scale (maximum)>>
    0>>
    Palermo Scale (maximum)>>
    -2.52>>
    Palermo Scale (cumulative)>>
    -2.52>>
    Impact Probability (cumulative)>>
    Number of Potential Impacts>>
    2>>
    >>
    12.59 km/s>>
    5.87 km/s>>
    H>>
    19.7>>
    0.250 km>>
    2.1e+10 kg>>
    4.0e+02 MT>>
    all above are mean values
    weighted by impact probability
    >>
    >>
    Analysis based on 2 radar delay, 5 Doppler, and
    731 optical observations spanning 884.52 days
    (2004-Mar-15.10789 to 2006-Aug-16.626954)
    >>
    >>
    Orbit diagram and elements available here. >>
    >>

    These results were computed on Oct 19, 2006>>
    99942 Apophis (2004 MN4)
    Earth Impact Table
    >>
    Date>>
    Distance>>
    Width>>
    Sigma
    Impact
    >>
    Sigma
    LOV
    >>
    Stretch
    LOV
    >>
    Impact
    Probability
    >>
    Impact
    Energy
    >>
    lace w:st="on">Palermolace>
    Scale>>
    lace w:st="on">Torinolace>
    Scale>>
    YYYY-MM-DD.DD>>
    (rEarth)>>
    (rEarth)>>
    >>
    >>
    (rEarth)>>
    >>
    (MT)>>
    >>
    >>
    2036-04-13.37>>
    0.53 >>
    1.19e-03 >>
    0.000 >>
    -2.43130 >>
    1.60e+03 >>
    4.02e+02 >>
    -2.52 >>
    0 >>
    2037-04-13.64>>
    0.63 >>
    1.11e-03 >>
    0.000 >>
    4.12077 >>
    1.58e+03 >>
    4.01e+02 >>
    -4.97 >>
    0 >>
    > >
    Basically, you will see on this chart some information on the calculated probabilities of impact, and so forth. You will note that on the lace w:st="on">Torinolace> scale there is a ZERO (0) showing no or extremely remote chance of impact.

    Looking more closely, you can see that there is something called the Palermo Scale. Anything between -2 and 0 indicates there is a situation that needs to be closely monitored. In this case, the scale is based on logarithms and so it is a non-linear scale. The closer to, say 0, you approach, the higher greater and greater possibilities become.
    According to not one, but two different shows I’ve watched in recent months, this particular asteroid will be approaching us well within the distance of standard satellite orbits. Even though the predictions are for “a non-event” this is a very, very, VERY – astronomically CLOSE contact with Earth.

    What many folks aren’t sure of is what happens later. Seven years later in fact. Seven years later, again on Friday the 13th, I believe in the month of June 2036 that particular asteroid will be approaching us yet again.

    Given NO change in its orbit it will miss us. However, given the fact that it will be highly affected by a close approach by the Earth’s gravitational field there is distinct chance of major perturbation to the asteroid’s orbit. It may come around and slam directly into the Earth, or it may be slowed or sped reasonably along its way so as to miss us completely for the next million years.

    I simply don’t know the answer and do not have the necessary mathematical skills to calculate that far into the future. I suspect though that given the attention this particular asteroid is being paid by the scientific community, there is reason for concern regarding its next approach. Science hasn’t raised a large enough stink about this, but we have 22 years left, then right NOW we have time to ensure this thing doesn’t hit us.

    If we wait until it passes by the next go around, we’re going to be down to a seven year stretch and not likely to have the means to move it. The best folks in science are saying that “given 10 years” we can likely do something about such a situation. I believe I’ve heard Micheo Kaku even say this before.
    > >
    Well, that’s it for now, going to track this asteroid here in this thread.
    > >
    Rick
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    Default Re: NEO 2004 MN4 - Asteriod 99942 Apophis - Impact with Earth

    The Asteroid Threat is Out There

    More than 100,000 asteroids hurtle past our planet. But only one--that we know of--may hit us in the next 30 years.

