Bruce Murray

1931 – 2013

Bruce Churchill Murray, Caltech Professor of Planetary Science, Emeritus, and former head of NASA's Jet Propulsion Laboratory (JPL), succumbed to complications of Alzheimer's disease on August 29, 2013. He was 81.

A founder of planetary science, Murray transformed our understanding of the solar system by applying his geologic training to the study of other worlds. He played a key role in equipping JPL's first Mars missions with cameras, an idea often dismissed at the time as a public relations gimmick; and as JPL's director during the Carter and Reagan administrations, he rescued the Galileo mission to Jupiter and Voyager 2's flybys of Uranus and Neptune from the budget ax.

Murray was born on November 30, 1931, in New York City. His parents moved to California soon after, and he graduated from Santa Monica High in 1949. Upon being refused admission to Caltech—"I got a D in physics my senior year," he explained in his oral history—he enrolled at MIT, emerging in 1955 with a PhD in geology. He married his first wife, Joan O'Brien, in 1954.

After graduating, Murray logged offshore drilling cores for the Standard Oil Company until 1958, when he entered the Air Force to fulfill his ROTC commitment. Assigned to Hanscom Field in Bedford, Massachusetts, Murray helped make the high-precision calculations of the geoid—Earth's gravitational field—needed to aim our ballistic missiles accurately.

When Murray's hitch ended in 1960, Caltech geochemist Harrison Brown hired him as a research fellow to study meteorites. Murray's interests were broader; in 1961, he, Kenneth Watson (MS '59, PhD '64), and Brown showed that significant water might remain on the dust-dry moon, preserved in the permanently shadowed areas near the poles—a prediction not confirmed until 2009. "It was a revolutionary idea," says David Stevenson, Caltech's Marvin J. Goldberger Professor of Planetary Science. "Bruce was the first person to think about the role of ice in the solar system, which is now absolutely fundamental to our understanding of, for example, the moons of Jupiter and Saturn."

A casual conversation would set the course of Murray's career. Soon after arriving on campus, he flew out to Dallas to give his final paper on the geoid. His seatmate led the "special projects" branch out at China Lake, a rocket lab that Caltech and the Navy had set up during World War II, and the special project was a top-secret, highly sensitive infrared detector for the heat-seeking Sidewinder missile. (Infrared light has longer wavelengths than visible light and is emitted by all warm objects.) Murray mentioned a desire to make infrared observations of the moon, "and he said, 'Why don't you come up and see us sometime?' I still had [my security] clearance . . . so I did."

Murray took master instrument builder Jim Westphal (then a senior engineer in geology; later a professor of planetary science) with him. Westphal had no security clearance, so they couldn't discuss the detector in any way. Instead, the Caltech duo specified the hardware and electronics needed to mate a detector to a telescope, and the missile men used those specs to build a "black box" containing the detector—on the condition, of course, that the box remained unopened.

The box blew the socks off civilian technology, and in December 1962, Murray, Westphal, and postdoc Robert Wildey (BS '57, MS '58, PhD '62) mounted it on the 200-inch Hale Telescope at Palomar Observatory to look at Venus while JPL's Mariner 2 made the first-ever flyby of another planet. Venus's cloud-covered face is a blank disk, and the spacecraft carried no camera. Instead, an infrared radiometer would construct a temperature profile of the Venusian atmosphere by scanning perpendicularly across the planet's edge. The plan was simply to check the radiometer data; however, the Hale is designed to peer into deepest space, and Venus is so close that a tiny patch of its surface filled the field of view. Unsure of the radiometer's exact aim, Murray and company methodically scanned the entire planet, recording their readings on a roll of chart paper. Discovering that the scans weren't uniform, they cut them up and laid them side by side across a circle drawn to represent Venus. The resulting temperature map had two cold spots on opposite edges of the circle—Venus's north and south poles—revealing the planet's rotational axis for the first time.

