DOCSLIB.ORG

But First... Asteroids and Meteorites Astro 202 a Few Words About Referencing in Science Writing

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
But First... Asteroids and Meteorites Astro 202 a Few Words About Referencing in Science Writing Lecture 3: Overview of But first... Asteroids and Meteorites Astro 202 A few words about Referencing in science writing... Prof. Jim Bell ([email protected]) (see http://astrosun2.astro.cornell.edu/academics/courses/a202/referencing.html) Spring 2008 Paper 2 is “Handed Out” online REMINDER: Paper 1 due at beginning of class this Thursday, Jan. 30 Asteroids... Asteroids !"Asteroid" is Greek for "star-like" Space junk...? !Asteroids are small, rocky objects that look star-like in telescopes, except they move Rosetta Stones...? across the sky like the planets do !The first asteroid was discovered in 1801 – Ceres, about 940 km diameter or Harbingers of DOOM? !There may be 1,000,000+ >1 km diameter Astro202 3 Astro202 4 Asteroids are discovered in telescopic images because they move at a different The Largest Asteroids speed across the sky than the stars !1 Ceres: Diam. = 940 km, a = 2.77 AU – Discovered by Guiseppe Piazzi in 1801 "Vermin of the skies" (!) – Piazzi was searching for a "missing planet" between Mars and Jupiter !2 Pallas: D=540 km, a=2.77 AU, disc. 1802 !4 Vesta: D=510 km, a=2.36 AU, disc. 1807 !13 main belt asteroids have D > 250 km Astro202 5 Astro202 6 Where are the Asteroids? The Main Asteroid Belt • The main belt extends from !Asteroids can be found throughout the solar about 2.2 to 3.3 AU system, but there are two main populations: • Most of the orbits lie at or near – The Main Belt between Mars and Jupiter (±10° to 20°) the plane of the – The Kuiper Belt beyond Neptune's orbit ecliptic !Most of the asteroids with well-determined • More than 100,000 main belt asteroids have well-known orbits are in the main belt orbital parameters !Other smaller populations exist too • The number has been recently – Trojans, Apollos, Amors, Centaurs, ... increasing by a few thousand per year because of new telescopic search programs Astro202 7 Astro202 Edge on 8 A snapshot of the locations of all known inner solar Gaps in the Belt... system asteroids as of today • Astronomer Daniel (Jan. 29, 2008) Kirkwood (1886) noticed that the main belt is not uniformly (outer circle is the populated orbit of Jupiter) • Asteroids "missing" from places where disturbances by Jupiter are strongest • These places are where resonances with Jupiter's orbit occur • May explain why no planet here: Jupiter only allowed small bodies to coalesce... Astro202 http://cfa-www.harvard.edu/iau/lists/InnerPlot.html 9 Astro202 10 In the news... Other Asteroid Groups Asteroid 2007 WD5: A Mars impactor? ! Near-Earth Asteroids (NEAs) – 436 Atens: orbits interior to Earth's – 2489 Apollos: orbits that cross Earth's – 2161 Amors: orbits exterior to Earth's (e.g. 433 Eros) Astro202 11 http://neo.jpl.nasa.gov/news/news151.html Tomorrow... A snapshot of the locations of all Other Asteroid Groups known outer solar system asteroids ! Near-Earth Asteroids (NEAs) as of today – 436 Atens: orbits interior to Earth's (outer circle is the – 2489 Apollos: orbits that cross Earth's orbit of Neptune) – 2161 Amors: orbits exterior to Earth's (e.g. 433 Eros) Astronomers !Trojans believe that there – 2319 asteroids leading and trailing Jupiter by 60° may be 100,000 – There are even a few Mars (4) and Neptune (5) Trojans or more Kuiper ! Centaurs Belt Objects still – 67 asteroids found between Jupiter & Neptune to be discovered... ! Trans-Neptunian or “Kuiper Belt” Objects The solar system – More than 1000 large asteroids beyond Neptune Pluto Neptune does not end at ! All these populations are incompletely counted Pluto! Astro202 13 Astro202 http://cfa-www.harvard.edu/iau/lists/OuterPlot.html 14 How Many Asteroids are There? Discovering Asteroids • The number of asteroids of a given ! For many years, most discoveries were random diameter D is proportional to 1/D2: ! Within the past decade, dedicated surveys have a collisional distribution begun in response to the possible threat of asteroid • For example: ! ! 