Seminare
Dr. Mark Schlutow
Thursday, Dec 10, 14:00
The gas centrifuge - An opportunity to study atmospheric gravity waves in the laboratory
Abstract
Ha and Stefan Hagemann, Helmholtz Zentrum Geesthacht
January 23rd 2020, 3:30 pm
High resolution modelling of discharge over Europe using the HD model and related internal variability in the regional coupled system model GCOAST-AHOI
Abstract
Dr. Miklos Vincze, von Karman Laboratory for Environmental Flows, Budapest, Hungary
November 27th 2019, 3:30 pm
Planetary Atmospheres and Laboratory Analogs
Dr. Andrei Sukanovskii, Institute of Continuous Media Mechanics, Russian Academy of Sciences, Perm, Russia
November 6th 2019, 3:30 pm
Atmospheric vortices in rotating flows and aspects of laboratory analogs to tropical cyclones
M.Sc. Mohammed Hussein from Ecole Polytechnique, Paris, France
September 19th 2019, 2:00 pm
Turbulence in stratified and rotating flows
Dr. Yuri Feldman from the Ben Gurion University of the Negev, Israel
April 12th 2019, 10:00 am
Semi-implicit direct forcing immersed boundary method for incompressible viscous thermal flow problems: A Schur complement approach
Dr. Peter Szabo from Heriot-Watt University, Edinburgh
April 2nd 2019, 4:00 pm
Thermomagnetic induced convection in a baroclinic annulus and spherical shell
Dr. Thomas Gastine, IPGP Paris, France
November 29th 2018, 3:30 pm
DNS of spherical shell convection at high Ray-leigh number iCal
Dr. Miklos Vincze, MTA-ELTE Theoretical Physics Research Group, Budapest, Hungary
November 7th 2018, 1:30 pm
Ekman layers, vortices, dead water and the Drake passage: an overview of recent ocean-motivated laboratory experiments iCal
Dr. Keshav J. Raja from the University of Grenoble
February 28th 2018, 3:30 pm
Forcing of mean flows by the reflection of three-dimensional internal wave beams
Dipl.-Phys Matren Klein, B-TU, Cotttbus
February 28th 2018, 3:00 pm
Pre-seminar: What is ... an internal wave?
Dr. Martin Baumann, AG Prof. Vincent Heuveline, URZ Heidelberg
January 16th 2018, 1:00 pm
CFD in a Server Rack
Dr. Najmeh Foroozani, Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy
Monday, December 18th 2017, 2:30 pm, LG3A room 352
effect of wall roughness on the large scale circulation in turbulent convection with cubic confinement
Dr. Marten Klein, Lehrstuhl Numerische Strömungs- und Gasdynamik, Cottbus, D
Monday, December 18th 2017, 2:00 pm, LG3A room 352
„What is … Rayleigh-Bénard convection?“
Jun.-Prof. Nikki Vercauteren, Multiskalen Geodatenanalyse, FB Mathematik und Informatik, FU Berlin
Monday, June 6th 2017, 3:45 pm, LG3A room 352
The quiet atmosphere – Data-driven ideas for modeling different regimes of nighttime turbulent flows.