JPL's Mariner 4 did carry a camera on the first-ever flyby of Mars in July 1965. Caltech astronomer Robert Leighton (BS '41, MS '44, PhD '47) led the so-called television experiment team, which included Robert Sharp (BS '34, MS '35), chair of the geology division and an expert on landforms, and Murray, by now Caltech's first associate professor of planetary science. Creating a single image takes an awful lot of pixels, and the camera had to share downlink time with the "real" data—the numbers being returned by the other six instruments. The engineers wanted to minimize the transmission load by encoding the images at 3 bits per pixel, or eight shades of gray. Murray insisted on 8 bits (256 shades)—not exactly high-def, but enough to show geologically interesting details. The resulting pictures of a heavily cratered moonscape destroyed the notion of Mars as a habitable, Earthlike world.

Murray and Leighton then used Mariner's atmospheric data to calculate the regional heat exchange between the surface of Mars and its atmosphere. They found that the poles got cold enough each winter to freeze the carbon-dioxide atmosphere into seasonal caps of dry ice, another revolutionary idea that has since proven true—Mars's atmospheric density varies by some 25 percent over the course of its year.

Murray continued exploring Mars as a TV team member on the Mariner 6 and 7 flybys of 1969 and on Mariner 9, which in 1971 became the first spacecraft to orbit another planet, photographing the entire globe in fine detail—eventually, that is. This Mariner arrived at Mars during the thickest dust storm ever seen, as Murray recounted in his oral history. In the weeks that followed, "there was a gradual clearing, like a stage scene, and three dark spots showed up." As the dust continued to settle, the spots developed into huge craters and slowly became the summits of volcanoes—each one some 10 miles tall and as wide as the state of Missouri. Other photos revealed a rift system, the Valles Marineris, long enough to stretch from San Francisco to Baltimore.

Murray revisited the inner solar system in 1974 as the TV team leader for Mariner 10, which flew by Venus and hitherto unexplored Mercury. By then, JPL could make "color" images by compositing pictures taken through various filters mounted on a wheel in front of the camera. Recent ultraviolet observations of Venus from Earth had found a faint, fast-moving feature resembling a sideways 'Y' that seemed to circle the planet every four days, so Murray persuaded JPL to add an ultraviolet segment to Mariner 10's filter wheel. These ultraviolet images—thousands of them—documented an exquisitely complex collection of markings that traced the circulation patterns in Venus's upper atmosphere.

From April 1, 1976 to June 30, 1982, Murray served as director of JPL—a tenure that balanced the highs of the Viking landings on Mars and the Voyagers' flights by Jupiter and Saturn against the constant battles with Washington to keep the Lab afloat. "He was like Lyndon Johnson. He pushed people hard, and he expressed his opinions forcefully," says Professor of Planetary Science Andrew Ingersoll, the "weatherman" on the Voyagers' atmospheric-science team. "But he never held a grudge; after a disagreement he would just forge ahead. And that's the key: he did forge."

Murray mobilized public support for JPL by cofounding The Planetary Society with Carl Sagan and Louis Friedman in 1980, serving variously as vice president, president, and chairman. "Nowadays, NASA expects every mission to do public outreach. They set aside money for it in the budget, and you have to do it," says David Stevenson. "Back then, it was not required, but Bruce felt very strongly that it was the right thing to do."

"Bruce was really dedicated to exploring the frontiers," concurs Ed Stone, the David Morrisroe Professor of Physics, director of JPL from 1991 to 2001 and Voyager's project scientist. "He recognized the power of scientific imaging, and the opportunity it provided to engage the public."

Murray was a fellow of the American Academy of Arts & Sciences and the American Association for the Advancement of Science, and a member of the American Astronomical Society and the American Geophysical Union. One of his books, Journey Into Space, won two awards for science writing. His other honors include NASA's Exceptional Scientific Achievement Medal, NASA's Distinguished Public Service Medal, and two NASA Distinguished Service Medals.

He is survived by Suzanne, his wife of 41 years; five children; and 10 grandchildren.

A public memorial service will be held at 2:00 p.m. on Sunday, November 10, at the Caltech Athenaeum. 


