New Evidence and Analysis for Chicxulub and the Evidence for a Dinosaur-Killing Impact

Link: Science Magazine Article ("The Chicxulub Asteroid Impact and Mass Extinction at the Cretaceous-Paleogene Boundary"): Science 5 March 2010: Vol. 327. no. 5970, pp. 1214 - 1218

The Chicxulub Asteroid Impact and Mass Extinction at the Cretaceous-Paleogene Boundary

Peter Schulte,1,* Laia Alegret,2 Ignacio Arenillas,2 José A. Arz,2 Penny J. Barton,3 Paul R. Bown,4 Timothy J. Bralower,5 Gail L. Christeson,6 Philippe Claeys,7 Charles S. Cockell,8 Gareth S. Collins,9 Alexander Deutsch,10 Tamara J. Goldin,11 Kazuhisa Goto,12 José M. Grajales-Nishimura,13 Richard A. F. Grieve,14 Sean P. S. Gulick,6 Kirk R. Johnson,15 Wolfgang Kiessling,16 Christian Koeberl,11 David A. Kring,17 Kenneth G. MacLeod,18 Takafumi Matsui,19 Jay Melosh,20 Alessandro Montanari,21 Joanna V. Morgan,9 Clive R. Neal,22 Douglas J. Nichols,15 Richard D. Norris,23 Elisabetta Pierazzo,24 Greg Ravizza,25 Mario Rebolledo-Vieyra,26 Wolf Uwe Reimold,16 Eric Robin,27 Tobias Salge,28 Robert P. Speijer,29 Arthur R. Sweet,30 Jaime Urrutia-Fucugauchi,31 Vivi Vajda,32 Michael T. Whalen,33 Pi S. Willumsen32

The Cretaceous-Paleogene boundary ~65.5 million years ago marks one of the three largest mass extinctions in the past 500 million years. The extinction event coincided with a large asteroid impact at Chicxulub, Mexico, and occurred within the time of Deccan flood basalt volcanism in India. Here, we synthesize records of the global stratigraphy across this boundary to assess the proposed causes of the mass extinction. Notably, a single ejecta-rich deposit compositionally linked to the Chicxulub impact is globally distributed at the Cretaceous-Paleogene boundary. The temporal match between the ejecta layer and the onset of the extinctions and the agreement of ecological patterns in the fossil record with modeled environmental perturbations (for example, darkness and cooling) lead us to conclude that the Chicxulub impact triggered the mass extinction.