    By David Noland


    Friday the 13th of April 2029 could be a very unlucky day for planet Earth. At 4:36 a.m. Greenwich Mean Time, a 25-million-ton, 820-foot-wide asteroid called 99942 Apophis will slice across the orbit of the moon and barrel toward Earth at more than 28,000 mph. The huge pockmarked rock, two-thirds the size of Devils Tower in Wyoming, will pack the energy of 65,000 Hiroshima bombs -- enough to wipe out a small country or kick up an 800-foot tsunami.


    On this day, however, Apophis is not expected to live up to its namesake, the ancient Egyptian god of darkness and destruction. Scientists are 99.7 percent certain it will pass at a distance of 18,800 to 20,800 miles. In astronomical terms, 20,000 miles is a mere stone's throw, shorter than a round-trip flight from New York to Melbourne, Australia, and well inside the orbits of Earth's many geosynchronous communications satellites. For a couple of hours after dusk, people in Europe, Africa and western Asia will see what looks like a medium-bright star creeping westward through the constellation of Cancer, making Apophis the first asteroid in human history to be clearly visible to the naked eye. And then it will be gone, having vanished into the dark vastness of space. We will have dodged a cosmic bullet.


    Maybe. Scientists calculate that if Apophis passes at a distance of exactly 18,893 miles, it will go through a "gravitational keyhole." This small region in space -- only about a half mile wide, or twice the diameter of the asteroid itself -- is where Earth's gravity would perturb Apophis in just the wrong way, causing it to enter an orbit seven-sixths as long as Earth's. In other words, the planet will be squarely in the crosshairs for a potentially catastrophic asteroid impact precisely seven years later, on April 13, 2036.


    Radar and optical tracking during Apophis's fly-by last summer put the odds of the asteroid passing through the keyhole at about 45,000-to-1. "People have a hard time reasoning with low-probability/high-consequence risks," says Michael DeKay of the Center for Risk Perception and Communication at Carnegie Mellon University. "Some people say, 'Why bother, it's not really going to happen.' But others say that when the potential consequences are so serious, even a tiny risk is unacceptable."


    Former astronaut Rusty Schweickart, now 71, knows a thing or two about objects flying through space, having been one himself during a spacewalk on the Apollo 9 mission in 1969. Through the B612 Foundation, which he co-founded in 2001, Schweickart has been prodding NASA to do something about Apophis -- and soon. "We need to act," he says. "If we blow this, it'll be criminal."


    If the dice do land the wrong way in 2029, Apophis would have to be deflected by some 5000 miles to miss the Earth in 2036. Hollywood notwithstanding, that's a feat far beyond any current human technology. The fanciful mission in the 1998 movie Armageddon -- to drill a hole more than 800 ft. into an asteroid and detonate a nuclear bomb inside it -- is about as technically feasible as time travel. In reality, after April 13, 2029, there would be little we could do but plot the precise impact point and start evacuating people.


    According to projections, an Apophis impact would occur somewhere along a curving 30-mile-wide swath stretching across Russia, the Pacific Ocean, Central America and on into the Atlantic. Managua, Nicaragua; San José, Costa Rica; and Caracas, Venezuela, all would be in line for near-direct hits and complete destruction. The most likely target, though, is several thousand miles off the West Coast, where Apophis would create a 5-mile-wide, 9000-ft.-deep "crater" in the water. The collapse of that transient water crater would trigger tsunamis that would hammer California with an hour-long fusillade of 50-ft. waves.



    BUT DON'T EVACUATE just yet. Although we can't force Apophis to miss the Earth after 2029, we have the technology to nudge it slightly off course well before then, causing it to miss the keyhole in the first place. According to NASA, a simple 1-ton "kinetic energy impactor" spacecraft thumping into Apophis at 5000 mph would do the trick. We already have a template for such a mission: NASA's Deep Impact space probe -- named after another 1998 cosmic-collision movie -- slammed into the comet Tempel 1 in 2005 to gather data about the composition of its surface. Alternatively, an ion-drive-powered "gravity tractor" spacecraft could hover above Apophis and use its own tiny gravity to gently pull the asteroid off course.