Douglas Smith
Exclude from News Hub: 
News Type: 
In Our Community
Friday, October 4, 2013

Undergraduate Teaching Assistant Orientation

Monday, August 12, 2013
Cahill, Hameetman Auditorium – Cahill Center for Astronomy and Astrophysics

Magnetic Fields: A Window to a Planet's Interior and Habitability

Seeing Snow in Space

Caltech helps capture the first image of a frosty planetary-disk region

Although it might seem counterintuitive, if you get far enough away from a smoldering young star, you can actually find snow lines—frosty regions where gases are able to freeze and coat dust grains. Astronomers believe that these snow lines are critical to the process of planet formation.

Now an international team of researchers, including Caltech's Geoffrey Blake, has used the Atacama Large Millimeter/submillimeter Array (ALMA) to capture the first image of a snow line around a Sun-like star. The findings appear in the current issue of Science Express.

"This first direct imaging of such internal chemical structures in an analog of the young solar nebula was made possible by the extraordinary sensitivity and resolution of the not-yet-completed ALMA and builds on decades of pioneering research in millimeter-wave interferometry at the Caltech Owens Valley Radio Observatory, by universities now part of the Combined Array for Research in Millimeter-wave Astronomy, and by the Harvard-Smithsonian Submillimeter Array," says Blake, a professor of cosmochemistry and planetary science and professor of chemistry at Caltech. "The role of these facilities, in research, in technology development, and in education, along the road to ALMA cannot be overstated."

Since different gases freeze at different distances from the star, snow lines are thought to exist as concentric rings of grains encased in the various frozen gases—a ring of grains coated with water ice, a ring of grains coated with carbon dioxide, and so on. They might speed up planet formation by providing a source of solid material and by coating and protecting dust grains that would normally collide with one another and break apart.

Earlier this year, Blake and his group used spectrometers onboard the Spitzer Space Telescope and Herschel Space Observatory to constrain the location of the water snow line in a star known as TW Hydrae. The star is of particular interest because it is the nearest example of a gas- and dust-rich protoplanetary disk that may show similarities to our own solar system at an age of only 10 million years.

Snow lines have escaped direct imaging up until this point because of the obscuring effect of the hot gases that exist above and below them. But thanks to work at the Harvard-Smithsonian Submillimeter Array and at Caltech, the team had a good idea of where to begin looking. Additionally, the lead authors of the new paper, Chunhua "Charlie" Qi (PhD '01), now of the Harvard-Smithsonian Center for Astrophysics, and Karin Öberg (BS '05), currently at Harvard University, figured out a novel way to trace the presence of frozen carbon monoxide—a trick that enabled them to use ALMA to chemically highlight TW Hydrae's carbon monoxide snow line.

"The images from ALMA spectacularly confirm the presence of snow lines in disks," Blake says. "We are eagerly looking forward to additional studies with the full ALMA telescope—especially those targeting less volatile species such as water and organics that are critical to habitability."

The paper is titled "Imaging of the CO snow line in a solar nebula analog." A full press release about the work can be found here.

Kimm Fesenmaier
Exclude from News Hub: 
News Type: 
Research News

Evidence for a Martian Ocean

Researchers at the California Institute of Technology (Caltech) have discovered evidence for an ancient delta on Mars where a river might once have emptied into a vast ocean.

This ocean, if it existed, could have covered much of Mars's northern hemisphere—stretching over as much as a third of the planet.

"Scientists have long hypothesized that the northern lowlands of Mars are a dried-up ocean bottom, but no one yet has found the smoking gun," says Mike Lamb, an assistant professor of geology at Caltech and a coauthor of the paper describing the results. The paper was published online in the July 12 issue of the Journal of Geophysical Research.

Although the new findings are far from proof of the existence of an ancient ocean, they provide some of the strongest support yet, says Roman DiBiase, a postdoctoral scholar at Caltech and lead author of the paper.

Most of the northern hemisphere of Mars is flat and at a lower elevation than the southern hemisphere, and thus appears similar to the ocean basins found on Earth. The border between the lowlands and the highlands would have been the coastline for the hypothetical ocean.

