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Karen Willacy

Photo of Karen Willacy


4800 Oak Grove Drive
M/S 169-506

Pasadena, CA 91109





Curriculum Vitae:

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Member of:

Interstellar and Heliospheric Physics


  • B.Sc. (Hons) Physics, University of Durham (1988)
  • M.Sc. Radioastronomy, University of Manchester (1990)
  • Ph.D. Astrophysics, Universtiy of Manchester Institute of Science and Technology (1993)

Professional Experience

  • Jet Propulsion Laboratory (1998-Present)
    • Research Scientist(2000-Present)
    • National Research Council Resident Research Associate (1998-1999)
  • UMIST, Postdoctoral research associate (1995-1998)
  • University of Edinburgh, Postdoctoral research associate, (1993-1995)
  • Logica Energy and Industry Systems Ltd, Computer programmer (1988-1989)

Community Service

  • JPL Astrophysics search committee member
  • Referee for MNRAS, A&A, and ApJ
  • Reviewer for NASA ROSES proposals

Research Interests

  • Links between the composition of comets and protostellar disks
  • Modeling the atmospheric chemistry of solar system planets and moons (Venus, Mars, Titan, Pluto) and exoplanets
  • Chemistry of the interstellar medium, including prestellar cores, protoplanetary disks and circumstellar envelopes around late-type stars
  • Formation and evolution of pre-biotic molecules
  • Gas/grain interactions in the interstellar medium
  • Deuterium chemistry

Selected Awards

  • NASA Exceptional Scientific Achievement Medal (2021)
  • NASA Group Achievement Award “Galactic Observations of Terahertz C+ Science Team” (2017)
  • NASA Group Achievement Award SIM Science Office Team (2011)

