United Nations - Nations Unies. COSPAR Symposium. Measuring the Universe. Looking Back in Time with Modern Astronomy. Monday, 2nd February 2015

Transcription

1 United Nations - Nations Unies COSPAR Symposium Measuring the Universe Looking Back in Time with Modern Astronomy Monday, 2nd February :00 18:00 Conference Rooms M1, Building M, Vienna International Centre Collecting information about and classifying stellar and planetary objects in our milky way and beyond is also the aim of space missions such as the recently launched Gaia spacecraft. Measuring positions and other properties of billions of stars provide a most fascinating survey of the inanimate nature out there in the space. Much as collecting and classifying animals and plants allowed Carl Linnaeus to lay the foundations of modern life science, astrometry will revolutionize our understanding of the evolution of our universe, its galaxies as stellar systems. The enormous amount of data collected by such missions constitutes the building blocks of future understand of our cosmos. Big data analysis provides new means of world interpretation. On the occasion of the Fifty-second session of the Scientific and Technical Subcommittee of the United Nations Committee on the Peaceful Uses of Outer Space Chair Karl-Heinz Glassmeier (COSPAR) 15:00 Measuring the Universe Karl-Heinz Glassmeier, COSPAR Bureau and Technical University of Braunschweig, Germany 15:10 The Gaia Mission Timo Prusti, ESA Scientific Support Office, ESTEC, Noordwijk, Netherlands, Netherlands 15:40 Gaia, the Galaxy in One Petabyte Carme Jordi, Institute of Cosmos Sciences, University of Barcelona 16:10 Space Science Satellites in Brazil 2014 Francisco Jablonski, INPE/MCTI, São José dos Campos, Brazil

2 16:40 GalileoMobile: Bringing Astronomy to Rural Areas Speakers: Maria Dasi Espuig & Mayte Vasquez, GalileoMobile Project, Imperial College London, England & DLR Oberpfaffenhofen, Munich, Germany 17:10 GAIA and the epistemology of astrophysics Sibylle Anderl, Universite Josephe Fourier, Grenoble, France 17:40 Discussion and summary of the symposium Abstracts: Title: Afiliation: The Gaia Mission Timo Prusti ESA Scientific Support Office, ESTEC, Noordwijk, Netherlands Gaia is a European Space Agency cornerstone mission launched 19 December 2013 from French Guyana. Gaia will map the sky down to the 20th magnitude for point sources. Astrometry and photometry is done for all detected objects and spectroscopy down to magnitude limit 16. The commissioning of Gaia was completed in July All subsystems have been successfully operated. Gaia is in its operational orbit around L2 point. The attitude control with use of the stars from the science instrument has been successfully executed. The alignment of optical elements is optimized with an iterative process involving focusing and spins speed adjustments as well. The Focal Plane Assembly is fully functional with all 106 CCDs operational and the Phased Array Antenna can transmit all science data down. The nominal operations are scheduled for 5 years. The scientific yield is expected to contain a billion stars with positions, distances and proper motions based on astrometry. With photometry the stellar properties of this sample can be deduced. Finally from the spectroscopy Gaia allows extraction of some 150 million radial velocities for the brightest stars. This information will allow addressing the main scientific goals of Gaia concerning the structure, history and evolution of our Milky Way Galaxy. In addition to Galactic structure, Gaia will allow addressing various other science areas. For stellar astrophysics Gaia will provide the long awaited distances and census of multiple star systems. Gaia is expected to discover thousands of exo-planets. The main belt asteroid orbits will be improved significantly. Eventually even fundamental physics can be done with tests on general relativity. The presentation will summarize the science goals, the status of the spacecraft and provide updated scientific performance estimates based on the in-orbit data from the commissioning and early operational phases.

3 Title: Gaia, the Galaxy in One Petabyte Carme Jordi Institute of Cosmos Sciences, University of Barcelona The Gaia space mission aims to repeatedly observe one billion stars in our Galaxy over five years, which means an average of 50 million observations every day equivalent to 60 gigabytes of data. A single observation of a given star consists of ten small images, plus two low-resolution and three high-resolution spectra of the incoming light. A complex on-ground data processing has been designed to derive scientific data from the information recorded in space. This is as challenging as the technical design of the spacecraft and payload due to the inter-relationship of all data of a given star and among all stars. Gaia final data base is estimated to have a size of one petabyte (one million gigabytes equivalent to the amount of space needed to store a movie with a run time of 50 years in HD quality). If each of the one trillion stellar images took one second to process, the final catalogue would be ready in 31,000 years. Thanks to the collaboration of about 400 engineers and researchers and five data centers around Europe, the early 2020s is the actual date for the publication of the final catalogue. The uniqueness of Gaia and its enormous potential for science can only be fully exploited by opening the mission data to the whole society. Therefore, the data will be publicly available without any priority data rights, and so the scientific community all around the world will have free access. The design of new, and the adaptation of current tools and models to the expected Gaia data is already in development. Also strong collaborations through networks, like the Gaia Research for European Astronomy Training network, are in place. Many more collaborations will rise in the near future. Title: Space Science Satellites in Brazil 2014 Francisco Jablonski INPE/MCTI, São José dos Campos, Brazil f.jablonski@inpe.br In this presentation I focus on short term space projects which are being built in Brazil: MIRAX, an Astrophysics payload consisting of a coded mask telescope for hard X-rays with the primary scientific goal of detecting and monitoring the time development of hard X-ray transient sources in the sky; and EQUARS, a Space Geophysics payload gathering a suite of experiments related to Space Weather, from ionospheric plasma properties, to electrostatic energy contents, and atmospheric glow/propagation parameters. Both satellites are small mass payloads which use the multi-mission

