Planetesimal formation

A virtual interdisciplinary workshop on planetesimal formation via the streaming instability that explores the connection to protoplanetary disc observations and the Solar System minor bodies.


17-20 November
Start time: 17 November 16:00 Central European Time (in your timezone)

Synchronous events: in a virtual conference room on zoom

Two and a half contact hours, the same each day, with presentations on zoom, between 16:00-18:30 Brussels / 10:00-12:30 New York / 08:00-10:30 Denver / 23:00-01:30 Taipei

Asynchronous activities: in a virtual lobby on slack

A slack workspace will be used for speaker Q&A, discussions and as place to host the posters.


Participating in the meeting

You can register here for the zoom event. Please sign up before 13 November.
Registered participants will receive an invite to the slack workspace Monday 16 November.

Contributing a poster on slack

Participants can choose to present a pdf poster on slack. A title will be requested when you register, but there is no abstract required. When contributing a poster, please register or let us know via email ( before 12 November. Then you will get early access to the slack workspace (13-16 November) to upload your poster.
There are no size or style requirements for the pdf posters. We have verified that uploading a classic A0-format pdf poster works, however, if you wish to, you are welcome to take advantage of the online format and present content like videos, papers and links, in addition to the pdf poster.

Program with confirmed invited speakers

Each talk will be about 10 minutes, review talks will be about 20 minutes. Talks are presented live on zoom and recorded (for participants only).

Tuesday 17 November

15:55 - 16:00 Michiel Lambrechts First-day welcome and practical information before starting our first session

Session chair: Michiel Lambrechts
Time (CET) Speaker  
16:00 - 16:30 Andrew Youdin Review of planetesimal formation theory
     Session 1: Planetesimal formation in pressure bumps
16:30 - 16:45 Kees Dullemond Observational and theoretical constraints of grain growth in ALMA’s dust rings
16:45 - 17:00 Daniel Carrera Protoplanetary Disk Rings as Sites for Planetesimal Formation
17:00 - 17:15 Linn Eriksson The formation and fate of planetesimals at planetary gap edges
17:15 - 17:30 break  
    Session 2: initial mass distribution / binary formation / resonant drag instability
17:30 - 17:45 Rixin Li Demographics of Planetesimals Formed by the Streaming Instability
17:45 - 18:00 David Nesvorný Binary Planetesimal Formation from Gravitationally Collapsing Pebble Clouds
18:00 - 18:15 Wladimir Lyra Orbital evolution of Arrokoth from a binary planetesimal into contact via Kozai-Lidov oscillations and nebular drag
18:15 - 18:30 Jonathan Squire  Understanding dust clumping in the streaming instability with toy models

Wednesday 18 November

Session chair: Anders Johansen
Time (CET) Speaker  
16:00 - 16:30 Andrea Mignone Numerical Methods for Dust-Gas Interaction: a Review
    Session 3: streaming instability with a dust size distribution
16:30 - 16:45 Leonardo Krapp Streaming instability for particle-size distributions
16:45 - 17:00 Noemi Schaffer The influence of multi-species grains on the outcome of the streaming instability
17:00 - 17:15 Zhaohuan Zhu The favorable conditions for SI with multiple dust species
17:15 - 17:30 break  
    Session 4: streaming instability and turbulence
17:30 - 17:45 Orkan Umurhan Streaming Instability and Turbulence: Issues, Questions and Challenges
17:45 - 18:00 Chao-Chin Yang Nonlinear evolution of the streaming instability
18:00 - 18:15 Phil Armitage The impact of small-scale turbulence
18:15 - 18:30 Konstantin Gerbig The importance of streaming instability driven particle diffusion for planetesimal formation