1 GeoZentrum Nordbayern, Universität Erlangen-Nürnberg, Schlossgarten 5, D-91054 Erlangen, Germany.
2 Departamento de Ciencias de la Tierra e Instituto Universitario de Investigación de Ciencias Ambientales de Aragón, Universidad de Zaragoza, Pedro Cerbuna 12, E-50009 Zaragoza, Spain.
3 Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ, UK.
4 Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK.
5 Department of Geosciences, Pennsylvania State University, University Park, PA 16802, USA.
6 Institute for Geophysics, Jackson School of Geosciences, University of Texas at Austin, J.J. Pickle Research Campus, 10100 Burnet Road 196-ROC, Austin, TX 78759, USA.
7 Earth System Science, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium.
8 Centre for Earth, Planetary, Space and Astronomical Research, Open University, Milton Keynes MK7 6AA, UK.
9 Earth Science and Engineering, Imperial College London, London SW7 2BP, UK.
10 Institut für Planetologie, Universität Münster, D-48149 Münster, Germany.
11 Department of Lithospheric Research, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria.
12 Tsunami Engineering Laboratory, Disaster Control Research Center, Graduate School of Engineering, Tohoku University, 6-6-11-1106 Aoba, Aramaki, Sendai 980-8579, Japan.
13 Programa de Geología de Exploracíon y Explotacíon, Dirección de Investigación y Posgrado, Instituto Mexicano del Petróleo, Eje Lázaro Cárdenas No. 152, C.P. 07730, México City, México.
14 Earth Sciences Sector, Natural Resources Canada, Ottawa, Ontario K1A 0E4, Canada.
15 Research and Collections Division, Denver Museum of Nature and Science, 2001 Colorado Boulevard, Denver, CO 80205, USA.
16 Museum für Naturkunde, Leibniz Institute at the Humboldt University Berlin, Invalidenstrasse 43, D-10115 Berlin, Germany.
17 Center for Lunar Science and Exploration, Universities Space Research Association–Lunar and Planetary Institute, 3600 Bay Area Boulevard, Houston, TX 77058–1113, USA.
18 Department of Geological Sciences, University of Missouri, Columbia, MO 65211, USA.
19 Planetary Exploration Research Center, Chiba Institute of Technology, 2-17-1 Tsudanuma, Narashino, Chiba 275-0016, Japan.
20 Earth and Atmospheric Sciences, Purdue University, 550 Stadium Mall Drive, West Lafayette, IN 47907–2051, USA.
21 Osservatorio Geologico di Coldigioco, 62021 Apiro (MC), Italy.
22 Department of Civil Engineering and Geological Sciences, 156 Fitzpatrick Hall, University of Notre Dame, Notre Dame, IN 46556, USA.
23 SIO Geological Collections, 301 Vaughan Hall, MS-0244, Scripps Institution of Oceanography, La Jolla, CA 92093–0244, USA.
24 Planetary Science Institute, 1700 East Fort Lowell Road, Suite 106, Tucson, AZ 85719, USA.
25 Department of Geology and Geophysics, School of Ocean and Earth Science and Technology, University of Hawaii, Manoa, Honolulu, HI 96822, USA.
26 Unidad de Ciencias del Agua, Centro de Investigación Científica de Yucatán, A.C., Calle 8, No. 39, Mz. 29, S.M. 64, Cancún, Quintana Roo, 77500, México.
27 Laboratoire des Sciences du Climat et de l’Environnement, Institut Pierre et Simon Laplace, Commission à l’Énergie Atomique/CNRS/Université de Versailles Saint Quentin en Yveunes–UMR 1572, Avenue de la Terrasse, F-91198 Gif-sur-Yvette Cedex, France.
28 Bruker Nano GmbH, Schwarzschildstraße 12, D-12489 Berlin, Germany.
29 Department of Earth and Environmental Sciences, K.U.Leuven, Box 2408, Celestijnenlaan 200E, 3001 Leuven, Belgium.
30 Natural Resources Canada, Geological Survey of Canada Calgary, 3303 33rd Street NW, Calgary, AB T2L 2A7, Canada.
31 Laboratorio de Paleomagnetismo y Paleoambientes, Programa Universitario de Perforaciones en Oceanos y Continentes, Instituto de Geofísica, Universidad Nacional Autónoma de México (UNAM), DF 04510 Mexico, Mexico.
32 Department of Earth and Ecosystem Sciences, Lund University, Sölvegatan 12, 223 62 Lund, Sweden.
33 Department of Geology and Geophysics, University of Alaska, Fairbanks, AK 99775, USA.

From NSF Press Release...

For decades, scientists have accumulated ever-larger datasets that suggest an enormous space rock crashed into the ocean off the Yucatan Peninsula more than 65 million years ago, resulting in the Cretaceous-Paleogene (K-Pg) extinction.

Recent research, supported in part by the National Science Foundation (NSF), suggested that the impact could have occurred 300,000 years prior to the K-Pg extinction, and that another cause--perhaps a second impact, or the long-lasting volcanic activity at the Deccan Traps in what is now India--drove numerous plant and animal species to their end.

Now, an interdisciplinary team of 41 scientists from 12 nations, also supported in part by NSF, has prepared a paper to specifically counter the volcanic and dual-impact alternatives, a comprehensive review of the multiple, global lines of evidence linking a single impact near what is now Chicxulub, Mexico, to the timing and breadth of the K-Pg extinction.

The researchers, led by Peter Schulte of the University of Erlangen-Nuremburg, present their findings in the March 5, 2010, issue of Science.

"We felt it important to present the wealth of data now available about the remarkable and exact correlation between the impact in the Yucatan and the extinction event at the K-Pg boundary," said University of Texas geophysicist Sean Gulick, one of the authors on the paper.

One factor that is not in dispute: the end of the Cretaceous 65.5 million years ago was marked by one of the most devastating extinctions our planet has faced. The most famous victims were the dinosaurs (their avian relatives notwithstanding), but the event also saw the loss of all flying reptiles, most marine reptiles, more than half of land plants and insects, and hosts of other terrestrial and marine organisms--50 to 70 percent of all species on Earth.

