Caltech Scientists Predict Greater Longevity for Planets with Life

Billion-year life extension for Earth also doubles the odds that advanced life will be found elsewhere in the universe

PASADENA, Calif.- Roughly a billion years from now, the ever-increasing radiation from the sun will have heated Earth into uninhabitability; the carbon dioxide in the atmosphere that serves as food for plant life will disappear, pulled out by the weathering of rocks; the oceans will evaporate; and all living things will disappear.

Or maybe not quite so soon, say researchers from the California Institute of Technology (Caltech), who have come up with a mechanism that doubles the future lifespan of the biosphere—while also increasing the chance that advanced life will be found elsewhere in the universe.

A paper describing their hypothesis was published June 1 in the early online edition of the Proceedings of the National Academy of Science.

Earth maintains its surface temperatures through the greenhouse effect. Although the planet's greenhouse gases—chiefly water vapor, carbon dioxide, and methane-have become the villain in global warming scenarios, they're crucial for a habitable world, because they act as an insulating blanket in the atmosphere that absorbs and radiates thermal radiation, keeping the surface comfortably warm.

As the sun has matured over the past 4.5 billion years, it has become both brighter and hotter, increasing the amount of solar radiation received by Earth, along with surface temperatures. Earth has coped by reducing the amount of carbon dioxide in the atmosphere, thus reducing the warming effect. (Despite current concerns about rising carbon dioxide levels triggering detrimental climate change, the pressure of carbon dioxide in the atmosphere has dropped some 2,000-fold over the past 3.5 billion years; modern, man-made increases in atmospheric carbon dioxide offset a fraction of this overall decrease.)

The problem, says Joseph L. Kirschvink, the Nico and Marilyn Van Wingen Professor of Geobiology at Caltech and a coauthor of the PNAS paper, is that "we're nearing the point where there's not enough carbon dioxide left to regulate temperatures following the same procedures."

Kirschvink and his collaborators Yuk L. Yung, a Caltech professor of planetary science, and graduate students King-Fai Li and Kaveh Pahlevan, say that the solution is to reduce substantially the total pressure of the atmosphere itself, by removing massive amounts of molecular nitrogen, the largely nonreactive gas that makes up about 78 percent of the atmosphere. This would regulate the surface temperatures and allow carbon dioxide to remain in the atmosphere, to support life, and could tack an additional 1.3 billion years onto Earth's expected lifespan.

In the "blanket" analogy for greenhouse gases, carbon dioxide would be represented by the cotton fibers making up the blanket. "The cotton weave may have holes, which allow heat to leak out," explains Li, the lead author of the paper.

"The size of the holes is controlled by pressure," Yung says. "Squeeze the blanket," by increasing the atmospheric pressure, "and the holes become smaller, so less heat can escape. With less pressure, the holes become larger, and more heat can escape," he says, helping the planet to shed the extra heat generated by a more luminous sun.

Strikingly, no external influence would be necessary to take nitrogen out of the air, the scientists say. Instead, the biosphere itself would accomplish this, because nitrogen is incorporated into the cells of organisms as they grow, and is buried with them when they die.

In fact, "this reduction of nitrogen is something that may already be happening," says Pahlevan, and that has occurred over the course of Earth's history. This suggests that Earth's atmospheric pressure may be lower now than it was earlier in the planet's history.

Proof of this hypothesis may come from other research groups that are examining the gas bubbles formed in ancient lavas to determine past atmospheric pressure: the maximum size of a forming bubble is constrained by the amount of atmospheric pressure, with higher pressures producing smaller bubbles, and vice versa.

If true, the mechanism also would potentially occur on any extrasolar planet with an atmosphere and a biosphere.

"Hopefully, in the future we will not only detect earth-like planets around other stars but learn something about their atmospheres and the ambient pressures," Pahlevan says. "And if it turns out that older planets tend to have thinner atmospheres, it would be an indication that this process has some universality."

Adds Yung: "We can't wait for the experiment to occur on Earth. It would take too long. But if we study exoplanets, maybe we will see it. Maybe the experiment has already been done."

Increasing the lifespan of our biosphere—from roughly 1 billion to 2.3 billion years—has intriguing implications for the search for life elsewhere in the universe. The length of the existence of advanced life is a variable in the Drake equation, astronomer Frank Drake's famous formula for estimating the number of intelligent extraterrestrial civilizations in the galaxy. Doubling the duration of Earth's biosphere effectively doubles the odds that intelligent life will be found elsewhere in the galaxy.

"It didn't take very long to produce life on the planet, but it takes a very long time to develop advanced life," says Yung. On Earth, this process took four billion years. "Adding an additional billion years gives us more time to develop, and more time to encounter advanced civilizations, whose own existence might be prolonged by this mechanism. It gives us a chance to meet."

