Properties of Cometary Nuclei
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Comet Section Observing Guide
Comet Section Observing Guide 1 The British Astronomical Association Comet Section www.britastro.org/comet BAA Comet Section Observing Guide Front cover image: C/1995 O1 (Hale-Bopp) by Geoffrey Johnstone on 1997 April 10. Back cover image: C/2011 W3 (Lovejoy) by Lester Barnes on 2011 December 23. © The British Astronomical Association 2018 2018 December (rev 4) 2 CONTENTS 1 Foreword .................................................................................................................................. 6 2 An introduction to comets ......................................................................................................... 7 2.1 Anatomy and origins ............................................................................................................................ 7 2.2 Naming .............................................................................................................................................. 12 2.3 Comet orbits ...................................................................................................................................... 13 2.4 Orbit evolution .................................................................................................................................... 15 2.5 Magnitudes ........................................................................................................................................ 18 3 Basic visual observation ........................................................................................................ -
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. -
Ice & Stone 2020
Ice & Stone 2020 WEEK 17: APRIL 19-25, 2020 Presented by The Earthrise Institute # 17 Authored by Alan Hale This week in history APRIL 19 20 21 22 23 24 25 APRIL 20, 1910: Comet 1P/Halley passes through perihelion at a heliocentric distance of 0.587 AU. Halley’s 1910 return, which is described in a previous “Special Topics” presentation, was quite favorable, with a close approach to Earth (0.15 AU) and the exhibiting of the longest cometary tail ever recorded. APRIL 20, 2025: NASA’s Lucy mission is scheduled to pass by the main belt asteroid (52246) Donaldjohanson. Lucy is discussed in a previous “Special Topics” presentation. APRIL 19 20 21 22 23 24 25 APRIL 21, 2024: Comet 12P/Pons-Brooks is predicted to pass through perihelion at a heliocentric distance of 0.781 AU. This comet, with a discussion of its viewing prospects for 2024, is a previous “Comet of the Week.” APRIL 19 20 21 22 23 24 25 APRIL 22, 2020: The annual Lyrid meteor shower should be at its peak. Normally this shower is fairly weak, with a peak rate of not much more than 10 meteors per hour, but has been known to exhibit significantly stronger activity on occasion. The moon is at its “new” phase on April 23 this year and thus the viewing circumstances are very good. COVER IMAGE CREDIT: Front and back cover: This artist’s conception shows how families of asteroids are created. Over the history of our solar system, catastrophic collisions between asteroids located in the belt between Mars and Jupiter have formed families of objects on similar orbits around the sun. -
The Castalia Mission to Main Belt Comet 133P/Elst-Pizarro C
The Castalia mission to Main Belt Comet 133P/Elst-Pizarro C. Snodgrass, G.H. Jones, H. Boehnhardt, A. Gibbings, M. Homeister, N. Andre, P. Beck, M.S. Bentley, I. Bertini, N. Bowles, et al. To cite this version: C. Snodgrass, G.H. Jones, H. Boehnhardt, A. Gibbings, M. Homeister, et al.. The Castalia mission to Main Belt Comet 133P/Elst-Pizarro. Advances in Space Research, Elsevier, 2018, 62 (8), pp.1947- 1976. 10.1016/j.asr.2017.09.011. hal-02350051 HAL Id: hal-02350051 https://hal.archives-ouvertes.fr/hal-02350051 Submitted on 28 Aug 2020 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. Distributed under a Creative Commons Attribution| 4.0 International License Available online at www.sciencedirect.com ScienceDirect Advances in Space Research 62 (2018) 1947–1976 www.elsevier.com/locate/asr The Castalia mission to Main Belt Comet 133P/Elst-Pizarro C. Snodgrass a,⇑, G.H. Jones b, H. Boehnhardt c, A. Gibbings d, M. Homeister d, N. Andre e, P. Beck f, M.S. Bentley g, I. Bertini h, N. Bowles i, M.T. Capria j, C. Carr k, M. -
2014 Annual Weather Report INCLUDING DATA from LIHOU ISLAND ALDERNEY SARK
