Report of the Task Force on Potentially Hazardous NEAR EARTH OBJECTS 188-001BNSC NEO FC/IFC/IBC/BC 5/9/00 3:16 Pm Page 3
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Spacewalch Discovery of Near-Earth Asteroids Tom Gehrele Lunar End
N9 Spacewalch Discovery of Near-Earth Asteroids Tom Gehrele Lunar end Planetary Laboratory The University of Arizona Our overall scientific goal is to survey the solar system to completion -- that is, to find the various populations and to study their statistics, interrelations, and origins. The practical benefit to SERC is that we are finding Earth-approaching asteroids that are accessible for mining. Our system can detect Earth-approachers In the 1-km size range even when they are far away, and can detect smaller objects when they are moving rapidly past Earth. Until Spacewatch, the size range of 6 - 300 meters in diameter for the near-Earth asteroids was unexplored. This important region represents the transition between the meteorites and the larger observed near-Earth asteroids (Rabinowitz 1992). One of our Spacewatch discoveries, 1991 VG, may be representative of a new orbital class of object. If it is really a natural object, and not man-made, its orbital parameters are closer to those of the Earth than we have seen before; its delta V is the lowest of all objects known thus far (J. S. Lewis, personal communication 1992). We may expect new discoveries as we continue our surveying, with fine-tuning of the techniques. III-12 Introduction The data accumulated in the following tables are the result of continuing observation conducted as a part of the Spacewatch program. T. Gehrels is the Principal Investigator and also one of the three observers, with J.V. Scotti and D.L Rabinowitz, each observing six nights per month. R.S. McMillan has been Co-Principal Investigator of our CCD-scanning since its inception; he coordinates optical, mechanical, and electronic upgrades. -
Detecting and Avoiding Killer Asteroids
Target Earth! Detecting and Avoiding Killer Asteroids by Trudy E. Bell (Copyright 2013 Trudy E. Bell) ARTH HAD NO warning. When a mountain- above 2000°C and triggering earthquakes and volcanoes sized asteroid struck at tens of kilometers (miles) around the globe. per second, supersonic shock waves radiated Ocean water suctioned from the shoreline and geysered outward through the planet, shock-heating rocks kilometers up into the air; relentless tsunamis surged e inland. At ground zero, nearly half the asteroid’s kinetic energy instantly turned to heat, vaporizing the projectile and forming a mammoth impact crater within minutes. It also vaporized vast volumes of Earth’s sedimentary rocks, releasing huge amounts of carbon dioxide and sulfur di- oxide into the atmosphere, along with heavy dust from both celestial and terrestrial rock. High-altitude At least 300,000 asteroids larger than 30 meters revolve around the sun in orbits that cross Earth’s. Most are not yet discovered. One may have Earth’s name written on it. What are engineers doing to guard our planet from destruction? winds swiftly spread dust and gases worldwide, blackening skies from equator to poles. For months, profound darkness blanketed the planet and global temperatures dropped, followed by intense warming and torrents of acid rain. From single-celled ocean plank- ton to the land’s grandest trees, pho- tosynthesizing plants died. Herbivores starved to death, as did the carnivores that fed upon them. Within about three years—the time it took for the mingled rock dust from asteroid and Earth to fall out of the atmosphere onto the ground—70 percent of species and entire genera on Earth perished forever in a worldwide mass extinction. -
Extraordinary Rocks from the Peak Ring of the Chicxulub Impact Crater: P-Wave Velocity, Density, and Porosity Measurements from IODP/ICDP Expedition 364 ∗ G.L