3 > 500 km and comet impacts on the Earth ! ! 13 > 250 km – NASA Spacewatch Program ! ! hundreds > 100 km – Air Force Near Earth Asteroid Tracking Program (NEAT) ! ! 10,000+ > 10 km (?) – Lowell Observatory Near Earth Object Survey (LONEOS) Number of • Total: >1,000,000 > 1 km (?) – Lincoln (MIT) Near Earth Asteroid Research Project (LINEAR) Near-Earth Asteroids • Most of the MASS is in the largest – Catalina (Arizona) Sky Survey (a model) few asteroids ! Hundreds of thousands of objects discovered, many are • Total mass of all asteroids is only Near-Earth Asteroids (NEAs)... ~5-10% the mass of the Moon Astro202 15 Astro202 16.
Load more

Recommended publications
  • Killer Asteroids Lab 1
    Killer Asteroids Lab #1: Learning how to measure positions and determine orbits GOALS: The goal of this assignment is to learn how to measure asteroid positions in digital images, and how to use these positions to determine the orbit of the asteroid. You will also learn what parameters are necessary to specify an orbit, and the effect of each on the shape and orientation of the orbit. Finally, you will learn how to generate alternate possible orbits for a given asteroid. You will use these skills over the coming weeks to study the asteroid 2007 WD5, which narrowly missed hitting Mars on January 30, 2008. In particular, you will estimate the probability of impact based upon what was known about this object’s orbit at various points between its discovery and the date of the possible impact. You should then understand why every “impact scare” to date has followed the same pattern: Odds first go up, but then they fall quickly to near zero. You’ll also get the “bigger picture”: Science involves uncertainty, and it takes time and hard work to get good results. Part I: Measuring Asteroid Positions with ImageJ The first goal of this assignment is to teach you how to measure the positions of celestial objects in digital images. In particular, you will be measuring the position of an asteroid as it streaks through a field of background stars. (The measurement of positions of celestial objects is known as astrometry.) Of course, since the asteroid is moving, it is also important to accurately note the time at which it was found at a particular position.
    [Show full text]
  • Deep Space Chronicle Deep Space Chronicle: a Chronology of Deep Space and Planetary Probes, 1958–2000 | Asifa
    dsc_cover (Converted)-1 8/6/02 10:33 AM Page 1 Deep Space Chronicle Deep Space Chronicle: A Chronology ofDeep Space and Planetary Probes, 1958–2000 |Asif A.Siddiqi National Aeronautics and Space Administration NASA SP-2002-4524 A Chronology of Deep Space and Planetary Probes 1958–2000 Asif A. Siddiqi NASA SP-2002-4524 Monographs in Aerospace History Number 24 dsc_cover (Converted)-1 8/6/02 10:33 AM Page 2 Cover photo: A montage of planetary images taken by Mariner 10, the Mars Global Surveyor Orbiter, Voyager 1, and Voyager 2, all managed by the Jet Propulsion Laboratory in Pasadena, California. Included (from top to bottom) are images of Mercury, Venus, Earth (and Moon), Mars, Jupiter, Saturn, Uranus, and Neptune. The inner planets (Mercury, Venus, Earth and its Moon, and Mars) and the outer planets (Jupiter, Saturn, Uranus, and Neptune) are roughly to scale to each other. NASA SP-2002-4524 Deep Space Chronicle A Chronology of Deep Space and Planetary Probes 1958–2000 ASIF A. SIDDIQI Monographs in Aerospace History Number 24 June 2002 National Aeronautics and Space Administration Office of External Relations NASA History Office Washington, DC 20546-0001 Library of Congress Cataloging-in-Publication Data Siddiqi, Asif A., 1966­ Deep space chronicle: a chronology of deep space and planetary probes, 1958-2000 / by Asif A. Siddiqi. p.cm. – (Monographs in aerospace history; no. 24) (NASA SP; 2002-4524) Includes bibliographical references and index. 1. Space flight—History—20th century. I. Title. II. Series. III. NASA SP; 4524 TL 790.S53 2002 629.4’1’0904—dc21 2001044012 Table of Contents Foreword by Roger D.