The Caltech team used new high-resolution images from the Mars Reconnaissance Orbiter (MRO) to study a 100-square-kilometer area that sits right on this possible former coastline. Previous satellite images have shown that this area—part of a larger region called Aeolis Dorsa, which is about 1,000 kilometers away from Gale Crater where the Curiosity rover is now roaming—is covered in ridge-like features called inverted channels.

These inverted channels form when coarse materials like large gravel and cobbles are carried along rivers and deposited at their bottoms, building up over time. After the river dries up, the finer material—such as smaller grains of clay, silt, and sand—around the river erodes away, leaving behind the coarser stuff. This remaining sediment appears as today's ridge-like features, tracing the former river system.

When looked at from above, the inverted channels appear to fan out, a configuration that suggests one of three possible origins: the channels could have once been a drainage system in which streams and creeks flowed down a mountain and converged to form a larger river; the water could have flowed in the other direction, creating an alluvial fan, in which a single river channel branches into multiple smaller streams and creeks; or the channels are actually part of a delta, which is similar to an alluvial fan except that the smaller streams and creeks empty into a larger body of water such as an ocean.

To figure out which of these scenarios was most likely, the researchers turned to satellite images taken by the HiRISE camera on MRO. By taking pictures from different points in its orbit, the spacecraft was able to make stereo images that have allowed scientists to determine the topography of the martian surface. The HiRISE camera can pick out features as tiny as 25 centimeters long on the surface and the topographic data can distinguish changes in elevation at a resolution of 1 meter.

Using this data, the Caltech researchers analyzed the stratigraphic layers of the inverted channels, piecing together the history of how sediments were deposited along these ancient rivers and streams. The team was able to determine the slopes of the channels back when water was still coursing through them. Such slope measurements can reveal the direction of water flow—in this case, showing that the water was spreading out instead of converging, meaning the channels were part of an alluvial fan or a delta.

But the researchers also found evidence for an abrupt increase in slope of the sedimentary beds near the downstream end of the channels. That sort of steep slope is most common when a stream empties into a large body of water—suggesting that the channels are part of a delta and not an alluvial fan.

Scientists have discovered martian deltas before, but most are inside a geological boundary, like a crater. Water therefore would have most likely flowed into a lake enclosed by such a boundary and so did not provide evidence for an ocean.

But the newly discovered delta is not inside a crater or other confining boundary, suggesting that the water likely emptied into a large body of water like an ocean. "This is probably one of the most convincing pieces of evidence of a delta in an unconfined region—and a delta points to the existence of a large body of water in the northern hemisphere of Mars," DiBiase says. This large body of water could be the ocean that has been hypothesized to have covered a third of the planet. At the very least, the researchers say, the water would have covered the entire Aerolis Dorsa region, which spans about 100,000 square kilometers.

Of course, there are still other possible explanations. It is plausible, for instance, that at one time there was a confining boundary—such as a large crater—that was later erased, Lamb adds. But that would require a rather substantial geological process and would mean that the martian surface was more geologically active than has been previously thought.

The next step, the researchers say, is to continue exploring the boundary between the southern highlands and northern lowlands—the hypothetical ocean coastline—and analyze other sedimentary deposits to see if they yield more evidence for an ocean. 

"In our work and that of others—including the Curiosity rover—scientists are finding a rich sedimentary record on Mars that is revealing its past environments, which include rain, flowing water, rivers, deltas, and potentially oceans," Lamb says. "Both the ancient environments on Mars and the planet's sedimentary archive of these environments are turning out to be surprisingly Earth-like."

The title of the Journal of Geophysical Research paper is "Deltaic deposits at Aeolis Dorsa: Sedimentary evidence for a standing body of water on the northern plains of Mars." In addition to DiBiase and Lamb, the other authors of the paper are graduate students Ajay Limaye and Joel Scheingross, and Woodward Fischer, assistant professor of geobiology. This research was supported by the National Science Foundation, NASA, and Caltech.

