People » Joshua Colwell

  • Pegasus Professor and Associate Chair
  • Planetary Sciences
  • PSB 434 (main office) / PSB 444 and PSB 461 (labs)
  • 407-823-2012
  • Curriculum Vitae

Dr. Colwell received his B.S. in Physics from Stetson University and a Ph.D. in Astrophysical, Planetary and Atmospheric Sciences from the University of Colorado at Boulder. He has been on the faculty at UCF since 2006.

I study the origin and evolution of the solar system and in particular small bodies such as planetary rings, asteroids, comets, dust, and small moons. I’m a Co-Investigator on the Ultraviolet Imaging Spectrograph (UVIS) on the Cassini spacecraft, leading observation design and data analysis and interpretation for observations of Saturn’s rings with that instrument. I am Director of the Center for Microgravity Research within the UCF Physics Department where we design, build and operate microgravity experiments to study the early stages of planet formation, the surfaces of small asteroids and moons, and the collisional evolution of planetary rings.

Becker, T. M., J. E. Colwell, L. W. Esposito, N. O. Attree, C. D. Murray 2018. Cassini UVIS Solar Occultations by Saturn’s F Ring and the Detection of Collision-Produced Micron-Sized Dust. Icarus306, 171-199, doi:10.1016/j.icarus.2018.02.006.

Brisset, J., J. Colwell, A. Dove, D. Maukonen 2018. The NanoRocks Experiment: Studying Planet Formation on the International Space Station. Rev. Sci. Inst., 88, doi:10.1063/1.4991857.

Colwell, J. E., L. W. Esposito, J. H. Cooney 2018. Particle Sizes in Saturn’s Rings from UVIS Stellar Occultations 1. Variations with Ring Region. Icarus300, 150-166.

French, R. G., C. A. McGhee-French, K. Lonergan, T. Sepersky, R. A. Jacobson, P. D. Nicholson, M. M. Hedman, E. A. Marouf, J. E. Colwell 2017. Noncircular Features in Saturn’s Rings IV: Absolute Radius Scale and Saturn’s Pole Direction. Icarus, 29014-45.

Hansen, C. J., L. W. Esposito, K.-M. Aye, J. E. Colwell, A. R. Hendrix, G. Portyankina, D. Shemansky 2017. Investigation of Diurnal Variability of Water Vapor in Enceladus’ Plume by the Cassini Ultraviolet Imaging Spectrograph. Geophys. Res. Lett., 44, doi:10.1002/2016GL071853.

Whizin, A. D., J. Blum, J. E. Colwell 2017. The Physics of Protoplanetesimal Dust Agglomerates. VIII. Microgravity Collisions Between Porous SiO2 Aggregates and Loosely-Bound Agglomerates. Astrophys. J.836, 94-102.

Jerousek, R. G., J. E. Colwell, P. D. Nicholson, M. M. Hedman, L. W. Esposito 2016. Small Particles and Self-Gravity Wakes in Saturn’s Rings from UVIS and VIMS Stellar Occultations. Icarus279, 36-50.

French, R. G., P. D. Nicholson, C. A. McGhee-French, K. Lonergan, T. Sepersky, M. M. Hedman, E. A. Marouf, J. E. Colwell 2016. Noncircular Features in Saturn’s Rings III: The Cassini Division. Icarus279, 131-162.

Schmidt, J., J. E. Colwell, M. Lehmann, E. A. Marouf, H. Salo, F. Spahn, M. S. Tiscareno 2016. On the Linear Damping Relation for Density Waves in Saturn’s Rings. Astrophys. J.824, 1(33). doi:10.3847/0004-637X/824/1/33.

Becker, T. M., J. E. Colwell, L. W. Esposito, and A. D. Bratcher 2016. Characterizing the Particle Size Distribution of Saturn’s A Ring with Cassini UVIS Occultation Data. Icarus  279, 20-35. doi:10.1016/j.icarus.2015.11.001.

French, R. G., P. D. Nicholson, M. M. Hedman, J. M. Hahn, C. A.McGhee-French, J. E. Colwell, E. A. Marouf, and N. J. Rappaport 2016. Deciphering the Embedded Wave in Saturn’s Maxwell Ringlet. Icarus279, 62-77.doi:10.1016/j.icarus.2015.08.020.

Kehoe, A. J., T. J. J. Kehoe, J. E. Colwell, S. F. Dermott 2015. Signatures of Recent Asteroid Disruptions in the Formation and Evolution of Solar System Dust Bands.Astrophys. J.811, #66, doi:10.1088/0004-637X/811/1/66.

Li, Y., A. Dove, J. S. Curtis, and J. E. Colwell 2015. 3D DEM Simulations and Experiments Exploring Low-Velocity Projectile Impacts into a Granular Bed. Powder Tech.  288, 303-314.

Pilorz, S., N. Altobelli, J. E. Colwell, and M. Showalter 2015. Thermal Transport in Saturn’s B Ring Inferred from Cassini CIRS. Icarus 254, 157-177, doi:10.1016/j.icarus.2015.01.002.

Nicholson, P. D., R. G. French, C. A. McGhee-French, K. Lonergan, T. Sepersky, M. M. Hedman, E. A. Marouf, and J. E. Colwell 2014. Noncircular Features in Saturn’s Rings II: The C Ring. Icarus 241, 373-396, doi:10.1016/j.icarus.2014.06.024.

Nicholson, P. D., R. G. French, M. M. Hedman, E. A. Marouf, and J. E. Colwell 2014. Noncircular Features in Saturn’s Rings I: The Edge of the B Ring. Icarus 227, 152-175, doi:10.1016/j.icarus.2013.09.002.

