Two Lowell Observatory astronomers are
members of the New Horizons science team selected by NASA to lead the
Pluto-Kuiper Belt mission, intended to explore our solar system’s most
distant planet and beyond.

John Spencer and Will Grundy, both experts on the compositions and physical
behaviors of icy solar system surfaces, are responsible for producing and
interpreting surface composition and temperature maps of Pluto and its moon,
Charon, from data gathered from the mission. In addition, they will work to
ensure that the spacecraft’s instrumentation, when launched, is optimized to
probe the surface and atmosphere of Pluto and Charon.

"This is an exciting time in astronomy," Grundy says. "Our ability to answer
fundamental questions about the surface properties, geological and interior
makeup, and atmospheric conditions of Pluto, Charon and Kuiper Belt Objects
will propel science into new and exciting frontiers, unraveling some of our
solar system’s greatest mysteries."

The mission, called New Horizons: Shedding Light on Frontier Worlds, seeks to
answer questions about the surfaces, atmospheres, interiors and space
environments of the outermost objects in our solar system. The spacecraft
first explores Pluto and its moon, Charon. It then journeys beyond Pluto to
visit one or more Kuiper Belt Objects — small, icy objects beyond Neptune’s
orbit believed to be a source of Earth’s water and the simple chemical
precursors of life. Set to launch in 2006, the spacecraft will fly past
Pluto and Charon in 2016 and then venture into the Kuiper Belt.

Spencer and Grundy will help choreograph the spacecraft’s close flyby of
Pluto and Charon in 2016. From data gathered, they will be able to map the
surfaces of both Pluto and Charon, and determine the location, temperatures,
and kinds of ices on each. Pluto’s surface is so cold that gases such as
nitrogen, methane and carbon dioxide partly freeze solid, resulting in a
strange, alien landscape.

"Given Lowell Observatory’s long history studying the Pluto-Charon system
and the Kuiper Belt, I’m proud that John Spencer and Will Grundy are
involved in this important mission," says Dr. Robert Millis, director of
Lowell Observatory.

Clyde Tombaugh discovered Pluto at Lowell Observatory in 1930. Today many
Lowell astronomers continue to study the ninth planet. In addition, Lowell
Observatory astronomers actively explore the Kuiper Belt, the area beyond
Neptune’s orbit where Kuiper Belt Objects reside.

"More than 500 Kuiper Belt Objects have been discovered since the first one
was found in 1992," Grundy says. "But this number represents only a tiny
fraction of the objects expected to exist in that distant region of the
solar system."

To explore the uncharted area beyond Pluto, the spacecraft will retarget
itself after visiting Pluto for encounters with one or more Kuiper Belt
Objects, hopefully one that is at least 50-100 kilometers across. Specific
target objects have not been identified yet, but are anticipated to be
irregularly shaped and about 50-100 kilometers across.

"Lowell astronomers will point their telescopes along the future spacecraft
track in an effort to find suitable Kuiper Belt Objects for the spacecraft
to visit," Spencer says. This is no easy task, says Grundy, because these
objects are so faint, making them incredibly difficult to detect.

Lowell Observatory’s Deep Ecliptic Survey, headed by Millis, has found more
Kuiper Belt Objects than any other program. When the time comes, the
techniques developed by the Observatory’s survey team are likely to find
several well-positioned objects for the spacecraft to target.

During its 20-year adventure, the spacecraft will gather data and images
using visible-wavelength cameras, infrared and UV spectrometers, radio
waves, and more. Using this information, scientists will be able to answer
important questions about these previously unexplored celestial bodies.

"Pluto and the Kuiper Belt comprise the unexplored frontier of the solar
system, and hold many secrets about how the solar system, and thus humanity
itself, came into being," Spencer says. "New Horizonswill help us to unlock
these secrets."

After years of reviewing mission proposals, NASA on Nov. 29 selected the New
Horizonsteam to lead the Pluto-Kuiper Belt mission. The team is lead by
Principal Investigator Dr. S. Alan Stern of the Southwest Research Institute
in Boulder, Colo. The team also includes members from the John Hopkins
University Applied Physics Lab, Laurel, Md., Ball Aerospace Corp., Boulder,
Colo., Stanford University, Palo Alto, Calif., and NASAÕs Goddard Space
Flight Center, Grennbelt, Md., and Jet Propulsion Laboratory, Pasadena,

For more information about the Pluto-Kuiper Belt mission, visit


Will Grundy joined Lowell Observatory’s staff in 1997 as a Hubble
Postdoctoral Fellow. As a leading expert in the remote sensing of icy and
organic materials in the outer solar system, Grundy has made state-of-the
art contributions both in laboratory studies of cryogenic ices and in the
modeling of Pluto and Charon, icy satellite spectra and Kuiper Belt Objects.
He is widely recognized for developing sophisticated techniques for
retrieving information about temperatures and textures of outer solar system
ices. For the Pluto-Kuiper Belt mission, Grundy serves on the Surface
Composition team, and is directly responsible for producing composition and
temperature maps from data gathered by the spacecraft. In addition, he works
to ensure that the spacecraft’s instrumentation is capable of successfully
probing the surface and atmosphere of Pluto and Charon. Grundy earned his
doctorate in planetary sciences from the University of Arizona in 1995.


John Spencer joined the Lowell Observatory staff in 1991, and has been
involved in planning for the Pluto mission since 1993. A recognized expert
on the small bodies of the outer solar system, he uses data from telescopes
and interplanetary spacecraft to understand the temperatures and
compositions of these distant worlds and has a particular interest in the
seasonal migration of frosts on Pluto. He is a member of the Galileo Jupiter
Orbiter science team, studying Jupiter’s moons with the
Photopolarimeter/Radiometer (PPR) instrument, and is a science-team
associate on the Cassini Saturn Orbiter mission. He is also a frequent user
of the Hubble Space Telescope. On the New Horizons mission, he is
responsible for using images and spectra of Pluto to map surface
temperatures and understand how frost on Pluto’s surface evaporates to
generate Pluto’s atmosphere. He will be working with the rest of the team to
make sure that the spacecraft’s instruments and observations are optimized
for this task. Spencer earned his doctorate in planetary sciences from the
University of Arizona in 1987.


Lowell Observatory is a private, non-profit institution dedicated to
astronomical research. In addition to studying the Pluto-Charon system and
the Kuiper Belt, Lowell astronomers also explore comets, Near-Earth
asteroids, the sun, planetary rings, and more. The Observatory also educates
more than 70,000 people about astronomy each year through its extensive
public outreach programs. Founded in 1894, Lowell Observatory has a staff of
55, including 20 Ph.D. astronomers. Lowell operates from a 740-acre forested
campus on Mars Hill, overlooking Flagstaff, Arizona. For more information,
visit our Web site at