Workshop of MW-Gaia COST Action 18104, Working Group 3, Planetary Systems Near and Far

Scientific Organizing Committee: Prof. Karri Muinonen (chair), Dr. Anne Virkki, Dr. Paolo Tanga, Dr. Alberto Cellino, Dr. Olga Muñoz, Dr. Gorden Videen, and Dr. Antti Penttilä

Local Organizing Committee: Dr. Antti Penttilä (chair),  Dr. Anne Virkki, Prof. Karri Muinonen, Department of Physics, University of Helsinki

Workshop dates: September 28–29, 2021

Workshop scope

Asteroids and comets are the key to the evolution of the Solar System. These small Solar System objects (SSOs) are being systematically observed, with unprecedented precision in photometry, spectroscopy, and astrometry, by the ESA Gaia Space Mission. The workshop will cover the synergies and challenges in the combination of the Gaia data and data from other sources, that is, from ground-based astronomical observations and space missions to small SSOs. The former include astrometry, occultations, spectroscopy, polarimetry, and photometry, whereas the latter include the high-resolution observations of asteroid Ryugu by the Hayabusa2 mission (JAXA), of asteroid Bennu by the OSIRIS-REx mission (NASA), and of Comet 67P/Churyumov-Gerasimenko by the Rosetta mission (ESA). How Gaia relates to future SSO space missions, such as DART (NASA) and Hera (ESA), Comet Interceptor (ESA), and Destiny+ (JAXA), will be addressed.

The workshop improves the understanding of the physics of small SSOs to draw inferences on their origin and formation. Topics cover, for example, exploitation of the extraordinary accuracy of, first, Gaia astrometry for orbit improvement, navigation to mission targets, and asteroid mass determination, and, second, Gaia photometry for the retrieval of asteroid phase curve parameters, shapes, and rotational characteristics. Tutorial sessions are organized using pre-recorded videos on data analysis techniques in astrometry and photometry, including applications of machine learning techniques to large samples of asteroid data.


Program with abstracts: MW_GAIA_Workshop_Program.pdf

The program is composed of invited oral presentations with a duration of 20 min each (15 min for the talk, 5 min for questions, answers, and change of speaker). Additionally, there will be specific sessions for discussion.

Tue 28.9. (EEDT)

8:55Karri MuinonenOpening of the workshop
9:00Paolo Tanga

The role of asteroid observations by Gaia: preparing the exploitation of the first full-size data release

9:20Nicholas MoskovitzAsteroid characterization at Lowell Observatory
9:40Irina BelskayaAsteroid magnitude phase curve parameters: accuracy and reliability
10:00Dagmara OszkiewiczAsteroid phase curves using dense differential and sparse relative photometry
10:20coffee break
10:50Alberto CellinoGoing toward a strengthened multi-disciplinary approach in asteroid science
11:10Eri TatsumiAre Ryugu and Bennu from the same parent body or not?
11:30Eric McLennanAsteroid shapes and thermophysical modeling: (3200) Phaethon as a case study
11:50Tomas KohoutComet Interceptor and Hera -- Revolutionary planetary mission concepts
13:30Antoine PommerolAsteroids and comets: The quest for suitable analogues
13:50Gorden VideenPolarized light scattering from regolith simulants
14:10Maria GritsevichIn search for the missing link: recovering samples from Small Solar System bodies
14:30Mikael GranvikIn-situ monitoring of the surface degradation on a near-Sun asteroid
14:50coffee break
15:20Marco DelboObservational constraints to the initial asteroid size distribution: the Gaia perspective.
15:40Federica SpotoA new weighting scheme to combine Gaia and ground-based observations
16:00Grigori FedoretsSearching for asteroid binaries in the wobble of Gaia astrometry
16:20Lauri SiltalaAsteroid mass determination with Gaia
16:40DiscussionGaia data analysis techniques
20:15Conference dinner

Wed 29.9. (EEDT)

8:55Karri MuinonenOpening of the day 2
9:00Annika GustafssonRevealing Regolith Properties of Asteroids Using Radiative Transfer Modeling
9:20Joe MasieroChasing asteroids in the infrared: NEOWISE and NEO Surveyor
9:40Xiaobin WangSSO data in time-domain photometric surveys
10:00Karri MuinonenAsteroid photometric and polarimetric phase curves interpreted using synoptic scattering models
10:20coffee break
10:50Julia MartikainenModeling light scattering by Martian atmospheric dust
11:10Matthew Berg

Digital Holography: Capabilities and Concepts for Cometary Grain and Regolith Characterization

11:30Johannes MarkkanenThermophysics of dust particles: Implications on cometary activity
11:50Yuna Kwon

Polarimetric study of the dust environment of comet 67P/Churyumov-Gerasimenko around the end of its Southern summer

13:30Evgenij ZubkoOn the nature of dispersion of linear polarization observed in comets at large phase angles
13:50Olga MunozUnderstanding the Negative Polarization Branch of comets and asteroids
14:10Jürgen BlumComets as clues to planetesimal formation
14:30coffee break
15:00Benoit CarryThe impact of Gaia on the study of asteroid interiors
15:20Anne VirkkiCharacterizing dielectric properties of near-Earth asteroids using radar observations
15:40Deborah DomingueComparing photometric properties of Eros, Itokawa, and Ryugu
16:00Antti PenttiläDeep learning tools for asteroid taxonomy with Gaia and other surveys
17:00Karri MuinonenClosing of the Workshop

Invited speakers (ViZ = virtually via Zoom,  OZ = on site via Zoom)

The workshop attendance is by invitation only, with the restriction of maximum 25 participants on site. The invited speakers are

Group photo at September 29, 2021

All other participants

Virtual attendance via Zoom, to follow the presentations, will be possible for MW-Gaia participants and other interested colleagues. Note that there is likely to be an upper limit for the number of participants. Please send email to to receive the connection details.


The workshop is organized in hybrid mode with participants attending virtually and on site. Both modes of attendance will involve scientific presentations via Zoom. Mankeliaitta of the Krapi Conference Center (Tuusula, Finland) serves as the workshop venue, with accommodation at the Onnela premises.


The workshop is supported by the Gaia COST Action MW-Gaia (CA18104) and the Academy of Finland projects InSight (345115) and PlanetS (325805).