The work described in the paper, "Atmospheric Pressure as a Natural Regulator of the Climate of a Terrestrial Planet with Biosphere," was funded by NASA and the Virtual Planetary Laboratory at Caltech.

Kathy Svitil

DOE Names Caltech Professor as Director of EFRC Focusing on Light-Material Interactions

Caltech also picked to partner in three additional EFRCs

PASADENA, Calif.--The U.S. Department of Energy (DOE) Office of Science has announced that it will fund the creation of 46 Energy Frontier Research Centers (EFRCs) over the next five years, including one that will be housed at the California Institute of Technology (Caltech). That EFRC will be headed by Harry Atwater, the Howard Hughes Professor and professor of applied physics and materials science.

"It is essential and very appropriate for a place like Caltech to serve as an intellectual center for fundamental scientific research in solar energy," says Atwater. "We have programs that support work on photovoltaic devices, but the Energy Frontier Research Center will address fundamental optical science issues relevant to solar energy. It's the kind of center that is best suited to our strengths."

In addition, Caltech researchers will partner with three additional EFRCs at other institutions.

According to Ares Rosakis, chair of Caltech's Division of Engineering and Applied Science, "Radical new approaches to harnessing solar energy are at the heart of many efforts here at Caltech to help contribute to the world's energy infrastructure with innovative, sustainable, core technologies. This new center brings Caltech one step closer to our goal of providing the resources necessary for some of the best minds in the country to lay the groundwork for a new energy economy."

This $777 million program is a major effort to accelerate the scientific breakthroughs needed to build a new 21st-century economy, the White House said in announcing the initiative. The 46 new EFRCs, which will each be funded at $2-5 million per year for a planned initial five-year period, will be established at universities, national laboratories, nonprofit organizations, and private firms across the nation.

Supported in part by funds made available under President Obama's American Recovery and Reinvestment Act, the EFRCs will bring together groups of leading scientists to address fundamental issues in fields ranging from solar energy and electricity storage to materials sciences, biofuels, advanced nuclear systems, and carbon capture and sequestration.

The EFRCs were selected from a pool of some 260 applications received in response to a solicitation issued in 2008 by the DOE's Office of Science. Over 110 institutions from 36 states plus the District of Columbia will be participating in the EFRC research. In all, the EFRCs will involve nearly 700 senior investigators and employ, on a full- or part-time basis, over 1,100 postdoctoral associates, graduate students, undergraduate students, and technical staff. Roughly a third of these researchers will be supported by Recovery Act funding.

Atwater's EFRC, entitled "Light Material Interactions in Energy Conversion," will include collaborations with scientists at Lawrence Berkeley National Laboratory and the University of Illinois, and some of the work will be done at the Molecular Foundry at Lawrence Berkeley National Laboratory.

"The goal of the center is to understand how to sculpt and mold the flow of light through materials," Atwater explains. "By that I mean we will be working to design structures at the nanoscale that steer and change the speed of light to optimally convert sunlight to electricity and chemical fuels."

The three additional EFRCs that will be partnering with Caltech researchers include

  • Rational Design of Innovative Catalytic Technologies for Biomass Derivative Utilization (headed by the University of Delaware), with Mark Davis, the Warren and Katharine Schlinger Professor of Chemical Engineering at Caltech
  • EFRC for Solid State Lighting Science (headed by Sandia National Laboratories), with Harry Atwater
  • Center for Catalytic Hydrocarbon Functionalization (headed by the University of Virginia), with William Goddard, the Charles and Mary Ferkel Professor of Chemistry, Materials Science, and Applied Physics at Caltech

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Lori Oliwenstein

Caltech Scientists Create New Enzymes for Biofuel Production

Enzymes are important step toward cheaper biofuels

Researchers at the California Institute of Technology (Caltech) and world-leading gene-synthesis company DNA2.0 have taken an important step toward the development of a cost-efficient process to extract sugars from cellulose--the world's most abundant organic material and cheapest form of solar-energy storage. Plant sugars are easily converted into a variety of renewable fuels such as ethanol or butanol.

In a paper published this week in the early edition of the Proceedings of the National Academy of Sciences, Frances H. Arnold, the Dick and Barbara Dickinson Professor of Chemical Engineering and Biochemistry at Caltech, and her colleagues report the construction of 15 new highly stable fungal enzyme catalysts that efficiently break down cellulose into sugars at high temperatures. Previously, fewer than 10 such fungal cellobiohydrolase II enzymes were known. In addition to their remarkable stabilities, Arnold's enzymes degrade cellulose over a wide range of conditions.

Biofuels are made by converting renewable materials--for example, corn kernels, wood chips left over from pulp and paper production, prairie grasses, and even garbage--into fuels and chemicals. Most biofuels used today are made from the fermentation of starch from corn kernels. That process, although simple, is costly because of the high price of the corn kernels themselves.