Earth and Planetary Science Letters 495 (2018) 1–11 Contents lists available at ScienceDirect Earth and Planetary Science Letters www.elsevier.com/locate/epsl Extraordinary rocks from the peak ring of the Chicxulub impact crater: P-wave velocity, density, and porosity measurements from IODP/ICDP Expedition 364 ∗ G.L. Christeson a, , S.P.S. Gulick a,b, J.V. Morgan c, C. Gebhardt d, D.A. Kring e, E. Le Ber f, J. Lofi g, C. Nixon h, M. Poelchau i, A.S.P. Rae c, M. Rebolledo-Vieyra j, U. Riller k, D.R. Schmitt h,1, A. Wittmann l, T.J. Bralower m, E. Chenot n, P. Claeys o, C.S. Cockell p, M.J.L. Coolen q, L. Ferrière r, S. Green s, K. Goto t, H. Jones m, C.M. Lowery a, C. Mellett u, R. Ocampo-Torres v, L. Perez-Cruz w, A.E. Pickersgill x,y, C. Rasmussen z,2, H. Sato aa,3, J. Smit ab, S.M. Tikoo ac, N. Tomioka ad, J. Urrutia-Fucugauchi w, M.T. Whalen ae, L. Xiao af, K.E. Yamaguchi ag,ah a University of Texas Institute for Geophysics, Jackson School of Geosciences, Austin, USA b Department of Geological Sciences, Jackson School of Geosciences, Austin, USA c Department of Earth Science and Engineering, Imperial College, London, UK d Alfred Wegener Institute Helmholtz Centre of Polar and Marine Research, Bremerhaven, Germany e Lunar and Planetary Institute, Houston, USA f Department of Geology, University of Leicester, UK g Géosciences Montpellier, Université de Montpellier, France h Department of Physics, University of Alberta, Canada i Department of Geology, University of Freiburg, Germany j SM 312, Mza 7, Chipre 5, Resid. -
Physical Characterization of the Potentially-Hazardous High-Albedo Asteroid (33342) 1998 WT from Thermal-Infrared Observations Alan W
Physical Characterization of the Potentially-Hazardous High-Albedo Asteroid (33342) 1998 WT from Thermal-Infrared Observations Alan W. Harris, Michael Mueller, Marco Delbó, Schelte J. Bus To cite this version: Alan W. Harris, Michael Mueller, Marco Delbó, Schelte J. Bus. Physical Characterization of the Potentially-Hazardous High-Albedo Asteroid (33342) 1998 WT from Thermal-Infrared Observations. Icarus, Elsevier, 2007, 188 (2), pp.414. 10.1016/j.icarus.2006.12.003. hal-00499067 HAL Id: hal-00499067 https://hal.archives-ouvertes.fr/hal-00499067 Submitted on 9 Jul 2010 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Accepted Manuscript Physical Characterization of the Potentially-Hazardous High-Albedo Asteroid (33342) 1998 WT24 from Thermal-Infrared Observations Alan W. Harris, Michael Mueller, Marco Delbó, Schelte J. Bus PII: S0019-1035(06)00446-5 DOI: 10.1016/j.icarus.2006.12.003 Reference: YICAR 8146 To appear in: Icarus Received date: 27 September 2006 Revised date: 6 December 2006 Accepted date: 8 December 2006 Please cite this article as: A.W. Harris, M. Mueller, M. Delbó, S.J. Bus, Physical Characterization of the Potentially-Hazardous High-Albedo Asteroid (33342) 1998 WT24 from Thermal-Infrared Observations, Icarus (2006), doi: 10.1016/j.icarus.2006.12.003 This is a PDF file of an unedited manuscript that has been accepted for publication. -
Near Earth Asteroid (NEA) Scout
https://ntrs.nasa.gov/search.jsp?R=20160007060 2019-08-08T05:23:13+00:00Z Near Earth Asteroid (NEA) Scout Les Johnson NASA MSFC Advance Concepts Office [email protected] Topics • What is a solar sail? • A brief history of solar sailing • NASA’s Near Earth Asteroid Scout mission How does a solar sail work? Solar sails use photon “pressure” or force on thin, lightweight reflective sheet to produce thrust. 3 Topics • What is a solar sail? • A brief history of solar sailing • NASA’s Near Earth Asteroid Scout mission The Planetary Society’s Cosmos-1 (2005) • 100 kg spacecraft • 8 triangular sail blades deployed from a central hub after launch by the inflating of structural tubes. • Sail blades were each 15 m long • Total surface area of 600 square meters • Launched in 2005 from a Russian Volna Rocket from a Russian Delta III submarine in the Barents Sea: The Planetary Society’s Cosmos-1 (2005) • 100 kg spacecraft • 8 triangular sail blades deployed from a central hub after launch by the inflating of structural tubes. • Sail blades were each 15 m long • Total surface area of 600 square meters • Launched in 2005 from a Russian Volna Rocket from a Russian Delta III submarine in the Barents Sea: Rocket Failed NASA Ground Tested Solar Sails in the Mid-2000’s Two 400 square meter sail were autonomously deployed and tested at Plumbrook NanoSail-D Demonstration Solar Sail Mission Description: • 10 m2 sail • Made from tested ground demonstrator hardware NanoSail-D2 Mission (2010) Interplanetary Kite-craft Accelerated by Radiation of the Sun (IKAROS) -
Using Resources from Near-Earth Space