Guernsey Met Office 2014 Annual Weather Report INCLUDING DATA FROM LIHOU ISLAND ALDERNEY SARK A division of the States of Guernsey Public Services Department Guernsey Airport Meteorological Office – Annual Report 2014 The 2014 Guernsey Annual Weather Report is produced by The Guernsey Meteorological Office A division of The States of Guernsey Public Services Department Front cover photo: 17th July 2014 – Bands of Altocumulus Castellanus approach the island from the south- west as shown by this photo looking south-west across the St Pierre du Bois countryside. Altocumulus Castellanus is a distinctive cloud which can appear in our sky at any time of the year but is most common by far in the summer. The cloud base is rarely lower that 8,000 feet but it’s large turrets can grow to reach over 20,000 feet. Usually this type of cloud passes over the island without producing any rain but it is quite capable of yielding some short heavy showers. Altocumulus Castellanus is often a sign that thundery weather is approaching and may arrive along with thick cirrus cloud and in front of the cumulonimbus which generate thunderstorms. In the event, the evening of the 17th July produced an impressive display of distant lightning but very little rain. Photo credit: Martin Crozier © States of Guernsey Public Services Department 2015 Contents SENIOR METEOROLOGICAL OFFICER’S REPORT ANNUAL AND MONTHLY COMMENTARY: Comment on the weather of 2014 January February March April May June July August September October November December MONTHLY STATISTICS: Annual Weather Summary Sunshine / Pressure / Rainfall Temperature Number of Days with... -
Extra-Terrestrial Meteors
LIST OF CONTRIBUTORS apostolos christou Armagh Observatory and Planetarium College Hill, BT61 9DG Northern Ireland, UK jeremie vaubaillon IMCCE, Observatoire de Paris Paris 75014, France paul withers Astronomy Department, Boston University 725 Commonwealth Avenue Boston MA 02215, USA ricardo hueso Fisica Aplicada I Escuela de Ingenieria de Bilbao Plaza Ingeniero Torres Quevedo 1 48013 Bilbao, Spain rosemary killen NASA/Goddard Space Flight Center Planetary Magnetospheres, Code 695 Greenbelt MD 20771, USA arXiv:2010.14647v1 [astro-ph.EP] 27 Oct 2020 1 1 Extra-Terrestrial Meteors 1.1 Introduction cometary orbits, all-but-invisible except where the particles are packed densely enough to be detectable, typically near The beginning of the space age 60 years ago brought about the comet itself (Sykes and Walker, 1992; Reach and Sykes, a new era of discovery for the science of astronomy. Instru- 2000; Gehrz et al., 2006). Extending meteor observations ments could now be placed above the atmosphere, allowing to other planetary bodies allows us to map out these access to new regions of the electromagnetic spectrum and streams and investigate the nature of comets whose mete- unprecedented angular and spatial resolution. But the im- oroid streams do not intersect the Earth. Observations of pact of spaceflight was nowhere as important as in planetary showers corresponding to the same stream at two or more and space science, where it now became possible – and this planets will allow to study a stream’s cross-section. In ad- is still the case, uniquely among astronomical disciplines – dition, the models used to extract meteoroid parameters to physically touch, sniff and directly sample the bodies and from the meteor data are fine-tuned, to a certain degree, for particles of the solar system. -
(2000) Forging Asteroid-Meteorite Relationships Through Reflectance
Forging Asteroid-Meteorite Relationships through Reflectance Spectroscopy by Thomas H. Burbine Jr. B.S. Physics Rensselaer Polytechnic Institute, 1988 M.S. Geology and Planetary Science University of Pittsburgh, 1991 SUBMITTED TO THE DEPARTMENT OF EARTH, ATMOSPHERIC, AND PLANETARY SCIENCES IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN PLANETARY SCIENCES AT THE MASSACHUSETTS INSTITUTE OF TECHNOLOGY FEBRUARY 2000 © 2000 Massachusetts Institute of Technology. All rights reserved. Signature of Author: Department of Earth, Atmospheric, and Planetary Sciences December 30, 1999 Certified by: Richard P. Binzel Professor of Earth, Atmospheric, and Planetary Sciences Thesis Supervisor Accepted by: Ronald G. Prinn MASSACHUSES INSTMUTE Professor of Earth, Atmospheric, and Planetary Sciences Department Head JA N 0 1 2000 ARCHIVES LIBRARIES I 3 Forging Asteroid-Meteorite Relationships through Reflectance Spectroscopy by Thomas H. Burbine Jr. Submitted to the Department of Earth, Atmospheric, and Planetary Sciences on December 30, 1999 in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Planetary Sciences ABSTRACT Near-infrared spectra (-0.90 to ~1.65 microns) were obtained for 196 main-belt and near-Earth asteroids to determine plausible meteorite parent bodies. These spectra, when coupled with previously obtained visible data, allow for a better determination of asteroid mineralogies. Over half of the observed objects have estimated diameters less than 20 k-m. Many important results were obtained concerning the compositional structure of the asteroid belt. A number of small objects near asteroid 4 Vesta were found to have near-infrared spectra similar to the eucrite and howardite meteorites, which are believed to be derived from Vesta. -
