ESO-connected data analysis activities have also grown sig-nificantly since the beginning of Finland’s membership in 2004. The project, called ESO-Sampo, conducts develop-ment of science data analysis environdevelop-ment for ESO. Four IT professionals worked full time for the in-kind contribution in the period 1.1.2005- 31.1.2008 in a Tekes-funded project at the Observatory, University of Helsinki, and has continued the same work with partial funding from ESO since then. The main result of the project is the ESO Reflex workflow engine, an advanced science analysis environment which ESO plans to implement as standard ESO software for the reduction of VLT and other ESO data.
HESA team has also participated actively in the prepa-ration of national technology return from ESO. These have already lead to a request from ESO to continue ESO Reflex development by partial ESO funding, and a parallel devel-opment of an application for other sciences and also com-mercial use with Tekes funding, which are still an ongoing activities. Further, future activities from this are (1) a Tekes project for developing a Situation Awareness System using Multidimensional Information (MIFSAS), and (2) a proposal to the Academy of Finland for Development and Applica-tion of New ComputaApplica-tional Methods and Analysis for Re-mote Sensing Data of Planets and the Earth (CorePlane).
2.4 External financing and resources
2008: Man-months of work: 108 Academy of Finland: 109 320e
National Technology Agency: 2 500 000e European Space Agency: 165 000e European Southern Observatory: 100 000e
2.5 Tests of learning
Alha, Lauri
Licentiate’s thesis: The performance of X-ray So-lar Monitor (XSM) and the first results; 2008, Univer-sity of Helsinki, Department of Astronomy
Takala, Tuure
M.Sc. thesis: Study of GOMOS instrumental age-ing and applicability for stellar spectroscopy; 2008, University of Helsinki, Department of Astronomy Ahoranta, Jussi
M.Sc. thesis: Measuring dark energy with super-novae Ia, Department of Astronomy
Raja-Halli, Arttu
M.Sc. thesis: Mass function of clusters of galax-ies – a study on systematic uncertaintgalax-ies on cosmologi-cal parameters due to the mass-observable relation, De-partment of Astronomy
2.6 Visits abroad
Alha, Lauri
Chandrayaan-1 C1XS science team meeting;
UCL, London, U.K., 7.–8.2.2008 Esko, Eero
CIXS Science Team Meeting; Aberystwyth Uni-versity, U.K., 15.–18.10.2008
Huovelin, Juhani
Chandrayaan-1 CIXS science team meeting;
UCL, London, U.K., 7.2.2008
BepiColombo SWG meeting ESTEC; Noordwijk, The Netherlands, 26.–27.3.2008
ESO Reflex project meeting, Munich, Germany, 2.4.2008
ESO-Reflex project meeting; Munich, Germany, 8.9.2008
BepiColombo SWG meeting; Sendai, Japan, 14.–
19.9.2008 Maisala, Sami
Sampo team meeting; ESO Garching, Germany, 16.–18.1.2008
SPIE Defence + security conference; Orlando, USA, 13.–22.3.2008
Sampo2 Kick-offmeeting; ESO, Garching, USA, 2.–3.4.2008
Sampo2 meeting; ESO,Garching, Germany, 8.–
9.9.2008
Interactive Tools/ESO-reflex meeting; ESO, Garching, Germany, 16.–18.12.2008
Nevalainen, Jukka
Universite Paris-Sud, France, 4.–7.5.2008 Granada conference center, Spain, 24.–31.5.2008 Oittinen, Tero
SPIE Defence + security conference; Orlando, USA, 13.–22.3.2008
Sampo2 Kick-offmeeting; ESO, Garching, Ger-many, 2.–3.4.2008
IBM Boeblingen Lab, application platform train-ing; Stuttgart, Germany, 12.–13.6.2008