Marcus Woo
Exclude from News Hub: 
News Type: 
Research News
Thursday, September 26, 2013

Graduate TA Orientation & Teaching Conference

A Stepping-Stone for Oxygen on Earth

Caltech researchers find evidence of an early manganese-oxidizing photosystem

For most terrestrial life on Earth, oxygen is necessary for survival. But the planet's atmosphere did not always contain this life-sustaining substance, and one of science's greatest mysteries is how and when oxygenic photosynthesis—the process responsible for producing oxygen on Earth through the splitting of water molecules—first began. Now, a team led by geobiologists at the California Institute of Technology (Caltech) has found evidence of a precursor photosystem involving manganese that predates cyanobacteria, the first group of organisms to release oxygen into the environment via photosynthesis.  

The findings, outlined in the June 24 early edition of the Proceedings of the National Academy of Sciences (PNAS), strongly support the idea that manganese oxidation—which, despite the name, is a chemical reaction that does not have to involve oxygen—provided an evolutionary stepping-stone for the development of water-oxidizing photosynthesis in cyanobacteria.

"Water-oxidizing or water-splitting photosynthesis was invented by cyanobacteria approximately 2.4 billion years ago and then borrowed by other groups of organisms thereafter," explains Woodward Fischer, assistant professor of geobiology at Caltech and a coauthor of the study. "Algae borrowed this photosynthetic system from cyanobacteria, and plants are just a group of algae that took photosynthesis on land, so we think with this finding we're looking at the inception of the molecular machinery that would give rise to oxygen."

Photosynthesis is the process by which energy from the sun is used by plants and other organisms to split water and carbon dioxide molecules to make carbohydrates and oxygen. Manganese is required for water splitting to work, so when scientists began to wonder what evolutionary steps may have led up to an oxygenated atmosphere on Earth, they started to look for evidence of manganese-oxidizing photosynthesis prior to cyanobacteria. Since oxidation simply involves the transfer of electrons to increase the charge on an atom—and this can be accomplished using light or O2—it could have occurred before the rise of oxygen on this planet.

"Manganese plays an essential role in modern biological water splitting as a necessary catalyst in the process, so manganese-oxidizing photosynthesis makes sense as a potential transitional photosystem," says Jena Johnson, a graduate student in Fischer's laboratory at Caltech and lead author of the study.

To test the hypothesis that manganese-based photosynthesis occurred prior to the evolution of oxygenic cyanobacteria, the researchers examined drill cores (newly obtained by the Agouron Institute) from 2.415 billion-year-old South African marine sedimentary rocks with large deposits of manganese.

Manganese is soluble in seawater. Indeed, if there are no strong oxidants around to accept electrons from the manganese, it will remain aqueous, Fischer explains, but the second it is oxidized, or loses electrons, manganese precipitates, forming a solid that can become concentrated within seafloor sediments.

"Just the observation of these large enrichments—16 percent manganese in some samples—provided a strong implication that the manganese had been oxidized, but this required confirmation," he says.

To prove that the manganese was originally part of the South African rock and not deposited there later by hydrothermal fluids or some other phenomena, Johnson and colleagues developed and employed techniques that allowed the team to assess the abundance and oxidation state of manganese-bearing minerals at a very tiny scale of 2 microns.

"And it's warranted—these rocks are complicated at a micron scale!" Fischer says. "And yet, the rocks occupy hundreds of meters of stratigraphy across hundreds of square kilometers of ocean basin, so you need to be able to work between many scales—very detailed ones, but also across the whole deposit to understand the ancient environmental processes at work."

Using these multiscale approaches, Johnson and colleagues demonstrated that the manganese was original to the rocks and first deposited in sediments as manganese oxides, and that manganese oxidation occurred over a broad swath of the ancient marine basin during the entire timescale captured by the drill cores.

"It's really amazing to be able to use X-ray techniques to look back into the rock record and use the chemical observations on the microscale to shed light on some of the fundamental processes and mechanisms that occurred billions of years ago," says Samuel Webb, coauthor on the paper and beam line scientist at the SLAC National Accelerator Laboratory at Stanford University, where many of the study's experiments took place. "Questions regarding the evolution of the photosynthetic pathway and the subsequent rise of oxygen in the atmosphere are critical for understanding not only the history of our own planet, but also the basics of how biology has perfected the process of photosynthesis."