Agricultural waste, such as corn stover (the leaves, stalks, and stripped cobs of corn plants, left over after harvest), is cheap. These materials are largely composed of cellulose, the chief component of plant-cell walls. Cellulose is far tougher to break down than starch. An additional complication is that while the fermentation reaction that breaks down corn starch needs just one enzyme, the degradation of cellulose requires a whole suite of enzymes, or cellulases, working in concert.

The cellulases currently used industrially, all of which were isolated from various species of plant-decaying filamentous fungi, are both slow and unstable, and, as a result, the process remains prohibitively expensive. "Even a two-fold reduction in their cost could make a big difference to the economics of renewable fuels and chemicals," says Arnold.

Arnold and Caltech postdoctoral scholar Pete Heinzelman created the 15 new enzymes using a process called structure-guided recombination. Using a computer program to design where the genes recombine, the Caltech researchers "mated" the sequences of three known fungal cellulases to make more than 6,000 progeny sequences that were different from any of the parents, yet encoded proteins with the same structure and cellulose-degradation ability.

By analyzing the enzymes encoded by a small subset of those sequences, the Caltech and DNA2.0 researchers were able to predict which of the more than 6,000 possible new enzymes would be the most stable, especially under higher temperatures (a characteristic called thermostability).

Thermostability is a requirement of efficient cellulases, because at higher temperatures--say, 70 or even 80 degrees Celsius--chemical reactions are more rapid. In addition, cellulose swells at higher temperatures, which makes it easier to break down. Unfortunately, the known cellulases from nature typically won't function at temperatures higher than about 50 degrees Celsius.

"Enzymes that are highly thermostable also tend to last for a long time, even at lower temperatures," Arnold says. "And, longer-lasting enzymes break down more cellulose, leading to lower cost."

Using the computer-generated sequences, coauthor Jeremy Minshull and colleagues from DNA2.0 of Menlo Park, California, synthesized actual DNA sequences, which were transferred into yeast in Arnold's laboratory. The yeast produced the enzymes, which were then tested for their cellulose-degrading ability and efficiency. Each of the 15 new cellulases reported in the PNAS paper was more stable, worked at significantly higher temperatures (70 to 75 degrees Celsius), and degraded more cellulose than the parent enzymes at those temperatures.

"This is a really nice demonstration of the power of synthetic biology," Arnold says. "You can rapidly generate novel, interesting biological materials in the laboratory, and you don't have to rely on what you find in nature. We just emailed DNA2.0 sequences based on what we pulled out of a database and our recombination design, and they synthesized the DNA. We never had to go to any organism to get them. We never touched a fungus."

Next, the researchers plan to use the structure-guided recombination process to perfect each of the half-dozen or so cellulases that make up the soup of enzymes required for the industrial degradation of cellulose. "We've demonstrated the process on one of the components. Now we have to create families of all of the other components, and then look for the ideal mixtures for each individual application," Arnold says, with the ultimate goal of creating a cost-efficient recipe for cellulosic biofuel.

"If you think about it, energy is the biggest industry there is," Arnold says. "If we can replace foreign oil with renewable biofuels, that's an enormous contribution. And that replacement is slow right now because these enzymes are just too expensive."

The work in the paper, "A Family of Thermostable Fungal Cellulases Created by Structure-Guided Recombination," was supported by the Army-Industry Institute for Collaborative Biotechnologies and the Caltech Innovation Institute.

Kathy Svitil
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Caltech Scientists Lead Deep-Sea Discovery Voyage

Research mission uncovers several new species and thousands of fossilized coral samples.

PASADENA, Calif.--Scientists from the California Institute of Technology (Caltech) and an international team of collaborators have returned from a month-long deep-sea voyage to a marine reserve near Tasmania, Australia, that not only netted coral-reef samples likely to provide insight into the impact of climate change on the world's oceans, but also brought to light at least three never-before-seen species of sea life.

"It was truly one of those transcendent moments," says Caltech's Jess Adkins of the descents made by the remotely operated submersible Jason. Adkins was the cruise's lead scientist and is an associate professor of geochemistry and global environmental science at Caltech. "We were flying--literally flying--over these deep-sea structures that look like English gardens, but are actually filled with all of these carnivorous, Seuss-like creatures that no one else has ever seen."

The voyage on the research vessel RV Thompson explored the Tasman Fracture Commonwealth Marine Reserve, southwest of Tasmania. The voyage was funded by the National Science Foundation and was the second of two cruises taken by the team, which included researchers from the United States--including scientists from Caltech and the Woods Hole Oceanographic Institution in Massachusetts, which owns and operates the submersible Jason--and Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO). The first of those voyages was taken in January 2008, with this most recent one spanning 33 days from mid-December 2008 through mid-January 2009.