Selected Publications

  1. Willacy, K., Turner, N., Bonev, B., Gibb, E., Dello Russo, N., DiSanti, M., Vervack, R.J. Jr. & Roth, N. X. (2022) Comets in context: Comparing comet compositions with protosolar nebula models, ApJ, 931, 164 arXiv:2204.07517
  2. Willacy, K., Chen, S., Adams, D. J., & Yung, Y. L. (2022) Vertical distribution of cyclopropenylidene and propadiene in the atmosphere of Titan, ApJ, 933, 230 arXiv:2204.13064
  3. Dash, S., Majumdar, L., Willacy, K., et al. (2022) Linking the atmospheric chemistry of the hot Jupiter HD208458b to its formation location through infrared transmission and emission spectra, ApJ, 932, 20 arXiv:2204.04103
  4. Tritsis, A., Federrath, C. Willacy, K. & Tassis, K. (2022) Non-ideal MHD simulations of subcritical prestellar cores with non-equilibrium chemistry, MNRAS 510 4420
  5. Seo, Y., Majumdar, L., Goldsmith, P., Yancy, S., Willacy, K. et al. (2019) An ammonia spectral map of the L1495-B218 filament in the Taurus molecular cloud. II. CCS and HC7N chemistry and three modes of star formation in filaments, ApJ, 871, 134
  6. Dodson-Robinson, S. E., Evans, N. J., Ramos, A., Yu, M. & Willacy, K. (2018) Ionization-driven depletion and redistribution of CO in protoplanetary disks ApJ, 868, L37
  7. Kleinböhl, A., Willacy, K., Friedson, A. J., Chen, P. & Swain, M. (2018) Buildup of abiotic oxygen and ozone in moist atmospheres in temperature terrestrial exoplanets and its impact on the spectral fingerprint in transit observations, ApJ, 862, 92
  8. Majumdar, L., Gratier, P., Wakelam, V., Caux, E., Willacy, K. & Ressler, M. (2018) Detection of HOCO+ in the protostar IRAS 16293-2422, MNRAS, 477, 525
  9. Douglas, K., Blitz, M. A., Feng, W., Heard, D. E., Plane, J. , Slater, E., Willacy, K. & Seakins, P. (2018) Low temperature studies of the removal reactions of 1CH2 with particular relevance to the atmosphere of Titan, Icarus, 303, 10
  10. Yo, M., Evans, N.J. II, Dodson-Robinson, S.E., Willacy, K. and Turner, N.J. (2017) The effects of protostellar disk turbulence on CO emission lines: A comparison study of disks with constant CO abundance versus chemically evolving disks ApJ, 850 169
  11. Langer W.D., Velusamy, T., Pineda, J. L., Willacy, K. & Goldsmith, P F. (2014) A Herschel [CII] Galactic plane survey II. CO-dark H2 in clouds A&A, 561, L122
  12. Yu, M., Evans, N.J. II, Dodson-Robinson, S.E., Willacy, K. & Turner, N. J. (2017) Disk masses around solar-mass stars are underestimated by CO Observations ApJ, 841, 39
  13. Chapman, J. W., Zellem, R. T., Line, M. R., Vasisht, G., Bryden, G., Willacy, K., Iyer, A.R., Bean, J., et al. (2017) Quantifying the Impact of Spectral Coverage on the Retrieval of Molecular Abundances from Exoplanet Transmission Spectra, PASP, 129, 4402
  14. Willacy, K., Allen, M. A., Yung, Y. (2016) A new astrobiological model of the atmosphere of Titan, ApJ, 829, 79
  15. Tritsis, A., Tassis, K. Willacy, K. (2016) Chemistry as a diagnostic of prestellar core geometry, MNRAS, 458, 789
  16. Willacy, K., Alexander, C., Ali-Dib, M., Ceccarelli, C., Charnley, S. B., Doronin, M., Ellinger, Y., Gast, P., Gibb, E., Milam, S. N., Mousis, O., Pauzat, F., Tornow, C., Wirstrom, E. & Zickler, E. (2015) Composition of the protosolar disk and the formation conditions for comets, Space Sci. Rev. 197, 151
  17. Mandt, K., Mousis, O., Marty, B., Cavelie, T., Harris, W., Hartogh, P., Willacy, K. & Gautier, D. (2015) Constraints from comets on the formation and volatile acquisition of the planets and satellites, Space Sci. Rev. 197, 297
  18. Langer, W.D., Velusamy, T., Pineda, J. L., Willacy, K. & Goldsmith, P F. (2014) A Herschel [CII] Galactic plane survey II. CO-dark H2 in clouds A&A, 561, L122
  19. Tassis, K., Willacy, K., Yorke, H. W. & Turner, N. J. (2012) Non-equilibrium chemistry of dynamically evolving prestellar cores I. Basic magnetic and non-magnetic models and parameter studies ApJ 753 29
  20. Bell, T. A., Willacy, K., Phillips, T. G. & Allen, A. (2011) The influence of deuteration and turbulence diffusion on the observed D/H ratio, ApJ 731 48
  21. Willacy, K. & Woods, P. (2009) Deuterium chemistry in protoplantary disks. II. The inner disk, ApJ, 703, 479
  22. Dodson-Robinson, S., Willacy, K., Bodenheimer, P., Laughlin, G., Turner, N. & Beichman, C. (2009) Ice lines, planetesimal composition and solid surface density in the solar nebula, Icarus, 200, 672
  23. Maret, S., Bergin, E., Neufeld, D., Green, J., Watson, D., Harwit, M., Kristensen, L., Melnick, G., Sonnentrucker, P., Tolls, V., Werner, M. & Willacy, K. (2009) Spitzer mapping o molecular hydrogen pure rotational lines in NGC 1333, ApJ, 698, 1244
  24. Woods, P. & Willacy, K. (2009) Carbon isotope fractionation in protoplanetary disks ApJ, 693, 1360
  25. Robinson, S., Bodenheimer, P., Laughlin, G., Willacy, K., Turner, N., & Beichman, C. (2008) Saturn forms by core-accretion in 3.37 Myrs, ApJ Letters, 688, L99
  26. Deutsch, M., Abilleira, F., Bell, D., Chodas, J., Harmon, C., Kerridge, S., Kinsey, R., Komarek, T., Lisman, D., Lopez, S., Riedel, E., Willacy, K. & Winterhalter, D. (2008) The Mars Science Orbiter Concept, IEEE conference paper
  27. Willacy, K. (2007) Deuterium chemistry in protoplanetary disks I. Outer disk models ApJ 660 441
  28. Woods, P. & Willacy, K. (2007) Benzene formation in the inner regions of protostellar disks ApJ 655 L49
  29. Willacy, K., Langer, W. D, Allen, M. & Bryden, G. (2006) Chemical effects of turbulent mixing in protoplanetary disks ApJ 644 1202
  30. Willacy, K. (2004) A chemical route to the formation of water in carbon-rich AGB stars – Fischer-Tropsch catalysis, ApJ 600 L87
  31. Willacy, K., Langer, W. D. & Allen, M. A. (2002) HI: A chemical tracer of turbulent diffusion in molecular clouds, ApJ 573 L119
  32. Willacy, K. & Langer, W. D. (2000) The importance of photoprocessing in protoplanetary disks, ApJ 544 903
  33. Willacy, K., Langer, W. D. & Velusamy, T. (1998) Dust emission and molecular depletion in L1498, ApJL 507 L17
  34. Willacy, K. & Millar, T. J. (1998) Desorption processes and the deuterium fractionation in molecular clouds, MNRAS 298 562