Once the team confirmed that the manganese had been deposited as an oxide phase when the rock was first forming, they checked to see if these manganese oxides were actually formed before water-splitting photosynthesis or if they formed after as a result of reactions with oxygen. They used two different techniques to check whether oxygen was present. It was not—proving that water-splitting photosynthesis had not yet evolved at that point in time. The manganese in the deposits had indeed been oxidized and deposited before the appearance of water-splitting cyanobacteria. This implies, the researchers say, that manganese-oxidizing photosynthesis was a stepping-stone for oxygen-producing, water-splitting photosynthesis.

"I think that there will be a number of additional experiments that people will now attempt to try and reverse engineer a manganese photosynthetic photosystem or cell," Fischer says. "Once you know that this happened, it all of a sudden gives you reason to take more seriously an experimental program aimed at asking, 'Can we make a photosystem that's able to oxidize manganese but doesn't then go on to split water? How does it behave, and what is its chemistry?' Even though we know what modern water splitting is and what it looks like, we still don't know exactly how it works. There is still a major discovery to be made to find out exactly how the catalysis works, and now knowing where this machinery comes from may open new perspectives into its function—an understanding that could help target technologies for energy production from artificial photosynthesis. "

Next up in Fischer's lab, Johnson plans to work with others to try and mutate a cyanobacteria to "go backwards" and perform manganese-oxidizing photosynthesis. The team also plans to investigate a set of rocks from western Australia that are similar in age to the samples used in the current study and may also contain beds of manganese. If their current study results are truly an indication of manganese-oxidizing photosynthesis, they say, there should be evidence of the same processes in other parts of the world.

"Oxygen is the backdrop on which this story is playing out on, but really, this is a tale of the evolution of this very intense metabolism that happened once—an evolutionary singularity that transformed the planet," Fischer says. "We've provided insight into how the evolution of one of these remarkable molecular machines led up to the oxidation of our planet's atmosphere, and now we're going to follow up on all angles of our findings."

Funding for the research outlined in the PNAS paper, titled "Manganese-oxidizing photosynthesis before the rise of cyanobacteria," was provided by the Agouron Institute, NASA's Exobiology Branch, the David and Lucile Packard Foundation, and the National Science Foundation Graduate Research Fellowship program. Joseph Kirschvink, Nico and Marilyn Van Wingen Professor of Geobiology at Caltech, also contributed to the study along with Katherine Thomas and Shuhei Ono from the Massachusetts Institute of Technology.

Katie Neith
Exclude from News Hub: 
News Type: 
Research News
bbell2's picture

Bethany Ehlmann Selected as National Geographic Emerging Explorer

National Geographic Society has named Bethany Ehlmann, assistant professor of planetary science at the California Institute of Technology (Caltech), a 2013 Emerging Explorer. Ehlmann joins 16 other young scientists, educators, artists, and entrepreneurs recognized by National Geographic for making an impact on the world while still in the early stages of their careers.

Ehlmann accepted her award at the Emerging Explorers Symposium in Washington, D.C., on June 12. The symposium was part of the society's 125th anniversary celebration running June 10-14.

None of the 2013 awardees can claim more distant explorations than Ehlmann. As a planetary scientist at Caltech and a Jet Propulsion Laboratory (JPL) research scientist, she is one of the investigators on NASA's Mars Curiosity mission. From a distance of tens of millions of kilometers, Ehlmann helps direct Curiosity's explorations and zaps Martian rocks and soils with its ChemCam laser spectrometer instrument in order to analyze their mineral and chemical compositions. Ehlmann uses data collected by orbiters and rovers in a search for clues about past Martian environments and whether Mars has ever been hospitable to living organisms.

Back on planet Earth, Ehlmann is a frequent visitor to remote, rocky, and extreme locales—places like the deserts of California and the Middle East or the sides of Icelandic volcanoes—that provide the closest terrestrial counterparts to the surfaces and geologic processes of distant planets.