As with all mass extinctions, paleontologists have long asked why so many organisms disappeared so quickly. The cause, or causes, would have to influence a large swath of the planet, on land and sea, and would have to reflect observations in the geological record.

As referenced in the new Science paper, one of the key arguments for impact is a well-studied clay layer that appears at K-Pg boundary sites across the globe, usually in association with melt-glass remnants, shocked minerals, and other materials generated by impacts. The authors point out that the layer thickness and the abundance of impact materials both increase systematically with proximity to the Chicxulub crater.

Until 1980, none of the K-Pg boundary sites was linked to an impact. It was not until physicist Luis Alvarez and his son, geologist Walter Alvarez, took a closer look at a thin and unusual clay layer at K-Pg boundary sediments in Italy that the researchers realized the source might be extraterrestrial.

Within the layer--which the current paper now references to at least 350 sites around the world--the researchers found high levels of iridium. The heavy element is not normally found in high concentrations at Earth's surface, but it is highly concentrated in undifferentiated solar system material, like asteroids and comets.

Since that initial discovery, further studies by a number of teams--some of which are represented in the Science paper--uncovered more impact evidence within the clay, including the spherules of altered melt-glass and impact-shocked minerals.

"This clay layer--with evidence for it being impact in origin--is found at every well-preserved K-Pg boundary site in the world, showing a truly global event," added Gulick.

Additional studies, both in the field and in laboratory simulations and models, led to a growing consensus in support of the impact hypothesis. As it currently stands, the extinction resulted from the collision of a space rock roughly 10 kilometers in diameter into carbon- and sulfur-rich rocks beneath what is now Chicxulub, Mexico, yielding a crater that is more than 180 kilometers in diameter; regional tsunami, earthquakes and fires; extended (but not total) darkness; cooling temperatures and acid rain.

"The impact event triggered tsunami many times the size of the wave that hit the Indian Ocean on Dec. 26, 2004," said marine geologist Tim Bralower of Penn State University, another of the paper's authors. "These waves caused massive destruction on the sea floor, with the multiple sediment layers representing the deposition of impact-derived material, mixed with sand and silt, by waves and currents over periods of days after the impact. As the energy levels gradually decreased, the materials settling down gradually became finer."

In some sites close to the impact, around the Gulf of Mexico and the Caribbean, there are two spherule-bearing layers, at times separated by sediment a few meters thick, and some of the recent controversy stems from this apparent duality. The lower layer consists of coarser particles including spherules and shocked minerals, and the upper layer consists of finer particles and has a higher iridium content.

"Reports of multiple horizons with elevated iridium concentrations fairly close to the Chicxulub crater have led to a lot of confusion, and suggestions of multiple impacts," said fellow author Greg Ravizza, a marine and environmental geologist at the University of Hawaii at Manoa. "A key point that cannot be ignored is that data from several sites far away from the Chicxulub crater provide no evidence of multiple large impacts. This observation lends very strong support to the careful stratigraphic synthesis in our paper demonstrating the very complex, and frequently disturbed, character of the sections closest to the Chicxulub crater."

The authors close their paper by discussing the speed and scale with which the impact affected living systems, particularly in relation to the speed and scale of volcanic activity.

An impact the size of the Chicxulub event would release large amounts of water, dust and gasses into the atmosphere, temporarily changing climate. While dust alone would not have been able to cause a global winter, tiny carbonate particulates and soot may have amplified the impact's cooling effects.

An estimated 100-500 gigatons of sulfur was also released, contributing to devastating acid rains on land and in the oceans, and producing sunlight-absorbing sulfur aerosols that may have further cooled the Earth for several years.

Because deep ocean temperatures were largely unaffected, the researchers suggest that the climate recovered relatively rapidly. Such a brief transition is in contrast to the centuries-long influx of material into the atmosphere that would result from volcanic activity. Despite the enormity of the Deccan Traps volcanism, sulfur release, for example, might not surpass one half of a gigaton in a year.

At the slower pace of volcanism, organisms would have more time to react, and climatic changes may have approached 2 degrees Celsius of warming, as opposed to cooling.