Sampo2 meeting; ESO,Garching, Germany, 8.–
9.9.2008
Interactive Tools/ESO-reflex meeting; ESO, Garching, Germany, 16.–18.12.2008
V¨a¨an¨anen, Mikko
7th International IGPP Conference, Kauai, Hawaii, USA, 6.–19.3.2008
2.7 Papers read at scientific conferences, sym-posia, meetings etc.
Esko, Eero
”Chandrayaan-1 XSM”, C1XS Science Team Meeting, 16.10.2008, Aberystwyth University, U.K., invited talk
Nevalainen, Jukka
”Mapping the non-thermal component in Coma cluster”, The X-ray Universe 2008, 28.5.2008, Granada, Spain, invited talk
V¨a¨an¨anen, Mikko
”Time evolution of the size of solar flare plasma loops along the main sequence”, 7th International IGPP Conference, 8.3.2008, Kauai, Hawaii, USA
2.8 Visiting academics
Nevalainen, Jukka
Bonamente, Massimiliano, PhD, assistant profes-sor, University of Alabama in Huntsville, USA, 18.–
22.5.2008
2.9 Membership in scientific and scholarly so-cieties
Huovelin, Juhani
Finnish COSPAR committee, Finland
Research school for astronomy and space physics, Finland, board
Tuorla Observatory of University of Turku, advi-sory board
Academy of Finland assessor pool, Finland, ex-pert
Finnish Space Committee (ANK), permanent ex-pert
Nevalainen, Jukka
XMM-Newton AO8 Time Allocation Committee, 23.–26.1. 2008, U.K.
Planck Working Group 5, 30.3.2007–, expert International Astronomical Consortium for High Energy Calibration, 9.5.2007–, expert
2.10 Refereeing and Other Publishing Activi-ties
Huovelin, Juhani
Earth and Planetary Science, Japan, referee Nevalainen, Jukka
Astrophysical Journal, referee
A group of Observatory faculty, students and staff March 26, 2008. (Photo: Anu Palo)
Photo: Leith Arar
3 Planetary System Research
Project number 02525008
Research agreements Academy of Finland Type of research Basic research Director of research Docent Muinonen, Karri
Telephone 19122941
Fax 19122952
E-mail Karri.Muinonen@Helsinki.Fi
Research staffwith a Ph.D. Karri Muinonen, Docent Kari Lumme, Prof. emer.
Serge Mouret, Ph.D.
Mikael Granvik, Ph.D.
Johanna Torppa, Ph.D.
Phd students Jyri N¨ar¨anen, M.Sc.
Dagmara Oszkiewicz , M.Sc.
Hannu Parviainen, M.Sc.
Antti Penttil¨a, M.Sc.
Jani Tyynel¨a, M.Sc.
Hannakaisa Lindqvist, M.Sc.
Students Jarkko Niemel¨a
Associated scientists Markku Poutanen, Prof.
Lauri Pesonen, Prof.
Jouni Peltoniemi, Docent Timo Nousiainen, Docent Jenni Virtanen, Ph.D.
3.1 Research activities
Research within the Planetary-System Research -group (PSR) at the University of Helsinki Observatory entails theo-retical, observational, and experimental studies on key top-ics of solar-system exploration. In fundamental planetary physics, PSR theoretical research is focused on light scatter-ing by sscatter-ingle small particles, on multiple scatterscatter-ing by com-plex media of small particles, and the celestial mechanics of the few-body problem. Experiments have been carried out to measure backscattering characteristics of particulate media (scatterometer at the Observatory), to assess the X-ray fluo-rescence by planetary-regolith analog samples (at the Depart-ment of Physical Sciences), and to measure meteorite spec-tra in visible and near-infrared wavelengths (at the Geologi-cal Survey of Finland and at the Finnish Geodetic Institute).
Observations have been made using both space-based and ground-based telescopes.
The numerical method for computing coherent backscat-tering by complex particulate media developed at UHO has been successfully applied to polarimetric observations of transneptunian objects (TNOs). At ESO/VLT, PSR has con-tinued to participate in polarimetric observations of TNOs, for example, through participation in the Large Program on the physical properties of TNOs. Furthermore, PSR has taken part in polarimetric observations of cometary nuclei at VLT:
these observations are the first-ever systematic polarimetric observations of cometary nuclei.
