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 Astrophysics & Space Sciences: People
Michael  Janssen's Picture
Jet Propulsion Laboratory
M/S 169-506
4800 Oak Grove Drive
Pasadena, CA 91109

Michael Janssen

Michael Janssen has over forty years of experience in radio astronomy and space research. He is currently a Senior Research Scientist at the Jet Propulsion Laboratory with roles in the Cassini mission to Saturn, ESA's Rosetta mission to land on a comet, the Planck mission to observe the cosmic background, and the New Frontiers Juno mission to investigate the origin and internal structure of Jupiter. For his thesis project to study the atmosphere of Venus, he and fellow student Richard Hills built the world's first millimeter-wavelength interferometer at UC Berkeley's Hat Creek Radio Observatory. After coming to JPL in 1972, he participated in the conception and development of the Cosmic Background Explorer (COBE) mission. He was a member of the COBE Science Working Group and played a major role in implementing the Differential Microwave Radiometer experiment on COBE that discovered the origin of structure in the universe. In the same period he edited a book on the microwave remote sensing of atmospheres that is widely used in the field. Afterwards he became involved in the management of the Earth & Space sciences Division at the lab and worked to improve the climate for research in the Division and at the Laboratory. He is now focusing on his flight involvements as lead for the Cassini RADAR radiometer, now in orbit around Saturn, and as Lead Co-Investigator for the Juno Microwave Radiometer, scheduled for arrival at Jupiter on July 4, 2016.

  • B.S., Physics, University of California at Berkeley (1963)
  • Ph.D., Atmospheric and Space Sciences, University of California at Berkeley (1972)

Research Interests
  • Microwave remote sensing of the Earth and solar system
  • Observational astrophysics and cosmology
  • Development and application of microwave instrumentation for astrophysics and remote sensing


Cassini-Huygens Icon Cassini-Huygens
The Cassini-Huygens spacecraft explored the ringed planet, its mysterious moons, the stunning rings and its complex magnetic environment.

Planck Icon Planck
Planck is the first European mission to study the birth of the Universe. Planck was launched on May 14, 2009.

Rosetta Icon Rosetta
The Rosetta mission is designed to study the origin of comets, the relationship between cometary and interstellar material and its implications with regard to the origin of the Solar System.

Juno Icon Juno
Juno is in 53-day polar orbits, observing Jupiter in order to understand the planet's gross size and structural properties, as well as measuring its atmospheric composition, temperature and deep wind profiles.

MIRO (Microwave Instrument for the Rosetta Orbiter) is a scientific instrument on the ROSETTA Spacecraft.

Professional Experience
  • Jet Propulsion Laboratory (1972-Present)
    • Member Senior Research Scientist Council (2014-present)
    • Senior Research Scientist (2010-Present)
    • Principal Scientist (2002-2010)
    • Assistant Manager, Earth and Space Sciences Division (1997-2002)
    • Acting Manager, Earth and Space Sciences Division (1999)
    • Discipline Program Manager for Astrophysics (1995-1997)
    • Lead Scientist for Astrophysics (1994-1997)
    • Manager, Space Physics and Astrophysics Section (1991-1993)
    • Group Supervisor, Radio/Submillimeter Astronomy (1989-1991)
    • Member of Technical Staff, Earth and Space Sciences Division (1976-1996)
    • Senior Scientist, Earth and Space Sciences Division (1974-1976)
    • National Research Council Resident Research Associate (1972-1974)

Selected Awards
  • NASA Group Achievement Award, Juno Science Team (2012)
  • NASA Group Achievement Award, Juno MWR Instrument Team (2012)
  • NASA Group Achievement Award, Juno Mission Operations Development Team (2012)
  • NASA Group Achievement Award, MIRO Flight Operations Team (2011)
  • Edward Stone Award for Outstanding Research Publication (2010)
  • NASA Exceptional Service Medal (2009)
  • Cosmology Prize of the Peter Gruber Foundation: Co-recipient as COBE team member (2006)
  • NASA Exceptional Scientific Achievement Medal for contributions to COBE (1992)
  • Member Phi Beta Kappa
  • National Research Council Postdoctoral Fellowship (1972-1974)