"I am very honored to have been recognized by National Geographic as an Emerging Explorer," Ehlmann says. "I've long been a follower and avid fan of the society's mission of exploration and discovery and am excited to join its family of explorers. It's an amazing group."

The Emerging Explorers Program "recognizes and supports uniquely gifted and inspiring adventurers, scientists, and innovators who are at the forefront of discovery, adventure, and global problem-solving while still early in their careers," according to a statement issued by the National Geographic Society. Emerging Explorers are profiled in National Geographic magazine and receive a $10,000 award to assist with research and further exploration.


Brian Bell
Home Page Title: 
Ehlmann Named Emerging Explorer
Listing Title: 
Ehlmann Named Emerging Explorer
Exclude from News Hub: 

Brown, Farley, and Seinfeld Elected to National Academy of Sciences

Based on their distinguished achievements in original research, three Caltech professors—Mike Brown, Ken Farley, and John Seinfeld—are among the 84 members and 21 foreign associates newly elected to the National Academy of Sciences. The announcement was made this week at the 150th annual meeting of the academy in Washington, D.C.

The three new elections bring the number of living Caltech faculty members who belong to the academy to 73, including four foreign associates. In addition, three current members of the Caltech Board of Trustees are academy members.

In total, there are now 2,179 active members and 437 foreign associates of the National Academy of Sciences.


Michael E. Brown, the Richard and Barbara Rosenberg Professor and professor of planetary astronomy

Mike Brown is known for discovering and characterizing bodies at the edge of the solar system. In 2005, he discovered a Kuiper-belt object, later named Eris, which is about the same size as Pluto but 27 percent more massive. That finding led to a scientific debate over how to define a planet, and to the eventual demotion of Pluto to "dwarf planet."

Brown received his undergraduate degree from Princeton University in 1987 and did his graduate work at UC Berkeley, completing his PhD in 1994. He came to Caltech as a visiting associate in 1995 and joined the faculty in 1997. Brown became a full professor in 2005 and was named the Rosenberg Professor in 2008.

Brown has won numerous awards for his work, including the 2001 Harold C. Urey Prize from the American Astronomical Society's Division for Planetary Sciences, a Presidential Early Career Award, a Sloan Research Fellowship, and the 2012 Kavli Prize in Astrophysics.


Kenneth A. Farley, chair of the Division of Geological and Planetary Sciences and the W. M. Keck Foundation Professor of Geochemistry

Ken Farley is recognized for his studies of the noble gases and what their concentrations in marine sediments, rocks, minerals, and seawater can tell us about geochemical processes and the timescales over which these processes have operated. He is also currently a participating scientist on NASA's Mars Science Laboratory rover mission.

Farley received a BS from Yale University in 1986 and a PhD from UC San Diego in 1991. He joined the Caltech faculty in 1993 and was appointed professor in 1998. Farley was named the Keck Foundation Professor in 2003, the same year he served as director of the Tectonics Observatory. He became division chair in 2004.

His distinctions include the 1999 James B. Macelwane Medal of the American Geophysical Union, the 2000 National Academy of Science Award for Initiatives in Research, and the 2008 Arthur L. Day Medal from the Geological Society of America, and he was named a 2013 Geochemical Fellow by the Geochemical Society and the European Association of Geochemistry.


John H. Seinfeld, the Louis E. Nohl Professor and professor of chemical engineering

John Seinfeld's work has greatly improved our understanding of the origin, chemistry, and evolution of particles, or aerosols, in the atmosphere. He has revealed the role of organic species in aerosols and the process by which vapor molecules become incorporated into particles. Today, his work continues to focus on large questions such as the effects of aerosols on cloud formation and Earth's climate.

Seinfeld received his BS from the University of Rochester in 1964 and his PhD from Princeton University in 1967. He joined the faculty at Caltech that same year, becoming a full professor in 1974 and the Nohl Professor in 1979. He served as executive officer for chemical engineering from 1974 until 1990 and was chair of the Division of Engineering and Applied Science from 1990 until 2000.