Astronomy & Astrophysics Colors of Minor Bodies in the Outer Solar
A&A 389, 641–664 (2002) Astronomy DOI: 10.1051/0004-6361:20020431 & c ESO 2002 Astrophysics Colors of Minor Bodies in the Outer Solar System⋆,⋆⋆ A statistical analysis O. R. Hainaut1 and A. C. Delsanti1,2 1 European Southern Observatory, Casilla 19001, Santiago, Chile 2 Observatoire de Paris-Meudon, 5 place Jules Janssen, 92195 Meudon Cedex, France Received 12 October 2001 / Accepted 14 February 2002 Abstract. We present a compilation of all available colors for 104 Minor Bodies in the Outer Solar System (MBOSSes); for each object, the original references are listed. The measurements were combined in a way that does not introduce rotational color artifacts. We then derive the slope, or reddening gradient, of the low resolution reflectance spectra obtained from the broad-band color for each object. A set of color-color diagrams, histograms and cumulative probability functions are presented as a reference for further studies, and are discussed. In the color-color diagrams, most of the objects are located very close to the “reddening line” (corresponding to linear reflectivity spectra). A small but systematic deviation is observed toward the I band indicating a flattening of the reflectivity at longer wavelengths, as expected from laboratory spectra. A deviation from linear spectra is noticed toward the B for the bluer objects; this is not matched by laboratory spectra of fresh ices, possibly suggesting that these objects could be covered with extremely evolved/irradiated ices. Five objects (1995 SM55, 1996 TL66, 1999 OY3, 1996 TO66 and (2060) Chiron) have almost perfectly solar colors; as two of these are known or suspected to harbour cometary activity, the others should be searched for activity or fresh ice signatures. -
Main-Belt Comets in the Palomar Transient Factory Survey – I
MNRAS 433, 3115–3132 (2013) doi:10.1093/mnras/stt951 Advance Access publication 2013 June 24 Main-belt comets in the Palomar Transient Factory survey – I. The search for extendedness A. Waszczak,1‹ E. O. Ofek,2 O. Aharonson,1,3 S. R. Kulkarni,1,4 D. Polishook,5 J. M. Bauer,6,7 D. Levitan,4 B. Sesar,4 R. Laher,8 J. Surace8 and the PTF Team 1Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA 2Benoziyo Center for Astrophysics, Faculty of Physics, Weizmann Institute of Science, Rehovot 76100, Israel 3Helen Kimmel Center for Planetary Science, Weizmann Institute of Science, Rehovot 76100, Israel 4Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, CA 91125, USA 5Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA 6Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA Downloaded from 7Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125, USA 8Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125, USA Accepted 2013 May 30. Received 2013 May 26; in original form 2013 January 8 http://mnras.oxfordjournals.org/ ABSTRACT Cometary activity in main-belt asteroids probes the ice content of these objects and provides clues to the history of volatiles in the inner Solar system. We search the Palomar Transient Factory survey to derive upper limits on the population size of active main-belt comets (MBCs). From data collected from 2009 March through 2012 July, we extracted ∼2 million observations of ∼220 thousand known main-belt objects (40 per cent of the known population, down to ∼1-km diameter) and discovered 626 new objects in multinight linked detections. -
Proposed 2020 NEA Targets (Med SNR)
Radar Characterization of NEAs: Moderate Resolution Imaging, Astrometry, and a Systematic Survey Anne K. Virkki (Arecibo Observatory, UCF), Patrick A. Taylor (LPI, USRA), Flaviane C.F. Ven- ditti, Sean E. Marshall, Dylan C. Hickson, Luisa F. Zambrano-Marin (Arecibo Observatory, UCF), Edgard G. Rivera-Valent´ın, Sriram S. Bhiravarasu, Betzaida Aponte-Hernandez (LPI, USRA), Michael C. Nolan, Ellen S. Howell (U. Arizona), Tracy M. Becker (SwRI), Jon D. Giorgini, Lance A. M. Benner, Marina Brozovic, Shantanu P. Naidu (JPL), Michael W. Busch (SETI), Jean-Luc Margot, Sanjana Prabhu Desai (UCLA), Agata Rozek˙ (U. Kent), Mary L. Hinkle (UCF), Michael K. Shepard (Bloomsburg U.), and Christopher Magri (U. Maine) Summary We propose the continuation of the long-running