    In 2005, Schweickart urged NASA administrator Michael Griffin to start planning a mission to land a radio transponder on Apophis. Tracking data from the device would almost certainly confirm that the asteroid won't hit the keyhole in 2029, allowing everyone on Earth to breathe a collective sigh of relief. But if it didn't, there still would be time to design and launch a deflection mission, a project that Schweickart estimates could take as long as 12 years. It would need to be completed by about 2026 to allow enough time for a spacecraft's tiny nudge to take effect.


    NASA, however, is taking a wait-and-see attitude. An analysis by Steven Chesley of the Near Earth Object program at the Jet Propulsion Laboratory (JPL) in Pasadena, Calif., concludes that we can safely sit tight until 2013. That's when Apophis swings by Earth in prime position for tracking by the 1000-ft.-dia. radio telescope in Arecibo, Puerto Rico. This data could also rule out a keyhole hit in 2029. But if it doesn't, the transponder mission and, if necessary, a last-resort deflection mission could still be launched in time, according to Chesley. "There's no rush right now," he says. "But if it's still serious by 2014, we need to start designing real missions."


    IN 1998, CONGRESS mandated NASA to find and track near-Earth asteroids at least 1 kilometer in diameter. The resulting Spaceguard Survey has detected, at last count, about 75 percent of the 1100 estimated to be out there. (Although Apophis was nearly 2500 ft. short of the size criterion, it was found serendipitously during the search process.) Thankfully, none of the giants so far discovered is a threat to Earth. "But any one of those couple of hundred we haven't found yet could be headed toward us right now," says former astronaut Tom Jones, an asteroid-search consultant for NASA and a Popular Mechanics editorial adviser. The space agency plans to expand Spaceguard to include asteroids down to 140 meters in diameter -- less than half the size of Apophis, but still big enough to do serious damage. It has already detected more than 4000 of these; NASA estimates approximately 100,000 exist.


    Predicting asteroid orbits can be a messy business, as the history of tracking Apophis in its 323-day orbit demonstrates. Astronomers at Arizona's Kitt Peak National Observatory discovered the asteroid in June 2004. It was six months before additional sightings -- many made by amateurs using backyard telescopes -- triggered alarm bells at JPL, home to the Sentry asteroid-impact monitoring system, a computer that predicts the orbits of near-Earth asteroids based on astronomical observations. Sentry's impact predictions then grew more ominous by the day. On Dec. 27, 2004, the odds of a 2029 impact reached 2.7 percent -- a figure that stirred great excitement in the small world of asteroid chasers. Apophis vaulted to an unprecedented rating of 4 on the Torino Impact Hazard Scale, a 10-step, color-coded index of asteroid and comet threat levels.


    But the commotion was short-lived. When previously overlooked observations were fed into the computer, it spit out reassuring news: Apophis would not hit the Earth in 2029 after all, though it wouldn't miss by much. Oh, and there was one other thing: that troublesome keyhole.


    The small size of the gravitational keyhole -- just 2000 ft. in diameter -- is both a blessing and a curse. On the one hand, it wouldn't take much to nudge Apophis outside it. Calculations suggest that if we change Apophis's velocity by a mere 0.0001 mph--about 31 in. per day--in three years its orbit would be deflected by more than a mile, a piddling amount, but enough to miss the keyhole. That's easily within the capabilities of a gravity tractor or kinetic energy impactor. On the other hand, with a target so minuscule, predicting precisely where Apophis will pass in relation to the keyhole becomes, well, a hit-or-miss proposition. Current orbit projections for 2029 have a margin of error -- orbital scientists call it the error ellipse -- of about 2000 miles. As data rolls in, the error ellipse will shrink considerably. But if the keyhole stubbornly stays within it, NASA may have to reduce the ellipse to a mile or less before it knows for sure whether Apophis will hit the bull's-eye. Otherwise, a mission risks inadvertently nudging Apophis into the keyhole instead of away from it.