Thursday 19 November

Session chair: Urs Schäfer
Time (CET) Speaker  
16:00 - 16:30 Will Grundy Review: Observational constraints from the solar system's small body populations
    Session 5: Kuiper belt and asteroid belt size distribution
16:30 - 16:45 Kelsi Singer What can we learn about the original size distribution of Kuiper belt objects from New Horizons results
16:45 - 17:00 Alessandro Morbidelli A re-assessment of the Kuiper belt size distribution for sub-kilometer objects, revealing collisional equilibrium at small sizes
17:00 - 17:15 Marco Delbo Observational constraints to the primordial size distribution of Main Belt asteroids
17:15 - 17:30 break  
    Session 6: Arrokoth & 67P / constraints from cosmochemistry / drag instabilities in the lab
17:30 - 17:45 Bill McKinnon What did we learn from the New Horizons Arrokoth encounter?
17:45 - 18:00 Jürgen Blum Observational and lab constraints on the formation of comet 67P Churyumov-Gerasimenko
18:00 - 18:15 Elishevah Van Kooten Bidirectional mass transport of chondritic components in the protoplanetary disk
18:15 - 18:30 Holly Capelo Testing prescriptions for dust-drag flow instability with laboratory experiments on Earth and at low gravitational acceleration

Friday 20 November

Session chair: Noemi Schaffer
Time (CET) Speaker  
16:00 - 16:30 Joanna Drążkowska From dust growth to planetesimal formation
    Session 7: planetesimal formation in protoplanetary discs
16:30 - 16:45 Hubert Klahr Testing the Jeans, Toomre and Bonnor-Ebert concepts for planetesimal formation: 3D streaming instability simulations of diffusion regulated formation of planetesimals
16:45 - 17:00  Jean-François Gonzalez  Self-induced dust traps in protoplanetary disks
17:00 - 17:15 Johan Appelgren Planetesimal formation in evolving protoplanetary discs
17:15 - 17:30 break  
    Session 8: streaming and vertical shear instability / Lucy space probe
17:30 - 17:45 Min-Kai Lin Stratified and vertically-shearing streaming instabilities in protoplanetary disks
17:45 - 18:00 Urs Schäfer Coexistence of streaming instability and vertical shear instability in protoplanetary disks
18:00 - 18:15 discussion  
18:15 - 18:30 Hal Levison Lucy - The First Mission to the Trojan Asteroids

Already confirmed contributions on slack

Last updated: 6/11 (13:00 CET)

First NameLast Name Title
Nienkevan der Marel A direct link between disk structure, disk evolution and exoplanet demographics
PaoloTanga CAI-enriched asteroids, a possible connexion to peculiar planetesimals?
EduardVorobyov Dust dynamics in the Stokes regime
HossamAly Dust structures and 'traffic jams' in misaligned circumbinary discs
VardanElbakyan Evolution of dust in gravitoviscous protoplanetary disks
JacksonBarnes Formation of Planetesimals through Gravitational Collapse
ÅkeNordlund Formation of rocky planets
BenSchubert ICAPS - Preliminary Results on Particle Agglomeration during TEXUS-56 Sounding Rocket Flight
LomaraMaksimova Long-term evolution of a convectively unstable protoplanetary disk.
DentonEbel Phenomenology of Chondritic Meteorites from Planetesimals
YuhitoShibaike Planetesimal formation via the streaming instability at the gas pressure bump following a migrating planet
AleksandraKuznetsova Protostellar Disks as Sites of Early Phase Planet Formation
HyerinJang Radial distance dependency of planetesimal growth
RyosukeTominaga Revised description of dust diffusion and dust-gas instabilities in protoplanetary disks
MorRozner The aeolian-erosion barrier for the growth of metre-size objects in protoplanetary-disks and implications
CarverBierson The intersection of formation dynamics and geophysics
HongpingDeng Turbulence and fragments in magnetised gravitoturbulent disks
SebastiaanKrijt The voyage of volatiles from discs and dust to pebbles and planetesimals
ThomasPfeil  The "Sandwich Mode" for Vertical Shear Instability
OlgaStoyanovskaya  Fast and implicit method to simulate mutigrain dusty gas by smoothed particle hydrodynamics with separate sets of particles
OctavioGuilera  Connecting dust growth, planetesimal formation and giant planet formation at pressure maxima
FrancescoLovascio  The Polydisperse Streaming Instability
Marie-LuiseSteinmeyer  Evolution and collapse of Particle Filaments
MarijaJankovic  MRI-active inner regions of protoplanetary discs
ZiyanXu  Dust Dynamics and Planetesimal Formation in MRI Turbulent Protoplanetary Disks
NataschaManger  A Parameter Study of the Vertical Shear Instability
ŁukaszTychoniec  Measuring initial solid reservoir for planet formation with ALMA and VLA.
Nienkevan der Marel  On the diversity of asymmetries in gapped protoplanetary disks.
RicoVisser  On the radial structure of planetary bodies formed by the streaming instability
AlvaroRibas  Modeling protoplanetary disk SEDs with artificial neural networks: revisiting the viscous disk model and updated disk masses
JosefRucska  Variability in the planetesimal mass distribution from the streaming instability
TroelsHaugbølle  Probing the protosolar accretion disk using dust filtering and cosmochemical constraints
EnriqueMacias  Characterizing the dust content of disk substructures in TW Hya
YapingLi  Effect of Dust Coagulation on the Sub-structures in Protoplanetary Disks
MichaelHammer  Planet-induced vortices with realistic planet formation timescales
ArnaudMichel  Bridging the gap between protoplanetary and debris disks
MichielLambrechts  Formation of terrestrial-like systems with pebble accretion
BeibeiLiu  A characteristic planetesimal mass scaling from streaming instability simulations