    [Show full text]
  • Near Earth Asteroid Rendezvous: Mission Summary 351
    Cheng: Near Earth Asteroid Rendezvous: Mission Summary 351 Near Earth Asteroid Rendezvous: Mission Summary Andrew F. Cheng The Johns Hopkins Applied Physics Laboratory On February 14, 2000, the Near Earth Asteroid Rendezvous spacecraft (NEAR Shoemaker) began the first orbital study of an asteroid, the near-Earth object 433 Eros. Almost a year later, on February 12, 2001, NEAR Shoemaker completed its mission by landing on the asteroid and acquiring data from its surface. NEAR Shoemaker’s intensive study has found an average density of 2.67 ± 0.03, almost uniform within the asteroid. Based upon solar fluorescence X-ray spectra obtained from orbit, the abundance of major rock-forming elements at Eros may be consistent with that of ordinary chondrite meteorites except for a depletion in S. Such a composition would be consistent with spatially resolved, visible and near-infrared (NIR) spectra of the surface. Gamma-ray spectra from the surface show Fe to be depleted from chondritic values, but not K. Eros is not a highly differentiated body, but some degree of partial melting or differentiation cannot be ruled out. No evidence has been found for compositional heterogeneity or an intrinsic magnetic field. The surface is covered by a regolith estimated at tens of meters thick, formed by successive impacts. Some areas have lesser surface age and were apparently more recently dis- turbed or covered by regolith. A small center of mass offset from the center of figure suggests regionally nonuniform regolith thickness or internal density variation. Blocks have a nonuniform distribution consistent with emplacement of ejecta from the youngest large crater.
    [Show full text]
  • Asteroids Upclose
    Asteroids UpClose Quick Views of Big Advances Asteroids Up Close The importance of spacecraft missions in the quest to understand asteroids is highlighted in a recent review paper by Thomas Burbine (Mount Holyoke College, Massachusettes). Burbine discusses achievements in understanding the chemistries and mineralogies of asteroids since the launch of NASA's NEAR-Shoemaker robotic spacecraft in 1996, the first mission dedicated to asteroid exploration. As two new robotic asteroid-sample-return missions are underway (NASA's OSIRIS-REx and JAXA's Hayabusa2), Burbine's review paper and a review by Derek Sears earlier this year (see the January 2016 PSRD CosmoSparks: Comprehending Asteroids) provide timely recaps of why asteroids are so important to our understanding of the building Simulated cratering and topography are overlaid on blocks of our Solar System. radar imagery of asteroid Bennu — one of the next asteroids to be visited up close by NASA's OSIRIS- Burbine reviews these mission highlights: REx mission. Click image for more information from University of Arizona News. NEAR-Shoemaker (NASA mission) flew by (253) Mathilde, a C-complex asteroid. It orbited and landed on (433) Eros, an S-type asteroid, and used an X-ray spectrometer to determine elemental ratios, which were consistent with a body that did not melt globally. Most likely meteorite matches for Eros are surface-altered ordinary chondrites or primitive achondrites. For more see PSRD article: The Composition of Asteroid 433 Eros. Hayabusa (JAXA mission) was a touch-and-go mission to (25143) Itokawa, an S-complex asteroid. It carried a multiband imager, near-infrared spectrometer, laser altimeter, LIDAR, X-ray spectrometer, and a sample capsule.