    Can we predict Apophis's orbit to the submile level far enough in advance to launch a deflection mission? That level of forecasting accuracy would require, in addition to a transponder, a vastly more complex orbital calculation model than the one used today. It would have to include calculations for such minute effects as solar radiation, relativity and the gravitational pulls of small nearby asteroids, none of which are fully accounted for in the current model.


    And then there's the wild card of asteroid orbital calculations: the Yarkovsky Effect. This small but steady force occurs when an asteroid radiates more heat from one side than the other. As an asteroid rotates away from the sun, the heat that has accumulated on its surface is shed into space, giving it a slight push in the other direction. An asteroid called 6489 Golevka, twice the size of Apophis, has been pushed about 10 miles off course by this effect in the past 15 years. How Apophis will be influenced over the next 23 years is anybody's guess. At the moment we have no clue about its spin direction or axis, or even its shape -- all necessary parameters for estimating the effect.


    IF APOPHIS IS INDEED headed for the gravitational keyhole, ground observations won't be able to confirm it until at least 2021. By that time, it may be too late to do anything about it. Considering what's at stake -- Chesley estimates that an Apophis-size asteroid impact would cost $400 billion in infrastructure damage alone -- it seems prudent to start taking steps to deal with Apophis long before we know whether those steps will eventually prove necessary. When do we start? Or, alternatively, at what point do we just cross our fingers and hope it misses? When the odds are 10-to-1 against it? A thousand-to-1? A million?


    When NASA does discover a potentially threatening asteroid like Apophis, it has no mandate to decide whether, when or how to take action. "We're not in the mitigation business," Chesley says. A workshop to discuss general asteroid-defense options last June was NASA's first official baby step in that direction.


    If NASA eventually does get the nod -- and more important, the budget -- from Congress, the obvious first move would be a reconnaissance mission to Apophis. Schweickart estimates that "even gold-plated at JPL," a transponder-equipped gravity tractor could be launched for $250 million. Ironically, that's almost precisely the cost of making the cosmic-collision movies Armageddon and Deep Impact. If Hollywood can pony up a quarter of a billion in the name of defending our planet, why can't Congress?



    Reprinted with permission of Hearst Communications, Inc.
    Last edited by American Patriot; January 16th, 2007 at 20:29.
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    Default Re: NEO 2004 MN4 - Asteriod 99942 Apophis - Impact with Earth

    UH panel will discuss threat of killer asteroids

    NASA astronaut Ed Lu will be among those speaking at the event

    Star-Bulletin staff
    citydesk@starbulletin.com
    NASA astronaut Ed Lu, former solar physicist at the University of Hawaii Institute for Astronomy, will join the institute's experts in a program on Monday on "Killer Asteroids and What we can do About Them."


    He will participate in a panel discussion with:



    » David Tholen, an astronomer who specializes in the study of asteroids and comets and developed an asteroid classification system in wide use. He discovered Apophis, the asteroid that will pass within 20,000 miles of the Earth in 2029.

    » Robert Jedicke, a planetary astronomer who specializes in study of asteroids that might impact Earth.


    » Nick Kaiser, cosmologist and principal investigator for the Pan-STARRS telescope project to detect and track asteroids from Hawaii.



    Lu was a postdoctoral fellow at the Institute for Astronomy from 1992 to 1995 when he became an astronaut.


    He spent six months aboard the International Space Station in 2003 and has proposed a "gravity tractor" that could alter the orbit of a dangerous asteroid.


    The free "Frontiers of Astronomy" community lecture will be open to the public at 7 p.m. in the UH-Manoa Art Building Auditorium. Co-sponsors are the Institute for Astronomy and NASA.


    The astronomers also will give an "AstroTalk" panel discussion at 7 p.m. Friday at UH-Hilo.



