News Article | February 17, 2017
It’s not something NASA likes to advertise, but ever since its creation in 1958, the space agency has only conducted one direct, focused hunt for extraterrestrial life—and that was more than 40 years ago. It happened in 1976, when the twin Viking landers touched down at separate sites on Mars to look for any signs of life lurking on the planet’s desolate, freeze-dried surface. The Viking mission was—and still is—the most expensive planetary science mission ever launched as well as a technical tour de force that laid the foundations for all future interplanetary exploration. Both landers came up empty in their search for life, however, and ever since NASA has favored a series of missions—most of them to Mars—that transformed our understanding of our neighboring worlds as they tiptoed around the central question of whether any of them harbor life. Now, after decades of wandering in Martian deserts, NASA’s astrobiologists are at last preparing to rekindle a direct search for a “second genesis” of life in our solar system—but not where one might think. This time, they will look well beyond Mars, the most Earthlike of our planetary neighbors, to the dark reaches of the outer solar system, where probes and space telescopes have revealed ever-more tantalizing signs of oceans hidden inside icy moons and dwarf planets. Warmed by tidal forces rather than sunlight, those environments could harbor life, scientists say. “These oceans may be close to the surface, or may be deeper, with thicker ice crusts, but there must be water in liquid or slush form there—even all the way out to Pluto,” says James Green, director of NASA’s Planetary Science Division and an architect of the agency’s embryonic Ocean Worlds exploration program. The program’s central focus is Europa, a moon of Jupiter that despite being slightly smaller than Earth’s lunar companion is thought to contain an ocean twice as voluminous as all our planet’s seas combined. Data from previous spacecraft flybys hint Europa’s ocean is billions of years old and in direct contact with the moon’s hot, rocky core, offering life sufficient time and energy to get started somewhere within. Locked below a crust with an average thickness of at least dozens of kilometers, any Europan biosphere might have remained forever out of reach. Occasionally seawater wells up through fissures in the crust to freeze at or near the surface, however, and recent observations by the Hubble Space Telescope suggest the ocean may even be venting vast amounts of water vapor into space through geyserlike plumes erupting from beneath the surface. If astronomers could collect the frozen material or the vapor they might learn what, if anything, lurks within Europa. NASA is already developing a spacecraft set to launch in the 2020s called the Europa Multiple Flyby Mission. The EMFM will orbit Jupiter, swooping by Europa 45 times to study the reputed plumes, measure the thickness of the moon’s icy crust and map the surface at high resolution. Yet the EMFM is only a prelude. Heeding a directive handed down by Congress in 2015, the agency is studying concepts for a lander to touch down on Europa’s surface with the explicit purpose of gathering and studying samples in search of alien biology. A new study produced by a 21-member panel of biologists, geologists, space scientists and flight engineers describes the potential lander in detail, and projects it could land on Europa as early as 2031. “That’s what we really want to know,” Green says. “What’s in that ocean, and is it alive? The lander is really all about that next step… I would like to see the lander sitting under a plume—the plume sloshing on its deck, fresh material coming out of the crack. Now, are we there yet? Not quite.” Despite Congress’s clamor for NASA to explore Europa, there is no guarantee it will actually provide the agency with funding necessary for the mission, which is conspicuously bereft of a price tag. Cost estimates would come later, NASA officials say, after careful consultation with the scientific community, not to mention sympathetic and powerful members of Congress. Bob Pappalardo, a senior research scientist at NASA’s Jet Propulsion Laboratory (JPL) and EMFM’s project scientist, believes there is a compelling case to launch both the orbital and lander missions in rapid succession. “It’s like peanut butter and jelly—neither one makes a great sandwich by itself but they are wonderful together,” he says, adding that either mission would still be wonderful on its own. “The EMFM will get at the key questions of Europa’s global habitability—its geology, chemistry, surface variation and the locations of its liquid water. If you want to really go for the brass ring and search for signs of life, then you’ll need to follow up on those findings by zooming in and going down to the surface…. I thought this was so far off that we would not see it in our lifetimes. Now, I’m not so sure.” Jonathan Lunine remains skeptical. The Cornell University planetary