Prof. Dr. Jügen Blum

Technische Universität Braunschweig
Institute of Geophysics and extraterrestrial Physics (IGEP)
Mendelssohnstr. 3
D-38106 Braunschweig
Phone: +49 531 391 5217
E-Mail: j.blum@tu-braunschweig.de
Website: www.igep.tu-bs.de

Researcher’s Career

  • University Professor at TU Braunschweig
  • Lecturer and Senior Scientist at University of Jena (Germany)
  • Associate Scientist at the Naval Research Laboratory (Washington, DC, USA) and the University of Florida (Gainesville, USA)
  • Postdoc at the Max Planck Research Unit “Dust in Star-Forming Regions” (Jena, Germany) and at the Max Planck Institute for Nuclear Physics (Heidelberg, Germany)
  • Habilitation at the University of Jena (Germany)
  • Doctorate degree from the University of Heidelberg (Germany)
  • Studies of physics and astronomy at the University of Gießen (Germany) and Heidelberg (Germany)

Mission Statement

The main goal of our research is to find out how planets form. We try to achieve answers to this question by investigating, in the laboratory and under zero-gravity conditions, dust-collision processes, by modeling the properties of pre-planetary bodies and by comparing our findings to results from space-exploration studies of primitive Solar System bodies, like comets, asteroids, or Kuiper-belt objects.

Research

Project A: Physics of dust agglomeration

We perform experiments on the collisional evolution of dust clouds in the laboratory and on all available microgravity platforms (drop tower, parabolic flights, suborbital rockets, orbital flights). In the past, we have studied the stickiness of micrometer-sized dust and ice particles, the formation of fractal agglomerates, the transition from fractal to non-fractal growth modes, bouncing and fragmentation in non-sticking collisions as well as the erosion of dust aggregates. Current investigations deal with the preparation of suborbital and orbital flights for a major dust-agglomeration study with various types of dust-analog materials and sizes.

credits: IGEP

Project B: Understanding the formation and activity of comets

Asteroid cratering, credits: IGEP
Aggregate fragmentation, credits: IGEP

credits: IGEP

Comets and their progenitors, the Kuiper-belt objects, are the most primitive bodies in the Solar System. Thus, we utilize information provided by recent exploration missions, such as Rosetta or New Horizons, to investigate whether their properties can be explained by one or the other models for the formation of planetesimals, the first massive planetary progenitors. To this extent, we develop numerical models for the mass and heat transport in comets to describe their activity patterns.

Project C: Collision processes in the Solar System and the evolution of asteroids

Planetary bodies in the asteroid belt between the orbits of the planets Mars and Jupiter have undergone many collisions since their formation billions of years ago. We are interested how these impacts have modified the physical properties of the asteroids. We perform high-speed impacts with our own laboratory gun with cm-sized projectiles and velocities up to more than 1000 m/s and analyze the shocked material, the forming craters and the outflowing debris. Based on this, we simulate how the appearance of asteroids have changed over time.

credits: IGEP

Selected Publications

  • J. Blum: Dust evolution in protoplanetary discs and the formation of planetesimals.  What have we learned from laboratory experiments? Space Science Reviews 214, 52, 2018.
  • J.E. Colwell, J. Blum, R. Clark, S. Kempf, and R.M. Nelson: Laboratory Studies of Planetary Ring Systems, in: Planetary Ring Systems (eds. M. Tiscareno, B. Murray), Cambridge University Press, pp. 494-516, 2018.
  • J. Blum, B. Gundlach, M. Krause, M. Fulle, A. Johansen, J. Agarwal, I. von Borstel, X. Shi, X. Hu, M. S. Bentley, F. Capaccioni, L. Colangeli, V. Della Corte, N. Fougère, S. F. Green, S. Ivanovski, T. Mannel, S. Merouane, A. Migliorini, A. Rotundi, R. Schmied, and C. Snodgrass: Evidence for the formation of comet 67P/Churyumov-Gerasimenko through gravitational instability of a pebble cloud, MNRAS 469, pp. 755-773, 2017.
  • M. Fulle and J. Blum: Fractal dust constrains the collisional history of comets, MNRAS 469, pp. 39-44, 2017.
  • E. Beitz, J. Blum, M.G. Parisi, and J. Trigo-Rodriguez: The collisional evolution of undifferentiated asteroids and the formation of chondritic meteoroids, Astrophys. J. 824, 12, 2016.
  • B. Gundlach and J. Blum: The stickiness of micrometer-sized water-ice particles, Astrophys. J. 798, 34, 2015.
  • J. Blum, B. Gundlach, S. Mühle, and J.M. Trigo-Rodriguez: Comets formed in solar-nebula instabilities! An experimental and modeling attempt to relate the activity of comets to their formation process, Icarus 235, pp. 156-169, 2014.
  • A. Johansen, J. Blum, H. Tanaka, C. Ormel, M. Bizzarro, and H. Rickman: The Multifaceted Planetesimal Formation Process, Protostars & Planets VI (eds. H. Beuther, R.S. Klessen, C.P. Dullemond, T. Henning), pp. 547-570, 2014.
  • L. Testi, T. Birnstiel, L. Ricci, S. Andrews, J. Blum, J. Carpenter, C. Dominik, A. Isella, A. Natta, J.P. Williams, and D.J. Wilner: Dust Evolution in Protoplanetary Disks, Protostars & Planets VI (eds. H. Beuther, R.S. Klessen, C.P. Dullemond, T. Henning), pp. 339-362, 2014.
  • B. Gundlach and J. Blum: A new method to determine the grain size of planetary regolith, Icarus 223, pp. 479-492, 2013.