Franklin & Marshall graduates and faculty star at the forefront of Mars research
Evening twilight gives way to darkness on a warm, summer evening in central Pennsylvania. Fireflies perform their nightly light show as crickets play a peaceful summer soundtrack. High above Earth, the clear nighttime sky glitters with stars. It is a perfect night for stargazing.
But this is a special night. In a few hours, a meteor shower will present one of nature's most spectacular events. Hearing the news—and not about to miss the celestial show—a young girl convinces her sister to sleep outside for the evening. The two children marvel as meteoroids enter the atmosphere and burn in fast-moving streaks of light.
It is a fond memory for Melissa Lane, Ph.D., '87, the girl who did the convincing. Lane still looks skyward today, having turned most of her attention to the planet Mars. But instead of camping in her backyard, she has set up shop as a senior scientist with the Planetary Science Institute (PSI) in Arizona. She uses thermal emission spectroscopy to determine the mineral composition of rocks on the Red Planet (or, as she says, the Ocher Planet).
Lane is one of a handful of Franklin & Marshall graduates who have carved out careers in the booming field of Mars research. Martha Gilmore, Ph.D., '91, associate professor of Earth & Environ-mental Sciences at Wesleyan University, is a planetary geologist whose specialty is Mars. Rebecca Eby Williams, Ph.D., '95 compares landforms on Earth to those on Mars as a research scientist with PSI. And Jake Bleacher, Ph.D., '00, a planetary geologist at NASA's Goddard Space Flight Center, has collaborated with F&M's Associate Professor of Geosciences Andy de Wet to determine whether particular features on Mars were created by water or flowing lava.
F&M's Mars explorers descended on Houston in March for the 41st annual Lunar and Planetary Science Conference (LPSC), a hallmark event each year for planetary scientists. They are among the stars in their field. Now at the forefront of Mars research, the alumni unfailingly credit F&M for the strong foundation upon which they have launched their careers.
"For undergraduate geology, F&M is one of the top schools in the country," Bleacher says. "The Geology Department gave me a lot of experience out in the field, and F&M in general taught me how to write. People I've encountered in my career, respected people in our field, really know F&M."
A Fascinating PuzzleEven with a childhood interest in space, Lane did not know she wanted to become a planetary scientist until well after college. In fact, she enrolled at F&M with intentions of becominga pre-med student.
"It was a bit of a left turn," Lane says. "I was encouraged to take a geology course by my sophomore year room-mate, Mary Cademartori '87. The last thing I needed was another lab course. But I took it and found an immediate love. I was enthralled by it and enjoyed the field trips. It was just a good fit for me."
After graduating from F&M, Lane landed at the Duke University Marine Laboratory as a research technician. During her time there, she took a trip to St. Louis, to visit her friend from F&M, Jennifer Smith Boylan '87, who was a graduate student at Washington University in St. Louis and to attend a meeting of the Geological Society of America that was also in St. Louis. There, Lane was introduced by Boylan to her friend Jeff Plaut of NASA's Jet Propulsion Laboratory.
"As he was describing his research, I said, 'This is what I love,'" Lane says. "With his guidance, I decided to pursue a Ph.D. in planetary science. Certain people and events pushed me in that direction. But it must have been stewing inside me since I was a kid."
Now Lane is trying to figure out what is stewing inside Mars. Her research explores thermal emission spectroscopy and its potential for mineral identification on Mars using data from the Mars Global Surveyor Thermal Emission Spectrometer (TES). Along with Williams, she is also a participating scientist on the team of the Mars Odyssey Thermal Emission Imaging System (THEMIS). TES and THEMIS are complementary tools and the data sets are used in concert, Lane says.
"We measure the heat the planet is emitting and pay particular attention to the absorption features in the data that tell us about the minerals that are on the surface," Lane says. "When we first started to interpret and understand the data, it felt so wonderful. We saw huge areas of Mars with coarse hematite, which forms in water. With each new discovery I thought, 'Wow, I am one of the few people on Earth who know about this.'"
Lane stresses that patience plays a large role in the work of planetary geologists because it takes a long time to gather data from orbit or by rovers and because "we can't just hop up there and pick up a rock," she says. "On Earth, geologists constantly use rock hammers to examine the inside of weathered rocks. On Mars, we can't get a clear view of the pristine rock because everything is covered with dust. It's a big puzzle, and that is what's fascinating."
Lane was particularly fascinated when a Mars rover collecting data on the planet's surface suffered a broken wheel. By chance, the damaged wheel uncovered white soil as it dragged across the surface. "The white soil was iron sulfate, which only occurs in acidic environments," she says. "Everyone had been predicting lots of carbonates on Mars, which form in alkaline environments. It was a real 'aha' moment and changed all of our expectations about which minerals we'd find and what the conditions were on Mars.
"Mars is full of surprises, and it will continue to be that way."
The Ancient History of WaterGilmore's path to planetary science began on the F&M campus—when she was 12. For three consecutive years, she attended summer programs with the John Hopkins University's Center for Talented Youth (CTY), which still takes place at the College each summer.
"I wanted to be an astronomer," Gilmore says. "At CTY, I took astronomy and geology courses. One year, we went on a field trip to West Virginia, where I mentioned that I wanted to study the geology of other planets. The instructor said, 'There's a field that allows you to do that.'"
From there, Gilmore knew she wanted to become a planetary geologist. A few years later, she returned to F&M as a transfer student prior to her junior year of college. "I knew what I wanted to do for my career, but I didn't know how wonderful F&M's geology program was and is. They trained me very well."
Early in her career, Gilmore spent most of her time focusing on another planet in our solar system—Earth's inner neighbor, Venus. After earning her Ph.D. from Brown University, she worked at NASA's Jet Propulsion Laboratory before landing at Wesleyan in 2000.