scientist has seen too many mission proposals crash and burn long before they reach the launch pad to be overly optimistic about near-term prospects for a lander. “I want to see this happen in my scientific career, but we are at an early stage and so it is hard to predict when this will happen,” he says. “I’ve always found that the political process—getting approval and funding—represents the most hazardous environment a planetary mission can be exposed to.” Whenever—if ever—NASA’s mission planners green-light a life-seeking Europa lander, the specter of Viking’s pitfalls will loom over every challenge. How can it safely land? Where should it go? And above all, how should it search for alien life? Low-resolution orbital imagery and simplistic retrorockets forced the Viking landers to touch down on drab, boulder-strewn plains that proved unfavorable to the search for life. The landers carried three relatively crude life-detecting experiments conceived when genetics and microbial ecology were still in their infancy and when knowledge of the Martian environment was much more limited. Each experiment investigated soil samples for signs of organic metabolism, the chemical reactions organisms rely on to produce and use energy. The samples, though, were scraped directly from the surface where intense ultraviolet radiation and cosmic rays would have killed almost any conceivable microbe, eliminating potential metabolic signatures. These and other troubles ensured that instead of making a robust case for life on Mars, Viking’s experiments delivered confusing, conflicting results. In contrast, a Europa lander would have to rely on profoundly different technologies for landing, operating and looking for life, largely based on lessons learned from Viking. Before the lander even approached Europa, the EMFM’s high-resolution reconnaissance would help locate a compelling landing site—ideally a region of young ice enriched with fresh material from the ocean beneath, perhaps pushed up through cracks or falling like snow from a nearby plume. It would touch down using a “skycrane” like the one that gently placed NASA’s Curiosity rover on Mars in 2012, improving the odds of achieving a pinpoint landing in obstacle-filled terrain. “The greatest technical hurdle is designing a spacecraft that can safely land on a surface that is largely unknown,” says Curt Niebur, program scientist for NASA’s outer solar system missions. “But if we can meet the challenge of landing at Europa, then we can land anywhere.” Although mission planners have yet to map Europa at very high resolution, the lower-resolution images they have already seen show a topography rugged enough to give them nightmares, says Britney Schmidt, a planetary scientist at Georgia Tech and study co-author. “Icy surfaces on Earth are incredibly complex, and Europa is rough on every scale we’ve ever observed it, so finding a flat spot might be impossible,” she says. “It’s hard not to be worried about that. Mars has been difficult for us—and it’s way flatter than Europa.” Many of the most tantalizing landing spots may in fact also be the most dangerous—so called “chaos regions” defined by the jumbles of ridges, pits and fissures that sprawl haphazardly across them. Such regions may be sites where liquid water has come close to the surface through relatively thin crust, causing the ground above to collapse and shift due to cycles of melting and refreezing. Schmidt’s personal favorite site for a lander—and one of the leading candidates in the study—is Thera Macula, a chaos region near a possible plume source that also resides in a relatively radiation-free area of the Europan surface. If it makes it to the surface successfully, a Europa lander would deploy a sophisticated instrument package to characterize its surroundings and perform a much broader search for life than anything possible during the Viking era. Stereoscopic cameras would find targets for sample collection and seismometers would map the subsurface using the echoes from icequakes. Instead of focusing on metabolism, spectrometers and microscopes would look for the biochemical building blocks of life—organic molecules, perhaps even individual cells—in pristine samples carved or drilled by a robotic arm that could penetrate as much as ten centimeters beneath the moon’s surface. Despite benefiting from 40 years of technological and scientific progress, there is one key area in which the Europa lander will be at a distinct disadvantage in comparison to Viking. The Jovian moon is a far more alien place with fewer obvious similarities to Earth or to Mars to guide the design of experiments. “Europa is the right next place to ask the always-tough question about how life might be detected beyond Earth,” says Jim Garvin, chief scientist at NASA Goddard Space Flight Center and co-chair of the lander study team. “What makes this both exciting and daunting is engineering the necessary analytical measurements to occur in an environment that is outright ‘nasty’ in comparison