Main organizers: Michiel Lambrechts & Anders Johansen
SOC: Anders Johansen, Kelsi Singer, Jacob Simon, Pablo Benítez-Llambay and Michiel Lambrechts
LOC: Noemi Schaffer, Urs Schäfer, Michiel Lambrechts and Anders Johansen

Already registered participants

Last updated: 16/11 (09:00 CET)

First NameLast NamePrimary host institute
CatalinaFloresUniversidad Andrés Bello
UmaGortiSETI Institute
JamesCadmanUniversity of Edinburgh
RichardBoothImperial College London
OrkanUmurhanSETI Institute
DanielCarreraIowa State University
PierreMarchandAmerican Museum of Natural History
GersonBarbosaNational Institute for Space Research (INPE)
Mohamed RamyEl-MaarryBirkbeck, University of London
RafaelRibeiroSao Paulo State University
KelsiSingerSouthwest Research Institute
RyosukeTominagaNagoya university
KatrinRosLund Observatory
TilBirnstielLMU Munich
DentonEbelAmerican Museum of Natural History
Sijme-JanPaardekooperQueen Mary, University of London
DarrylSeligmanUniversity of Chicago
ŁukaszTychoniecESO Garching
María JoséColmenaresUniversidad de Los Andes
BenoitCommerconCentre de Recherche Astrophysique de Lyon
JoannaDrążkowskaLMU Munich
NoemiSchafferLund University
DimitrisStamatellosUniversity of Central Lancashire
CongYuSun Yat-sen University
YuhitoShibaikeUniversity of Bern
LukeDonesSouthwest Research Institute
AkimasaKataokaNational Astronomical Observatory of Japan
ZhaohuanZhuUniversity of Nevada Las Vegas
RajaniDhingraJet Propulsion Laboratory
Yi-JehngKuanNational Taiwan Normal University
HiroyukiKurokawaELSI, Tokyo Tech
SebastianLorekLund Observatory
AdamDempseyLos Alamos National Laboratory
MarkBoothFriedrich-Schiller University, Jena
MatthäusSchulikImperial College London
OctavioGuileraAstrophysical Institute of La Plata
AayushGautamBirendra Multiple Campus, Tribhuvan University, Nepal
WladimirLyraNew Mexico State University
HongpingDengUniversity of Cambridge
MartinPessahNiels Bohr Institute
MartinSandbergNiels Bohr
Paula StellaTeixeiraUniversity of St Andrews
StéphaneMichoulierCentre de Recherche Astrophysique de Lyon
NgocTruongCornell University
MyriamBenistyIPAG Grenoble & U Chile
CathyOlkinSouthwest Research Institute
beibeiLiuZhejiang University
JJKavelaarsNRC Canada
CarolinKimmigInstitute for Theoretical Astrophysics Heidelberg
Yueh-NingLeeNational Taiwan Normal University
JonRamseyUniversity of Virginia
ErikAsphaugU Arizona
SimonCasassusU. de Chile
StanleyBaronettUniversity of Nevada Las Vegas
WillGrundyLowell Observatory
A. PaulaGranados ContrerasASIAA
MichaelKüffmeierUniversity of Virginia
Ya-WenTangInstitute of Astronomy and Astrophysics, Academia Sinica
ThomasPfeilLMU Munich
TroelsHaugbølleNiels Bohr Institute
CiceroLuJohns Hopkins University
MicheleBannisterUniversity of Canterbury
KieranHirshCentre de Recherche Astrophysique de Lyon
SebastianPerezUniversidad de Santiago de Chile
JonathanMarshallAcademia Sinica Institute of Astronomy and Astrophysics
GeorgeTurpinQueen Mary University London