Up until now, the area of the reef the scientists were exploring--called the Tasman Fracture Zone--had only been explored to a depth of 1,800 meters (more than 5,900 feet). Using Jason, the researchers on this trip were able to reach as far down as 4,000 meters (well over 13,000 feet).

"We set out to search for life deeper than any previous voyage in Australian waters," notes scientist Ron Thresher from CSIRO's Climate Adaptation and Wealth from Oceans Flagships.

The cruise had two main goals, says Adkins. One was to try to use deep-sea corals to reconstruct the paleoclimate--with an emphasis on the changes in climate over the last 100,000 years--and to understand the fluctuations in CO2 found in the ice-core records. Investigators also wanted to look at changes in the ocean over a much smaller slice of time--the past few hundred to one thousand or so years. "We want to see what's happened to the corals over the Industrial Revolution timescale," says Adkins. "And we want to see if we can document those changes."

The second goal? "Simply to document what's down there," says Adkins.

"In one sense, the deep ocean is less explored than Mars," he adds. "So every time you go to look down there you see new things, magical things."

Among the "magical things" seen on this trip were

  • a new species of carnivorous sea squirt that "looks and behaves like a Venus fly trap," says Adkins;
  • new species of barnacles (some of which Adkins says may even belong to an entirely new family); and
  • a new species of sea anemone that Adkins calls "the bane of our existence," because it looks just like the coral they were trying to collect.

The sea anemone was particularly vexing for the researchers, because they were hoping to find deep-sea (or abyssal) samples of the fossilized coral, but were unable to find the coral much below 2,400 meters (nearly 7,800 feet). The look-alike sea anemone, on the other hand, kept popping up all over the place on the deep-sea floor, raising--and then dashing--the scientists' hopes.

This carnivorous sea squirt was one of the new species seen during the voyage of the RV Thompson.
Credit: Advanced Imaging and Visualization Laboratory, WHOI/Jess Adkins, Caltech

"Not being able to find the coral down deeper was our single biggest disappointment on the trip," says Adkins.

Still, the 10,000-plus samples collected will help the researchers begin their work of deciphering just what has been happening to the ocean throughout the centuries of climate change, and during and between glacial cycles. First up: dating the fossils collected on this trip in order to determine which slice of history they came from.

"The deep ocean is part and parcel of these rapid climate changes," says Adkins. "These corals will be our window into what their impact is on climate, and how they have that impact. The info is there; now we just have to unpack it."

Further funding for the research came from CSIRO, the Commonwealth Environmental Research Facilities' Marine Biodiversity Hub, and the Australian Department of the Environment, Water, Heritage and the Arts.

Lori Oliwenstein

Caltech Researchers Find Ancient Climate Cycles Recorded in Mars Rocks

PASADENA, Calif.-- Researchers at the California Institute of Technology (Caltech) and their colleagues have found evidence of ancient climate change on Mars caused by regular variation in the planet's tilt, or obliquity. On Earth, similar "astronomical forcing" of climate drives ice-age cycles.

Using stereo topographic maps obtained by processing data from the high-resolution camera onboard NASA's Mars Reconnaissance Orbiter, the Caltech scientists, led by graduate student Kevin Lewis and Oded Aharonson, associate professor of planetary science, along with John Grotzinger, the Fletcher Jones Professor of Geology, identified and measured layered rock outcrops within four craters in the planet's Arabia Terra region. The layering in different outcrops occurs at scales ranging from a few meters to tens of meters, but at each location the layers all have similar thicknesses and exhibit similar features.

Based on a pattern of layers within layers measured at one location, known as Becquerel crater, the scientists propose that each layer was formed over a period of about 100,000 years and that these layers were produced by the same cyclical climate changes.

In addition, every 10 layers were bundled together into larger units, which were laid down over an approximately one-million-year period; in the Becquerel crater, the 10-layer pattern is repeated at least 10 times. This one-million-year cycle corresponds to a known pattern of change in Mars's obliquity caused by the dynamics of the solar system.

"Due to the scale of the layers, small variations in Mars's orbit are the best candidate for the implied climate changes. These are the very same changes that have been shown to set the pacing of ice ages on the Earth and can also lead to cyclic layering of sediments," says Lewis, the first author of a paper about the work published in this week's issue of Science.

Sequences of cyclic sedimentary rock layers exposed in an unnamed crater in Arabia Terra, Mars.
Credit: Topograpy, Caltech; HiRISE Images, NASA/JPL/University of Arizona

The tilt of Earth on its axis varies between 22.1 and 24.5 degrees over a 41,000-year period. The tilt itself is responsible for seasonal variation in climate, because the portion of the Earth that is tipped toward the sun--and that receives more sunlight hours during a day--gradually changes throughout the year. During phases of lower obliquity, polar regions are less subject to seasonal variations, leading to periods of glaciation.