to Mars.” At Europa’s equator, the average surface temperature hovers around a chilly –160 degrees Celsius, and the entire surface is continuously pummeled by deadly radiation from particles trapped in Jupiter’s immense magnetic field, not to mention the occasional incoming space rock. Most of the lander’s delicate instruments would be kept relatively warm and protected within a radiation-shielded vault, leaving little more than the robotic arm and cameras exposed. The lander would operate for perhaps a month before expiring on that cold, hostile surface. The mysterious aquatic world within Europa pushes standard concepts of habitability to extremes and demands an entirely new approach to searching for life. “The influence of abundant photosynthetic productivity permeates our atmosphere, oceans and upper crust, so our intuition about what an inhabited world looks like is very much couched in this context,” says Tori Hoehler, an astrobiologist at NASA Ames Research Center and co-author of the lander study. “A Europan biosphere, if one exists, is constrained by a very different set of environmental factors.” There can be no life-giving sunlight in Europa’s ocean, so organisms there, scientists believe, would probably be chemosynthetic rather than photosynthetic, much like the creatures that live at hydrothermal vents on Earth’s seafloor. Life in that cold, dark, briny abyss would likely be quite languorous, with biochemistry throttled by a relative paucity of usable energy and nutrients, analogous to the minimalist aquatic ecosystems found in Antarctica such as the subglacial Lake Vostok and the hypersaline Lake Vida. Unable to probe these undersea environments directly, the Europa lander would instead have to look for biological by-products that might suffuse the sea and become incorporated in surface ice. In a similar fashion, scientists can estimate deep-sea biological activity on Earth by measuring concentrations of cells and amino acids diluted in huge volumes of seawater. Based on such terrestrial measurements, the Europa study team set high standards for a lander’s life-seeking experiments, which must be able to discern organic material diluted to roughly one part per 50 billion and as few as 100 cells in a cubic centimeter of ice. “We basically wanted to have a very strong approach to understanding any ambiguous results,” explains Kevin Hand, a planetary scientist at JPL and co-chair of the lander study team. “If the lander finds no evidence of complex organics or cells of microbes in the ice, we’ll know that if there is life on Europa, it leaves only a faint bio-signature that is below the organic and cell count levels found in places like Antarctica’s Lake Vostok.” Such a result would be disappointing, but according to Hoehler and his co-authors the greater disappointment would be if it was perceived as a failure that stifled momentum for further missions to Europa and other icy moons. It would be unlikely for Europa to give up all its secrets to the very first lander that sets down there, and such a mission could be just the beginning for NASA’s Ocean Worlds program. Missions could someday explore subsurface seas in Saturn’s Enceladus and Titan, Neptune’s Triton or even deep down in Pluto. Sensing a coming sea change, optimistic researchers are already sketching out wild ideas like interplanetary submarines built to bore or melt through kilometers of ice. “Even if we somehow convinced ourselves that Europa wasn’t inhabited, and I don’t really think it's possible to do so,” Hoehler says, “it would remain an extraordinarily interesting place to understand.”
News Article | November 11, 2016
At its start, the universe was a superhot melting pot that very briefly served up a particle soup resembling a "perfect," frictionless fluid. Scientists have recreated this "soup," known as quark-gluon plasma, in high-energy nuclear collisions to better understand our universe's origins and the nature of matter itself. The physics can also be relevant to neutron stars, which are the extraordinarily dense cores of collapsed stars. Now, powerful supercomputer simulations of colliding atomic nuclei, conducted by an international team of researchers including a Berkeley Lab physicist, provide new insights about the twisting, whirlpool-like structure of this soup and what's at work inside of it, and also lights a path to how experiments could confirm these characteristics. The work is published in the Nov. 1 edition of Physical Review Letters. This soup contains the deconstructed ingredients of matter, namely fundamental particles known as quarks and other particles called gluons that typically bind quarks to form other particles, such as the protons and neutrons found at the cores of atoms. In this exotic plasma state -- which can reach trillions of degrees Fahrenheit, hundreds of thousands of times hotter than the sun's core -- protons and neutrons melt, freeing quarks and gluons from their usual confines at the center of atoms. These record-high temperatures have