University of Central Florida

Dr. Harrington began observing and modeling giant planets as an undergraduate at MIT. His pre-impact model of the collision of comet Shoemaker-Levy 9 with Jupiter in 1994 was published on the cover of Nature and sparked the worldwide media spree surrounding that event. Dr. Harrington then held a National Research Council Fellowship at the NASA Goddard Space Flight Center, during which he modeled the aftermath of the Shoemaker-Levy 9 impact and also identified the majority of planetary waves known on planets other than Earth. From 1997 - 2006, he worked as a staff scientist at Cornell University, where his interests shifted to observing extrasolar planets. He was part of the team that first measured light from an extrasolar planet, a result published in Nature in April 2005.

Harrington's research is focused on two main areas: Directly measuring extrasolar planets and modeling the impacts of the fragmented comet Shoemaker-Levy 9 on Jupiter.

The extrasolar planets effort seeks to further our understanding of the origin, physics, and chemistry of planets, and to develop the techniques that will ultimately let us identify planets that could harbor life. The first component of this effort measures the intrinsic brightness of planets and also the planets' radii using infrared photometry from the Spitzer Space Telescope. The program includes target-of-opportunity observations to measure any newly-discovered planets. The second component uses ground-based, high-resolution spectroscopy from the world's largest telescopes to identify molecular constituents in the atmospheres of planets.

Many of the phenomena observed when comet Shoemaker-Levy 9's fragments hit Jupiter in July 1994 have not been explained. Harrington's program focuses on realistic, 3D models that are rigorously based on and tested by the observations. The group's dedicated, 36-node cluster supercomputer follows the energy of icy and rocky impactors that are up to several km in diameter and that hit Jupiter at 60 km/sec. The impactors vaporize completely in under 10 sec, a process that raises their temperatures to 40,000 K. The vaporized comet and a great deal of entrained Jovian air leave the atmosphere at supersonic speeds and flies ballistically for thousands of km before landing on the planet in a secondary impact. These events drive exotic chemistry, shocks, and wave activity. Some of the chemical fallout is still observed today. Through this study, the team has identified unanticipated behavior that is relevant to impacts on Earth.

Each of these projects consists of many separate datasets, and each dataset contains as many as 48,000 images or 200 GB of model output. Combining his interests in computing and planetary science, Harrington and his group have published automated methods for analyzing astronomical data. Software is available at Dr. Harrington's web site, linked above.

The planetary group seeks sharp, self-motivated members for positions at all levels, from undergraduate through faculty. If you are interested in work on these particular topics, please contact Dr. Harrington at the email address above.