"The Chicxulub impact was an extremely rapid perturbation of the Earth's ecosystems, at a scale greater than that of any single volcanic event at the time, or of any other impact known since life became prevalent on Earth," added Gulick. "The rate of change and scale of the effects were clearly the cause of the mass extinction at the end of the Cretaceous."

Additionally, the boundary between the end of the Cretaceous and the start of the Paleogene is marked by clear changes in the plants and animals that existed, a change that is not gradual. Species across the globe showed either extinction or major changes in abundance.

Darkness would have severely affected photosynthesis for ocean micro-organisms, eliminating the base for numerous food chains. As a result, the geologic record shows preferential extinction of organisms in food chains relying on plankton as a food source, and preferential survival for organisms in food-chains relying on a foundation of detritus and decayed matter. Many of the organisms that survived were also smaller, indicating survival was dependent on the ability to subsist on limited resources.

"As with the ocean, land-based ecosystems showed the same pattern of greater impact on food chains dependent on live plants," said paleobotanist Kirk Johnson of the Denver Museum of Nature & Science, another author on the paper. "All large, land animals perished. The survivors included groups of animals who either lived in rivers, streams, and lakes or who were small or lived in burrows. Forests were destroyed globally and the earliest Paleogene landscape was covered by ferns, a type of plant that can grow directly from spores--as opposed to conifers and flowering plants that require pollen to interact with a living plant for reproduction."

Across ecosystems, the Paleogene also marks a rapid radiation of new species filling in empty ecological niches, a process that would be unlikely following a more gradual extinction. Such biological evidence, the authors assert, matches best to an impact scenario, corroborating the evidence from the geologic record.

"I think it is likely that Deccan volcanism did have a global effect on Earth's climate, but several hundred thousand years before the end Cretaceous mass extinction," added Ravizza. "Clear evidence demonstrating massive volcanism right at the mass extinction horizon is lacking. While it may be tempting to make this connection, existing data constraining the timing and duration of volcanism just don't support the idea."

According to the authors, no alternative theory yet proposed addresses the global distribution of evidence for the Cretaceous-Paleogene extinction, nor does any other theory clearly present mechanisms that could have led to such abrupt and complete biotic changes.

"The precise correlation of this huge impact crater with a worldwide layer of impact debris--one that lies directly above the extinction level of both marine and land animals and plants--is one of the most phenomenal discoveries in Earth history," said Johnson. "The science is complex, but the story is simple: a single asteroid impact caused global extinctions at the K-Pg boundary."

H. Richard Lane, program director within the Earth Sciences Division at NSF has helped support the work of both research teams. "This ongoing exchange between two groups of scientists has fostered spirited community dialogue around an issue that is riveting to an engaged public," added Lane. "It feeds the appetite of a science-starved audience, and can only benefit science as a whole, while improving the public's understanding of how science progresses."

Link: National Science Foundation (NSF) Press Release

International Asteroid Search Campaign

This is a public outreach campaign, called the International Asteroid Search Campaign which has 7 participating countries located on 4 continents as participants. This campaign, called the NASA WISE Asteroid Search Campaign is "part of the public outreach program for the Wide-field Infrared Survey Explorer mission launched in December 2009." From the one of Galileo Teacher Training Program site in regards to the campaign...

The International Asteroid Search Campaign (IASC) is a program for high school and college students who search just hours-old astronomical images for original discoveries. These discoveries include Main Belt asteroids and near-Earth objects (NEOs). Students download the images on a daily basis, perform the analysis with provided software tools, and report their discoveries, which ultimately are recognized by the Minor Planet Center (MPC; Harvard University) and the International Astronomical Union (IAU).

This program is brought to schools at no cost for either participation or the software as an educational service provided by the Astronomical Research Institute (ARI; Charleston, IL), Hardin-Simmons University (HSU; Abilene, TX), Global Hands-On Universe Association (Portugal), and Lawrence Hall of Science (University of California, Berkeley). The software is provided by Astrometrica (Austria).

During times of Moon-less skies, the ARI takes images along the ecliptic using its 0.61-m and 0.81-m telescopes. The following morning these images are prepared and made available to the participating schools. The schools go to Hardin-Simmons University web site (http://iasc.hsutx.edu) where they download the images and use the software package Astrometrica to produce a plate solution and identify all of the moving objects. Astrometrica checks to see which of the objects are found within the MPC database. Those objects not found are identified as new discoveries

In order to complete the discovery, the ARI must take a follow-up image within seven days. When this is completed, the MPC officially recognizes the discovery and credits the students having conducted the analysis.