    [Show full text]
  • Final Report Asteroid Impact Monitoring
    Final Report Asteroid Impact Monitoring Environmental and Instrumentation Requirements A component of the Asteroid Impact & Deflection Assessment (AIDA) Mission By the AIM Advisory Team Dr. Patrick MICHEL (Univ. Nice, CNRS, OCA), Team Leader Dr. Jens Biele (DLR) Dr. Marco Delbo (Univ. Nice, CNRS, OCA) Dr. Martin Jutzi (Univ. Bern) Pr. Guy Libourel (Univ. Nice, CNRS, OCA) Dr. Naomi Murdoch Dr. Stephen R. Schwartz (Univ. Nice, CNRS, OCA) Dr. Stephan Ulamec (DLR) Dr. Jean-Baptiste Vincent (MPS) April 12th, 2014 Introduction In this report, we describe the knowledge gain resulting from the implementation of either the European Space Agency’s Asteroid Impact Monitoring (AIM) as a stand- alone mission or AIM with its second component, the Double Asteroid Redirection Test (DART) mission under study by the Johns Hopkins Applied Physics Laboratory with support from members of NASA centers including Goddard Space Flight Center, Johnson Space Center, and the Jet Propulsion Laboratory. We then present our analysis of the required measurements addressing the goals of the AIM mission to the binary Near-Earth Asteroid (NEA) Didymos, and for two specified payloads. The first payload is a mini thermal infrared camera (called TP1) for short and medium range characterisation. The second payload is an active seismic experiment (called TP2). We then present the environmental parameters for the AIM mission. AIM is a rendezvous mission that focuses on the monitoring aspects i.e., the capability to determine in-situ the key properties of the secondary of a binary asteroid. DART consists primarily of an artificial projectile aims to demonstrate asteroid deflection. In the framework of the full AIDA concept, AIM will also give access to the detailed conditions of the DART impact and its outcome, allowing for the first time to get a complete picture of such an event, a better interpretation of the deflection measurement and a possibility to compare with numerical modeling predictions.
    [Show full text]
  • Daniel J. Scheeres, Phd. Degrees Professional Positions
    Daniel J. Scheeres, PhD. University of Colorado Distinguished Professor A. Richard Seebass Endowed Chair Celestial and Spaceflight Mechanics Laboratory Head Colorado Center for Astrodynamics Research Member Address: 429 UCB, Boulder, CO 80309-0429 USA Office: ECOT 611 Tel: (720) 544-1260, Fax: (303) 492-7881 Website: ccar.colorado.edu/scheeres [email protected] Degrees Ph.D. Aerospace Engineering The University of Michigan, 1992 On symmetric central configurations with application to satellite motion about rings Prof. N.X. Vinh, Chairman. M.S.E. Aerospace Engineering The University of Michigan, 1988 B.S.E. Aerospace Engineering (summa cum laude) The University of Michigan, 1987 B.S. Letters and Engineering Calvin College, 1985 Professional Positions The University of Colorado Boulder Ann & H.J. Smead Department of Aerospace Engineering Sciences University of Colorado Distinguished Professor 11/14 { present A. Richard Seebass Endowed Chair Professor 2/08 { present Associate Chair for Graduate Studies 7/13 { 6/15 Visiting Professor 8/07 { 2/08 The University of Michigan Department of Aerospace Engineering Adjunct Professor 2/08 { 9/10 Graduate Chair, Department of Aerospace Engineering 10/06 { 12/07 Associate Professor 9/02 { 1/08 Assistant Professor 9/99 { 8/02 Institute of Space and Astronautical Science, Japan Visiting Professor, JSPS Fellow 8/05 { 12/05 Japan Society for the Promotion of Science Fellow 5/99 { 8/99 Iowa State University Department of Aerospace Engineering and Engineering Mechanics Assistant Professor 8/97 { 8/99 Daniel J. Scheeres, PhD. 1 September 18, 2017 Jet Propulsion Laboratory, California Institute of Technology Senior Member of Engineering Staff 3/97 { 7/97 Member of the Technical Staff 9/92 { 3/97 Summer Intern/On-call employee 5/89 { 9/92 Honors and awards • 2017 Department of Aerospace Engineering Sciences Faculty Award for Outstanding Re- search ($1,000 Award).