MarcoDelboCNRS-Observatoire de la Cote d'Azur
CarverBiersonArizona State University
Mordecai-MarkMac LowAmerican Museum of Natural History
JürgenBlumIGeP, TU Braunschweig
LeandroEstevesUniversidade Estadual Paulista
RalucaRufuSouthwest Research Institute
OlgaStoyanovskayaLavrentiev Institute of Hydrodynamics SB RAS, Novosibirsk State University
Marie-LuiseSteinmeyerGlobe Institute, University of Copenhagen
Holly LarsonCapeloNCCR PlanetS
JiayinDongPenn State
SarahStewartU. California Davis
Chao-ChinYangUniversity of Nevada, Las Vegas
AnibalSierraDepartamento de Astronomia U Chile
XueningBaiTsinghua University
GiovanniRosottiLeiden University
SebastiaanKrijtUniversity of Exeter
ErnestoVieira NetoUNESP
AshleyHerbstArizona State University
Josef (Joey)RucskaMcMaster University
EduardKuznetsovUral Federal University
ArnaudMichelQueen's University
SebastianStammlerUniversity Observatory / LMU Munich
MarijaJankovicInstitute of Astronomy, University of Cambridge
IrinaSan SebastiánInstituto de Astrofísica de La Plata (CONICET-UNLP)
EnriqueMaciasJoint ALMA Observatory
NicolasCimermanUniversity of Cambridge
SimonaPiraniUniversity of Copenhagen
PaulEstradaNASA Ames Research Center
MaitrayeeBoseArizona State University
EduardVorobyovUniversity of Vienna
ThomasHaworthQueen Mary University of London
TomKonijnAnton Pannekoek Institute
Elishevahvan KootenCentre for Star and Planet Formation
JonathanSquireUniversity of Otago
NataschaMangerCCA - Flatiron Institute
FabianBinkertLMU Munich
SaverioCambioniLunar and Planetary Laboratory
PatrickOliveiraObservatório Nacional
JamesOwenImperial College London
LauraSchaeferStanford University
ZahraAfkanpourFerdowsi University of Mashhad
AntoinePetitLund Observatory
AndreySobolevUral Federal University
HubertKlahrMax-Planck-Institut for Astronomy
ApostolosZormpasUSM-LMU Munich
RichardNelsonQueen Mary University of London
DaohaiLiLund University
YaroslavPavlyuchenkovInstitute of astronomy, Russian Academy of Sciences
JacobSimonIowa State University
JaehanBaeCarnegie Institution for Science
JuliaVenturiniISSI Bern
FujunDuPurple Mountain Observatory
WilfLe BrocqImperial College London
LeonardoKrappDepartment of Astronomy and Steward Observatory, University of Arizona
NelsonNduguMbarara University of Science and Technology
ManuelCanasNew Mexico State University
SayantanAuddyIowa State University
María PaulaRoncoInstituto de Astrofísica - Pontificia Universidad Católica - Chile
Kyoung HeeKim 
Julio CesarMonteiro dos SantosSao Paulo State University (UNESP)
LinnErikssonLund Observatory
MichaelHaahrUniversity of Copenhagen
AndersJohansenUniversity of Copenhagen
silviaGiuliatti WinterSão Paulo State Univ.
MichaelHammerUniversity of Arizona
OthonWinterSão Paulo State University - UNESP
TimothyHoltUniversity of Southern Queensland
DebanjanSenguptaNASA Ames Research Center
YapingLiLos Alamos National Laboratory
HossamAlyCentre de Recherche Astrophysique de Lyon (CRAL)