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    Default Re: NEO 2004 MN4 - Asteriod 99942 Apophis - Impact with Earth

    Image:2004mn4d5 s.gif

    From Wikipedia, the free encyclopedia

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    2004mn4d5_s.gif‎ (2KB, MIME type: image/gif)

    The close approach of 99942 Apophis (previously better known by its provisional designation 2004 MN4) to the Earth and Moon on April 13, 2029
    The white bar indicates uncertainty in the range of possible positions. (Percent error)
    See also: Image:2004mn4d4 s.gif.


    This file is in the public domain because it was created by NASA. NASA copyright policy states that "NASA material is not protected by copyright unless noted". (NASA copyright policy page or JPL Image Use Policy). Warnings:
    • NASA logos (which include the current "meatball" logo, the old "worm" logo, and the seal) are copyrighted.
    • Materials from the Hubble Space Telescope may be copyrighted if they do not explicitly come from the STScI. [1]
    • All materials created by the SOHO probe are copyrighted and require permission for commercial non-educational use. [2]
    • Images featured on the Astronomy Picture of the Day (APOD) web site may be copyrighted. [3]


    [edit] Source

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    Default Re: NEO 2004 MN4 - Asteriod 99942 Apophis - Impact with Earth

    Here's the Wikipedia for this asteroid:

    http://en.wikipedia.org/wiki/99942_Apophis
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    Default Re: NEO 2004 MN4 - Asteriod 99942 Apophis - Impact with Earth

    Radar Observations Refine the Future Motion of Asteroid 2004 MN4

    Paul Chodas, Steve Chesley, Jon Giorgini and Don Yeomans
    NASA's Near Earth Object Program Office
    February 3, 2005

    Radar observations taken at the Arecibo Observatory in Puerto Rico on January 27, 29, and 30 have significantly improved our estimate for the orbit of asteroid 2004 MN4 and changed the circumstances of the Earth close approach in 2029.



    On April 13, 2029, the predicted trajectory now passes within 5.7 Earth radii (36,350 km or 22,600 miles) of the Earth's center - just below the altitude of geosynchronous Earth satellites.


    However, an Earth collision in 2029 is still ruled out. The asteroid's motion subsequent to the 2029 Earth close approach is very sensitive to the circumstances of the close approach itself and a number of future Earth close approaches will be monitored as additional observations are received.


    However, our current risk analysis for 2004 MN4 indicates that no subsequent Earth encounters in the 21st century are of concern.


    In the accompanying diagrams, the most likely trajectory of asteroid 2004 MN4 is shown as a blue line that passes near the Earth on 13 April 2029.


    The second of the two figures is an enlarged view of the Earth close approach circumstances. Since the asteroid's position in space is not perfectly known at that time, the white dots at right angles to the blue line are possible alternate positions of the asteroid. Neither the nominal position of the asteroid, nor any of its possible alternative positions, touches the Earth, effectively ruling out an Earth impact in 2029.



    Based on albedo contraints by Andrew Rivkin and Richard Binzel (MIT), the diameter of the object is about 320 meters. At the time of the closest approach, the asteroid will be a naked eye object (3.3 mag.) traveling rapidly (42 degrees per hour!) through the constellation of Cancer.



    On average, one would expect a similarly close Earth approach by an asteroid of this size only every 1300 years or so.

    Updated Set of Possible Positions of 2004 MN4 on
    April 13, 2029


    Closeup View

    The passage of the asteroid by the Earth in 2029 alters its subsequent trajectory and causes its position uncertainty region to expand rapidly as it moves away from Earth (i.e., the line of white dots increases in extent). As a result, the asteroid's motion is much less predictable after the 2029 close Earth approach. Even so, the asteroid's uncertainty region is not large enough to extend to the moon as it passes by, and so a lunar impact is not possible.


    Lance Benner (JPL), Mike Nolan (NAIC), Steve Ostro (JPL), and Jon Giorgini (JPL) provided the Arecibo radar data that made these updated results possible.