USING RESOURCES FROM NEAR-EARTH SPACE JOHN S. LEWIS University of Arizona DAVIDS. McKAY NASA Johnson Space Center and BENTON C. CLARK Martin Marietta Civil Space & Communications The parts of the solar system that are most accessible from Earth (the Moon, the near Earth asteroids, and Mars and its moons) are rich in materials of great potential value to humanity. Immediate uses of these resources to manufacture propellants, structural metals, refractories, life-support fluids and glass can support future large-scale space acitivites. In the longterm, non-terrestrial sources of rare materials and energy may be of great importance here on Earth. I. INTRODUCTION Space activities have become so much a part of modem life that they are almost invisible. We are aware how important communications satellite relays are for inexpensive long-distance telephone calls and television news broadcast, and we see the color images of Earth's cloud cover in the weather reports on TV. But we are usually not aware that the commercial airplane in which we fly or the ferry we ride locates itself by using navigation satellites 12,000 miles above our heads. We may never hear that the Soviet Union launched several satellites each year dedicated to assessing the American, Canadian, and Argentine wheat crops to help plan their grain purchases. We may be even more astonished to know that the truck we just passed on the highway is being tracked by a satellite, or that the strategic balance between the great powers has long been monitored based on photographic, electronic imaging, radar, infrared, and signal monitoring from space. -
Negotiating Uncertainty: Asteroids, Risk and the Media Felicity Mellor
Accepted pre-publication version Published at: Public Understanding of Science 19(1): (2010) 16-33. Negotiating Uncertainty: Asteroids, Risk and the Media Felicity Mellor ABSTRACT Natural scientists often appear in the news media as key actors in the management of risk. This paper examines the way in which a small group of astronomers and planetary scientists have constructed asteroids as risky objects and have attempted to control the media representation of the issue. It shows how scientists negotiate the uncertainties inherent in claims about distant objects and future events by drawing on quantitative risk assessments even when these are inapplicable or misleading. Although the asteroid scientists worry that media coverage undermines their authority, journalists typically accept the scientists’ framing of the issue. The asteroid impact threat reveals the implicit assumptions which can shape natural scientists’ public discourse and the tensions which arise when scientists’ quantitative uncertainty claims are re-presented in the news media. Keywords: asteroids, impact threat, astronomy, risk, uncertainty, science journalism, media, science news Introduction Over the past two decades, British newspapers have periodically announced the end of the world. Playful headlines such as “The End is Nigh” and “Armageddon Outta Here!” are followed a few days later by reports that there’s no danger after all: “PHEW. The end of the world has been cancelled” (Britten, 1998; Wickham, 2002; Evening Standard , 1998). These stories, and others like them appearing in news media around the world, deal with the possibility that an asteroid or comet may one day collide with the Earth causing global destruction. The threat posed by near-Earth objects (NEOs) has been actively promoted by a group of astronomers and planetary scientists since the late 1980s. -
The Eltanin Impact and Its Tsunami Along the Coast of South America: Insights for Potential Deposits