been achieved by colliding gold nuclei at Brookhaven National Laboratory's RHIC (Relativistic Heavy Ion Collider), for example, and lead nuclei at CERN's LHC (Large Hadron Collider). Experiments at RHIC discovered in 2005 that quark-gluon plasma behaves like a fluid. In addition to gold nuclei, RHIC has also been used to collide protons, copper and uranium. The LHC began conducting heavy-ion experiments in 2014, and has confirmed that the quark-gluon plasma behaves like a fluid. There remain many mysteries about the inner workings of this short-lived plasma state, which may only have existed for millionths of a second in the newborn universe, and nuclear physicists are using a blend of theory, simulations and experiments to glean new details about this subatomic soup. "In our sophisticated simulations, we found that there is much more structure to this plasma than we realized," said Xin-Nian Wang, a theorist in the Nuclear Science Division at Berkeley Lab who has worked for years on the physics of high-energy nuclear collisions. When plotted out in two dimensions, the simulations found that slightly off-center collisions of heavy nuclei produce a wobbling and expanding fluid, Wang said, with local rotation that is twisted in a corkscrew-like fashion. This corkscrew character relates to the properties of the colliding nuclei that created the plasma, which the simulation showed expanding along -- and perpendicular to -- the beam direction. Like spinning a coin by flicking it with your finger, the simulations showed that the angular momentum properties of the colliding nuclei can transfer spin properties to the quark gluon plasma in the form of swirling, ring-like structures known as vortices. The simulations showed two of these doughnut-shaped vortices -- each with a right-handed orientation around each direction of the separate beams of the colliding nuclei -- and also many pairs of oppositely oriented vortices along the longest dimension of the plasma. These doughnut-shaped features are analogous to swirling smoke rings and are a common feature in classical studies of fluids, a field known as hydrodynamics. The simulations also revealed a patterned outward flow from hot spots in the plasma that resemble the spokes of a wheel. The time scale covered in the simulation was infinitesimally small, Wang said, roughly the amount of time it takes light to travel the distance of 10-20 protons. During this time the wobbling fluid explodes like a fireball, spurting the particle soup outward from its middle more rapidly than from its top. Any new understanding of quark-gluon plasma properties should be helpful in interpreting data from nuclei-colliding experiments, Wang said, noting that the emergence of several localized doughnut-like structures in the simulations was "completely unexpected." "We can think about this as opening a completely new window of looking at quark-gluon plasmas, and how to study them," he said. "Hopefully this will provide another gateway into understanding why this quark-gluon fluid is such a perfect fluid -- the nature of why this is so is still a puzzle. This work will benefit not only theory, but also experiments." The simulations provide more evidence that the quark-gluon plasma behaves like a fluid, and not a gas as had once been theorized. "The only way you can describe this is to have a very small viscosity," or barely any friction, a characteristic of a so-called 'perfect fluid' or 'fundamental fluid,'" Wang said. But unlike a familiar fluid like water, the simulation focuses on a fluid state hundreds of times smaller than a water molecule. Michael Lisa, a physics professor at Ohio State University who is part of the collaboration supporting the Solenoidal Tracker at RHIC (STAR), said the so-called vorticity or "swirl structure" of this plasma has never been measured experimentally, though this latest theoretical work may help to home in on it. STAR is designed to study the formation and characteristics of the quark-gluon plasma. "Wang and his collaborators have developed a sophisticated, state-of-the-art hydrodynamic model of the quark-gluon plasma and have identified swirling structures that vary within the fluid itself," he said. "Even more useful is the fact that they propose a method to measure these structures in the laboratory." Lisa also said there is ongoing analysis work to confirm the simulation's findings in data from experiments at RHIC and the LHC. "It is precisely innovations like this, where theory and experiment collaborate to explore new phenomena, that hold the greatest hope for greater insight into the quark-gluon plasma," he said. "Many tools have been used to probe the inner working mechanics and symmetry properties of this unique matter," said Zhangbu Xu, a spokesperson for the STAR collaboration and a staff scientist at Brookhaven National Laboratory. He also said that preliminary results from STAR also suggest some spinning motion in the fluid, and the simulation work "adds a new dimension" to this possibility.
