Deutsches Zentrum für Luft- und Raumfahrt e.V. German Aerospace Center Institute of Planetary Research SECTION: “PHYSICS OF SMALL BODIES AND EXTRA-SOLAR PLANETS” Annual Report 2003 OBSERVATIONS MODELLIN G FIREWATCH TECHNOLOGY SPACE MISSIONS http://solarsystem.dlr.de/KK 0 From left to right: First row: Detlef de Niem [email protected] Scientific staff member Dr. Alan W. Harris [email protected] Deputy section leader Dr. Anders Erikson1 [email protected] Scientific staff member Dr. Carmen Tornow [email protected] Scientific staff member Second row: Holger Voss1 [email protected] PhD student Dr. Gerhard Hahn [email protected] Scientific staff member Prof. U. Motschmann [email protected] Guest scientist Dr. Heike Rauer1 [email protected] Group leader Dr. Ekkehard Kührt [email protected] Section leader Dr. Jörg Knollenberg [email protected] Scientific staff member Rosemarie Mooseder Secretary (retired) Michael Müller [email protected] PhD student Martin Prescher Guest student Egon Braatz [email protected] Technical staff member Not appearing in the photo: Dr. Stefano Mottola [email protected] Scientific staff member Ralph Kahle [email protected] PhD student Michael Weiler 1 [email protected] PhD student Stephanie Werner [email protected] PhD student 1 Group: Extrasolar planets and cometary atmospheres 1 Contents Contents................................................................................................................................ 2 1. Introduction (E. Kührt)....................................................................................................... 3 2. Asteroid science................................................................................................................ 4 2.1 Keck thermal-infrared observations of near-Earth asteroids (A. W. Harris)..................... 4 2.2 Investigations of the physical properties of near-Earth asteroids with data from the NASA Infrared Telescope Facility (A. W. Harris, M. Müller) ...................................... 5 2.3 Asteroid thermal modelling (A. W. Harris, M. Müller) ................................................... 6 2.4 Asteroid search programmes and Databases (G. Hahn)................................................. 7 ODAS – OCA-DLR Asteroid Survey ............................................................................... 7 UDAS – Uppsala-DLR Asteroid Survey........................................................................... 7 ADAS – Asiago-DLR Asteroid survey ............................................................................. 7 Databases .................................................................................................................... 7 3. Cometary Science ............................................................................................................. 8 3.1 Modelling activity of Hale-Bopp (E. Kührt, O. Groussin, J. Knollenberg)......................... 8 3.2 Percolation in cometary nuclei (O. Groussin, E. Kührt, J. Knollenberg)........................... 8 3.3 The gas and dust environment of comets (J. Knollenberg) .......................................... 10 3.4 Plasma environment of comet Churyumov-Gerasimenko (T. Bagdonat1, U. Motschmann 1, E. Kührt, 1 Technische Universität Braunschweig).......................... 11 4. Impact phenomena and Earth protection ........................................................................ 12 4.1 Hypervelocity impacts of comets and asteroids (D. de Niem, U. Motschmann) ............ 12 4.2 Deep Impact simulations (D. de Niem, J. Knollenberg, E. Kührt).................................. 13 4.3 Mission analysis for in-situ exploration and deflection of hazardous asteroids and ...... 13 comets (R. Kahle, G. Hahn, Kührt).............................................................................. 13 5. Extrasolar Planets ............................................................................................................. 14 5.1 Radio emission from magnetospheres of extrasolar planets (J.-M. Grießmeier 1, U. Motschmann 1, E. Kührt , 1 Technische Universität Braunschweig) .......................... 14 6. Investigation of Mars........................................................................................................ 15 6.1 Modelling of the solar wind - Mars interaction (A. Bößwetter 1, T. Bagdonat 1, U. Motschmann 1, E. Kührt, 1 Technische Universität Braunschweig)........................... 15 6.2 Chronostratigraphy on Mars (S. Werner, G. Neukum1, B.A. Ivanov1, A.T. Basilevsky 1, S. van Gasselt 1, FU Berlin)........................................................................................... 16 7. Scientific prospects.......................................................................................................... 