project R3035 to physically and dynamically characterize the population of near-Earth asteroids with the Arecibo S-band (2380 MHz; 12.6 cm) planetary radar system. The objectives of project R3035 are to: (1) provide basic characterizations (size, shape, and radar scattering properties) of dozens of objects, (2) report ultra-precise radar astrometry for all detections, and (3) conduct a monthly survey of newly discovered objects around new moon. These observations will be carried out as part of the NASA-funded Arecibo planetary radar program, Grant No. 80NSSC19K0523, to PI Anne Virkki (Arecibo Observatory, University of Central Florida) with Patrick Taylor as Institutional PI at the Lunar and Planetary Institute (Universities Space Research Association). Background Radar is arguably the most powerful Earth-based technique for post-discovery physical and dynamical characterization of near-Earth asteroids (NEAs) and plays a crucial role in the nation’s planetary defense initiatives led through the NASA Planetary Defense Coordination Office. -
Radar Observations of Asteroid 3908 Nyx
Icarus 158, 379–388 (2002) doi:10.1006/icar.2002.6869 Radar Observations of Asteroid 3908 Nyx Lance A. M. Benner and Steven J. Ostro Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109-8099 E-mail: [email protected] R. Scott Hudson School of Electrical Engineering and Computer Science, Washington State University, Pullman, Washington 99164-2752 Keith D. Rosema,1 Raymond F. Jurgens, and Donald K. Yeomans Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109-8099 Donald B. Campbell National Astronomy and Ionosphere Center, Space Sciences Building, Cornell University, Ithaca, New York 14853 and John F. Chandler and Irwin I. Shapiro Harvard–Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusets 02138 Received August 30, 2001; revised February 21, 2002 was discovered on August 6, 1980, by H.-E. Schuster at the We report Doppler-only (cw) radar observations of basaltic near- European Southern Observatory in La Silla (Marsden 1980). It Earth asteroid 3908 Nyx obtained at Arecibo and Goldstone in was the subject of an extensive observational campaign at visi- September and October of 1988. The circular polarization ratio of ble, infrared, and radar wavelengths during its approach within 0.75 ± 0.03 exceeds ∼90% of those reported among radar-detected 0.062 AU of Earth in October 1988. Lightcurves obtained in near- Earth asteroids and it implies an extremely rough near-surface 1988 (Drummond and Wisniewski 1990) and in 1996 by Pravec at centimeter-to-decimeter spatial scales. Echo power spectra over and co-workers (in preparation) indicate direct rotation with a narrow longitudinal intervals show a central dip indicative of at 4.426-h period and yield two pole direction solutions that pro- least one significant concavity. -
– Near-Earth Asteroid Mission Concept Study –
ASTEX – Near-Earth Asteroid Mission Concept Study – A. Nathues1, H. Boehnhardt1 , A. W. Harris2, W. Goetz1, C. Jentsch3, Z. Kachri4, S. Schaeff5, N. Schmitz2, F. Weischede6, and A. Wiegand5 1 MPI for Solar System Research, 37191 Katlenburg-Lindau, Germany 2 DLR, Institute for Planetary Research, 12489 Berlin, Germany 3 Astrium GmbH, 88039 Friedrichshafen, Germany 4 LSE Space AG, 82234 Oberpfaffenhofen, Germany 5 Astos Solutions, 78089 Unterkirnach, Germany 6 DLR GSOC, 82234 Weßling, Germany ASTEX Marco Polo Symposium, Paris 18.5.09, A. Nathues - 1 Primary Objectives of the ASTEX Study Identification of the required technologies for an in-situ mission to two near-Earth asteroids. ¾ Selection of realistic mission scenarios ¾ Definition of the strawman payload ¾ Analysis of the requirements and options for the spacecraft bus, the propulsion system, the lander system, and the launcher ASTEX ¾ Definition of the requirements for the mission’s operational ground segment Marco Polo Symposium, Paris 18.5.09, A. Nathues - 2 ASTEX Primary Mission Goals • The mission scenario foresees to visit two NEAs which have different mineralogical compositions: one “primitive'‘ object and one fragment of a differentiated asteroid. • The higher level goal is the provision of information and constraints on the formation and evolution history of our planetary system. • The immediate mission goals are the determination of: – Inner structure of the targets – Physical parameters (size, shape, mass, density, rotation period and spin vector orientation) – Geology, mineralogy, and chemistry ASTEX – Physical surface properties (thermal conductivity, roughness, strength) – Origin and collisional history of asteroids – Link between NEAs and meteorites Marco Polo Symposium, Paris 18.5.09, A.