News Article | February 25, 2017
It’s taken a year and a half, but the International Astronomical Union and the science team behind NASA’s New Horizons mission have finally struck a deal for naming the features on Pluto and its moons. The agreement, announced today, will open the way for the already well-known “informal” names for places on Pluto, such as Tombaugh Regio and Sputnik Planum, to become formal. It also allows for features on Charon, Pluto’s biggest moon, to be officially associated with fictional characters and locales – including Mordor from “Lord of the Rings,” Mr. Spock from “Star Trek” and Princess Leia from “Star Wars.” The scheme is mostly based on names that were suggested even before New Horizons flew past Pluto on July 14, 2015, as part of the SETI Institute’s “Our Pluto” campaign. The IAU and the New Horizons team agreed on a few tweaks to the categories for Pluto and Charon. For example, the revised scheme allows for naming places on Pluto after pioneering space missions and spacecraft, and naming features on Charon after authors and artists associated with space exploration. Back in 2015, the IAU wasn’t willing to go along with those themes, because they were similar to themes used for Mercury, Venus and Mars. The revised scheme means that Sputnik Planum – the informal name for the bright left half of Pluto’s “heart” – and Kubrick Mons on Charon are more likely to be OK’d. Now the New Horizons team will go ahead and submit its dozens of informal names for the IAU’s approval, in accordance with the international body’s longstanding procedures. Some of the scientists on the New Horizons mission, including principal investigator Alan Stern, haven’t always gotten along with the IAU, which engineered the reclassification of Pluto as a dwarf planet in 2006. But today, both sides had good things to say about each other. “I’m very happy with both the process and partnership that New Horizons and the IAU undertook that led to wonderful, inspiring and engaging naming themes for surface features on Pluto and its moons,” Stern said in today’s announcement. The IAU’s Working Group for Planetary System Nomenclature will work with Stern and his colleagues to sign off on the formal names. “I am very pleased that the close collaboration of the WGPSN with the New Horizons Team led to these beautiful, inspirational categories for naming the features on Pluto and its satellites,” said Rita Schulz, who’s in charge of the working group. “We are ready now for receiving the proposals for names. Good things take time, but it will be worth it.” Here are the naming themes that have been approved for Pluto and its moons: The agreement means that some of the thousands of names that were suggested and voted on during the “Our Pluto” campaign could soon start appearing on official planetary maps. “Imagine the thrill of seeing your name suggestion on a future map of Pluto and its moons,” said Jim Green, director of NASA’s Planetary Science Division. “Months after the Pluto flyby, the New Horizons mission continues to engage and inspire.” New Horizons is now on its way to an encounter in 2019 with yet another icy object in the Kuiper Belt, currently known as 2014 MU69. Someday, that mini-world and its features will have to be given official names as well. Any suggestions?
News Article | February 15, 2017
One of NASA's two new Discovery Program missions, Lucy will perform the first reconnaissance of the Jupiter Trojan asteroids orbiting the sun in tandem with the gas giant. The Lucy spacecraft will launch in 2021 to study six of these exciting worlds. The mission is led by Principal Investigator Dr. Harold Levison of the Southwest Research Institute in Boulder, Colorado. NASA's Goddard Space Flight Center in Greenbelt, Maryland will manage the mission. The program has a development cost cap of about $450 million. "This is a thrilling mission as the Jupiter Trojan asteroids have never been studied up close," said Guy Beutelschies, director of Interplanetary Systems at Lockheed Martin Space Systems. "The design of the spacecraft draws from the flight-proven OSIRIS-REx spacecraft currently on its way to a near-Earth asteroid. This heritage of spacecraft and mission operations brings known performance, reliability and cost to the mission." Lucy will study the geology, surface composition and bulk physical properties of these bodies at close range. It's slated to arrive at its first destination, a main belt asteroid, in 2025. From 2027 to 2033, Lucy will explore six Jupiter Trojan asteroids. These asteroids are trapped by Jupiter's gravity in two swarms that share the planet's orbit, one leading and one trailing Jupiter in its 12-year circuit around the sun. The Trojans are thought to be relics of a much earlier era in the history of the solar system, and may have formed far beyond Jupiter's current orbit. "This is a unique opportunity," said Dr. Levison. "Because the Trojans are remnants of the primordial material that formed the outer planets, they hold vital clues to deciphering the history of the solar system. Lucy, like the human fossil for which it is named, will revolutionize the understanding of our origins." Lucy is the seventh NASA Discovery Program mission in which Lockheed Martin has participated. Previously, the company developed the Lunar Prospector spacecraft; developed the aeroshell entry system for Mars Pathfinder; developed and operated the spacecraft for both Stardust missions; developed and operated the Genesis spacecraft; developed and operated the two GRAIL spacecraft; and developed and will operate the InSight Mars lander set to launch in May 2018. NASA's Discovery program class missions are relatively low-cost, their development capped at a specific cost. They are managed for NASA's Planetary Science Division by the Planetary Missions Program Office at Marshall Space Flight Center in Huntsville, Alabama. The missions are designed and led by a principal investigator, who assembles a team of scientists and engineers, to address key science questions about the solar system. About Lockheed Martin Headquartered in Bethesda, Maryland, Lockheed Martin is a global security and aerospace company that employs approximately 98,000 people worldwide and is principally engaged in the research, design, development, manufacture, integration and sustainment of advanced technology systems, products and services. Please follow SpaceRef on Twitter and Like us on Facebook.
