14 AAS Newsletter 105 ª June 2001

transfer orbits and DIVISIONS cometary transport by W. S. Koon, Dynamical Astronomy Caltech; and Marc Murison, Secretary planetary rings by Phil Nicholson, Highlights: Houston Meeting Cornell. John All photos by Alan Fiala, except as noted otherwise. Connolly,an The 2001 Annual engineer with the Exploration office Meeting of Johnson Space The 2001 meeting, held at the Center, presented Lunar and Planetary Institute in an enthusiastic talk, John Connolly, JSC, (right) entertained guests at the Houston on April 22-25, was “Leaving the banquet with a talk entitled “Leaving the Cradle,” or, organized by Hal Levison Cradle,” after the space exploration beyond the International Space (Program Chair) and Joe Hahn banquet. Station. Fritz Benedict, left, discusses it afterwards. (Local Host). The facilities were DDA Student excellent, the support staff was very helpful, and the weather Stipend was mild with a little rain (and Program some exciting Houston For the seventh lightening). The meeting consecutive year, program, prepared well in two student stipends advance by Hal Levison and Joe Hahn, local host, signals the start were awarded at the of the meeting. posted on our web site through annual DDA Doug Mink’s effort, was printed meeting. The in a handsome booklet with an outstanding arresting image of Saturn’s rings recipients were Eric as cover art. Barnes (LSU), The 2001 Brouwer Award was who spoke on (From the left) Bill van Altena, Bob Greenberg, and formally presented to E. Myles “Characterizing 3D Doug Hamilton enjoy the banquet. Standish, Jr., for the Stellar Orbits with development of the JPL Correlation planetary ephemerides. His Integrals,” and from invited lecture at the meeting Cornell Britt was an historical talk on one of Scharringhausen, whose Myles’s favorite topics, topic was “Adaptive “Galileo’s Observations of Optics Observations of Neptune,” wherein he Saturn’s Inner Moons.” reconsidered Galileo’s They each presented their identification(s) of Neptune that first papers at our annual E. Myles Standish, Jr., recipient of the appeared in his early sketches of meeting. 2001 Dirk Brouwer Award, and his the positions of Jupiter’s To increase student wife, Jeannine. satellites. participation at DDA Invited papers at the 2001 meetings, the Division From LSU: Eric Barnes, Student Stipend meeting were presented on the makes available up to two Awardee, and Joel Tohline, his advisor. dynamical stability of Upsilon student stipends of $400 Andromedae by Pavel each. Any full or part-time Artymowicz, Stockholm; student presently enrolled collisionless dark matter halos by in an academic program at Edward Bertschinger, MIT; a college or university is extrasolar planet candidates by eligible and encouraged to Dave Black, LPI; celestial apply. For next year’s mechanical effects on Europa’s April 2002 meeting, habitability by Rick Greenberg, submit an abstract of a U. Arizona; dynamics of paper for presentation, interplanetary dust by Keith along with an advisor’s Grogan, Goddard; a dynamical recommendation, to Dr. systems approach to the circular Jane Russell, NASA’s From Cornell University: (From the left) Joe restricted three-body problem GSFC, Code 664, Burns, Division Chair; Britt Scharringhausen, Terry Alfriend spoke on aspects of with applications to lunar Greenbelt, MD 20771, Student Stipend Awardee; Phil Nicholson, her flying satellites in formation. [email protected]. advisor and invited speaker. gov. AAS Newsletter 105 ª June 2001 15

Nominate for Wisdom To Receive 2003 Brouwer The 2002 Brouwer Award The 2002 Brouwer Award was The Brouwer given to Jack Wisdom, Award Selection Professor of Planetary Science Committee of the at MIT. The citation reads as DDA invites follows: nominations from “Jack Wisdom (Massachusetts any member of the Institute of Technology) AAS for an award pioneered the application of competition. The modern nonlinear dynamics and Those who keep the Division running: (From the left) Brouwer Award the theory of Hamiltonian chaos Peter Shelus, Treasurer; Hal Levison, Chair; and was established to in the field of solar system The Division announced that Jack Marc Murison, Secretary. Not pictured: Dave Merritt, recognize dynamics. As a graduate Wisdom of MIT is