MSc. Mathias Etzold, Process Engineering, FMP TECHNOLOGY GMBH, Erlangen
May 3rd 2017, 2:00 pm
Monodisperser Tropfengenerator
Dr. Ramis Örlü, KTH Stockholm, S
Mar. 21st 2017, 2:00 pm
A synergetic approach to wall turbulence – exemplified on a zero-pressure-gradient turbulent boundary layer
Prof. Ralf Deiterding, Aerodynamics and Flight Mechanics Research Group University of Southampton
Nov. 8th 2016, 3:30 pm
Adaptive Cartesian CFD methods for fluid-structure interaction simulation
24. Jahrestagung GALA (Ges. Angewandte LaserAnemometrie), Cottbus
6.-8. September 2016 Cottbus
Dr. Andreas Schröder et al., DLR, AS-EXV, Göttingen
August 30th 2016, 2:30 pm
Image based measurement techniques in aerodynamics and Shake-The-Box Lagrangian particle tracking for turbulence researc
Dr. Isabelle Raspo from the University of Marseille
July 20th 2016, 3:30 pm
Simulation of peculiar behaviors of near-critical fluids
Dr. Vadim Travnikov, Bremen
Thursday, July 14th 2016, 2 pm
Influence of the thermo-electric coupling on the heat transfer in cylindrical annulus with a dielectric fluid under microgravity
Dr. Evgeny Ermanyuk from Laboratoire de Physique ENS de Lyon, and Lavrentyev Institute of Hydrodynamics, Novosibirsk, Russia
Wednesday, June 29th 2016, 3:30 pm
Energy cascade in internal wave attractors
Prof. Innocent Mutabazi, University of LeHavre, France
Thursday, June 23rd 2016, 2:30 pm
Convection in cylinders - numerical simulation and theoretical work
Prof. Friedrich Busse of Bayreuth University, Germany
Thursday, June 20th 2016, 11 am
Thermische Konvektion in rotierenden zylindrischen Annuli und rotierenden Kugelschalen
Dr. Danielle Moreau, University of New South Wales, Australia
Thursday, June 16th 2016, 2 pm
The flow and noise of a wall-mounted finite airfoil
Dr. El Sayed Zanoun, Banha University, ET
Wed, Feb. 2nd 2016, 3:30 pm
Flow transition and development in Erlangen and Cottbus Pipe facilities over a wide range of Reynolds numbers
Dr. George Peixinho, University of Le Havre, F
Wed, Feb. 24th 2016, 3:30 pm
Localized turbulence in circular expansion pape flows
Prof. Gualtiero Badin, Institute of Oceanography, University of Hamburg, D
Wed, Feb. 10th 2016, 3:30 pm
Geostrophic turbulence below the deformation radius
Abstract
Dr. Moritz Fragner vom Deutschen Zentrum für Luft- und Raumfahrt (DLR), Institut für Aerodynamik und Strömungstechnik
Wed, Oct. 14th 2015, 4:00 pm
Investigating cross-wind stability of high speed trains with large-scale parallel CFD
M.Sc. Costanza Rodda, Netherland Institute for Sea Research, NL
Mon, Jul. 6th 2015, 11:00 am
The ocean in a tank: numerical simulations on the wave-mean flow interactions in a rotating box
Abstract
Dr. Miklos Vincze, University of Budapest, HUN
Thu, Feb. 19th 2015, 3:30 pm
BAROCLINIC INSTABILITY AND DOUBLE-DIFFUSIVE CONVECTION IN A ROTATING LABORATORY TANK
Msaidie Ali Zainoudine, University of Marseille, F
10. Februar 2015, 10:00 Uhr
3D flow structures around a sphere.
Strömungs-Messkampagnen mit Hilfe des Particle-Image-Velocimetrie-Verfahrens (PIV) an der "Cottbus Large Pipe Test Facility, CoLa_pipe"
9.-13. Februar 2015
Diese Messungen ermöglichen mit einem hochauflösenenden PIV-Meßaufbau der Fa. LAVISION (Göttingen) und mit (BTU-)eigener PIV-Messtechnik 3D- Messungen in voll-turbulenter Rohrströmung bei Reynolds-Zahlen bis zu 1.0 Mio.