    Related Articles

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    Default Re: NEO 2004 MN4 - Asteriod 99942 Apophis - Impact with Earth

    Animation of Possible Positions of 2004 MN4 in April 2029

    Small Animated GIF (62K)
    Large Animated GIF (119K)
    Animation showing the cloud of possible positions of asteroid 2004 MN4 relative to Earth in April 2029 is shown in white. The Moon's orbit is also shown, for scale. A tiny portion of the cloud intersects the Earth. The length of the cloud is directly related to current uncertainties in our knowledge of this new object's orbit. This animation will repeat itself ten times.
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    Default Re: NEO 2004 MN4 - Asteriod 99942 Apophis - Impact with Earth


    Friday the 13th, 2029
    Asteroid 2004 MN4 will come scarily close to Earth on April 13, 2029, but it will not hit.

    Listen to this story via streaming audio, a downloadable file, or get help.
    May 13, 2005: Friday the 13th is supposed to be an unlucky day, the sort of day you trip on your shoe laces or lose your wallet or get bad news.


    But maybe it's not so bad. Consider this: On April 13th--Friday the 13th--2029, millions of people are going to go outside, look up and marvel at their good luck. A point of light will be gliding across the sky, faster than many satellites, brighter than most stars.
    What's so lucky about that? It's asteroid 2004 MN4 ... not hitting Earth.
    For a while astronomers thought it might. On Christmas Eve 2004, Paul Chodas, Steve Chesley and Don Yeomans at NASA's Near Earth Object Program office calculated a 1-in-60 chance that 2004 MN4 would collide with Earth. Impact date: April 13, 2029.


    Right: The orbits of Earth and asteroid 2004 MN4. [More]


    The asteroid is about 320 meters wide. "That's big enough to punch through Earth's atmosphere," devastating a region the size of, say, Texas, if it hit land, or causing widespread tsunamis if it hit ocean, says Chodas. So much for holiday cheer.


    Asteroid 2004 MN4 had been discovered in June 2004, lost, then discovered again six months later. With such sparse tracking data it was difficult to say, precisely, where the asteroid would go. A collision with Earth was theoretically possible. "We weren't too worried," Chodas says, "but the odds were disturbing."




    Sign up for EXPRESS SCIENCE NEWS delivery
    This is typical, by the way, of newly-discovered asteroids. Step 1: An asteroid is discovered. Step 2: Uncertain orbits are calculated from spotty tracking data. Step 3: Possible Earth impacts are noted. Step 4: Astronomers watch the asteroid for a while, then realize that it's going to miss our planet.


    Killer Asteroid! headlines generally appear between steps 3 and 4, but that's another story.


    Astronomers knew 2004 MN4 would miss Earth when they found pictures of the asteroid taken, unwittingly, in March 2004, three months before its official discovery. The extra data ruled out a collision in 2029.


    Instead, what we're going to have is an eye-popping close encounter:
    On April 13, 2029, asteroid 2004 MN4 will fly past Earth only 18,600 miles (30,000 km) above the ground. For comparison, geosynchronous satellites orbit at 22,300 miles (36,000 km). "At closest approach, the asteroid will shine like a 3rd magnitude star, visible to the unaided eye from Africa, Europe and Asia--even through city lights," says Jon Giorgini of JPL. This is rare. "Close approaches by objects as large as 2004 MN4 are currently thought to occur at 1000-year intervals, on average."


    Above: The trajectory (blue) of asteroid 2004 MN4 past Earth on April 13, 2029. Uncertainty in the asteroid's close-approach distance is represented by the short white bar. [More]

    The asteroid's trajectory will bend approximately 28 degrees during the encounter, "a result of Earth's gravitational pull," explains Giorgini. What happens next is uncertain. Some newspapers have stated that the asteroid might swing around and hit Earth after all in 2035 or so, but Giorgini discounts that: "Our ability to 'see' where 2004 MN4 will go (by extrapolating its orbit) is so blurred out by the 2029 Earth encounter, it can't even be said for certain what side of the sun 2004 MN4 will be on in 2035. Talk of Earth encounters in 2035 is premature."