    [Show full text]
  • Oca Club Meeting Star Parties Coming Up
    February 2008 Free to members, subscriptions $12 for 12 issues Volume 35, Number 2 On January 14, 2008, MESSENGER became the first spacecraft to visit Mercury since Mariner 10 more than 30 years ago. This image shows the hemisphere of Mercury that was not previously imaged by Mariner 10; the Caloris impact basin is visible at upper right. MESSENGER will complete two more flybys of Mercury, in October 2008 and September 2009, before entering orbit around the planet in 2011. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington OCA CLUB MEETING STAR PARTIES COMING UP The free and open club The Black Star Canyon site will be open on The next session of the meeting will be held Friday, February 9th. The Anza site will be open on Beginners Class will be held on February 8th at 7:30 PM in February 2nd. Members are encouraged to Friday, February 1st (our annual the Irvine Lecture Hall of the check the website calendar, for the latest ‘Basics of Astrophotography Hashinger Science Center updates on star parties and other events. class’) at the Centennial at Chapman University in Heritage Museum at 3101 West Orange. The featured Please check the website calendar for the Harvard Street in Santa Ana. speaker this month is Scott outreach events this month! Volunteers GOTO SIG: TBA (contact Kardel of Palomar are always welcome! coordinator for details) Observatory, discussing You are also reminded to check the web Astro-Imagers SIG: Feb. 19th, the 60th anniversary of the site frequently for updates to the calendar Mar.
    [Show full text]
  • The Landing of the NEAR-Shoemaker Spacecraft on Asteroid 433 Eros
    letters to nature ................................................................. images were buffered in real-time and then played back while the next The landing of the NEAR-Shoemaker set was being acquired. All images were shuttered using an exposure of 15 ms to limit smear. Here we summarize the major insights spacecraft on asteroid 433 Eros about the surface of Eros obtained from the images. More detailed analyses of speci®c observations are provided in accompanying 5 4 J. Veverka*, B. Farquhar², M. Robinson³, P. Thomas*, S. Murchie², contributions describing ponded deposits and ejecta blocks . A. Harch*, P. G. Antreasian§, S. R. Chesley§, J. K. Miller§, The selection of the landing site was dictated by several practical W. M. Owen Jr§, B. G. Williams§, D. Yeomans§, D. Dunham², G. Heyler², considerations that are summarized in the legend to Fig. 1. One aim M. Holdridge², R. L. Nelson², K. E. Whittenburg², J. C. Ray², B. Carcich*, was to land the NEAR spacecraft in a region where details of surface A. Cheng², C. Chapmank, J. F. Bell III*, M. Bell*, B. Bussey³, B. Clark*, modi®cation by ejecta and downslope movement of regolith could D. Domingue², M. J. Gaffey¶, E. Hawkins², N. Izenberg², J. Joseph*, be studied. We hoped to land in the vicinity of one of the enigmatic R. Kirk#, P. LuceyI, M. Malin**, L. McFadden²², W. J. Merlinek, `ponds' discovered during the 28 October 2000 low-altitude ¯yby6 C. Peterson*, L. Prockter², J. Warren² & D. Wellnitz²² and viewed at even better resolution (0.5 m) in late January 2001. The location of the landing site, within the 9-km depression * Space Sciences Building, Cornell University, Ithaca, New York 14853, USA Himeros, is shown in Fig.