Among the highlights of the TNO studies was the dis-covery of two distinct polarimetric behaviours of transneptu-nian objects by Bagnulo et al. (2008B1). Polarimetric obser-vations of the dwarf planet (136199) Eris were reported by Belskaya et al. (2008B1). Belskaya et al. (2008abB2) re-viewed the polarimetric VLT observations, assessing the
sur-Figure 6: Linear polarimetry of nine TNOs as a function of phase angle. Two distinctly different populations are distin-guished: on the left, the large TNOs show rather shallow de-pendences; whereas, on the right, the small TNOs show steep dependences. The difference can be explained by the differing physical properties of the surfaces of large and small TNOs.
face properties of Kuiper-Belt objects and centaurs from pho-tometry and polarimetry. The first polarimetric observations of a cometary nucleus, concerning comet 2P/Encke, were re-ported by Boehnhardt et al. (2008B1, 2008B2).
The single-scattering polarization and intensity
mecha-Figure 7: All dipoles of the Gaussian-random-sphere parti-cle which have the intensity of the longitudinal component at least 30% from the maximum. The volume-equivalent-sphere size parameter x=8, the refractive index m =1.55, the rel-ative standard deviation of radiusσ=0.245, and the power-law index of the covariance functionν = 4. The incident polarization (blue color) and the wave vector (gray color) are shown on the lower left.
Figure 8: An aggregate of 100 spheres and its concave-hull transformations. The concave-hull transformation provides a method for generating nonspherical particle shapes and inho-mogeneous internal compositions, which are essential quali-ties in modeling light scattering by small solar-system parti-cles.
nisms deriving from the internal electric fields of Gaussian-random-sphere particles were studied by Tyynel ¨a et al.
(2008B1), similar to the study previously carried out for spherical particles. The study was further continued for ori-ented spheroids by Tyynel¨a et al. (2008B2). Tyynel¨a et al.
(2008abB2) carried out radar-scattering computations from spherical and spheroidal particles, as well as clusters of spher-ical particles in the C-band using the discrete-dipole approx-imation method (DDA). The results were compared to those from exact methods.
Parviainen and Lumme (2008B1) investigated scat-tering from rough thin films using DDA. Erkkil ¨a and Muinonen (2008B2) studied light scattering by inhomoge-neous concave-hull-transformed clusters of spheres. Nousi-ainen et al. (2008B2) focused on optical modeling of thin calcite flakes using DDA. Zubko et al. (2008abcB2) studied light scattering by highly absorbing irregularly shaped parti-cles, light scattering by agglomerated debris particles com-posed of highly absorbing material, and the applicability of DDA to conductive particles. Muinonen et al. (2008aB2) in-troduced diffuse scatterers in the ray-optics treatment for light scattering by particles large compared to wavelength.
In studies of orbit computation, Granvik and Muinonen (2008B1) presented a new method for the previously un-solved problem of linking scarce sets of astrometry of solar-system objects over apparitions. The new method is based on statistical orbital inversion, typically Ranging, and results from tests with simulated data were presented by Granvik and Muinonen (2008aB2). Granvik et al. (2008bB2) published an open-source orbit-computation package called OpenOrb which includes, for example, the statistical ranging method.
Virtanen et al. (2008B2) reviewed transneptunian orbit com-putation.
Figure 9: Al/Si elemental ratios on the Moon as measured with X-ray fluorescence spectrometers onboard the Apollo 15 and 16 missions. Red and blue imply high and low ratios, re-spectively. As the lunar silicon abundance as determined by these missions is relatively constant, this map depicts effec-tively the aluminium abundance. Picture courtesy of NASA.
Figure 10: Collapse of orbital-element p.d.f.s with improving accuracy of the observations. Sets of distributions each com-posed of 5000 possible orbit solutions for (4) Vesta obtained from simulated Gaia data for the epoch of 2010 Aug 5.0 TDT.
The distributions were obtained using four observations from a single scan (0.32 days observational time interval). Different colors correspond to different assumptions about the observational astrometric error in Right Ascension and Declination (red color impliesσα,δ=1.0 arcsec, greenσα,δ=0.1 arcsec, blueσα,δ=0.01 arcsec, and blackσα,δ=0.001 arcsec). The yellow asterisk indicates the end-of-mission least-squares solution. The distributions were obtained using MCMC ranging.
