15th Annual Bullitt Lecture

Bullitt poster 2015

Speaker:  Hal Weaver (Johns Hopkins Univ. Applied Physics Lab)
When: 6pm, Thu. Oct. 8
Where: Gheens Science Hall & Rauch Planetarium
Parking: available from 5pm, North Info Lot and Red Reserved Lot
at the College of Business (gates will be up)

Abstract:
     Our Solar System has three zones: the "terrestrial" zone is comprised of  relatively small, solid bodies
(Mercury, Venus, Earth, Mars), while the "giant planet" zone has behemoth worlds (Jupiter, Saturn, Uranus,
Neptune) with swirling gas envelopes surrounding their cores. Only in the early 1990s did we discover the
existence of a third zone, the Kuiper Belt, populated with icy dwarf planets and at least a hundred thousand
objects larger than 50 miles across. The architecture of the Kuiper Belt (with "cold classical", "resonant",
and "scattered" objects) has revolutionized our view of the Solar System's formation and evolution, suggesting
a much more turbulent beginning than previously imagined.
     The New Horizons spacecraft made the first fly-by of Pluto  on 2015 July 14, capturing a flood of data
on  this magnificent "mini solar system" comprised of the binary dwarf planets Pluto and Charon and the
small moons Styx, Nix, Kerberos, and Hydra. Pluto has just been transformed from a pixelated blob into a
spectacularly complex and diverse world with water-ice mountains as high as the Rockies on Earth and
exotic nitrogen-ice sheets with glacier-like flows. Charon has huge chasms bigger than Earth's Grand Canyon
and a giant hood of dark material covering its north pole. New Horizons has shown Nix and Hydra to be
highly elongated objects, covered in water ice, and with crater-like surface features.
     While New Horizons was busy investigating "resonant" objects in the Kuiper Belt, the European
Space Agency's Rosetta mission has been conducting an historic rendezvous with one of the Kuiper Belt's
"scattered" objects, comet 67P/Churyumov-Gerasimenko. Rosetta has been following the evolution of this
"rubber duckie" comet for over a year as it moves through the inner Solar System. The Philae lander, with
a sophisticated suite of instruments, was dropped down to the surface in early November 2014, only to
bounce away when some of its landing gear failed to operate properly, until the craft finally settled
precariously next to a cliff. In the meantime, the Rosetta orbiter spacecraft continues to acquire a wealth
of data, most recently capturing the eruption of spectacular jets as 67P reached its closest approach to the
Sun in early August 2015. In this Bullitt Lecture, I will highlight the most exciting new results returned
by the New Horizons and Rosetta missions.

Hal Weaver, has been pursuing space-borne, rocket-borne, airborne, and ground-based
investigations in planetary science since 1978. After earning his BS at Duke in 1975, he
finished a PhD at Johns Hopkins Univ. (JHU) in 1982, where he analyzed cometary spectra
obtained with the NASA/ESA International Ultraviolet Observer satellite. This was the first
systematic investigation of cometary ultraviolet emissions and demonstrated that water was
the dominant volatile constituent in cometary nuclei.

In 1985-1986 he made infrared observations of Comet Halley from the NASA Kuiper Airborne
Observatory, which resulted in the first unambiguous, direct detection of water in comets, and
for which he was awarded the NASA Medal for Exceptional Scientific Achievement in 1988.
Weaver led many investigations of comets using the Far Ultraviolet Spectroscopic Explorer
and the NASA/ESA Hubble Space Telescope,  including serving as the Chair of the science
team investigating Comet D/Shoemaker-Levy 9 as it plunged into Jupiter's atmosphere in 1994.  
In 1996, asteroid 1984 FN was renamed to asteroid "Halweaver" in recognition of Weaver's
work on the chemical composition of comets. Weaver joined the Senior Professional Staff at
The JHU Applied Physics Laboratory in 2002, and is also a Research Professor at JHU. In
2007, he was appointed as a Co-Investigator on the Alice Ultraviolet Spectrograph, which
is one of the principal NASA contributions to the ESA-led Rosetta comet mission.