    [Show full text]
  • An Innovative Solution to NASA's NEO Impact Threat Mitigation Grand
    Final Technical Report of a NIAC Phase 2 Study December 9, 2014 NASA Grant and Cooperative Agreement Number: NNX12AQ60G NIAC Phase 2 Study Period: 09/10/2012 – 09/09/2014 An Innovative Solution to NASA’s NEO Impact Threat Mitigation Grand Challenge and Flight Validation Mission Architecture Development PI: Dr. Bong Wie, Vance Coffman Endowed Chair Professor Asteroid Deflection Research Center Department of Aerospace Engineering Iowa State University, Ames, IA 50011 email: [email protected] (515) 294-3124 Co-I: Brent Barbee, Flight Dynamics Engineer Navigation and Mission Design Branch (Code 595) NASA Goddard Space Flight Center Greenbelt, MD 20771 email: [email protected] (301) 286-1837 Graduate Research Assistants: Alan Pitz (M.S. 2012), Brian Kaplinger (Ph.D. 2013), Matt Hawkins (Ph.D. 2013), Tim Winkler (M.S. 2013), Pavithra Premaratne (M.S. 2014), Sam Wagner (Ph.D. 2014), George Vardaxis, Joshua Lyzhoft, and Ben Zimmerman NIAC Program Executive: Dr. John (Jay) Falker NIAC Program Manager: Jason Derleth NIAC Senior Science Advisor: Dr. Ronald Turner NIAC Strategic Partnerships Manager: Katherine Reilly Contents 1 Hypervelocity Asteroid Intercept Vehicle (HAIV) Mission Concept 2 1.1 Introduction ...................................... 2 1.2 Overview of the HAIV Mission Concept ....................... 6 1.3 Enabling Space Technologies for the HAIV Mission . 12 1.3.1 Two-Body HAIV Configuration Design Tradeoffs . 12 1.3.2 Terminal Guidance Sensors/Algorithms . 13 1.3.3 Thermal Protection and Shield Issues . 14 1.3.4 Nuclear Fuzing Mechanisms ......................... 15 2 Planetary Defense Flight Validation (PDFV) Mission Design 17 2.1 The Need for a PDFV Mission ............................ 17 2.2 Preliminary PDFV Mission Design by the MDL of NASA GSFC .
    [Show full text]
  • Dawn Mission Reveals Dwarf Planet Else in the Solar System
    Fossil Planet With lowlands, highlands, weird white spots, and even a pyramid, the largest object in the asteroid belt is unlike anything Dawn mission reveals dwarf planet else in the solar system. by Eric Betz IN THE BEGINNING, with a mass equivalent to just 4 percent of that contained in Earth’s Moon. What was OUR SOLAR SYSTEM left is what we still see today. One-third of that mass is held by a single WAS A VIOLENT PLACE. world, Ceres. At 590 miles (950 kilometers) NASA’s Dawn mission Radiation from neighboring massive across, it’s our solar system’s largest asteroid captured Ceres from stars bombarded our small part of a large and the only dwarf planet this side of Pluto. Ceres 8,400 miles (13,600 kilometers) away in molecular cloud — a many light-years-wide It’s also a relic of our violent origins. May as it spiraled body of gas and dust resembling the Eagle This icy body is the current focus of into ever-lower Nebula’s “Pillars of Creation” — as the NASA’s Dawn mission — a small spacecraft orbits. ALL IMAGES: NASA/ JPL-CALTECH/UCLA/MPS/DLR/IDA, whole expanse coalesced like a figure skater that’s powered its way across the inner solar EXCEPT WHERE NOTED pulling her limbs in tight for a spin. system since 2007 using unconventional Some 99.8 percent of the mass drew to ion propulsion. The engine allowed Dawn the center, forming our Sun. And out of the to become the first mission to ever orbit firmament 4.6 billion years ago, tiny bits of two extraterrestrial bodies.