Seinfeld is a member of the National Academy of Engineering and a fellow of the American Academy of Arts and Sciences. Among other distinctions, he won the Tyler Prize for Environmental Achievement in 2012, the American Chemical Society's Award for Creative Advances in Environmental Science and Technology in 1993, the Fuchs Award in 1998, the Nevada Medal in 2001, and the Stodola Medal from the Swiss Federal Institute of Technology in 2008. He has also received honorary doctorates from the University of Patras, Carnegie Mellon University, and Clarkson University.


The National Academy of Sciences is a private, nonprofit honorific society of distinguished scholars engaged in scientific and engineering research, dedicated to the furthering of science and technology and to their use for the general welfare. Established in 1863, the National Academy of Sciences has served to "investigate, examine, experiment, and report upon any subject of science or art" whenever called upon to do so by any department of the government.

For more information about the academy, or for the full list of newly elected members, visit www.nationalacademies.orgFor an extensive list of Caltech awards and honors, visit

Kimm Fesenmaier
Exclude from News Hub: 
News Type: 
In Our Community

Mars Science Laboratory: The Search for Habitable Environments

Watson Lecture Preview

John Grotzinger, Caltech's Fletcher Jones Professor of Geology, is the project scientist for JPL's newest Mars rover—Curiosity, the Mars Science Laboratory. The rover is exploring the floor of Gale Crater, and Grotzinger will describe its discoveries so far during a free public lecture at 8 p.m. on Wednesday, April 24, in Caltech's Beckman Auditorium.


Q: What do you do?

A: I oversee the science team and the way that it interfaces with the engineering team. I started back in 2007 when all the instruments on the rover were still in development. We had to test them all individually and then test how they performed with the rover. There were reviews every step of the way as the instruments were completed and certified for flight. This was a totally different experience for me; getting involved with the mission in the very early stages of development and seeing what goes into the whole process has been the most intense learning experience of my career. I went from having a few graduate students and postdocs to suddenly trying to lead a group of 400 scientists and engineers.

After we launched, the science team spent the next eight months practicing how to use the instruments, and now I'm basically helping work out the path of discovery. We work as a group to figure out what we're going to do with the rover each day. There are probably a dozen meetings in a typical day, of which I attend four to six. For me, the highlight of each day is the science discussion, where we have a two-hour block of time in which different team members present all the science data that we've got, and we just talk about it. It's a lot of fun.


Q: Aside from the fact that you're driving around on Mars, which is just inherently cool, what's the best thing about what you do?

A: Nobody ever before has seen what we're seeing. Every day new data arrive. New images of the terrain we're in the course of discovering; new measurements from the analytical instruments. (Mars is behind the sun right now, so we aren't getting any new data, but we should regain contact around the first of May.) The downlink's timing is based on the sol—the Martian day, which is 39 minutes longer than an Earth day—so some days we wake up and the data have arrived hours earlier. Other times, when the data come down later in the day, all the team members who are physically at JPL gather in one or two rooms where the downlink is actually happening. Those hours, days, are really an amazing experience because we really are going where nobody has gone before. And that's pretty special.


Q: How did you get into this line of work?

A: In 2003, I got involved with the Mars Exploration Rovers as one of the long-term planning leads. I was at MIT at the time, but I came out to JPL for a year to do that. Two years later, I joined Caltech's geobiology group. What we do on Mars is pretty much what I do on Earth with my students—investigate rocks that are billions of years old and look for evidence of habitable environments. I went to college to be a biologist. I changed majors to chemistry and then finally went into geology.

Geology represents this great nexus of physics and chemistry and biology and math. You get to do it all at the same time, and if you do field geology you get to do it outdoors.



Named for the late Caltech professor Earnest C. Watson, who founded the series in 1922, the Watson Lectures present Caltech and JPL researchers describing their work to the public. Many past Watson Lectures are available online at Caltech's iTunes U site.

Douglas Smith
Listing Title: 
Watson Lecture: "Mars Science Laboratory: The Search for Habitable Environments"
Exclude from News Hub: 
News Type: 
In Our Community