Hal Weaver is currently the Project Scientist on the New Horizons Mission, which is the first
spacecraft mission to Pluto and the Kuiper belt. In 2005, he co-led a team that discovered
two new satellites around Pluto (Nix and Hydra), and he was on the team that discovered
two other small Pluto satellites (Kerberos and Styx) in 2011 and 2013.

Weaver has published over 100 refereed papers, including studies of comets, planets, and
satellites, and has a longstanding interest in the formation and evolution of planetary systems.
 

      We will record the lecture for our talk archive


The Physics & Astronomy Departmentís Bullitt Lecture is a free lecture aimed at the general
public. 
Since 2001, the Physics & Astronomy Departmentís Bullitt Lecture has presented a
distinguished astrophysicist to a Louisville audience in the Gheens Science Hall and Rauch
Planetarium.  Gale Christianson, Hubble's biographer at Indiana State, Fred Espenak, an
eclipse expert at NASA Goddard Space Flight Center, stellar astrophysicists
James Kaler of U. Illinois, C. R. O'Dell of Vanderbilt and Caty Pilachowski of Indiana U,
cosmologists Fang Li Zhi of Arizona, J. Richard Gott of
Princeton, Alan
Dressler of the Carnegie Observatories and lunar experts Ferenc Pavlics of GM and the Apollo
project and Phillip Abel of NASA have been Bullitt Lecturers.

College and high school students, teachers, and many others from the community interested in
the impact and excitement that astrophysics has generated have attended Bullitt Lectures in
large numbers. The public and members of the University community are warmly invited!

The Lecture is endowed through a grant from the family of William Marshall Bullitt, the
Solicitor General of the United States under President William Howard Taft.  Here is
a brief biography and description of his connection to the University of Louisville.


Several of the 2006-2008 popular and Bullitt lectures are available in streaming (.asx) format in the
UL astronomy talk archive.

Later Bullitt Lectures (from 2009 onward) are linked at the Louisville Astro talk
archive here.
Posters for all of the current and previous Bullitt Lectures are available:
2001 Gale Christianson, "Edwin Hubble: An Astronomer's Life"
2002 Fred Espenak, "Solar Eclipses and Mysteries of the Sun"
2003 James Kaler, "The Life and Death of Stars"
2004 Fang Li Zhi, "Dark Energy in the Universe"
2005 J. Richard Gott, "A Map of the Universe"
2006 Alan Dressler, "Galaxies, Stars, Planets and Life: the Birth of the Modern Universe"
Dr.  Dressler was interviewed on Louisville's WFPL (NPR) radio on April 20, 2006 on State of Affairs, which has an archive edition of the radio interview. 
2007 C.R. O'Dell, "Creating the Hubble Space Telescope"
2008 Caty Pilachowski, "The Star Cities of the Milky Way"  flier
Dr. Pilachowski was interviewed on Louisville's WFPL (NPR) radio on October 29, 2008 on State of Affairs, which has an archive edition of the radio interview. 
2009 Ferenc Pavlics and Phillip Abel, "40 Years: Lunar Exploration"  flier
Mr. Pavlics and Dr. Abel were interviewed on Louisville's WFPL (NPR) radio on October 8, 2009 on State of Affairs, which has an archive edition of the radio interview. 
2010 Don York, "The History of the Telescope and Its Relation to Culture"
   
The Louisville Courier-Journal wrote a piece about the lecture in its Oct. 6, 2010 edition. poster
2011 Linda Spilker, "Cassini-Huygens explores the Saturn System: Recent Discoveries and Science Highlights" poster
2012 Kris Stanek
, "Measuring the Size and Age of the Universe" poster
     Interview on WFPL-NPR "Here and Now", 11 Oct 2012
2013 Virginia Trimble, "Blurring the Boundaries Among Physics, Chemistry and Astronomy:
   The Moseley and Bohr Centeneries" poster
 
2014 Rogier Windhorst, "The James Webb Space Telescope", article on WFPL-NPR, 16 Oct 2014 poster
2015 Hal Weaver, "Exploring the Solar System's Third Zone"

Links to other Bullitt Lectures and Bullitt book collections:
Bullitt Lecture in Mathematics
Bullitt Lecture in Fine Arts
William Marshall Bullitt Collection of Rare Mathematics and Astronomy Books
More on the Bullitt Collection of Books at UofL