    In January 2004, a team of astronomers led by Lance Benner of JPL pinged 2004 MN4 using the giant Arecibo radar in Puerto Rico. (Coincidentally, the Arecibo dish is about the same size as the asteroid.) Echoes revealed the asteroid's precise distance and velocity, "allowing us to calculate the details of the 2029 flyby," says Giorgini, who was a member of the team along with Benner, Mike Nolan (NAIC) and Steve Ostro (JPL).


    More data are needed to forecast 2004 MN4's motion beyond 2029. "The next good opportunities are in 2013 and 2021," Giorgini says. The asteroid will be about 9 million miles (14 million km) from Earth, invisible to the naked eye, but close enough for radar studies. "If we get radar ranging in 2013, we should be able to predict the location of 2004 MN4 out to at least 2070."


    Right: The Arecibo radar in Puerto Rico is coincidentally about the size of asteroid 2004 MN4. [More]


    The closest encounter of all, Friday the 13th, 2029, will be a spectacular opportunity to explore this asteroid via radar. During this encounter, says Giorgini, "radar could detect the distortion of 2004 MN4's shape and spin as it passes through Earth's gravity field. How the asteroid changes (or not) would provide information about its internal structure and material composition." Beautifully-detailed surface maps are possible, too.


    The view through an optical telescope won't be so impressive. The asteroid's maximum angular diameter is only 2 to 4 arcseconds, which means it will be a starlike point of light in all but the very largest telescopes.


    But to the naked eye--wow! No one in recorded history has ever seen an asteroid in space so bright.


    Friday the 13th might not be so bad after all.
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    Default Re: NEO 2004 MN4 - Asteriod 99942 Apophis - Impact with Earth

    Will Earth break up 2004 MN4?


    An asteroid buzzing past Earth in 2029 will come closer than expected — and may not survive intact.


    Bill Cooke
    February 10, 2005


    For a few days at the end of December, an asteroid named 2004 MN4 looked like it might be Earth's biggest impact threat. Based on available information about its orbit, astronomers gave odds of 1 in 37 that 2004 MN4 would strike Earth April 13, 2029. But astronomers found images of the asteroid taken before its discovery, giving them a longer arc of its orbit, and the collision threat evaporated. It appeared the rock would miss Earth by 40,000 miles (64,400 kilometers).

    Now, radar measurements suggest MN4 will miss us by half that distance — and come so close Earth's gravity could rip it apart.

    Between January 27 and 30, a team led by Lance Benner of the Jet Propulsion Laboratory in Pasadena, California, tracked the asteroid using the enormous Arecibo radio telescope in Puerto Rico. By bouncing radio waves off the asteroid, the astronomers received precise information about its position and speed that enabled them to plot the object's course over the next 24 years with great accuracy.

    The results shocked some astronomers. The new orbit indicates the asteroid will miss Earth by 22,000 miles (35,400 km), passing just inside the belt of geostationary satellites.

    A miss is still a miss, so what's the big deal? At first glance, the change in the miss distance doesn't seem surprising. Astronomers are constantly updating comet and asteroid orbits, and changes are expected.

    But for 2004 MN4, the change in the miss distance was greater than the error computed in the December analyses. Put another way, 2004 MN4 is now outside the uncertainty box — the region astronomers thought would contain the object's most likely locations on April 13, 2029.

    The asteroid, whose chance of striking Earth was once computed to be improbably high, has presented us with the improbable once again. Scientists place great store in their error estimates — sometimes too much. One of the most prominent asteroid researchers, Clark Chapman of the Southwest Research Institute (SWRI) in Boulder, Colorado, notes that who deal with low-probability, high-consequence events, like airplane crashes, place very little faith in error estimates. Perhaps, he suggests, this is a lesson the asteroid community needs to learn.

    But there's another reason for concern. According to Dan Durda, another SWRI astronomer, 2004 MN4 is likely to be a "rubble-pile" asteroid, consisting of material only loosely held together by gravity. Because the asteroid will pass us at just 2.5 times Earth's diameter, tidal forces could tear it apart. The result would be a trail of rocks drifting slowly apart with the passage of time. One or more of these might hit Earth in the more distant future, creating a spectacular fireball as it burns up in the atmosphere.

