Sixth International Mars Conference will Include Public Event

Caltech News Release
For Immediate Release
July 14, 2003

Contact: Mark Wheeler
(626) 395-8733


Sixth International Mars Conference will Include Public Event

PASADENA, Calif. - Next year, if all goes well, NASA's two Mars
rovers, Spirit and Opportunity, along with the British rover Beagle
2, will begin streaming back reams of data about the Red Planet, much
to the delight of Mars researchers everywhere.

That data won't be available in time for scientists attending the
Sixth International Conference on Mars at the California Institute of
Technology, July 20-25, but small matter. Data from two earlier
orbiter missions, the Mars Global Surveyor (MGS), launched in 1996,
and the Odyssey, launched in 2001, will give those attending the
conference an opportunity to review and debate some of the key
questions and controversies that have matured as a result of this
flood of information. "It's time for another review," says Arden
Albee, a professor of geology and planetary science, emeritus, at
Caltech. "Never before have scientists had such a comprehensive
record of the processes that operated on the surface of Mars and in
its atmosphere."

The conference will also include a free public event. On Wednesday
evening, July 23, the conference will sponsor "A Mars Picture
Gallery--Every Picture Tells a Story," from 8 to 10 p.m. in Caltech's
Beckman Auditorium. Featured will be Michael Malin, principal
investigator of MGS's Mars Orbiter Camera, and Philip Christensen,
principal investigator of Odyssey's THEMIS camera.

Malin, a 1976 Caltech graduate and an experienced planetary
geologist, is currently president and chief scientist of Malin Space
Science Systems, which operates the MGS camera. The camera has
returned more than 20,000 new images from Mars, showing the planet's
enigmatic features in great detail and tracking changes in its
atmosphere. Recently Malin has been able to obtain images at an
unprecedented resolution of 1.5 meters per pixel. This past spring,
Malin received a Caltech Distinguished Alumni Award for his work.

Christensen, a planetary geologist at Arizona State University, will
display recent images and results from the THEMIS (thermal emission
imaging system) camera, on the newest mission to Mars. "THEMIS
provides a unique new view of Mars in thermal infrared images that is
providing details on the physical properties of its surface, and the
processes that have acted over time," says Christensen. "These views
provide a broad perspective of Martian processes, and a context from
which to understand the history and evolution of the planet."

Both cameras, for example, have observed sites where water--and
therefore life--may have existed in ancient times.

The role of water and the possibility of life on Mars will attract
much attention at the sixth conference, says Albee, just as it did at
the earlier conferences. "Now we can focus questions in three
specific areas. The role of water in the climate of early Mars; the
current extent and location of water ice; and the tantalizing
evidence for the existence of very recent liquid water on its
surface."

Investigators using the new data argue that precipitation, either
rain or snow, and flowing water eroded the surface of Mars in its
first billion years despite the planet's frigid climate, says Albee.
Precise digital topography from MGS's laser altimeter now also makes
it possible to analytically compare valley networks on Earth and
Mars. "Unlike Earth," he says, "Mars has preserved much of its
ancient landscape, which may yield clues to the climatic conditions
under which it formed."

Instruments on Odyssey have mapped the presence of water ice in the
immediate subsurface of Mars and have shown that it is less abundant
toward the equator. Images show the presence of soil flowage and
other features found in permafrost regions on Earth.

The discovery of young gullies in photos of Mars has changed the
conception that it has been a dry and frigid planet in the recent
past, says Albee, noting that new theories abound. One suggests these
recent gullies were formed by debris flows that involved liquid water
of subsurface origin. Others have proposed flows driven by carbon
dioxide, while still others have proposed localized surface heating
under certain conditions.

The arguments over water are simply a sample of the many viewpoints
that will be argued during the conference, says Albee, including a
session on Tuesday afternoon entitled "Future Missions." In all, some
400 scientists from a number of countries are expected to attend.