StuartRobbinsSouthwest Research Institute
ÅkeNordlundNiels Bohr Institute
TimLichtenbergUniversity of Oxford
RixinLiCornell University
AndreIzidoroRice University
KonstantinGerbigYale University
XimenaRamosNiels Bohr Institute - University of Copenhagen
OndrejChrenkoCharles University
MikiNakajimaUniversity of Rochester
RichardTeagueCenter for Astrophysics | Harvard & Smithsonian
LomaraMaksimovaINASAN, Institute of Astronomy, Russian Academy of Sciences, Moscow, Russia
BenSchubertInstitute for geophysics and extraterrestrial physics (TU Braunschweig)
NaiaraPatiñoLos Andes' University (ULA)
KeriHoadleyCalifornia Institute of Technology
JosuéCardoso dos SantosTechnion - Israel Institute of Technology
AlanSternSouthwest Research Institute
He-FengHsiehInstitute of Astronomy, National Tsing Hua University
Jean-FrançoisGonzalezCentre de Recherche Astrophysique de Lyon
UrsSchäferGLOBE Institute, University of Copenhagen
KarinaMaucoInstituto de Física y Astronomía, Universidad de Valparaíso
JohnSpencerSouthwest Research Institute
SpencerWallaceUniversity of Washington
AdityaMahadeva ArabhaviDelft University of Technology
ZiyanXuPeking University
PhilArmitageCenter for Computational Astrophysics
ChristianLenzMax Planck Institute for Astronomy
FrancescoLovascioQueen Mary University of London
FrediQuispeObservatorio Nacional
RogerioDeiennoSouthwest Research Institute
AntranikSefilianUniversity of Cambridge
JohanAppelgrenLund Observatory
PabloBenítez-LlambayNiels Bohr Institute
DavidNesvornySouthwest Research Institute
JiaqingBiUniversity of Victoria
JacksonBarnesMichigan State University
JohnGillanLund University
DongLaiCornell University
AleksandraKuznetsovaAmerican Museum of Natural History
RaphaelMarschallSouthwest Research Institute
WilliamMcKinnonWashington University in St. Louis
VardanElbakyanSouthern Federal University
AndrewYoudinSteward Observatory, University of Arizona
RobertCitronUC Davis
JuditSzulagyiUniversity of Zurich
DorotheaBischoffInstitut für Geophysik and extraterrestrische Physik
Horst UweKellerIGEP TU Braunschweig
RicoVisserUniversity of Amsterdam
HyerinJangLund Observatory
KanChenUniversity of Cambridge
PaoloTangaObservatoire de la Côte d'Azur
PhilippWeberUniversidad de Chile, Santiago
Nienkevan der MarelUniversity of Victoria
HannahJang-CondellNASA Headquarters
I-HsuanKuoInstitute of Astronomy & Astrophysics, Academia Sinica, Taiwan
AudreyBouvierBayerisches Geoinstitut
JacquesKluskaKU Leuven
AdrienHougeUniversity of Exeter, England
SethJacobsonMichigan State University
YajieLiangUniversity Heidelberg
SiminTongLeiden University
GeoffreyAndamaMbarara University of Science and Technology

Code of conduct

We welcome discussion on social media. However, we ask participants not to share the full recorded talks, or verbatim slack conversations, outside of the group of meeting participants.
Please contact any LOC member for reporting inappropriate behaviour of any kind.