Mars's tilt varies by tens of degrees over a 100,000-year cycle, producing even more dramatic variation. When the obliquity is low, the poles are the coldest places on the planet, while the sun is located near the equator all the time. This could cause volatiles in the atmosphere, like water and carbon dioxide, to migrate poleward, where they'd be locked up as ice.

When the obliquity is higher, the poles get relatively more sunlight, and those materials would migrate away. "That affects the volatiles budget. If you move carbon dioxide away from the poles, the atmospheric pressure would increase, which may cause a difference in the ability of winds to transport and deposit sand," Aharonson says. This is one effect that could change the rate of deposition of layers such as those seen by the researchers in the four craters.

Another effect of the changing tilt would be a change in the stability of surface water, which alters the ability of sand grains to stick together and cement in order to form the rock layers.

"The whole climate system would be different," Aharonson says.

However, such large changes in climate would influence a variety of geologic processes on the surface. While the researchers cannot tie the formation of the rhythmic bedding on Mars to any particular geologic process, "a strength of the paper is that we can draw conclusions without having to specify the precise depositional process," Aharonson says.

"This study gives us a hint of how the ancient climate of Mars operated, and shows a much more predictable and regular environment than you would guess from other geologic features that indicate catastrophic floods, volcanic eruptions, and impact events," Lewis adds. "More work will be required to understand the full extent of the information contained within these natural geologic archives," he says.

"One of the fun things about this project for me is that we were able to use techniques on Mars that are the bread and butter of studies of stratigraphy on Earth," says Aharonson. "We substituted a high-resolution camera in orbit around Mars and stereo processing for a geologist's Brunton Compass and mapboard, and were able to derive the same quantitative information on the same scale. This enabled conclusions that have qualitative meaning similar to those we chase on Earth."

The paper, "Quasi-Periodic Bedding in the Sedimentary Rock Record of Mars," will be published in the December 5 issue of Science. The work was supported by NASA's Mars Data Analysis Program and the NASA Earth and Space Science Fellowship program.

Kathy Svitil

Caltech's Novel Approach to Sustainability: Harvesting Olives

PASADENA, Calif.--Once considered a messy sidewalk annoyance on the California Institute of Technology (Caltech) campus, the fruit of the 130 olive trees lining the campus pathways is now being embraced for its contribution to Caltech's sustainability. The olives will be harvested and pressed into olive oil in Caltech's second annual Olive Harvest Festival on Friday, November 7.

Caltech students, faculty, and staff will join together for this harvesting event. If members of the public would like to participate in the Olive Harvest Festival, they can contact Caltech by e-mail at

The olive oil will be sold in the Caltech Bookstore approximately one month after the event, with the proceeds going to fund student scholarships and activities.

The Olive Harvest Festival serves as a signature celebration of the ongoing sustainability initiatives at Caltech. Campus sustainability projects range from installation and operation of Pasadena's largest solar-power facility on top of Caltech's Holliston parking lot to the operation of a thriving campus recycling center.

Activities during the Festival occur throughout the entire day. They include:

Olive Harvesting 8 a.m. - 3 p.m. Using tarps, ladders, buckets, rakes, and other tools, harvesting teams will begin at the Olive Walk location and sweep through the rest of the campus, collecting olives by hand. Harvesters will transfer picked olives to large crates for processing by the Regalo Extra Virgin Olive Oil Company; then on to the Santa Barbara Olive Company for bottling and labeling.

Olive Milling, Pressing, and Brining/Pickling 10:30 a.m. - 4 p.m. Using a mill and press commissioned specifically for this event, ten people will push the 1,600-pound wheels, and the olives will be put through the manual process that extracts the oil.

Culinary Tastings and Sustainability Exhibits 11:30 a.m. - 4 p.m. Student clubs involved in promoting Caltech's sustainability will host various exhibits and tasting opportunities.

Edible Tour of Campus Noon - 4 p.m. Maps for a self-guided tour will instruct people on how to find, recognize, and prepare the plants and herbs around campus.

"Green" Tour of Campus Noon - 4:00 p.m. Guides will lead tours of the campus while discussing on-campus efforts toward sustainability, including Pasadena's largest-ever solar facility atop Caltech's Holliston Parking lot, several new clubs, and three new LEED gold-certified buildings that are under construction.

Caltech Jazz Band Noon -1:00 p.m. Musicians from the Caltech Jazz Bands will perform.

Ice Sculpture Carving 1 p.m. - 1:30 p.m. An ice carving demonstration will be presented by one of the sous-chefs from the Athenaeum, Caltech's faculty club.

Harvest Festival Games 1:30 p.m. - 2:30 p.m. A variety of Festival games will be played in the theme of the Olive Harvest, including olive-branch limbo, hot olive (potato), and olive in a spoon races.