    [Show full text]
  • Near Earth Asteroid Thermal Modeling
    42nd Lunar and Planetary Science Conference (2011) 2583.pdf Near Earth Asteroid Thermal Modeling [NEATM] and Thermophysical Modeling of 10 low albedo NEAs using Infrared Spectrograph (IRS) on NASA’s Spitzer Space Telescope R.Dave1([email protected]), J.P. Emery1([email protected]), 1Univ. Tennessee. Introduction: Near-Earth Asteroids (NEAs- the peak in thermal emission. These data enable more 0.983AU<q<1.3AU) are fragments of remnant accurate and detailed modeling of the surface primordial bodies dating since the formation of Solar temperature distributions. System. Information about the albedo and size Observations: Spitzer observed the ten asteroids in distribution of the NEAs is an essential prerequisite for this study between June 2004 and April 2006. Thermal exploring their physical nature, thermal properties, spectra from 5.2 to 38 µm were measured with the mineralogy, taxonomy and for developing reliable NEA Infrared Spectrograph (IRS), which collects data in four population models [1]. In support of the ExploreNEOs different modules: campaign of the Warm Spitzer program, the current Low-resolution, short-wavelength - 5.2 - 14 microns, project is a study of a sample of NEAs using the Infrared Low-resolution, long-wavelength - 14 - 38 microns, Spectrograph (IRS) on NASA’s Spitzer Space Telescope High-resolution, short-wavelength - 10 - 19.5 microns, [Programs 88 and 91- Extinct Comets and Low- albedo High-resolution, long-wavelength - 19 - 37 microns. Asteroids]. The 5.2-38 m thermal emission µ The spectra analyzed here use only the low-spectral spectra[R~60- 130] are fitted with models of the thermal resolution modules (R=λ/Δλ~64 to 128).
    [Show full text]
  • Near-Earth Objects in the Sloan Digital Sky Survey
    Near-Earth Objects in the Sloan Digital Sky Survey S. Kent Nov 27, 2009 Steve Kent, Tom Quinn, Gil Holder, Mark Schaffer, Alex Szalay, Jim Gray, Zeljko Ivezic Outline I. Near-Earth Objects II. Brief Description of SDSS imaging survey III. NEO population IV. NEO Composition and origin Particle to Astro Translation Guide Particle Physics Term Astrophysics Term Beam Line Telescope Monte Carlo Simulation Calorimetry Photometry Energy histogram Spectrum Pedestal Bias Trigger table Target Selection Algorithm Tracking Astrometry Silicon Pixel Detector Silicon Pixel Detector Charged particle track Signal Noise I. NEO Basic Information 1. Definition: NEO = Near Earth Object (asteroid or comet). Perihelion q < 1.3 AU. ~7000 known. 2. PHA = Potentially Hazardous Asteroid ( big & might hit the earth). 997 Known H=13 10 km diam - Dinosaur extinction H=18 1 km diam - Goal for completeness (H is apparent mag of asteroid viewed face-on from sun at a distance of 1 AU) Distribution of Main Belt Asteroids Orbits of NEO's Typical NEA Orbit Programs to find NEOs 1. LINEAR (Lincoln Near Earth Asteroid Research) MIT/Lincoln Lab Telescope near Socorro, NM 2. NEAT ( Near Earth Asteroid Tracking) JPL Telescopes in Hawaii / Palomar (CA) 3. LONEOS (Lowell Observatory) Lowell, AZ 4. Spacewatch (Steward Observatory) Kitt Peak 5. Catalina Sky Survey Steward Observatory; ANU 3 telescopes (Catalina Mtns; Siding Springs) SpaceGuard - Goal is to find 90% of all NEAs D > 1 km (H~18) Aside ... The “measure” of a NEO ● Absolute Magnitude H ● Diameter D ● Mass M ● Energy E (Megatons) ● Crater diameter ● Inter-relationships depend on – Density – Albedo – Impact target (Moon v.
    [Show full text]