The Mars Pathfinder mission in 1997 opened up a new world of research for Gilmore and her colleagues. "As planetary geologists, we go to where the data is," she says. "All of these data sets, cameras and spectrometers represent a great leap forward. It's led to a revolution in the understanding of Mars."
Gilmore is interested in the history of water on Mars, a popular topic in space science in recent years. She combines satellite photography with infrared imaging to explore areas where large bodies of water might have existed. Determining the mineralogy of rocks enables Gilmore to figure out where the rocks came from and whether water played a role in their history.
"It's wonderful to be able to monitor the ancient history of water," Gilmore says. "We know there were multiple episodes of water on Mars but have no idea of the amounts. I'm trying to figure out how much water was there and how long it persisted."
Gilmore also is developing software for Mars rovers. The software would help the rovers to recognize minerals during their travels and contact scientists on Earth to let them know about it. Similar instruments currently detect dust devils on Mars.
Still, Gilmore says the ultimate goal is for humans to collect samples of Martian soil and rock. "Much of our understanding of the Earth results from rock analysis," she says. "We know a great deal about the moon because of the rocks returned by the Apollo program. The ideal is to have a Mars sample return.This summer, Gilmore is participating in the Planetary Science Decadal Survey, a NASA initiative to determine the state of planetary science and plan future space missions. As a member of one of the survey's panels, she is helping to shape the next 10 years of American space exploration.
Searching for Clues on EarthFor Williams, the best way to understand Mars is to travel to Utah, the Mojave Desert or even a remote location in northeast Australia. Anywhere, really, that has landforms similar to those on the Red Planet. As a planetary geologist specializing in fluvial geomorphology, Williams scours Earth to piece together the history of water on Mars.
"We've recognized a much larger history of flowing water on Mars," says Williams, a participating scientist with the THEMIS instrument aboard Mars Odyssey. "But we're still sorting out oscillations in climate to figure out when water could have existed. We want to understand when it flowed and for how long."
Of particular interest to Williams is inverted topography, especially river channels and valleys. Erosion can produce inverted landforms if a valley floor is more resistant to wear than its surrounding walls. "I'm interested in all kinds of water-carved landforms," she says. "In my first job out of graduate school, I was targeting one of the cameras capturing images of Mars. I kept seeing landforms that resembled river formations, but they also looked like ridges."
Williams decided to study similar landforms in Utah, thanks to a conversation with her father, David Eby, Ph.D., '69, a geologist and owner of Eby Petrography & Consulting based in Colorado. "My dad said, 'Oh, yeah, we've seen inverted river channels in Utah,'" she says. "We got to work together. It's fun to boss your dad around and tell him to go and measure something. But I wanted to be clear about our differences. I would say, 'No, Dad, you do Earth, and I do Mars.'"
The experience brought Williams full circle from her days as an undergraduate at F&M, when she intended to major in physics. "I took a geo class to appease my father, and it turned into my major," she says. "Things came more into focus, and I spent all my time in Pfieffer (now the Hackman Physical Sciences Building). F&M gave me the tools to do my work in the field."
Last fall, Williams expanded on her research in Utah by making the multi-day journey to a remote location on Cape York Peninsula, the northernmost point on mainland Australia. Battling thick vegetation and numerous wild critters, she was successful in finding rock outcrops with cemented stream sediments.
The trip to Australia reinforced Williams' belief that there is no substitute for taking in-person measurements. For this reason, she is cautiously optimistic about President Barack Obama's plan to focus on space exploration beyond the moon.
"I think the new path could re-establish American leadership in space," she says. "I hope we're moving closer to sending humans to Mars, but it would take a huge commitment. I do hope manned exploration of terrestrial planets occurs. We'd learn so much, so quickly."
The Curious Case of Lava
Even if a feature on Mars looks like it was created by water, it does not rule out other possibilities. Just ask Jake Bleacher '00 and Andy de Wet, who have spent countless hours examining a channel on the southwest flank of Mars' Ascraeus Mons volcano. One of three clustered volcanoes collectively called the Tharsis Montes, it was thought to be clear evidence of water-based erosion on the planet.
Bleacher and de Wet, however, suggest that lava built the channel. They presented the results of their study at the LPSC in Houston in March.
"NASA is looking for habitable places in the solar system and that requires water," Bleacher says. "On Mars, we're looking for places where water might have flowed as a liquid. But we have to be cautious because some people have jumped to conclusions. We're taking a step back to make sure we have the right conclusion."
Bleacher, who majored in geology at F&M, has forged a professional collaboration in recent years with his undergraduate adviser, de Wet. The F&M connection grew deeper in 2008, when Michele Trumble '08 interned at Goddard with Bleacher and worked on the same project. "Michele helped to map part of the channel as more images came together," Bleacher says.
The debate over water and lava on Mars has been occurring since the first images from Mars arrived on Earth, Bleacher says. When de Wet continued Trumble's work last year and realized that lava likely created the channel, members of the Franklin & Marshall community contributed to the debate.
"As more images were sent down to NASA and processed, we could see that what initially looked like river channels were clearly volcanic in nature," de Wet says. "It became pretty obvious as I downloaded the images. We're not saying there was no water on Mars, just that this particular feature was not formed by water."
When he is not examining ancient Martian lava channels, Bleacher spends much of his time in the field with NASA's Desert Research and Technology Studies (D-RATS). The D-RATS are a team of engineers and research partners working to prepare for human-robotic exploration by testing operational concepts for rovers and ground support. Most of his field research takes place on lava flows in New Mexico, Arizona, Hawaii and the Mojave Desert.
Bleacher says his career has come full circle, especially after working with Trumble. He remembers a day when an F&M graduate returned to campus and influenced his own career decision while giving a presentation to the department. That person was Martha Gilmore.