Olive Harvest Dinner 5 p.m. - 7 p.m. A Mediterranean-themed dinner will be prepared by the chefs from the Athenaeum and Caltech Dining Services. Undergrad student waiters will be assisting in serving the family-style dinner that attracted 2,000 people last year.

For more information and the complete schedule of the Olive Harvest Festival, visit



Martin Voss
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Caltech Geobiologists Discover Unique "Magnetic Death Star" Fossil

Fossil and other new forms date to ancient period of global warming

PASADENA, Calif.-- An international team of scientists has discovered microscopic, magnetic fossils resembling spears and spindles, unlike anything previously seen, among sediment layers deposited during an ancient global-warming event along the Atlantic coastal plain of the United States.

The researchers, led by geobiologists from the California Institute of Technology (Caltech) and McGill University, describe the findings in a paper published online this week in the Proceedings of the National Academy of Sciences (PNAS).

Fifty-five million years ago, Earth warmed by more than 9 degrees Fahrenheit after huge amounts of carbon entered the atmosphere over a period of just a few thousand years. Although this ancient global-warming episode, known as the Paleocene-Eocene Thermal Maximum (PETM), remains incompletely explained, it might offer analogies for possible global warming in the future.

Perhaps in response to the environmental stress of the PETM, many land mammals in North America became dwarfed. Almost half of the common sea bottom-dwelling microorganisms known as foraminifera became extinct in newly warmer waters that were incapable of carrying the levels of dissolved oxygen for which they were adapted.

"Imagine our surprise to discover not only a fossil bloom of bacteria that make iron-oxide magnets within their cells, but also an entirely unknown set of organisms that grew magnetic crystals to giant sizes," said Caltech postdoctoral scholar Timothy Raub, who collected the samples from an International Ocean Drilling Program drill-core storehouse at Rutgers University in New Jersey.

A typical "giant" spearhead-shaped crystal is only about four microns long, which means that hundreds would fit on the period at the end of this sentence. However, the crystals found recently are eight times larger than the previous world record for the largest bacterial iron-oxide crystal.

According to Dirk Schumann, a geologist and electron microscopist at McGill University and lead author of the study, "It was easy to focus on the thousands of other bacterial fossils, but these single, unusual crystals kept appearing in the background. It soon became evident that they were everywhere."

In addition to their unusually large sizes, the magnetic crystals occur in a surprising array of shapes. For example, the spearhead-like crystals have a six-sided "stalk" at one end, a bulbous middle, and a sharp, tapered tip at the other end. Once reaching a certain size, spearhead crystals grow longer but not wider, a directed growth pattern that is characteristic of most higher biological organisms.

The spearhead magnetic crystals compose a minor fraction of all of the iron-oxide crystals in the PETM clay layer. Most of the crystals have smaller sizes and special shapes, which indicate that they are fossils of magnetotactic bacteria. This group of microorganisms, long studied at Caltech by study coauthor Joseph Kirschvink, the Nico and Marilyn Van Wingen Professor of Geobiology, use magnets to orient themselves within Earth's magnetic field, and proliferate in oxygen-poor water.

Spearheads are not, however, the rarest fossil type in the deposit. That honor belongs to a spherical cluster of spearheads informally dubbed the "Magnetic Death Star" by the researchers. The Magnetic Death Star may have preserved the crystals as they occurred in their original biological structure.

The researchers could not find a similar-shaped organism anywhere in the paleontological annals. They hypothesize that it may have been a single-celled eukaryote that evolved for the first time during the PETM and was outcompeted once the strange climate conditions of that time diminished. Alternatively, it may still exist today in a currently undiscovered location.

"The continental shelf of the mid-Atlantic states during the PETM must have been very iron-rich, much like the Amazon shelf today," notes study coauthor Robert Kopp of Princeton University, who first started working on the project while a graduate student at Caltech. "These fossils may be telling a story of radical environmental transformation: imagine a river like the Amazon flowing at least occasionally where the Potomac is today."

The paper, "Gigantism in unique biogenic magnetite at the Paleocene-Eocene Thermal Maximum," will appear in the early online issue of PNAS the week of October 20. The Caltech work was supported by the NASA Exobiology program.

Kathy Svitil

Caltech Solar Project Receives City Rebate

Project is largest of its kind in Pasadena

PASADENA, Calif.-- The California Institute of Technology (Caltech) and EI solutions, a leader in solar solutions, announced today that the City of Pasadena has granted a rebate to the city's largest-ever solar-energy facility as part of the Pasadena Water & Power Pasadena Solar Initiative (PSI) program. The facility is located on top of Caltech's Holliston parking structure and will begin operation in the next few months. The project is the city's first large-scale power purchase agreement in the area. An official ribbon-cutting ceremony will take place November 4.

