Michael F. A'Hearn
Distinguished University Professor Emeritus
and Research Professor

Department of Astronomy
University of Maryland
College Park MD 20742-2421 USA

Office Location: Computer and Space Science Building, Room 1207A
Express Service Deliveries: 1113 Physical Sciences Complex, Bldg 415 Telephone: +1 301 405 6076
Electronic contact is also possible by this encoded link.


Deep Impact

On 7 July 1999 NASA announced the selection of our Deep Impact mission to be the eighth flight in the Discovery Program. On 23 May 2001, the mission was confirmed to go into the construction phase (phase C/D in NASA jargon). The project underwent its Critical Design Review Jan 29-31, 2002. The instruments were handed over to the spacecraft team in August 2003 for integration into the spacecraft. The complete flight system then went through its environmental tests and was shipped to Florida in October 2004. Launch occurred on 12 January 2005 and encounter occurred on 4 July 2005.

Some details about the mission are on our Deep Impact web pages. These pages are still being developed and more information will be added to them regularly. Papers about Deep Impact are linked from my publications page. Several PowerPoint presentations about Deep Impact are available. Here are a few - one that was presented at the Erice Workshop at the Ettore Majorana Center for Science and Culture in summer 2001 and another that was presented in June 2002 at a Meudon Workshop on the interior structure of small bodies. More recent presentations include one that I have used as the basis for several recent talks and one that Karen Meech gave as a colloquium at ESO. For now, they are available only as binary Power Point files. BEWARE: The files are about 15 to 17 MBytes each so don't download them unless you have plenty of storage space and bandwidth. A recent short paper presented at the IAU General Assembly in July 2003 is also available.

Sublimation of Ices

Web forms are available for calculating sublimation of ices


A list of recent and forthcoming publications is available.

"Scenic" photographs of comet Hale-Bopp taken by me from Flagstaff are available here.


Undergraduate Courses

Fall 2000: Astronomy 330. The syllabus and other details about the course are available on-line. Details are here.

Graduate Courses

Fall 1998: Astronomy 610 Astronomical Instrumentation and Techniques.
A brief course description is available.

Fall 2006: Astronomy 688P - Planetary Science.
The syllabus and other details will be available on line here.

International Astronomical Union

Home pages for several IAU activities can be found here. These include Division III: Planetary Systems Sciences, and the Committee for Small Body Nomenclature .

Planetary Data System - Small Bodies Node

We also manage the Small Bodies Node of NASA's Planetary Data System. Our primary job is to archive all data from NASA missions to comets and asteroids, from similar missions by other space agencies, from all instruments related to interplanetary dust. We also archive many types of supporting data, mostly from ground-based and Earth-orbital remote sensing.

Updated: Thursday, 14-May-2015 17:48:23 EDT, mfa