Selected Publications
  1. Janssen, M.A, A. Le Gall, M.J. Malaska, R.M. Lopes, A. Solomonidou, R.D. Lorenz, C.D. Neish, K.L. Mitchell, J. Radebaugh, P.J. Encrenaz, and M. Mastrogiuseppe, Titan’s surface at 2.2-cm wavelength imaged by the Cassini RADAR radiometer: Results and interpretations through the first ten years of observation, Icarus, doi: 10.1016/jicarus.2015.09.027, 2016
  2. A. Le Gall, M.J. Malaska, R.D. Lorenz, M.A. Janssen, T. Tokano, A.G. Hayes, M. Mastrogiuseppe, J.I. Lunine, G. Veyssière, P. Encrenaz, and O. Karatekin, Composition, seasonal change and bathymetry of Ligeia Mare, Titan, derived from its microwave thermal emission. J. Geophys. Res. Planets, 121, doi:10.1002/2015JE004920., 2016.
  3. Ries, P.A., and M.A. Janssen, A large-scale anomaly in Enceladus’ thermal emission. Icarus 215, 88-102, 2015
  4. Le Gall, A., M.A. Janssen, R.L. Kirk, and R.D. Lorenz, Modeling microwave backscatter and thermal emission from fields of linear dunes: Application to Titan, Icarus 230, 198-207, 2014.
  5. Janssen, M.A., A. Ingersoll, M.D. Allison, S. Gulkis, A. Laraia, K.Baines, S. Edgington, Y. Anderson, K. Kelleher, Saturn’s Thermal Emission at 2.2-cm Wavelength as Imaged by the Cassini Radar Radiometer, Icarus 226, 522-535, 2013.
  6. Janssen, M.A., A. Le Gall and L.C. Wye. Anomalous radar backscatter from Titan's surface? Icarus 212, 321-328, 2011.
  7. Le Gall, A., M.A. Janssen, P. Paillou, R.D. Lorenz, and the Cassini Radar Team, Radar-bright channels on Titan. Icarus 207, 948-958, 2010.
  8. Janssen, M.A. , R.D. Lorenz, R. West, F. Paganelli, R. M. Lopes, R.L. Kirk, C. Elachi, S.D. Wall, W.T.K. Johnson, Y. Anderson, R.A. Boehmer, P. Callahan, Y. Gim, G.A. Hamilton, K.D. Kelleher, L. Roth, B. Stiles, A. Le Gall, and the Cassini Radar Team, Titan's surface at 2.2-cm wavelength imaged by the Cassini RADAR radiometer: calibration and first results, Icarus, 200, 222-239, 2009.
  9. Gulkis. S., M. Allen, C. Backus, G. Beaudin, N. Biver, D. Bockelee-Morvan, J. Crovisier, D. Despois, P. Encrenaz, M. Frerking, M. Hofstadter, P. Hartogh, W. Ip, M. Janssen, L. Kamp, T. Koch, E. Lellouch, I. Mann, D. Muhleman, H. Rauer, P. Schloerb, T. Spilker, Remote sensing of a comet at millimeter and submillimeter wavelengths from an orbiting spacecraft, Planetary and Space Science 55, 1050-1057, 2007.
  10. Janssen, M.A., M.D. Hofstadter, S. Gulkis, A.P. Ingersoll, M.Allison, S.J. Bolton, and L.W. Kamp, Microwave Remote Sensing of Jupiter's Atmosphere from an Orbiting Spacecraft, Icarus, 173, 447-453, 2005.
  11. Janssen, M. A., Ruf, C. S., and Keihm, S. J., TOPEX/Poseidon Microwave Radiometer (TMR): II. Antenna Pattern Correction and Brightness Temperature Algorithm, IEEE Trans. Geosci. Remote Sensing 33, 138-146, 1995.
  12. Janssen, M. A., and Lawrence, C. L., Primordial Structure Investigation (PSI): A Low-Cost Space Mission to Image the Intermediate-Scale Cosmic Microwave Background, Astrophys. Lett. and Comm. 32, 289-296, 1995.
  13. Janssen, M.A., editor, Atmospheric Remote Sensing by Microwave Radiometry, Wiley & Sons, New York (1993).
  14. Janssen, M. A. and Gulkis, S., "Mapping the Sky with the COBE Differential Microwave Radiometers", in The Infrared and Submillimeter Sky after COBE, Eds. M. Signore and C. Dupraz, Kluwer Academic Publishers, 391-408 (1992).
  15. Bennett, C. L., Smoot, G. F., Janssen, M. A., Gulkis, S, Kogut, A., Hinshaw, G., Backus, C., Hauser, M. G., Mather, J. C., Rokke, L., Tenorio, L., Wilkinson, D. T., Wright, E. L., Aymon, J., DeAmici, G., Boggess, N. W., Cheng, E. S., Jackson, P. D., Keegstra, P., Kelsall, T., Kummerer, R., Lineweaver, C., Lubin, P. M., Meyer, S. S., Moseley Jr., S. H., Murdock, T. L., Santana, J., Shafer, R. A., Silverberg, R. F., Weiss, R., COBE Differential Microwave Radiometers (DMR): Calibration Techniques, Ap.J. 391, 466-482 (1992).
  16. Smoot, G. F., Bennett, C. L., Kogut, A., Wright, E. L., Aymon, J., Boggess, N. W., Cheng, E. S., De Amici, G., Gulkis, S., Hauser, M. G., Hinshaw, G., Lineweaver, C., Loewenstein K., Jackson, P. D., Janssen, M. A., Kaita, E., Kelsall, T., Keegstra, P., Lubin, P., Mather, J. C., Meyer, S. S., Moseley Jr., S. H., Murdock, T. L., Rokke, L., Silverberg, R. F., Tenorio, L., Weiss, R., and Wilkinson, D. T., Structure in the COBE Differential Microwave Radiometer First-Year Maps, Ap.J. 396, L1-L5 (1992).
  17. Janssen, M. A., A New Instrument for the Determination of Radio Path Delay Due to Atmospheric Water Vapor, IEEE Trans. Geosci. Remote Sensing, GE-23, No. 4, 485-490 (1985).
  18. Janssen, M. A., Bednarczyk, S. M., Gulkis, S., Marlin, H. W. and Smoot, G. F., Pattern Measurements of a Low-Sidelobe Horn Antenna, IEEE Trans. on Antennas and Propagat., AP-28, 759-763 (1979).
  19. Hills, R. B., M. A. Janssen, D. D. Thornton, W. J. Welch, The Hat Creek Millimeter-Wavelength Interferometer, Proc. IEEE, 61, 9, 1278 (1973).
  20. Janssen, M. A., R. Hills, D. D. Thornton, W. J. Welch, Venus: New Microwave Measurements Show No Atmospheric Water Vapor, Science, 179, 994 (1973).

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