"We appreciate the city's help and assistance in achieving this milestone for all of Pasadena," says Jim Cowell, Caltech associate vice president for facilities. "This facility will allow us to reduce our dependence on nonrenewable sources of energy and allow Caltech to conduct research in a more sustainable way."

The PSI is offered by Pasadena Water and Power as an incentive to power customers. Caltech's rebate is a performance-based incentive (PBI) and will return to Caltech $0.632 per kilowatt-hour. The rebate will be paid in "five annual PBI payments based on actual metered energy output of solar power produced during each of the first five years of operation."

Pasadena-based EI Solutions designed the innovative system and is near completion of the installation. Under a power purchase agreement, the system will be owned by Solar Power Partners of Mill Valley, California. Through the agreement, Caltech will purchase, at a fixed price, 100 percent of the energy generated by the system.

The majority of Caltech's energy is supplied by an on-site campus cogeneration plant and by the City of Pasadena. The on-site generation facility provided 77 percent of campus consumption last year. Ultimately, Caltech hopes to add more solar facilities to the campus in an effort to further reduce its reliance on nonrenewable sources.

"We will be working with the city on future solar installations and appreciate the Pasadena Water and Power staff for working with us along the way," says Cowell.

This facility is expected to have an annual energy production of approximately 320,000 kilowatt-hours. The overall size of the structure is about 220 feet long by 90 feet wide, utilizes 1,404 Suntech solar panels, and covers more than half of the top level of the structure. Suntech solar panels were chosen for their consistent high quality and reliable performance and efficiency.

"As a local solar integrator, we're especially proud to be working with our neighbor, Caltech, on what will soon be the largest solar installation in Pasadena," says Andrew Beebe, president of EI Solutions. "By taking advantage of Pasadena's generous rebate program, Caltech is also setting a great example for other area companies on how economically feasible solar can be."

The solar-energy facility is one of many sustainability efforts the Caltech campus has undertaken in recent years. In addition to the cogeneration plant on campus, dining facilities use compostable food containers; incandescent light bulbs are being switched to compact fluorescent bulbs; grounds planners use water-wise landscaping; a green cleaning program is in use by the custodial staff; an award-winning recycling program accepts items from the campus and local community; construction is underway on three new buildings that are anticipated to receive LEED Gold certification; and the Caltech Electric Vehicle Club has electric cars that qualified users are free to drive.

About Caltech: With an outstanding faculty, including five Nobel laureates, and such off-campus facilities as the Jet Propulsion Laboratory, Palomar Observatory, and the W. M. Keck Observatory, the California Institute of Technology is one of the world's major research centers. The Institute also conducts instruction in science and engineering for a student body of approximately 900 undergraduates and 1,200 graduate students who maintain a high level of scholarship and intellectual achievement. Caltech's 124-acre campus is situated in Pasadena. Caltech is an independent, privately supported university. Learn more on the Web at

About EI Solutions: EI Solutions is one of California's fastest growing providers of commercial and utility-scale solar-power systems. The company has completed projects for a wide variety of public agencies and private companies including Sony, BT, and the largest solar installation on a U.S. corporate campus, a 1.6-megawatt system on Google's Mountain View headquarters. EI Solutions' headquarters are in San Rafael, California, where all engineering, project management, finance, and administrative functions are based. EI Solutions also operates a sales and marketing office in Pasadena, at the home of its parent company, Energy Innovations. Energy Innovations, an Idealab company, is a manufacturer of commercial solar products that maximize usable energy from the sun. More information can be found at or by calling 800.237.0916.

For a more comprehensive list of green initiatives at Caltech, go to the Sustainability at Caltech website at

Jon Weiner
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Caltech Scientists Awarded $20 Million to "Power the Planet"

PASADENA, Calif.--In the dreams of Harry Gray, Beckman Professor of Chemistry at the California Institute of Technology, the future energy needs of the world are met with solar-fuel power plants. Now, a $20 million award from the Chemical Bonding Center (CBC), a National Science Foundation (NSF) Division of Chemistry program, will help bring this dream one step closer to reality.

In 2005, NSF granted three Phase I CBC awards. Gray formed a group of Caltech and MIT scientists who spent the $1.5 million and three years of Phase I conducting initial research and establishing public outreach plans for their idea.

Of the three Phase I projects, Caltech's is the only one to advance to Phase II, a $20 million, five-year extension. "We have added outstanding investigators from many other institutions to our Caltech-MIT team in order to ramp up our efforts in Phase II of the 21st century grand challenge to make solar fuels using materials made from Earth-abundant elements," says Gray.

In Phase I, the Caltech-MIT alliance, called "Powering the Planet," proposed to develop nanoscale materials to make fuel from sunlight and water. They designed a nanorod-catalyst water splitter that incorporates a membrane to separate the oxygen- and hydrogen-making parts of the system.