Weiterführende Informationen
Dr. Santiago Triana, Katholieke Universiteit Leuwen, Belgium
Wed, Nov. 26th 2014, 3:30 pm
Inertial waves in the spherical shell
Prof. Jorge Peixinho, University of Le Havre, F
Wed, Nov. 19th 2014, 3:30 pm
Laminar-turbulent transition in the flow through a gradual expansion in a circular pipe
Abstract
Prof. Tuliszka-Sznitko, Universität Poznan, PL
Wed, Sept. 10th 2014, 3:30 pm
Taylor-Couette flow with asymmetric boundary conditions
Prof. M. Kurgansky, Obukhov Institute Moscow, RUS
Mon, Aug. 25th 2014, 4:15 pm, Campus North, Building of LS Umweltmeteorologie, Seminar room in the second floor
Summary and Discussion of Mean flow generation due to longitudinal librations of side-walls of a rotating annulus
Abstract
Prof. Francisco Marques, University of Barcelona, E
Thu, June 6th 2014, 11:00 am
Rapidly rotating cylinder flow with an oscillating sidewall
Abstract
Dipl.Met. Nico Becker, Institut für Meteorologie, FU Berlin, D
Wed, June 18th 2014, 3:30 pm
Orography-driven large scale secondary circulations in a regional climate model
Abstract
Prof. Rist, Institut für Aerodynamik und Gasdynamik, Universität Stuttgart, D
Tue, Apr. 15th 2014, 11:00 am
Laminar-turbulente Transition in der Grenzschicht
Borja Martinez Arias from the University of LeHavre, F
Do, 27.2.14, 11:00 Uhr
Effect of the number of vortices on the torque scaling in the Taylor-Couette flow
Prof. Dr. Michael Kurgansky, LMU Moscow and Obukhov Institute, Moscow, RUS
Di, 31.1.14, 14:30 Uhr
Campus Nord, Seminar-room 3.21
Mean flow generation due to longitudinal librations of side-walls of a rotating
Prof. Jörn Sesterhenn, ISTA, FG Numerische Fluiddynamik, TU-Berlin, D
Di, 14.1.14, 11:00 Uhr
Overview of research at TNT-ISTA
Prof. Innocent Mutabazi, Univ. LeHavre, F
Prof. Patrice LeGal, Univ. Aix-Marseille, F
Fr., 10.01.2014, 11:00 Uhr
Aktuelle Projekte zu rotierenden und geschichteten Strömungen
Actual projects on rotating stratified flows
Prof. El-Sayed Zanoun, Kairo University, ET
Mi., 11.12.2013, 11:00 Uhr
Recent studies on wall bounded shear flows
Prof. Jeanette Hussong, Lehrstuhl für hydraulische Strömungsmaschinen, Ruhr-Universität Bochum, D
Fr., 22.11.2013, 10:00 Uhr
Numerische und experimentelle Untersuchungen des Fluidtransportes deformierender poröser Wandschichten
Weitere Informtionen
Peder A. Tyvand und Mikkel. L. Lepperod, Department of Mathematical Sciences and Technology, Norwegian University of Life Sciences, N
Fr., 8.11.2013, 14:00 Uhr
Oscillatory line source for water waves in shear flow
Further Informations
Prof. Ewa Tuliszka-Sznitko, Universität Poznan, PL
17.7.2013 10:00 Uhr
Turbulent heat transfer in rotor/stator cavity: physics, correlations and numerical modeling
Dr. Borja Martinez-Arias von der Universität Le Havre, F
16.7.2013 14:00 Uhr
Torque measurements in Newtonian and non-Newtonian fluids in Couette-Taylor flow
Dr. Santiago Andres Triana vom Astronomischen Institut
der Universität Leuven, B
10.7.2013
Inertial waves driven by differential rotation: a laboratory experiment
Further Informations
Prof. Hendrik Kuhlmann von der TU Wien, A
3.7.2013 14:00 Uhr
Flow topology and particle accumulation in thermocapillary liquid bridges
Prof. Michael Kurgansky, A. M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, Moscow, RUS
6.6.2013
Applications of the concept of helicity in geophysical fluid dynamics
Dr. Stephane Viazzo, Univ.Aix-Marseille 3/IUT/ St Jérôme, F
5.6.2013
LES simulations of jets and flows in rotating and stratified fluids: an overview
Dr. Johann Herault, Laboratoire de Physique Statistique, ENS Paris, F
22.5.2013 13:30 Uhr
EXPERIMENTAL INVESTIGATION OF LARGE SCALE CIRCULATION GENERATED OVER A 2D TURBULENT FLOW
Further Informations
Prof. Sebastian Popescu, Al. I. Cuza University, Faculty of Physics, Laboratory of Complex Systems, Iasi, ROM
15.5.2013
Hysterezis Phenomena in Nonequilibrium Phase Transitions
Further Informations
Dr. Wolf-Gerit Früh, Heriot-Watt University, Edinburgh, UK
Fr., 26.4.2013 10:30 Uhr
Simulation eines Offshore Windparks
Further Informations
