Physical Characterization Studies of Near-Earth Object Spacecraft Mission Targets
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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. -
The Catalina Sky Survey
The Catalina Sky Survey Current Operaons and Future CapabiliKes Eric J. Christensen A. Boani, A. R. Gibbs, A. D. Grauer, R. E. Hill, J. A. Johnson, R. A. Kowalski, S. M. Larson, F. C. Shelly IAWN Steering CommiJee MeeKng. MPC, Boston, MA. Jan. 13-14 2014 Catalina Sky Survey • Supported by NASA NEOO Program • Based at the University of Arizona’s Lunar and Planetary Laboratory in Tucson, Arizona • Leader of the NEO discovery effort since 2004, responsible for ~65% of new discoveries (~46% of all NEO discoveries). Currently discovering NEOs at a rate of ~600/year. • 2 survey telescopes run by a staff of 8 (observers, socware developers, engineering support, PI) Current FaciliKes Mt. Bigelow, AZ Mt. Lemmon, AZ 0.7-m Schmidt 1.5-m reflector 8.2 sq. deg. FOV 1.2 sq. deg. FOV Vlim ~ 19.5 Vlim ~ 21.3 ~250 NEOs/year ~350 NEOs/year ReKred FaciliKes Siding Spring Observatory, Australia 0.5-m Uppsala Schmidt 4.2 sq. deg. FOV Vlim ~ 19.0 2004 – 2013 ~50 NEOs/year Was the only full-Kme NEO survey located in the Southern Hemisphere Notable discoveries include Great Comet McNaught (C/2006 P1), rediscovery of Apophis Upcoming FaciliKes Mt. Lemmon, AZ 1.0-m reflector 0.3 sq. deg. FOV 1.0 arcsec/pixel Operaonal 2014 – currently in commissioning Will be primarily used for confirmaon and follow-up of newly- discovered NEOs Will remove follow-up burden from CSS survey telescopes, increasing available survey Kme by 10-20% Increased FOV for both CSS survey telescopes 5.0 deg2 1.2 ~1,100/ G96 deg2 night 19.4 deg2 2 703 8.2 deg 2 ~4,300 deg per night New 10k x 10k cameras will increase the FOV of both survey telescopes by factors of 4x and 2.4x. -
Cassini RADAR Sequence Planning and Instrument Performance Richard D
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 47, NO. 6, JUNE 2009 1777 Cassini RADAR Sequence Planning and Instrument Performance Richard D. West, Yanhua Anderson, Rudy Boehmer, Leonardo Borgarelli, Philip Callahan, Charles Elachi, Yonggyu Gim, Gary Hamilton, Scott Hensley, Michael A. Janssen, William T. K. Johnson, Kathleen Kelleher, Ralph Lorenz, Steve Ostro, Member, IEEE, Ladislav Roth, Scott Shaffer, Bryan Stiles, Steve Wall, Lauren C. Wye, and Howard A. Zebker, Fellow, IEEE Abstract—The Cassini RADAR is a multimode instrument used the European Space Agency, and the Italian Space Agency to map the surface of Titan, the atmosphere of Saturn, the Saturn (ASI). Scientists and engineers from 17 different countries ring system, and to explore the properties of the icy satellites. have worked on the Cassini spacecraft and the Huygens probe. Four different active mode bandwidths and a passive radiometer The spacecraft was launched on October 15, 1997, and then mode provide a wide range of flexibility in taking measurements. The scatterometer mode is used for real aperture imaging of embarked on a seven-year cruise out to Saturn with flybys of Titan, high-altitude (around 20 000 km) synthetic aperture imag- Venus, the Earth, and Jupiter. The spacecraft entered Saturn ing of Titan and Iapetus, and long range (up to 700 000 km) orbit on July 1, 2004 with a successful orbit insertion burn. detection of disk integrated albedos for satellites in the Saturn This marked the start of an intensive four-year primary mis- system. Two SAR modes are used for high- and medium-resolution sion full of remote sensing observations by a dozen instru- (300–1000 m) imaging of Titan’s surface during close flybys. -
An Early Warning System for Asteroid Impact