17 7.1 New access to telescopes ........................................................................................... 17 7.2 SOFIA science (C. Tornow, H.-W. Hübers)................................................................... 18 7.3 Origin of life on Earth (C. Tornow, E. Kührt, U. Motschmann)..................................... 19 8. Space missions................................................................................................................ 22 8.1 Rosetta ...................................................................................................................... 22 8.2 Earthguard-I - Phase-A study for ESA (S. Mottola, A. W. Harris, E. Kührt, D. de Niem, G. Hahn) .......................................................................................................................... 23 8.3 DAWN (S. Mottola, R. Jaumann, H. Michaelis, E. Kührt) ............................................. 23 8.4 Bepi Colombo ............................................................................................................ 24 9. Technology Projects ........................................................................................................ 25 9.1 AWFS/FIREWATCH (E. Kührt, J. Knollenberg, V. Mertens, T. Behnke).......................... 25 9.2 Airborne FIREWATCH AFW (E. Kührt, J. Knollenberg) ................................................. 25 Appendix ............................................................................................................................. 26 2 1. Introduction (E. Kührt) The Section “Physics of Small Bodies and Extrasolar Planets“ was established in the Institute of Planetary Research of the DLR (German Aerospace Center) in January 1997. Its scientific work focuses on investigations of comets, asteroids, and extrasolar planets. At the end of 2003 the staff numbers 9 scientists, one technical employee, 4 PhD students, a secretary, and two guest scientists from the Technical University of Braunschweig and from LAS, Marseille, respectively. This report describes the results of our research and other activities in 2003. Our scientific goal is to investigate small bodies by observing them in the visible, infrared, and other wavelength ranges, contributing to relevant space missions and modelling physical processes associated with this class of object. Other fields of interest are risk evaluation of impacts of small bodies on our home planet, participation in the SOFIA project, the origin of life and the transfer of space technology to solve environmental problems on Earth. In 2003 a group was formed in our section to concentrate on extrasolar planets and atmospheres of comets. This group, headed by H. Rauer, will release a separate report. Comets and asteroids are thought to be remnant material from the processes of formation and initial development of planets and, therefore, a source of information on conditions in the early Solar System. Many scientists believe that comets and asteroids have significantly influenced the evolution of the terrestrial planets and life on Earth. In particular, public interest in near-Earth asteroids has risen dramatically in recent years as a result of the recognition that such objects occasionally collide with the Earth with potentially catastrophic consequences. Activities in this field are a part of our DLR-project “Comets and asteroids”. In 2004 the European Rosetta spacecraft will be launched. It should arrive at comet Churyumov-Gerasimenko in 2014 and provide us with a great deal of new information about comets. Our team is involved in numerous experiments on this ESA cornerstone mission. Some new research projects were started in 2003. Sections 7 describes activities to get access to further telescopes, some ideas for possible contributions to the SOFIA project and to one of the DLR basic research fields “Water and origins of life in space”. The Appendix summarises publications, project contributions, observation campaigns, public outreach activities, and our funding. Berlin, February 2004 3 2. Asteroid science 2.1 Keck thermal-infrared observations of near-Earth asteroids (A. W. Harris) The completion of a programme of thermal-infrared observations of near-Earth asteroids (NEAs) with the 10-m Keck 1 telescope was marked by the publication of the results in the journal Icarus in November. This work was carried out in collaboration with M. Delbo (Univ. Turin, formerly a doctoral student at DLR, Berlin), R. P. Binzel (MIT), P. Pravec (Astronomical Inst., Ondrejov) and J. K. Davies (ATC, Edinburgh). The paper presents the albedos and diameters of 20 NEAs, derived by fitting thermal-model emission continua to the measured thermal-infrared