Christian Löffelholz, Zürcher Hochschule für Angewandte Wissenschaften ZHAW, CH
17.4.2013
CFD as tool for engineering characterization of single-use bioreactors and scaling-up of biopharmaceutical production processes
Further Informations
PD Dr. Christoph Garbe, Interdisciplinary Center for Sientific Computing, Uni Heidelberg
16.1.2013
Von der Mikrofluidik zur Satellitenfernerkundung: bildbasierte Ansätze zur Untersuchung fluiddynamischer Prozesse
Weitere Informationen
Prof. Michael Breuß, Juniorprofessor zur Numerik Partieller Differentialgleichungen der BTU Cottbus
12.12.2012
Numerik hyperbolischer Differentialgleichungen mit Anwendungen im Computer-Vision-Bereich
Prof. Dominique Thévenin, Universität Magdeburg
28.11.2012
Main research activities at the Department of Fluid Dynamics
Priv.-Doz. Gábor Janiga, Universität Magdeburg
Optimization based on Computational Fluid Dynamics
Dr. Bogdan Bedelean, University Transilvania, Brasov, Rumänien
21.11.2012
Performance assessment of a laboratory timber drying kiln designed with and without baffles using CFD and TORKSIM softwareOptimal Taylor-Couette flow: direct numerical simulations
Dr. Rodolfo Ostilla-Monica, Universität Twente, NL
Fr., 16.11.2012
Optimal Taylor-Couette flow: direct numerical simulations
Dr. Matthew Salewski, Faculty of Physics,
Philipps University Marburg, D
Do., 8.11.2012, 14:30 Uhr
Torque Transitions in Taylor-Couette Flow without Curvature
Prof. Alex Oron Technion-Israel Institute of Technology, Haifa, IL
Mo., 5.11.2012, 15:30 Uhr
Stability analysis of a thin liquid film on a axially oscillating cylindrical surface
Further Informations
Prof. Innocent Mutabazi von der Uni LeHavre, F
Di., 30.10.2012, 10:45 Uhr
ThermalElectroHydrodanymic effects with and without curvature
Dr. Jan-Peter Schulz (Deutscher Wetterdienst Offenbach und Goethe Universität Frankfurt)
und
Gerd Vogel (Deutscher Wetterdienst Lindenberg)
17.10.2012
The influence of thermal soil and vegetation characteristics on the ground heat flux and temperature
Further Informations
Dr. Catalin Gabriel Borcia, Faculty of Physics, University "A. I. Cuza" Iasi, RO
Fr., 21.9.2012, 9:30
Atmospheric pressure plasma for surface modification of polymers in film and fibre form
Further Informations
Dr. Harunori Yoshikawa, LOMC, University of Le Havre, F
19.07.2012, DEP force-‐driven thermal convection in annular geometry
Dr. Claus Duschel, Frauenhoferinstitut IBMT, Potsdam, D
06.06.2012, Manipulation and Monitoring of Single Cells Using High Frequency Electromagnetic Fields and Microfluidics
Alan R. Kerstein, Consultant, Danville CA, USA
09.05.2012, 14:00 Uhr
Formulation and Application of a Sparse-Modes Method for Turbulence Simulation
Further Informations
Prof. Piotr Smolarkiewicz, National Center for Atmospher-ic Research, Boulder, USA
Mo., 23.04.2012,
Soundproof simulations of stratospheric gravity waves on unstructured meshes
Dr. Tom Jacoby, University of Oxford, GB
Do., 19.04.2012,
Generation of internal waves in the rotating differentially heated annulus
Dr. Jonas Moeck, TU Berlin, D
09.02.2012, 11:00 Uhr
Dynamik von Drallflammen und deren Interaktion mit dem akustischen Feld einer Brennkammer
Prof. Michael Bestehorn, BTU Cottbus, D
25.01.2012,
Dünne Filme und Instabilitäten
Miklos Vincze, von Kármán Laboratory for Environmental Flows, Eötvös Loránd University, Budapest, H
13:30 Uhr 14.01.2012,
Nonlinear resonance in barotropic-baroclynic transfer generated by bottom sills
Dr.-Ing. Martin Meier, machtwissen.de AG, Bremen, D
25.08.2011, Donnerstag 13:00
"water hammer effect"
Prof. Juergen Czarske, TU Dresden, D
07.07.2011, Donnerstag 11:15
Optische Geschwindigkeitsmessungen von komplexen Scherströmungen
Dr. Axel Liebscher, Institute for Applied Geosciences, Technical University of Berlin, D
Die geologische Speicherung von CO2 - 36 Monate Injektionsbetrieb am Standort Ketzin
Dr. Anthony Randriamampianina, Universität Marseille, F
07.12.2011,
Baroclinic instability from a numerical point of view
Abstract
Dr. rer. nat. Dominic Merkt, BTU Cottbus, D
09.11.2011,