Cuzzi, J. N., A. D. Whizin, R. C. Hogan, A. R. Dobrovolskis, L. Dones, M. R. Showalter, J. E. Colwell, and J. D. Scargle 2013. Saturn’s F Ring Core: Calm in the Midst of Chaos. Icarus 232, 157-175, doi:10.1016/j.icarus.2013.12.027.

Baillié, K., J. E. Colwell, L. W. Esposito, and M. C. Lewis 2013. Meter-sized Moonlet Population in Saturn’s C Ring and Cassini Division. Astron J. 145, 171, doi:10.1088/0004-6256/145/6/171.

Bradley, E. T., J. E. Colwell, L. W. Esposito 2013. Scattering Properties of Saturn’s Rings in the Far Ultraviolet from Cassini UVIS Spectra. Icarus 225, 726-739 doi: 10.1016/j.icarus.2013.04.008.

Albers, N., Sremčević, M., Colwell, J. E., Esposito, L. W. 2012. Saturn’s F Ring as seen by Cassini UVIS: Kinematics and Statistics. Icarus 217, 367-388, doi:10.1016/j.icarus.2011.11.016.

Esposito, L. W., N. Albers, B. K. Meinke, M. Sremčević, P. Madhusudhanan, J. E. Colwell, R. G. Jerousek 2012. A Predator-Prey Model for Moon-triggered Clumping in Saturn’s Rings. Icarus 217, 103-114, doi:10.1016/j.icarus.2011.09.029.

Jerousek, R. G., J. E. Colwell, L. W. Esposito 2011. Morphology and Variability of the Titan Ringlet and Huygens Ringlet Edges. Icarus, 216, 280-291, doi:10.1016/j.icarus.2011.09.001.

Baillié, K., J. E. Colwell, L. W. Esposito, M. Sremčević 2011. Waves in Cassini UVIS Stellar Occultations 2. Waves in the C Ring. Icarus, 216, 292-308, doi:10.1016/j.icarus.2011.05.019.

Hansen, C., D. Shemansky, L. Esposito, I. Stewart, A. Hendrix, J. Colwell, R. West 2011. The Composition and Structure of Enceladus’ Plume. Geophys. Res. Lett. 38, L11202, doi:10.1029/2011GL047415.

Colwell, J. E., L. W. Esposito, D. Pettis, M. Sremčević, R. G. Jerousek, E. T. Bradley 2010. Cassini UVIS Stellar Occultation Observations of Saturn’s Rings. Astron. J. 140, 1569-1578, doi:10.1088/0004-6256/140/6/1569.

Cuzzi, J. N., J. A. Burns, S. Charnoz, R. N. Clark, J. E. Colwell, L. Dones, L. W. Esposito, G. Filacchione, R. G. French, M. M. Hedman, S. Kempf, E. A. Marouf, C. D. Murray, P. D. Nicholson, C. C. Porco, J. Schmidt, M. R. Showalter, L. J. Spilker, J. N. Spitale, R. Srama, M. Sremčević, M. S. Tiscareno, J. Weiss 2010. An Evolving View of Saturn’s Dynamic Rings. Science, 327, 1470-1475, doi:10.1126/science.1179118.

Bradley, E. T., J. E. Colwell, L. W. Esposito, J. N. Cuzzi, H. Tollerud, L. Bruesch-Chambers 2010. Far Ultraviolet Spectral Properties of Saturn’s Rings from Cassini UVIS. Icarus, 206, 458-466, doi:10.1016/j.icarus.2009.12.021.

Robbins, S. J., G. R. Stewart, M. C. Lewis, J. E. Colwell 2010. Estimating the Masses of Saturn’s A and B Rings from High-Optical Depth N-Body Simulations and Stellar Occultations. Icarus 206, 431-445, doi:10.1016/j.icarus.2009.09.012.

Colwell, J. E., L. W. Esposito, G. R. Stewart, and M. Sremčević 2009. Density Waves in Cassini UVIS Stellar Occultations 1. The Cassini Division. Icarus, 200, 574-580,  doi:10.1016/j.icarus.2008.12.031.

Hansen, C. J., Esposito, Stewart, A. I. F., L. W., Meinke, B., Wallis, B., Colwell, J. E., Hendrix, A. R., Larsen, K., Pryor, W., Tian, F. 2008. Water Vapor Jets inside the Plume of Gas Leaving Enceladus. Nature 456, 477-479, doi:10.1038/nature07542.

Colwell, J. E., S. R. Robertson, M. Horányi, X. Wang, A. Poppe, and P. Wheeler 2009. Lunar Dust Levitation. J. Aerospace Eng., 22, 2-9, doi:10.1061/(ASCE)0893-1321(2009)22:1(2).

With colleagues Addie Dove and Jim Cooney, I host a fun astronomy podcast called Walkabout the Galaxy. Subscribe to the podcast here or anywhere that provides podcasts. Follow us on facebook.

Physics and Astronomy demonstration videos:

Phases and orbit of the Moon.

Lunar and Solar Eclipses.

I’m the Assistant Director of the Florida Space Institute, UCF’s space research and engineering institute that partners with universities across the state to enhance our space research programs in Florida.

Oversees the following Graduate Students

  • Monday

    • 2:30 PM to 3:30 PM
  • Tuesday

    • 2:00 PM to 3:00 PM
  • Wednesday

    • Not Available
  • Thursday

    • 2:00 PM to 3:00 PM
  • Friday

    • Not Available