    Although a miss in 2029 is virtually certain, if MN4 survives its Earth flyby, astronomers cannot rule out potential collisions in the 2030's. Therefore, 2004 MN4 still holds at 1 on the Torino impact hazard scale, a classification designed to quantify the impact risk of near-Earth asteroids (similar to the Ritcher scale for earthquakes).

    Clark Chapman says the past few weeks have been "educational for the asteroid impact community," and he refers to 2004 MN4 as the "most significant event, by far, in decades."

    So, take note: On Friday, April 13, 2029, from dark-sky sites throughout Europe, 2004 MN4 will look like a 3rd-magnitude star. It will be moving a quarter of the way across the sky in just an hour, its motion among the stars clearly evident.

    And maybe, just maybe, you'll see an asteroid die.



    Bill Cookeis an astronomer with NASA's Marshall Space Flight Center in Huntsville, Alabama. His article, "Killer impact," appeared in the December 2004 issue of Astronomy.

    Related articles
    2004 MN4: swing and a miss
    Avoiding impacts
    Those weren't snowballs
    A rock that just missed us
    Did the Celts see a comet impact in 200 B.C.?
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    Default Re: NEO 2004 MN4 - Asteriod 99942 Apophis - Impact with Earth

    NASA initially estimated the energy that Apophis would have released if it impacted Earth as the equivalent of 1480 megatons of TNT. A more refined later NASA estimate was 880 megatons. The impacts which created the Barringer Crater or caused the Tunguska event are estimated to be in the 10-20 megaton range. The 1883 eruption of Krakatoa was the equivalent of roughly 200 megatons.
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    Default Re: NEO 2004 MN4 - Asteriod 99942 Apophis - Impact with Earth

    Asteroid Threat Demands Response, Experts Warn
    New Scientist ^ | 2-17-2007 | Ivan Semeniuk

    Asteroid threat demands response, experts warn
    16:26 17 February 2007
    NewScientist.com news service
    Ivan Semeniuk, San Francisco


    If the asteroid Apophis hits Earth in 2036, it could slam into the Pacific Ocean, generating a tsunami that could devastate the west coast of North America (Illustration: Don Davis/NASA)

    Kamchatkans and Venezuelans beware. A 20-million-tonne asteroid could be heading your way. Californians have even more reason to worry - the asteroid is more likely to hit the Pacific Ocean, triggering a tsunami that could devastate the west coast of North America.
    These are among the scenarios projected for asteroid Apophis, which researchers now say has a 1 in 45,000 chance of hitting Earth on 13 April 2036. Calculations show it would strike somewhere along a narrow track that stretches eastward from Siberia to the west coast of Africa.
    Compared to earlier estimates, the new figure represents a further reduction in the threat posed by Apophis (see Risk of asteroid smashing into Earth reduced). But the threat is real enough, experts argue, to merit a United Nations protocol for dealing with the problem.
    "Someone will have to make a decision," says Russell Schweickart, a former Apollo astronaut and founder of the Association of Space Explorers. Because any plan for deflecting the asteroid away from Earth will need to be implemented well before an impact site is precisely known, he says, "this is inherently going to be an international decision".
    Sky surveys
    Beginning in the next few months, Schweickart's group will host a series of meetings to provide the UN with a 'decision process' for assessing and acting on the hazard posed by Apophis and other near-Earth asteroids (NEAs). A draft document ready for consideration by the United Nations Committee on the Peaceful Uses of Outer Space is expected by

    (Excerpt) Read more at space.newscientist.com ...
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  20. #20
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    Default Re: NEO 2004 MN4 - Asteriod 99942 Apophis - Impact with Earth

    Fox news just reported that a group of scientists and astronauts have gone to the United Nations basically demanding that the UN put together a planning mission to deflect this asteroid.

    Apparently -- For once, I have hit something that is indeed a serious matter here.
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