When it comes to the Red Planet, everyone knows what color it is (duh),
but what does that color really tell us about Mars and its mysterious
past? This is the question that Dr. Jim Bell ponders on a regular basis.
The simple answer is that there are oxidized or 'rusted' iron minerals
on the planet's surface and in the dust that gets lifted up into the
atmosphere. But why is the surface rusted? There is very little free
oxygen in the Martian atmosphere and no liquid water on the surface
today. So how did the original rocks and minerals get rusted? The
atmosphere or the climate—or both—might have been different in the
past, and the details of exactly what those iron (and other) minerals
are might provide clues to how different it was back then.
Bell has long been interested in using the colors of rocks and soils to
figure out what they are made of, so when the leader of the 2003 MER
(Mars Exploration Rover) science team asked him to come on board, he
happily agreed. His official MER title is "Payload Element Lead" or
"PEL" for short. He heads up the effort on Pancam, a high-powered stereo
camera system located on the rover's mast. Pancam is the only camera
system on the rover that obtains color pictures.
When the project first began, Bell helped design and test Pancam and
define the kinds of science measurements it would make. Eventually he'll
analyze the data from the photographs and begin to figure out what they
tell us about Mars.
Bell is also a member of the camera team on both the Mars Odyssey
mission that has been orbiting Mars for about a year now, and the Mars
Reconnaissance Orbiter mission, which will launch to Mars in 2005. "On
Odyssey we're taking color images of Mars with resolutions as good as 20
meters," He explains. "The camera is taking beautiful color pictures
that we're putting together into a global color map to study the
composition of the surface and atmosphere in detail." Bell was also a
member of the Mars Pathfinder team in 1997, and of the NEAR Eros
asteroid orbiter team in 1999-2001. "These have all been fun,
successful and rewarding missions," he says, "but it doesn't always work
out that way…." The Mars Climate Orbiter mission burned up when it
passed too close to Mars in 1999. And on the CONTOUR mission, the
spacecraft broke apart for unexplained reasons shortly after leaving the
Earth's orbit. "Space exploration sure is risky business," says Bell.
Bell is an astronomy professor at Cornell University, an Ivy League
college in the Finger Lakes region, about 4-hours driving distance north
of New York City. He divides his work time between teaching college
courses on astronomy and planetary science, advising and doing research
with undergraduate and graduate students, and pursuing his own
scientific research projects. Bell is particularly interested in using
telescopes and spacecraft to figure out what the surfaces of planets,
moons, asteroids, and comets are made of, and what that can then tell us
about how these places have formed and changed with time. "By studying
other places in our solar system," he explains, "I believe that we can
learn a lot about our own planet that we might not have understood
otherwise."
One of Bell's biggest challenges in taking part in space missions is
trying to balance work and family time. "At home, it seems like I'm
always doing the dishes," he says. "Seriously, my family
responsibilities are also very important, but if you let it, a big
project like MER can take every waking moment of your time." Bell's
wife and kids are supportive of his work, despite the frequent travel
away from home and the many other distractions that impose upon family
life. "I couldn't do this without their support," he says.
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Even though the life of a scientist is a busy one, there's more to
science than measurements and projections—there's also cool equipment!
As a scientist involved in planetary exploration, Bell gets the
opportunity to experience, first-hand, some of NASA's state-of-the-art
technology. "I was very fortunate to get to ride in NASA's KC-135
low-gravity airplane, also known as the 'Vomit Comet,'" says Bell. The
KC-135 is a research aircraft that flies in big parabolic swoops up and
down. At the top of each swoop—as the airplane is going over the top of
its curve like a roller coaster—there's about 30 to 45 seconds of zero
gravity. "It's awesome!" Bell declares. He was a member of a team of
engineers who were performing tests on a component for NASA's CONTOUR
comet flyby mission.
Bell remembers what is was like sitting in the cockpit with the pilot
and co-pilot for one of the parabolas, "It was a little scary, but very
exciting to have a front row seat while this big jet started taking a
downhill dive!" At one point, Bell scrunched down into a fetal position,
and when the gravity went away, he began floating upward; a crewmember
spun him around and around, end over end, about a dozen times. "It was
disorienting and thrilling to be floating and spinning like that!" Bell
says, "and now I know how the Vomit Comet gets its name!"