Search campaigns are run for 30 days at a time. A key goal of these campaigns is to establish ongoing astronomy research programs at high schools and colleges. These schools will be able to directly access the images from the Astronomical Research Institute on an ongoing basis, and integrate these searches into their science curriculums.

Link: International Asteroid Search Campaign

Link: Galileo Teacher Training Program on International Asteroid Search Campaign

Call for Proposals: The Planetary Society 2010 Gene Shoemaker NEO Grant

The call for proposals is out for the 2010 Gene Shoemaker NEO grants by The Planetary Society (TPS), more information from the announcement...

The trends identified in the 2006 and 2008 Shoemaker NEO Grant calls for proposals continue. Therefore, the 2010 call for proposals, issued on March 16, 2010, is identical to the ones from previous years. The deadline for applications is June 10, 2010.

Since its founding, The Planetary Society has actively supported a number of efforts to discover and characterize the population of near-Earth objects (NEOs) that both threaten our planet and hold great promise for future exploration. In 1997, the Society began the Gene Shoemaker NEO grant program to help in the global effort to meet the Spaceguard goal of discovering 90% of the 1-kilometer (0.6-mile) and larger NEOs that can impact our planet. The program honors pioneering planetary geologist Gene Shoemaker, who did so much to help us understand the process of impact cratering on the planets and the nature of the NEO population, and seeks to assist amateur observers, observers in developing countries, and under-funded professional observers in contributing to vital NEO research.

To date, the Society has awarded 32 Shoemaker NEO grants totaling more than $202,000 to observers around the world. Grant recipients have played critical roles in recovering small asteroids newly discovered by the major asteroid survey programs by providing the crucial follow-up observations to determine precise orbits for these objects.

Applications for the current round of Shoemaker NEO grants are due June 10, 2010. Grant sizes are typically $3,000 to $10,000. The Planetary Society welcomes applications from amateur and under-funded professional observers anywhere in the world. All applications will be reviewed by an international panel of NEO experts.

Link: 2010 Shoemaker NEO Grant Call for Proposals

Link: Update on Shoemaker NEO grants (18 March 2010)

Link: The Planetary Society Announcement (17 March 2010)

Help WISE Find Asteroids

How to help the Wide-field Infrared Survey Explorer (WISE) spacecraft follow-up on potential asteroids/comets it has detected. Selected Q/A from the WISE Spacecraft website...

Q: I thought WISE was going to find all these asteroids?

A: WISE will make initial observations of hundreds of NEOs and tens of thousands of Main Belt asteroids, but because it orbits the Earth over the day-night terminator and always looks up, WISE will only observe each asteroid approximately 10 times over about 30 hours.  Without more observations within about 10-14 days, all of the new NEOs and PHAs WISE finds will be lost.
 
Q: When an asteroid is lost, where does it go?

A: Well, it doesn't really 'go' anywhere.  Asteroids (just like planets andcomets) orbit the Sun, which makes them move when compared to the background stars.  From many observations over weeks, months, and years we can calculate a very accurate orbit for the asteroids that will allow us to find them again anytime in the future.  But if we only have a short window over which we observe the object (like the observations WISE will make) then the orbits are more uncertain, and if we wait too long we won't be able to find them again.  The asteroids are still there in space orbiting the Sun, but we don't know where.  That's why we need ground-based observers' help to nail down the orbits.
 
Q: So how can I help?

A: It's easy! All you need to do is look up WISE NEOs on the Minor Planet Center's NEO confirmation page (http://www.cfa.harvard.edu/iau/NEO/ToConfirm.html), download their predicted positions and errors, and start observing them.  In particular, you'll need to measure the position of the object on the sky, called its astrometry.  You'll also find an estimate of each object's brightness at optical wavelengths, called its visual magnitude.  This tells you whether or not the object will be bright enough to see with your telescope, and how long an exposure time you will need.

Link: WISE Mission Site (Science: Asteroids)

Presentations from NRC Planetary Science Decadal Survey: Presentations to Primitive Bodies Panel September 2009

A little older set of presentations, but some on meteor/asteroid science. Here is the information from the NRC Planetary Science website...