An Early Warning System for Asteroid Impact John L. Tonry(1) ABSTRACT Earth is bombarded by meteors, occasionally by one large enough to cause a significant explosion and possible loss of life. It is not possible to detect all hazardous asteroids, and the efforts to detect them years before they strike are only advancing slowly. Similarly, ideas for mitigation of the danger from an impact by moving the asteroid are in their infancy. Although the odds of a deadly asteroid strike in the next century are low, the most likely impact is by a relatively small asteroid, and we suggest that the best mitigation strategy in the near term is simply to move people out of the way. With enough warning, a small asteroid impact should not cause loss of life, and even portable property might be preserved. We describe an \early warning" system that could provide a week's notice of most sizeable asteroids or comets on track to hit the Earth. This may be all the mitigation needed or desired for small asteroids, and it can be implemented immediately for relatively low cost. This system, dubbed \Asteroid Terrestrial-impact Last Alert System" (AT- LAS), comprises two observatories separated by about 100 km that simulta- neously scan the visible sky twice a night. Software automatically registers a comparison with the unchanging sky and identifies everything which has moved or changed. Communications between the observatories lock down the orbits of anything approaching the Earth, within one night if its arrival is less than a week. The sensitivity of the system permits detection of 140 m asteroids (100 Mton impact energy) three weeks before impact, and 50 m asteroids a week be- fore arrival. -
Linking the Solar System and Extrasolar Planetary
Linking the Solar System and Extrasolar Planetary Systems with Radar Astronomy Infrastructure for \Ground Truth" Comparison Authors: Joseph Lazio (Jet Propulsion Laboratory, California Institute of Technology), Am- ber Bonsall (Green Bank Observatory), Marina Brozovic (Jet Propulsion Laboratory, California Institute of Technology), Jon D. Giorgini (Jet Propulsion Laboratory, California Institute of Tech- nology), Karen O'Neil (Green Bank Observatory) Edgard Rivera-Valentin (Lunar & Planetary Institute), Anne Katariina Virkki (Univ. Central Florida) Endorsers: Francisco Cordova (Arecibo Observatory; Univ. Central Florida), Michael Busch (SETI Institute), Bruce A. Campbell (Smithsonian Institution), P. G. Edwards (CSIRO Astron- omy & Space Science), Yanga R. Fernandez (Univ. Central Florida), Ed Kruzins (Canberra Deep Space Communications Center), Noemi Pinilla-Alonso (Univ. Central Florida), Martin A. Slade (Jet Propulsion Laboratory, California Institute of Technology), F. C. F. Venditti (Univ. Central Florida) Point of Contact: Joseph Lazio, 818-354-4198; [email protected] (Left) Planetary radar image of Dione Regio on Venus. White arrows indicate radar- bright features that potentially represent debris from previous volcanic eruptions on Earth's twin planet. (Campbell et al. 2017) (Right) Planetary radar image of the near- Earth asteroid 2017 BQ6, acquired by the Goldstone Solar System Radar, showing sharp facets on this object. Near-Earth asteroids display a range of surface features, from which evolution and collisional processes occurring in the Sun's debris disk can be constrained. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration. The Arecibo Planetary Radar Program is supported by the National Aeronautics and Space Administration's Near-Earth Object Observa- tions Program through Grant No. -
Arxiv:1406.5253V1 [Astro-Ph.EP] 20 Jun 2014
Physical Properties of Near-Earth Asteroid 2011 MD M. Mommert Department of Physics and Astronomy, Northern Arizona University, PO Box 6010, Flagstaff, AZ 86011, USA D. Farnocchia Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA J. L. Hora Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 65, Cambridge, MA 02138-1516, USA S. R. Chesley Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA D. E. Trilling Department of Physics and Astronomy, Northern Arizona University, PO Box 6010, Flagstaff, AZ 86011, USA P. W. Chodas Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA arXiv:1406.5253v1 [astro-ph.EP] 20 Jun 2014 M. Mueller SRON Netherlands Institute for Space Research, Postbus 800, 9700 AV, Groningen, The Netherlands A. W. Harris DLR Institute of Planetary Research, Rutherfordstrasse 2, 12489 Berlin, Germany H. A. Smith –2– Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 65, Cambridge, MA 02138-1516, USA and G. G. Fazio Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 65, Cambridge, MA 02138-1516, USA Received ; accepted accepted by ApJL –3– ABSTRACT We report on observations of near-Earth asteroid 2011 MD with the Spitzer Space Telescope. We have spent 19.9 h of observing time with channel 2 (4.5 µm) of the Infrared Array Camera and detected the target within the 2σ positional uncertainty ellipse. Using an asteroid thermophysical model and a model of non- gravitational forces acting upon the object we constrain the physical properties of 2011 MD, based on the measured flux density and available astrometry data. -