4 platform developed at Instituto Nacional de Pesquisas Espaciais and presently have a schedule for launching extending up to Title: GalileoMobile: Bringing Astronomy to Rural Areas Maria Dasi Espuig1 & Mayte Vasquez2 on behalf of GalileoMobile 1: Imperial College London; 2: Deutschen Zentrums für Luft- und Raumfahrt, Oberpfaffenhofen m.dasi-espuig@imperial.ac.uk; mayte.vasquez@dlr.de Astronomy is a powerful and inspiring tool that can be used to motivate children to learn more about the world beyond their immediate neighborhood, to encourage critical thinking, and engage them in different scientific disciplines. Although in our modern world there are many outreach programs that bring astronomy to the classroom, most of them act in cities within developed countries and rely heavily on internet connection. Thus, schools in rural and remote areas rarely benefit from such efforts. Thus, pupils and teachers in rural and remote areas rarely benefit from such efforts, making it difficult to know about modern space missions like GAIA and world interpretations based on modern astronomy. GalileoMobile is an itinerant astronomy education initiative with the aim to bridge this gap. We do this by performing teacher workshops, activities with students, and donating educational material. The initiative is run on a voluntary basis by an international team of astronomers, educators, and science communicators. Since its creation in 2008, we have travelled to Chile, Bolivia, Peru, India, Uganda, and Brazil, and worked with about 65 schools. From our experiences, we learnt that (1) bringing experts from other countries was very stimulating for children as they are naturally curious about other cultures and encourages a collaboration beyond borders; (2) high-school students who were already interested in science were always very eager to interact with astronomers doing research to ask for career advice; (3) inquiry-based methods are important to make the learning process more effective; (4) local teachers and university students involved in our activities have the potential to carry out follow-up activities. Our next project for 2015, Constellation, aims to establish a South American network of schools committed to organize and share astronomical outreach activities.

5 Title: GAIA and the epistemology of astrophysics Sibylle Anderl Universite Josephe Fourier, Grenoble, France The GAIA mission aims at creating a three-dimensional map of our galaxy and will provide a census of about one billion stars. It will produce hundreds of Terabytes of data, which will then need to be reduced, analyzed and interpreted by the astronomical community. Its first goal, the mapping of the structure of our Milky Way is already a complicated enterprise by itself as the spatial structure of our galaxy needs to be reconstructed from its two-dimensional projection on the celestial sphere as GAIA sees it. However, the further goals of understanding the formation and evolution of the Milky Way and its stellar populations sound even more ambitious, given that we only get a short snapshot of the life of our Galaxy. Experimental scientists might just create a number of sample galaxies and study their behavior in different environments. Obviously, this is not the way to go in astrophysics: astrophysicists can t perform experiments in a sense that hypotheses are investigated by means of controlled test conditions. The missing possibility of direct intervention, marking the difference between observational and experimental sciences, puts the astronomer in a situation in which he or she is only able to study the information sent out by the astronomical objects spontaneously. Therefore, the astronomical method resembles much more the criminology of Sherlock Holmes than it does the methodology of the classical experimental scientist. Astrophysics can, however, at least partially compensate for the lack of interaction with its research objects by the fact that the universe, being a "Cosmic Laboratory, is filled with phenomena and on-going processes in all conceivable evolutionary stages, constrained by different environments. Accordingly, the astronomer s challenge is to statistically sample, analyze and model this diversity, in order to reach generalized conclusions about cosmic phenomena. But what are the preconditions inherent to this approach astrophysical research, and how might this method implicitly determine what we can possibly know? What assumptions are implicit with these simulations? How justified are the assumptions and what are their downstream implications? How can we optimally make use of our astronomical data? Contemporary philosophers of science are now actively studying the epistemology of modelling, simulations, experiments and data handling that may well provide incentive for broader philosophical reflection on modern astrophysics. In this talk, I will review points of contact between the philosophy of science and astrophysics and I will demonstrate the utility of philosophical tools for the reflection of astrophysical research practice.