Earth and Planetary Science Letters 409 (2015) 175–181 Contents lists available at ScienceDirect Earth and Planetary Science Letters www.elsevier.com/locate/epsl The Eltanin impact and its tsunami along the coast of South America: Insights for potential deposits Robert Weiss a, Patrick Lynett b, Kai Wünnemann c a Department of Geosciences, Virginia Tech, VA 24061, USA b Sonny Astani Department of Civil and Environmental Engineering, University of Southern California, Los Angeles, CA 90089-2531, USA c Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstrasse 43, 10115 Berlin, Germany a r t i c l e i n f o a b s t r a c t Article history: The Eltanin impact occurred 2.15 million years ago in the Bellinghausen Sea in the southern Pacific. Received 21 June 2014 While a crater was not formed, evidence was left behind at the impact site to prove the impact origin. Received in revised form 10 October 2014 Previous studies suggest that a large tsunami formed, and sedimentary successions along the coast of Accepted 19 October 2014 South America have been attributed to the Eltanin impact tsunami. They are characterized by large clasts, Available online xxxx often several meters in diameter. Our state-of-the-art numerical modeling of the impact process and its Editor: J. Lynch-Stieglitz coupling with non-linear wave simulations allows for quantifying the initial wave characteristic and the Keywords: propagation of tsunami-like waves over large distances. We find that the tsunami attenuates quickly with −1.2 Eltanin impact η(r) ∝ r resulting in maximum wave heights similar to those observed during the 2004 Sumatra tsunamis and 2011 Tohoku-oki tsunamis. -
A PROTEROZOIC 40Ar/39Ar AGE for the SUVASVESI SOUTH STRUCTURE (FINLAND)
72nd Annual Meteoritical Society Meeting (2009) 5076.pdf A PROTEROZOIC 40Ar/39Ar AGE FOR THE SUVASVESI SOUTH STRUCTURE (FINLAND). E. Buchner1, M. Schmieder1, W. H. Schwarz2, M. Trieloff2, J. Moilanen3, T. Öhman4 and H. Stehlik5. 1Institut für Planetologie, Universität Stuttgart, D-70174 Stuttgart, Germany. Email: [email protected]. 2Institut für Geowissenschaften, Universität Heidelberg, D-69120 Heidelberg. 3Pinkelikatu 6 B 48, FI-90520 Oulu, Finland. 4Department of Geosciences, FI-90014 University of Oulu, Finland. 5Hagedornweg 2/2/12, A-1220 Vienna, Austria Introduction: The Suvasvesi North (diameter ~3.5 km) and South (diameter ~4.0 km) structures [1-3] in Finland are thought to represent a double impact crater system, similar to the Clearwater lakes in Canada [4]. As no isotopic data have so far been available, only the age of the ~1.88 Ga Paleoproterozoic (and some ~2.7 Ga Archean) crystalline target rocks of the Baltic Shield [1] is cited as the maximum impact age. Paleomagnetic data suggested either a Permo-Triassic (~230-280 Ma) or a Neoproterozoic (770-790 Ma) age for the Suvasvesi North impact structure [4,5]. We here present the first 40Ar/39Ar age for the Suvasvesi South structure. Samples and analytical procedure: Clast-poor particles of impact melt rock (87.1 mg) recovered by one of the authors (J. M.) from the Mannamäki area were chosen for 40Ar/39Ar dat- ing at the University of Heidelberg [6,7]. Results and interpretation: 40Ar/39Ar step-heating analysis yielded no plateau within a perturbed, hump-shaped [8] age spectrum with younger apparent ages (~100-450 Ma) within the low-temperature (T) heating steps (~13% of 39Ar released), older apparent ages (~820 Ma) in the mid-T fractions (~47% of 39Ar), and intermediate apparent ages (~715-710) Ma in the four final high-T steps (~40% of 39Ar). -
Distribution and Orientation of Boulders on Asteroid 25143 Itokawa
Distribution and Orientation of Boulders on Asteroid 25143 Itokawa Sara Mazrouei-Seidani A Thesis submitted to the Faculty of Graduate Studies in Partial Fulfillment of the Requirements for the Degree of Master of Science Graduate Program in Earth and Space Science, York University, Toronto, Ontario September 2012 © Sara Mazrouei-Seidani 2012 Library and Archives Bibliotheque et Canada Archives Canada Published Heritage Direction du 1+1 Branch Patrimoine de I'edition 395 Wellington Street 395, rue Wellington Ottawa ON K1A0N4 Ottawa ON K1A 0N4 Canada Canada Your file Votre reference ISBN: 978-0-494-91769-5 Our file Notre reference ISBN: 978-0-494-91769-5 NOTICE: AVIS: The author has granted a non L'auteur a accorde une licence non exclusive exclusive license allowing Library and permettant a la Bibliotheque et Archives Archives Canada to reproduce, Canada de reproduire, publier, archiver, publish, archive, preserve, conserve, sauvegarder, conserver, transmettre au public communicate to the public by par telecommunication ou par I'lnternet, preter, telecommunication or on the Internet, distribuer et vendre des theses partout dans le loan, distrbute and sell theses monde, a des fins commerciales ou autres, sur worldwide, for commercial or non support microforme, papier, electronique et/ou commercial purposes, in microform, autres formats. paper, electronic and/or any other formats. The author retains copyright L'auteur conserve la propriete du droit d'auteur ownership and moral rights in this et des droits moraux qui protege cette these. Ni thesis. Neither the thesis nor la these ni des extraits substantiels de celle-ci substantial extracts from it may be ne doivent etre imprimes ou autrement printed or otherwise reproduced reproduits sans son autorisation. -