Ratscheneffekte in konvektiven hydrody-namischen Systemen
Dr. Olivier Eiff, Universität Grenoble, F
02.11.2011,
Temporal behavior and vortex topology of topographic wave-breaking
Further Informations
Dr. Nils Wedi, European Center for Medium Range Weather Forecast, Reading, GB
26.10.2011,
Numerical Simulation (DNS, LES) of geophysical laboratory experiments: the Quasi-Biennial Oscillation (QBO) and the Madden-Julian Oscillation (MJO)
Further Informations
Dr. Kornilov, Moscow University, Russia
19.10.2011,
Turbulent boundary-layer control by microblowing through micro-hole perforated wall
Dr. Kornilov, Moscow University, Russia
Di., 18.10.2011,
Flat-plate turbulent boundary-layer control using vertical LEBU
Prof. Andreas Tilgner, Universität Göttingen, D
12.10.2011,
High Rayleigh number convection with double diffusive fingers
Dr. Andreas Dobler, Goethe-Universität Frankfurt/Main, D
09.03.2011
Downscaling von GCMs in den zwei alpinen Regionen europäische Alpen und Himalaja
weitere Informationen
Dr. Felix Rieper, Goethe-Universität Frankfurt/Main, D
04.02.2011, Freitags 14:00
PincFloit - ein 3D-Strömungslöser mit implizitem LES zur Simulation von Schwerewellen
Prof. Ennes Sarradj, BTU Cottbus, D
26.01.2011
Der leise Flug der Eulen: Untersuchungen im Windkanal und im Freiflug
Dr. Marco Giorgetta, Max Planck Institut für Meteorologie Hamburg, D
19.01.2011
The Quasi-Biennial Oscillation in Analyses and in ECHAM Simulations
weitere Informationen
Prof. Thomas Frisius, Univ. Hamburg, Klima Campus, D
12.01.2011
Mechanismen zur Superintensität tropischer Wirbelstürme
Dr. Michael Oevermann, FU-Berlin, D
20.01.2010
Simulation von Partikelströmungen
Weitere Informationen
Dr. Peter Carl, IAMARIS, Berlin, D
verschoben auf 24.03.2010
Synchronized Motions and Detached Events from Global Climate to the River Basin Scale
- A Time Series Study
Further informations
Dr. Rainer Hollerbach, School of Mathematics, Leeds, UK
14.04.2010
Review on Taylor-Couette flows
Prof. apl. Uwe Harlander, Prof. Christoph Egbers
21. und 22.04.2010
The differentially heated rotating annulus - new experimental and numerical results
Dr. Olivier Crumeyrolle, Université du Havre, F
19.05.2010 14:00 Uhr
Vertical versus radial gravity in the heated cylindrical annulus.
Dr. Holzdeppe TLT-Turbo GmbH, Zweibrücken, D
26.05.2010 13:45 Uhr, LG3A Raum 406
im Rahmen der Vorlesung Fahrzeugaerodynamik
Spezielle Aspekte zu Windkanälen und Formel 1 Fahrzeugen.
Prof. Genady N. Panin, Institute of Water Problems, RussianAcademy of Sciences, Moscow, RUS
2.6.2010
Regional and global climate changes in the 20th and 21th centuries
Dipl. Math. Alexander Lohse, Hamburg,D
Donnerstag, 3.6.2010, 14:00 Uhr
Eine mathematische Sicht auf GEOFLOW: Sphärische Verzweigungsprobleme
Dr. Kai Born, Universität Köln, D
9.6.2010
Grundlagen der statistischen und dynamischen Modellierung, ihre Vor- und Nachteile
Dr. Werner Jürgens, DLR Berlin, D
Freitag, 18.6.2010 12:30 Uhr
Mischungserhöhung in freien Scherschichten mittels schräg laufender Wirbel
Weitere Informationen
Dr. Florian Zaussinger, MPI Garching, D
23.6.2010
Konvektion mit verschiedenen Zeitskalen
Dipl.-Ing. Christian Lübbert, BTU Cottbus, D
Donnerstag, 24.6.2010
1D-Simulation des Corona-Quenchings im Rohr-Draht Elektroabscheider
Dr. Alfonso Castrejon Pita, University, UK
6.10.2010 10:00 Uhr
Synchronization of chaotic modulated travelling waves in coupled rotating annuli: bringing atmospheric teleconnections to the lab
Prof. Peter L. Read, Head of Atmospheric, Oceanic & Planetary Physics, University of Oxford, UK
20.10.2010 13:00 Uhr
Circulation regimes in simple models of planetary atmosphere
Dr. Olivier Crumeyrolle, Université du Havre, F
20.05.2009
Complex demodulation of flow patterns: principle and applications
Prof. Dr. Illia Horenko, FU-Berlin, D
27.05.2009
Computational Time Series Analysis of Multidimensional Non-Stationary Data
Prof. Dr. Mohamed Gad-el-Hak, Virginia Commonwealth University, USA
Dienstag, 02.06.2009
The Taming of the Shrew: Why Is It So Difficult to Control Turbulence?