Neofixer a Broker for Near Earth Asteroid Follow-Up Rob Seaman & Eric Christensen Catalina Sky Survey
NEOFIXER A BROKER FOR NEAR EARTH ASTEROID FOLLOW-UP ROB SEAMAN & ERIC CHRISTENSEN CATALINA SKY SURVEY Building the Infrastructure for Time-Domain Alert Science in the LSST Era • May 22-25, 2017 • Tucson CATALINA SKY SURVEY • LPL runs 2 NEO projects, CSS and SpacewatcH • Talk to Eric or me about CSS, Bob McMillan for SW • CSS demo at 3:30 pm CONGRESSIONAL MANDATE • Spaceguard goal: 1 km Near EartH Objects ✔ • George E Brown Act to find > 140m (H < 22) NEOs • 90% complete by 2020 ✘ (2017: ~ 30%) • ROSES 2017 language is > 100m • Chelyabinsk was ~20m (H ~ 25.8) or ~400 kiloton (few per century likeliHood) SUMMARY • Near EartH Asteroid inventory is “retail Big Data” • NEOfixer will be NEO-optimized targeting broker • No one broker will address all use cases • Will benefit LSST as well as current surveys • LSST not tasked to study NEOs, but ratHer tHe Solar System (slower objects and fartHer away) • What is tHe most valuable NEO observation a particular telescope can make at a particular time? CHESLEY & VERES (1705.06209) • 55 ± 5.0% for LSST baseline operating alone • But 42% of NEOs witH H < 22 will be discovered before 2022 • And witHout LSST, current surveys would discover 61% of the catalog by 2032 • Completion CH<22 will be 77% combined LSST will add 16% to CH<22 Can targeted follow-up increase this? CHESLEY & VERES (CAVEATS) • Lots of details worth reading • CH<22 degrades by ~1.8% for every 0.1 mag loss in sensitivity • Issues of linking efficiency including: • Efficiency down to H < 25 is lower • 4% false MBA-MBA links ASTROMETRIC -
Exploration of the Planets – 1971
Video Transcript for Archival Research Catalog (ARC) Identifier 649404 Exploration of the Planets – 1971 Narrator: For thousands of years, man observed the rising and setting Sun, the cycle of seasons, the fixed stars, and those he called wanderers, or planets. And from these observations evolved his notions of the universe. The naked eye extended its vision through instruments that saw the craters on the Moon, the changing colors of Mars, and the rings of Saturn. The fantasies, dreams, and visions of space travel became the reality of Apollo. Early in 1970, President Nixon announced the objectives of a balanced space program for the United States that would include the scientific investigation of all the planets in the solar system. Of the nine planets circling the Sun, only the Earth is known to us at firsthand. But observational techniques on Earth and in space have given us some idea of the appearance and movement of the planets. And enable us to depict their physical characteristics in some detail. Mercury, only slightly larger than the Moon, is so close to the Sun that it is difficult to observe by telescope. It is believed to be one large cinder, with no atmosphere and a day-night temperature range of nearly 1,000 degrees. Venus is perpetually cloud-covered. Spacecraft report a surface temperature of 900 degrees Fahrenheit and an atmospheric pressure 100 times greater than Earth’s. We can only guess what the surface is like, possibly a seething netherworld beneath a crushing, poisonous carbon dioxide atmosphere. Of Mars, the Red Planet, we have evidence of its cratered surface, photographed by the Mariner spacecraft. -
Newsletter December 2016
Current NEO statistics A refinement of the method used for analysing the asteroid hazard led to an increase in the number of objects in the risk list. Known NEOs: 15 271 asteroids and 106 comets NEOs in risk list*: 576 New NEO discoveries since last month: 161 NEOs discovered since 1 January 2016: 1750 Focus on Whenever a new set of observations for an object is published, our Impact Monitoring routines perform a new search for possibly impacting orbits compatible with such set of observations. The system is capable of detecting all possibly impacting orbits down to an impact probability threshold, named “generic completeness level”. The search begins by investigating a set of initial