The Comet's Tale
THE COMET’S TALE Journal of the Comet Section of the British Astronomical Association Number 33, 2014 January Not the Comet of the Century 2013 R1 (Lovejoy) imaged by Damian Peach on 2013 December 24 using 106mm F5. STL-11k. LRGB. L: 7x2mins. RGB: 1x2mins. Today’s images of bright binocular comets rival drawings of Great Comets of the nineteenth century. Rather predictably the expected comet of the century Contents failed to materialise, however several of the other comets mentioned in the last issue, together with the Comet Section contacts 2 additional surprise shown above, put on good From the Director 2 appearances. 2011 L4 (PanSTARRS), 2012 F6 From the Secretary 3 (Lemmon), 2012 S1 (ISON) and 2013 R1 (Lovejoy) all Tales from the past 5 th became brighter than 6 magnitude and 2P/Encke, 2012 RAS meeting report 6 K5 (LINEAR), 2012 L2 (LINEAR), 2012 T5 (Bressi), Comet Section meeting report 9 2012 V2 (LINEAR), 2012 X1 (LINEAR), and 2013 V3 SPA meeting - Rob McNaught 13 (Nevski) were all binocular objects. Whether 2014 will Professional tales 14 bring such riches remains to be seen, but three comets The Legacy of Comet Hunters 16 are predicted to come within binocular range and we Project Alcock update 21 can hope for some new discoveries. We should get Review of observations 23 some spectacular close-up images of 67P/Churyumov- Prospects for 2014 44 Gerasimenko from the Rosetta spacecraft. BAA COMET SECTION NEWSLETTER 2 THE COMET’S TALE Comet Section contacts Director: Jonathan Shanklin, 11 City Road, CAMBRIDGE. CB1 1DP England. Phone: (+44) (0)1223 571250 (H) or (+44) (0)1223 221482 (W) Fax: (+44) (0)1223 221279 (W) E-Mail: [email protected] or [email protected] WWW page : http://www.ast.cam.ac.uk/~jds/ Assistant Director (Observations): Guy Hurst, 16 Westminster Close, Kempshott Rise, BASINGSTOKE, Hampshire. -
Detecting the Yarkovsky Effect Among Near-Earth Asteroids From
Detecting the Yarkovsky effect among near-Earth asteroids from astrometric data Alessio Del Vignaa,b, Laura Faggiolid, Andrea Milania, Federica Spotoc, Davide Farnocchiae, Benoit Carryf aDipartimento di Matematica, Universit`adi Pisa, Largo Bruno Pontecorvo 5, Pisa, Italy bSpace Dynamics Services s.r.l., via Mario Giuntini, Navacchio di Cascina, Pisa, Italy cIMCCE, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universits, UPMC Univ. Paris 06, Univ. Lille, 77 av. Denfert-Rochereau F-75014 Paris, France dESA SSA-NEO Coordination Centre, Largo Galileo Galilei, 1, 00044 Frascati (RM), Italy eJet Propulsion Laboratory/California Institute of Technology, 4800 Oak Grove Drive, Pasadena, 91109 CA, USA fUniversit´eCˆote d’Azur, Observatoire de la Cˆote d’Azur, CNRS, Laboratoire Lagrange, Boulevard de l’Observatoire, Nice, France Abstract We present an updated set of near-Earth asteroids with a Yarkovsky-related semi- major axis drift detected from the orbital fit to the astrometry. We find 87 reliable detections after filtering for the signal-to-noise ratio of the Yarkovsky drift esti- mate and making sure the estimate is compatible with the physical properties of the analyzed object. Furthermore, we find a list of 24 marginally significant detec- tions, for which future astrometry could result in a Yarkovsky detection. A further outcome of the filtering procedure is a list of detections that we consider spurious because unrealistic or not explicable with the Yarkovsky effect. Among the smallest asteroids of our sample, we determined four detections of solar radiation pressure, in addition to the Yarkovsky effect. As the data volume increases in the near fu- ture, our goal is to develop methods to generate very long lists of asteroids with reliably detected Yarkovsky effect, with limited amounts of case by case specific adjustments.