NRC Planetary Science Decadal Survey: Presentations to Primitive Bodies Panel September 2009. The following presentations were made to the first meeting of the Primitive Bodies panel of the National Research Council's (NRC's) Planetary Science Decadal Survey.  The meeting was held on September 9-11, 2009 in Washington, D.C.  Titles of the presentations are from the agenda for the meeting.  Adobe 8.0 or higher is needed to open most of these files.  Some are quite large and may take a few moments to load; please be patient.   If a presentation is missing from this list, it was unavailable or too large to post.

• Lessons Learned from the 2003 Decadal Survey, Dale Cruikshank, NASA Ames
• Charge to the Decadal Survey, James Green and Lindley Johnson, NASA HQ
• NSF's Support for the Planetary Sciences, Vernon Pankonin, NSF
• SBAG's Goals and Priorities, Mark Sykes, Planetary Science Institute
• Asteroid Science Goals 1, Faith Vilas, Director, MMT Observatory
• Asteroid Science Goals 2, Erik Asphaug, Univ. of Calif. Santa Cruz
• Comet Science Goals 1, Jessica Sunshine, University of Maryland
• Comet Science Goals 2, Donald Brownlee, University of Washington
• Meteorite Science Goals 1, Timothy McCoy, Smithsonian
• Meteorite Science Goals 2, Mark Sephton, Imperial College
• Kuiper Belt Science Goals 1, Michael Brown, CalTech
• Kuiper Belt Science Goals 2, Marc Buie, Southwest Research Institute
• Rosetta Status Report, Rita Schulz, European Space Agency
• EPOXI Status Report, Michael A'Hearn, University of Maryland
• Hayabusa Status Report, Donald Yeomans, JPL
• Dawn Status Report, Harry Y. McSween, University of Tennessee, Knoxville
• Stardust-NEXT Status Report, Joseph Veverka, Cornell

Link: NRC Planetary Science Decadal Survey: Presentations to Primitive Bodies Panel September 2009

Apophis Exploration and Mitigation Platform (AEMP)

The AEMP is a Apophis mission design. They have a LEO demonstrator they are working on with King Abdulaziz City for Science and Technology (KACST). KACST is involved through a US$1M proposal to help develop the LEO demonstrator (more on AEMP website). From the AEMP website...

The Apophis Exploration and Mitigation Platform (AEMP) mission is to study the physical characteristics and accurately determine the trajectory of the NEA Apophis 99942 in order to determine the probability of an Earth impact in 2036 and mitigte the probability of that impact and future impacts by applying short term and long-term mitigation techniques.

The AEMP mission is a collaboration between four groups. The TAMU Apophis Study Group consists of graduate students developing the payload and mission concept. The undergraduate AERO 426 program, part of the Learning Through Research program at Texas A&M, is responsible for the preliminary design of a LEO flight test of the albedo change payload. NASA Ames Research Center is providing technical expertise and mission control aspects. The King Abdulaziz City for Science and Technology (KACST) will be responsible for the spacecraft bus and integration.

Link: Apophis Exploration and Mitigation Platform (AEMP) Homepage

Link: AEMP Graduate Student Shen Ge Homepage (additional documents)

United Nations Committee on the Peaceful Uses of Outer Space, Draft report of the Working Group on Near-Earth Objects (17 February 2010)

NEO report from the 47th Scientific and Technical Subcommittee of the Committee on the Peaceful Uses of Outer Space that was held from 8 to 19 February 2010 at the United Nation Office at Vienna, Vienna International Center, Vienna, Austria.

Link: Draft report of the Working Group on Near-Earth Objects (17 February 2010)

Link: 47th UNCOPUOS S&T Sub Subcommittee: Agenda and Reports/Presentations

Secure World Foundation (SWF) Report on NEOs: Legal Aspects of NEO Threat Response and Related Institutional Issues (09 February 2010)

From the SWF Press Release about a report on the findings of an international set of experts on how to deal with policy issues dealing with NEOs, following up on the work of the ASE report from last year.

In a presentation at the United Nations, Secure World Foundation (SWF) released the findings of a group of international experts that outlines needed steps and concerns in establishing a global detection and warning network to deal with possible Near Earth Object (NEO) threats to Earth.