Prof. Dr. Mohamed Gad-el-Hak, Virginia Commonwealth University, USA
Donnerstag, 02.06.2009, 10:00 Uhr
The Art and Science of Large-Scale Disasters
Prof. (em.) Dr. rer. nat. Karl G. Roesner, TU Darmstadt, D
17.06.2009
Reelle und virtuelle Strömungen in Zylinder- und Kugelgeometrie
Prof. Innocent Mutabazi Université du Havre, Frankreich
Montag, 15.06.2009, 15:00 Uhr
Ginzburg-Landau theory in Hydrodynamics: model, experimental verification in case of thermal convection and Taylor-Couette flows
Dr.-Ing. Thomas von Larcher, FU-Berlin, D
08.07.2009
The Fourier-Spectral Element Method: numerical approach for thermal convection in rotating containers
Dr. Baumert, IAMARIS e.V.
24.06.2009, unbestimmt verschoben
Turbulenz und Wellen in geschichteten Medien unter besonderer Berücksichtigung geophysikalischer Bedingungen
Prof. Michael Kurgansky, Department of Geophysics, University of Concepcion, Chile
A.M. Obukhov, Institute of Atmospheric Physics, Moscow, Russia
27.08.2009
Micro-meteorological conditions for dust devil occurence in the Atacama Desert
Dr. Matthias Sommer, FU-Berlin, D
21.10.2009
Ein Energie- und Enstrophieerhaltendes Schema für das ICON-Flachwassermodell
weitere Informationen
Dr. Dimitri Mironov, Deutscher Wetterdienst, Offenbach, D
04.11.2009
Flake: A Lake Parameterisation Scheme for Numerical Weather Prediction and Climate Models
weitere Informationen
Prof. Richard Lueptow, Northwestern University, Evanston, Illinois, USA
11.11.2009, 11:15 Uhr
Taylor Couette Flow for Water Purification for Manned Space Flight
PD. Dr. H. Hubertus Klahr Max-Planck-Institut für Astronomie, Heidelberg, D
18.11.2009
The Role of Turbulence in Planet Formation and the Baroclinic Instability in Disks around Young Stars
Prof. Roland Strietzel, DLR-Adlershof, Berlin, D
2.12.2009
Aus dem All ins Innere der Erde geschaut - Die CHAMP-Mission
Prof. L.R.M. Maas, NIOZ und Universität Utrecht, NL
29.10.2008
Internal waves and wave attractors in the oceans
Dr. Björn Hof, Max-Planck-Institut für Dynamik und Selbstorganisation Göttingen
03.12.2008
Lebensdauer derTurbulenz in der Rohrströmung
Dr. rer.nat. Nicoleta Scurtu, Lehrstuhl für Aerodynamik und Strömungslehre, BTU-Cottbus
Donnerstag, 11.12.2008 16:00 Uhr
Introduction of GeoFlow II as experiment on mantle convection
Dr. Helmut Harder, Universität Münster, Institut für Geophysik
Donnerstag, 11.12.2008 16:15 Uhr
Numerical Simulations of Mantle Convection with variable Viscosity
Prof. Dr. Doris Breuer, DLR Berlin-Adlershof, Institut für Planetenforschung
Donnerstag, 11.12.2008 16:45 Uhr
Thermal convection in terrestrial planets