Figure 11: Comparison of reflectance spectra from a variety of meteorite subgroups. All of these, except one, are Chondrites that are primitive form of meterorite. The Eucrite is an HED that is from a differentiated body. The legend shows chart labels that consist of a letter and a number. The letter denotes the amount of free iron in the meteorite (High or Low) and the number denotes the amount of thermal alteration with 3 being the lowest and 6 the highest amount. Numbers below 3 refer to aqueous alteration. All groups have similar spectral characteristics with broad absorption bands (band I and band II) due to the presence of olivine and pyroxene. The bands are superimposed on a continuum that may increase or decrease with wavelength. Analyzing the features in the spectra can make a quantitive comparison between spectra.
Oszkiewicz et al. (2008B2) reported preliminary results of novel Markov-chain Monte-Carlo methods (MCMC) for asteroid orbit computation. The methods are to be applied, in particular, in the data analysis and processing chain for the ESA Gaia mission. Lindegren et al. (2008B2) described the training of the next generation of space astrometrists in the context of the ELSA project supporting the Gaia mis-sion. Hildebrand et al. (2008B2) showed that the Near-Earth-Object Surveillance Satellite (NEOSSat) Mission will conduct an efficient space-based asteroid survey at low solar elongations. Grundy et al. (2008B1) developed a statisti-cal ranging method for instrinsic orbit computation in binary systems such as those involving two asteroids or two TNOs.
They scheduled astrometric observations for (42355) Typhon Echidna based on the new method.
In studies of asteroid phase curves and lightcurves, Muinonen et al. (2008bB2) presented methods for the deriva-tion of empirical magnitude and polarizaderiva-tion systems for as-teroid phase curves. Their goal is to develop a new magnitude system for asteroids, revising the two-parameter H, G magni-tude system. Torppa et al. (2008B1) provided asteroid shape and spin statistics from convex models. They showed that the resulting convex shape models can be fitted by ellipsoids at the 5% level but that the convex method is a key element in obtaining such ellipsoid models. Muinonen (2008B2) and Muinonen and Oszkiewicz (2008B2) provided preliminary results for lightcurve inversion using Markov-Chain Monte-Carlo methods.
Laboratory measurements on the effect that the physical properties of the regolith (primarily surface roughness) have on soft X-ray fluorescence spectroscopy of planetary surfaces were performed both at the University of Helsinki (in collab-oration with the Department of Physics) and at the University of Leicester (UK) Space Research Centre. Preliminary results from these studies were published by N¨ar¨anen et al. 2008B1.
They confirmed that a hardening of the spectrum occurs as a function of growing phase angle and that the hardening is also larger for rougher surfaces. This effect will be important for the analyses of present and future X-ray spectrometer data from orbiting platforms (e.g., BepiColombo at Mercury and Chandrayaan-1 at Moon).
PSR has been collaborating with the Finnish Geodetic In-stitute during the past years in laboratory and field studies of multiangular light-scattering properties of terrestrial surfaces (such as understory vegetation of boreal forests). Peltoniemi et al. (2008B1) described parts of the equipment used in these studies and presented the highlights of the studies.
Parviainen and Muinonen (2008abB2) studied volume and surface shadowing in particulate random media, provid-ing a realistic light-scatterprovid-ing model for rough particulate sur-faces. Muinonen et al. (2008B2) assessed the scalar approxi-mation to coherent backscattering by spherical media. Foing et al. (2008B2), Koschny et al. (2008B2), and Grieger et al.
(2008B2) described the ESA SMART-1 mission lunar
high-lights, lunar science planning, and the coverage and pointing accuracy of SMART-1/AMIE images. PSR launched an in-depth study on the interpretation of the AMIE photometry:
the results of these investigations were submitted for publica-tion.
Preparations continued for the Marco Polo near-Earth-object sample return mission, with PSR represented in the ESA Science Study Team of the mission. The Marco Polo mission was described by Koschny et al. (2008B2) and Dotto et al. (2008B2).