the 2002 Vice Chair. outstanding student, he was the first to apply Dirk Brouwer Award winner contributions to the resonance overlap criterion the field of dynamical astronomy, including celestial mechanics, to this field, demonstrating that the band of chaotic, short-lived astrometry, stellar systems, galactic and extragalactic dynamics. orbits near a perturbing body results from the overlap of mean Complete information regarding the Brouwer Award can be found motion resonances. He subsequently solved the long-standing at the DDA web site http://dda.harvard.edu or by contacting the problem of the origin of the Kirkwood gaps. After developing an Committee Chair, Dr. William F. Van Altena, Dept. of Astronomy, algebraic mapping to permit rapid numerical integration of Yale University, PO Box 208101, New Haven, CT 06520-8101, trajectories near the 3/1 Kirkwood gap, Jack showed that chaotic [email protected]. Nominations must be received by orbits in this gap undergo intermittent jumps in eccentricity that 31 December 2001. lead to planet-crossing orbits. This not only provides a means of clearing the gap but also demonstrates a means of delivering Future DDA Meetings meteoritic material to the Earth. The boundary of the numerically The next DDA meeting will be held at the Timberline Lodge near determined 3/1 chaotic zone corresponds to the observed boundary Portland, Oregon, 21–24 April 2002. The local host will be Alan of the 3/1 Kirkwood gap, giving the first clear evidence of a Harris of JPL, and the program committee will consist of Harris, physical manifestation of dynamical chaos in our solar system. David Merritt (Vice Chair), and Marc Murison (Secretary). The “Through continued, careful investigations, Jack has illustrated 2003 meeting is scheduled for May 5-8 at Cornell University with the ubiquitous role that dynamical chaos plays in the evolution of Joe Burns as local host. The DDA is considering holding its 2004 our solar system. Through Jack’s efforts, we now know that the meeting abroad, perhaps in Brazil. Saturnian moon Hyperion tumbles chaotically, and that every Officers and Membership satellite passes through a period of chaotic rotation as it tidally evolves toward synchronous rotation. We also know, from his The officers elected for 2001-2002, Committee members work with student Jihad Touma, that the obliquity of Mars varies elected for 2001-2003, and continuing Committee members, chaotically, a result with profound implications for the climate of are Chair: Hal Levison (SwRI); Vice Chair: David Merritt that planet. In addition, Jack and his student, William Tittemore, (Rutgers); Past Chair: Joe Burns (Cornell); Secretary: Marc demonstrated that the anomalously high inclination of Miranda Murison (USNO); and Treasurer: Pete Shelus (U. Texas at resulted from a temporary capture in the 3/1 resonance with Austin). Committee members are: First Year: Robin Canup Umbriel. Through long-term numerical integrations on a (SwRI); Phil Nicholson (Cornell); Tom Statler (Ohio U.); special-purpose computer, Jack and colleague Gerald Sussman Second Year: Jane Morrison (STScI); Judit Ries (U. Texas at shattered the long-held view of the clockwork motion of the Austin); and Steve Unwin (JPL). planets by revealing the chaotic evolution of Pluto’s orbit. They The Division has went on to confirm the chaotic evolution of continued to grow, the outer planets and the full solar system. reaching 216 regular Most recently, Jack’s work with Touma has members and 39 provided new insights into the complex affiliates for a total evolution of the Moon’s orbit. Throughout membership of 255, up his career, Jack has developed numerous 10% from last year and analytical and numerical techniques upon over 30% from 1998. which our community has relied and built. We are saddened that A notable example is the symplectic map for three members (James the n-body problem, a technique that now H. Bartlett, Samuel J. forms the core of nearly every solar system Goldstein and Joseph dynamics integration scheme in use today. W. Siry) passed away. For his fundamental contributions and leadership in the field, we find Jack Wisdom an outstanding candidate for the Brouwer Almost the whole DDA meeting. Award.” Photo by Debra Rueb, LPI. Continued on next page