Nathan Lewis, Caltech's Argyros Professor and professor of chemistry, and chemist Bruce Brunschwig, a Member of Caltech's Beckman Institute (BI) and Director of the Materials Resource Center for the BI, headed a group of students and postdocs who began working on a silicon nanorod-studded plastic sheet to harvest sunlight. The hydrogen-making catalyst team was headed by Gray, Jay Winkler (a Caltech faculty associate in chemistry), and Jonas Peters (a former Caltech chemistry professor now at MIT). Research with the goal of finding efficient catalysts for the oxidation of water to oxygen was led by MIT scientists Dan Nocera, a former graduate student of Gray's, and Christopher Cummins.

With a conceptual design in place, and with promising results in all three investigation areas, the alliance expanded--18 senior researchers at 12 institutions signed on to compete for Phase II of the CBC award and participate in testing and refining the nanoscale water-splitting device.

Luis Echegoyen, Director of the NSF Division of Chemistry, says, "The Division of Chemistry is pleased and excited to establish this new CBC devoted to elucidating some basic science aspects of solar energy research. This center and its excellent team of researchers will enable NSF to partner with the scientific community to explore fundamental aspects of solar-driven splitting of water into hydrogen and oxygen."

The CBC Program is designed to support the formation of centers that can address long-term, high-risk, and high-impact basic chemical research problems. The centers are expected to be responsive to rapidly emerging opportunities and make full use of cyberinfrastructure to enhance collaborations.

"We are excited about our prospects, as we are lucky to have a very talented and dedicated group of students and postdocs who are ready and able to tackle the fundamental chemistry problems that must be solved before it will be feasible to produce clean solar fuels on a large scale," Gray adds. The Phase II award may be extended for an additional five years.

For more information on the award, visit


Elisabeth Nadin

Caltech Scientists Offer New Explanation for Monsoon Development

PASADENA, Calif.--Geoscientists at the California Institute of Technology have come up with a new explanation for the formation of monsoons, proposing an overhaul of a theory about the cause of the seasonal pattern of heavy winds and rainfall that essentially had held firm for more than 300 years.

The traditional idea of monsoon formation was developed in 1686 by English astronomer and mathematician Edmond Halley, namesake of Halley's Comet. In Halley's model, monsoons are viewed as giant sea-breeze circulations, driven by the differences in heat capacities between land and ocean surfaces that, upon heating by sunlight, lead to temperature differences between warmer land and cooler ocean surfaces--for example, between the Indian subcontinent and the oceans surrounding it.

"These circulations form overturning cells, with air flowing across the equator toward the warmer land surface in the summer hemisphere, rising there, flowing back toward and across the equator aloft, and sinking in the winter hemisphere," explains Tapio Schneider, associate professor of environmental science and engineering at Caltech.

A different explanation is offered by Schneider and Simona Bordoni of the National Center for Atmospheric Research in Boulder, Colorado. The duo used a computer-generated, water-covered, hypothetical earth (an "aquaplanet") to simulate monsoon formation and found that differences in heat capacities between land and sea were not necessary. Bordoni was a Moore Postdoctoral Scholar at Caltech and will return to Caltech as an assistant professor in 2009.

Monsoons arise instead because of an interaction between the tropical circulation and large-scale turbulent eddies generated in the atmosphere in middle latitudes. These eddies, which can span more than 300 miles across, form the familiar systems that govern the weather in middle latitudes.

The eddies, Schneider says, are "basically large waves, which crash into the tropical circulation. They 'break,' much like water waves on the beach, and modify the circulation as a result of the breaking. There are feedbacks between the circulation, the wind pattern associated with it in the upper atmosphere, and the propagation characteristics of the waves, which make it possible for the circulation to change rapidly." This can quickly generate the characteristic high surface winds and heavy rainfall of the monsoon.

Bordoni adds: "These feedbacks provide one possible explanation for the rapidity of monsoon onset, which had been a long-standing conundrum in the traditional view of monsoons," because substantial differences between land and sea temperatures can only develop slowly through heating by sunlight.

Although the results won't immediately produce better forecasts of impending monsoons, Schneider says, "in the long run, a better understanding of monsoons may lead to better predictions with semi-empirical models, but much more work needs to be done."

The paper, "Monsoons as eddy-mediated regime transitions of the tropical overturning circulation," appears in the advance online edition of Nature Geosciences. The work was supported by the Davidow Discovery Fund, a David and Lucile Packard Fellowship, a Moore Postdoctoral Fellowship, and the National Science Foundation. The National Center for Atmospheric Research is sponsored by the National Science Foundation. Any opinions, findings and conclusions or recommendations expressed in this publication are those of the author and do not necessarily reflect the views of the National Science Foundation.

Kathy Svitil