3.2 External financing and resources
2008: Man-months of work: 100
Academy of Finland, ’Mercury, Lunar and Solar Science with BepiColombo and SMART-1: X-ray flu-orescence from small-particle media’:
20 000e
European Commission, ’European Leadership in Space Astrometry’ (ELSA)’: 64 000e
Finnish Cultural Foundation 16 000e
Tekes project Nanopap (Improvement of Optical Properties of Paper by Increasing Refractive Indices of Materials): 21 000e
Tekes forest cluster project Re-engineering paper:
30 448e
3.3 Tests of learning
Granvik, Mikael
Ph.D. Thesis: Asteroid identification using sta-tistical orbital inversion methods; 2008, University of Helsinki, Department of Astronomy
Torppa, Johanna
Ph.D. Thesis: Lightcurve inversion for asteroid spins and shapes; 2008, University of Helsinki, Depart-ment of Astronomy
Erkkil¨a, Hannakaisa M.Sc. thesis: Light scattering by small inhomogeneous solar-system particles; 2008, University of Helsinki, Department of Astronomy
3.4 Visits abroad
Muinonen, Karri
International Space Science Institute (ISSI), Switzerland, 6.–12.1.2008
Observatoire de Paris, France, 29.–30.1.2008 ESA/EST, The Netherlands, 18.–19.3.2008 ESA/ESTEC, The Netherlands, 26.–27.3.2008
ESA/ESTEC, The Netherlands, 13.–14.4.2008 Li`ege Observatory, Belgia, 14.–17.5.2008 Observatoire de la Cote d’Azur, France, 5.–
7.6.2008
AOGS meeting, Busan, South Korea, 12.–
20.6.2008
ACM’2008 meeting, Baltimore, USA, 13.–
18.6.2006
ELSA meeting, Barcelona, Spain, 31.8.–6.9.2008 ELS meeting, Hatfield, U.K., 7.–12.9.2008 ESA/ESTEC, The Netherlands, 29.–30.10.2008 Observatoire de Bordeaux, France, 19.–
22.11.2008
International Space Science Institute (ISSI), Switzerland, 30.11.–5.12.2008
Mouret, Serge
IMCCE – Paris observatory, France, 80 days Oszkiewicz, Dagmara
ESAC, Spain, 15.–19.1.2008 ESAC, Spain, 15.–20.6.2008 GAIA DPAC, Belgia, 14.–17.5.2008
Johns Hopkins University Applied Physics Labo-ratory, USA, 12.–19.7.2008
Li`ege University, Belgia, 24.–29.8.2008 Barcelona University, Spain, 29.8.–7.9.2008 Parviainen, Hannu
SMART-1 meeting; Madrid, Spain, 9.–12.4.2008 ELS XI meeting, U.K., 7.–12.9.2008
DPS 2008, USA, 9.–20.10.2008
MIXS IPDR; London, U.K., 10.–13.11.2008 Penttil¨a, Antti
ISSI – International Space Science Institute, Switzerland, 1.–5.12.2008
3.5 Papers read at scientific conferences, sym-posia, meetings etc.
Mouret, Serge
”Asteroid mass determination with Gaia mission”, The 10th Asteroids, Comets, Meteors, Baltimore, MD, USA
Muinonen, Karri
”Light scattering by solar-system small parti-cles”, Visit at the Physics Department, University of Jyv¨askyl¨a, 7.3.2008, Jyv¨askyl¨a, Finland, invited talk
”Polarimetry of transneptunian objects and cometary nuclei with VLT”, National meeting of the Finnish ESO scientists and students, 23.–24.10.2008, Tuorla Observatory, Finland
”Planetary-System Research at UH/Obs”, Visit at the Finnish Geodetic Institute, 11.11.2008, Helsinki, Finland, invited talk
”Marco Polo: a near Earth object sample return mission”, Lunar and Planetary Science XXXIX, 10.–
14.3.2008, League City, TX, USA
”SMART-1 lunar highlights”, Lunar and Plane-tary Science XXXIX, 10.–14.3.2008, League City, TX, USA
”Coverage and pointing accuracy of SMART-1/AMIE images”, Lunar and Planetary Science XXXIX, 10.–14.3.2008, League City, TX, USA
”Marco Polo: Near-Earth object sample return mission”, European Geosciences Union, General As-sembly, 13.–18.4.2008, Vienna, Austria, invited talk
”Physical properties of cosmic dust particles from light scattering”, Asia Oceania Geosciences Society, 16.–20.6.2008, Busan, South Korea, invited talk