conditions taken along a specific line of parameters, called Line of Variations (LoV), inside the orbit uncertainty region. The NEODyS impact monitoring system was recently switched to a new method to sample the LoV, which decreased the generic completeness level from 4×10-7 to 10-7 (i.e. a factor of four better than the previous approach). The whole risk list has been updated with the outcome of the new method, and it is now available on both the NEODyS and the NEOCC risk pages. Upcoming interesting close approaches To date no known object is expected to come closer than one lunar distance to our planet in December, thus deserving special attention. New discoveries likely will. The closest known approach will be 2016 WQ3 at 1.5 lunar distances on 1 December. Recent interesting close approaches Four new objects came closer than the Moon in November. -
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. -
AAS/DPS Poster (PDF)
Spacewatch Observations of Asteroids and Comets with Emphasis on Discoveries by WISE AAS/DPS Poster 13.22 Thurs. 2010 Oct 7: 15:30-18:00 Robert S. McMillan1, T. H. Bressi1, J. A. Larsen2, C. K. Maleszewski1,J. L. Montani1, and J. V. Scotti1 URL: http://spacewatch.lpl.arizona.edu 1University of Arizona; 2U.S. Naval Academy Abstract • Targeted recoveries of objects discovered by WISE as well as those on impact risk pages, NEO Confirmation Page, PHAs, comets, etc. • ~1900 tracklets of NEOs from Spacewatch each year. • Recoveries of WISE discoveries preserve objects w/ long Psyn from loss. • Photometry to determine albedo @ wavelength of peak of incident solar flux. • Specialize in fainter objects to V=23. • Examination for cometary features of objects w/ comet-like orbits & objects that WISE IR imagery showed as comets. Why Targeted Followup is Needed • Discovery arcs too short to define orbits. • Objects can escape redetection by surveys: – Surveys busy covering other sky (revisits too infrequent). – Objects tend to get fainter after discovery. • Followup observations need to outnumber discoveries 10-100. • Sky density of detectable NEOs too sparse to rely on incidental redetections alone. Why Followup is Needed (cont’d) • 40% of PHAs observed on only 1 opposition. • 18% of PHAs’ arcs <30d; 7 PHAs obs. < 3d. • 20% of potential close approaches will be by objects observed on only 1 opposition. • 1/3rd of H≤22 VI’s on JPL risk page are lost and half of those were discovered within last 3 years. How “lost” can they get? • (719) Albert discovered visually in 1911. • “Big” Amor asteroid, diameter ~2 km. -
Research Paper in Nature
Draft version November 1, 2017 Typeset using LATEX twocolumn style in AASTeX61 DISCOVERY AND CHARACTERIZATION OF THE FIRST KNOWN INTERSTELLAR OBJECT Karen J. Meech,1 Robert Weryk,1 Marco Micheli,2, 3 Jan T. Kleyna,1 Olivier Hainaut,4 Robert Jedicke,1 Richard J. Wainscoat,1 Kenneth C. Chambers,1 Jacqueline V. Keane,1 Andreea Petric,1 Larry Denneau,1 Eugene Magnier,1 Mark E. Huber,1 Heather Flewelling,1 Chris Waters,1 Eva Schunova-Lilly,1 and Serge Chastel1 1Institute for Astronomy, 2680 Woodlawn Drive, Honolulu, HI 96822, USA 2ESA SSA-NEO Coordination Centre, Largo Galileo Galilei, 1, 00044 Frascati (RM), Italy 3INAF - Osservatorio Astronomico di Roma, Via Frascati, 33, 00040 Monte Porzio Catone (RM), Italy 4European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei M¨unchen,Germany (Received November 1, 2017; Revised TBD, 2017; Accepted TBD, 2017) Submitted to Nature ABSTRACT Nature Letters have no abstracts. Keywords: asteroids: individual (A/2017 U1) | comets: interstellar Corresponding author: Karen J. Meech [email protected] 2 Meech et al. 1. SUMMARY 22 confirmed that this object is unique, with the highest 29 Until very recently, all ∼750 000 known aster- known hyperbolic eccentricity of 1:188 ± 0:016 . Data oids and comets originated in our own solar sys- obtained by our team and other researchers between Oc- tem. These small bodies are made of primor- tober 14{29 refined its orbital eccentricity to a level of dial material, and knowledge of their composi- precision that confirms the hyperbolic nature at ∼ 300σ. tion, size distribution, and orbital dynamics is Designated as A/2017 U1, this object is clearly from essential for understanding the origin and evo- outside our solar system (Figure2).