An additional report, sponsored by SWF, has been issued by the space law department at the University of Nebraska-Lincoln, examining the legal and institutional issues linked to potential future threats posed by NEOs.

The findings presented to the UN were the result of a workshop organized earlier this year by Secure World Foundation in coordination with the Association of Space Explorers and the Regional Centre for Space Science and Technology Education in Latin America and the Caribbean (CRECTEALC). The meeting was hosted by the Mexican Ministry of Foreign Affairs in Mexico City.

An interdisciplinary group, including asteroid tracking specialists, space scientists, former astronauts, United Nations authorities, and disaster management, risk psychology and warning communication experts gathered to take part in the seminal workshop held January 18-20 in Mexico City.

Link: SWF Press Release

Link: SWF Website (Key Reports Related to NEOs)

NASA News Release: "Suspected Asteroid Collision Leaves Trailing Debris"

From NASA news release:

NASA's Hubble Space Telescope has observed a mysterious X-shaped debris pattern and trailing streamers of dust that suggest a head-on collision between two asteroids. Astronomers have long thought the asteroid belt is being ground down through collisions, but such a smashup has never been seen before.

Asteroid collisions are energetic, with an average impact speed of more than 11,000 miles per hour, or five times faster than a rifle bullet. The comet-like object imaged by Hubble, called P/2010 A2, was first discovered by the Lincoln Near-Earth Asteroid Research, or LINEAR, program sky survey on Jan. 6. New Hubble images taken on Jan. 25 and 29 show a complex X-pattern of filamentary structures near the nucleus.

"This is quite different from the smooth dust envelopes of normal comets," said principal investigator David Jewitt of the University of California at Los Angeles. "The filaments are made of dust and gravel, presumably recently thrown out of the nucleus. Some are swept back by radiation pressure from sunlight to create straight dust streaks. Embedded in the filaments are co-moving blobs of dust that likely originated from tiny unseen parent bodies."

Hubble shows the main nucleus of P/2010 A2 lies outside its own halo of dust. This has never been seen before in a comet-like object. The nucleus is estimated to be 460 feet in diameter.

Normal comets fall into the inner regions of the solar system from icy reservoirs in the Kuiper belt and Oort cloud. As comets near the sun and warm up, ice near the surface vaporizes and ejects material from the solid comet nucleus via jets. But P/2010 A2 may have a different origin. It orbits in the warm, inner regions of the asteroid belt where its nearest neighbors are dry rocky bodies lacking volatile materials.

This leaves open the possibility that the complex debris tail is the result of an impact between two bodies, rather than ice simply melting from a parent body.

"If this interpretation is correct, two small and previously unknown asteroids recently collided, creating a shower of debris that is being swept back into a tail from the collision site by the pressure of sunlight," Jewitt said.

The main nucleus of P/2010 A2 would be the surviving remnant of this so-called hypervelocity collision.

"The filamentary appearance of P/2010 A2 is different from anything seen in Hubble images of normal comets, consistent with the action of a different process," Jewitt said. An impact origin also would be consistent with the absence of gas in spectra recorded using ground-based telescopes.

The asteroid belt contains abundant evidence of ancient collisions that have shattered precursor bodies into fragments. The orbit of P/2010 A2 is consistent with membership in the Flora asteroid family, produced by collisional shattering more than 100 million years ago. One fragment of that ancient smashup may have struck Earth 65 million years ago, triggering a mass extinction that wiped out the dinosaurs. But, until now, no such asteroid-asteroid collision has been caught "in the act."

At the time of the Hubble observations, the object was approximately 180 million miles from the sun and 90 million miles from Earth. The Hubble images were recorded with the new Wide Field Camera 3 (WFC3), which is capable of detecting house-sized fragments at the distance of the asteroid belt.

Link: NASA News Release

Link: Hubble News Release

NASA New Budget for FY2011 (Increases by $16M/year for NEO Identificaiton and Cataloging + Programs for robotic precursors)

On the new NASA Budget for FY2011 there is a major new funding for NEO identification and cataloging of NEOs, specifically an increase by $16M/year. This will an emphasis on various robotic precursor programs including "demonstrating a factory to process lunar or asteroid materials for use for various purposes."

Link: NASA FY2011 Budget Documents