”Marco Polo: NEO sample return mission”, Asia Oceania Geosciences Society, Annual Meeting, 16.–
20.6.2008, Busan, South Korea
”Polarimetry of transneptunian objects”, Astro-nomical Polarimetry 2008, 6.–11.7.2008, La Malbaie, Quebec, Canada
”First phase-angle resolved polarimetry of a bare comet nucleus: comet 2P/Encke”, Astronomical Po-larimetry 2008, 13.–20.7.2008, La Malbaie, Quebec, Canada, poster
”Science of Marco Polo: Near-Earth object sam-ple return mission”, 37th COSPAR Scientific Assem-bly, 13.–20.7.2008, Montreal, Canada, invited talk
”Effect of regolith on planetary X-ray fluores-cence spectroscopy: laboratory and numerical studies”, 37th COSPAR Scientific Assembly, 13.–20.7.2008, Montreal, Canada, poster
”Photometric study of the Moon with SMART-1/AMIE”, 37th COSPAR Scientific Assembly, 13.–
20.7.2008, Montreal, Canada
”Planetary protection issues for the Marco Polo NEO sample return mission”, 37th COSPAR Scientific Assembly, 13.–18.6.2008, Montreal, Canada, invited talk
”TNO ESO-VLT Large Program (2006–2008):
Results and implications”, Asteroids, Comets, Mete-ors 2008, 13.–18.6.2008, Baltimore, MD, USA, invited talk
”Polarimetry of transneptunian objects and cen-taurs with VLT”, Asteroids, Comets, Meteors 2008, 13.–18.6.2008, Baltimore, MD, USA, poster
”Imaging and polarimetry of the nucleus of Comet 2P/Encke”, Asteroids, Comets, Meteors 2008, 13.–
18.6.2008, Baltimore, MD, USA
”OpenOrb: Open-source asteroid-orbit-computation software including statistical orbital ranging”, Asteroids, Comets, Meteors 2008, 13.–
18.6.2008, Baltimore, MD, USA, poster
”New method for identifying asteroids between apparitions among a wealth of scarce astrometry”, As-teroids, Comets, Meteors 2008, 13.–18.6.2008, Balti-more, MD, USA
”Marco Polo – a mission to return a sample from a near-Earth object”, Asteroids, Comets, Meteors 2008, 13.–18.6.2008, Baltimore, MD, USA
”Lightcurve inversion using Markov-Chain Monte-Carlo methods”, Asteroids, Comets, Meteors 2008, 13.–18.6.2008, Baltimore, MD, USA, poster
”Inversion of asteroid phase curves for empiri-cal magnitude and polarization systems”, Asteroids, Comets, Meteors 2008, 13.–18.6.2008, Baltimore, MD, USA
”Markov-Chain Monte-Carlo methods for aster-oid orbit computation”, Asteraster-oids, Comets, Meteors 2008, 13.–18.6.2008, Baltimore, MD, USA, poster
”A realistic light-scattering model for rough par-ticulate surfaces”, Asteroids, Comets, Meteors 2008, 1.–5.9.2008, Baltimore, MD, USA, poster
”Markov-Chain Monte-Carlo methods”, ELSA Workshop on Software Engineering and Numerics, 7.–
12.9.2008, Barcelona, Spain, invited talk
”Light scattering by inhomogeneous concave-hull-transformed clusters of spheres”, Electromagnetic and Light Scattering by Nonspherical Particles, 7.–
12.9.2008, University of Hertfordshire, Hatfield, U.K.
”Volume and surface shadowing in particulate random media”, Electromagnetic and Light Scattering by Nonspherical Particles, 7.–12.9.2008, University of Hertfordshire, Hatfield, U.K.
”Markov-Chain Monte-Carlo inversion of aster-oid photometric lightcurves”, Electromagnetic and Light Scattering by Nonspherical Particles, 7.–
12.9.2008, University of Hertfordshire, Hatfield, U.K., poster
”Optical modeling of thin calcite flakes using DDA”, Electromagnetic and Light Scattering by Non-spherical Particles, 7.–12.9.2008, University of Hert-fordshire, Hatfield, Gibraltar, poster
”Light scattering by agglomerated debris parti-cles composed of highly absorbing material”, Electro-magnetic and Light Scattering by Nonspherical
”Light scattering by agglomerated debris parti-cles composed of highly absorbing material”, Electro-magnetic and Light Scattering by Nonspherical