News Article | February 25, 2017
On Thursday, the International Astronomical Union approved themes for naming surface features on Pluto and its moons. For the dwarf planet, most of the naming themes relate to the underworld. If someone asks you to pick a planet in our solar system that most resembles the Greek kingdom of the dead, which one would you choose? If your answer is Pluto, then congratulations, you now have something in common with the folks over at NASA and the International Astronomical Union (IAU). On Thursday, two years after the IAU endorsed NASA's “Our Pluto” naming campaign — which allowed the public to propose names for surface features that had still not been discovered — the agency approved themes submitted by NASA’s New Horizons team for naming surface features on Pluto and its moons. Not surprisingly, most of the naming themes for Pluto relate to the underworld. “Imagine the thrill of seeing your name suggestion on a future map of Pluto and its moons,” Jim Green, director of NASA’s Planetary Science Division in Washington, D.C., said in a statement released Thursday. “Months after the Pluto flyby, the New Horizons mission continues to engage and inspire.” Even prior to IAU’s imprimatur, astronomers associated with the New Horizons mission had been informally assigning similar names to newly discovered features on the dwarf planet — Krun Macula (Krun is the lord of the underworld in the ancient Mandaean religion, and a macula is a dark feature on a planetary surface), Tartarus Dorsa (In Greek mythology, Tartarus is the name of a region of the underworld where the greatest sinners are sent for their transgressions.) Pluto is a lot like what Hades’ realm is often portrayed as, minus the souls of dead humans, of course. It is dark, cold and barren, with temperatures ranging from -400 degrees Fahrenheit to about -360 degrees Fahrenheit. Here are the IAU-approved themes that the naming process would now stick to: Pluto ● Gods, goddesses and other beings associated with the underworld from mythology, folklore and literature ● Names for the underworld and for underworld locales from mythology, folklore and literature ● Heroes and other explorers of the underworld ● Scientists and engineers associated with Pluto and the Kuiper Belt ● Pioneering space missions and spacecraft ● Historic pioneers who crossed new horizons in the exploration of the Earth, sea and sky Charon ● Destinations and milestones of fictional space and other exploration ● Fictional and mythological vessels of space and other exploration ● Fictional and mythological voyagers, travelers and explorers ● Authors and artists associated with space exploration, especially Pluto and the Kuiper Belt For Pluto’s smaller moons: • Styx: River gods • Nix: Deities of the night • Kerberos: Dogs from literature, mythology and history • Hydra: Legendary serpents and dragons
News Article | February 26, 2016
You won't need a time machine to know what Earth's weather was like billions of years ago. Climate data from Jupiter and Saturn can provide insight to our own planet's past and future atmospheric conditions, an expert from the University of Houston said. Assistant Professor Liming Li is leading a team of scientists from the University of Wisconsin-Madison and NASA's Jet Propulsion Laboratory to analyze data from instruments on board the Cassini. The spacecraft is currently on a mission to explore Saturn's systems. NASA's Planetary Science Division awarded Li and his colleagues with two new projects worth $700,000 for the chance to study climate in other planets thru Cassini. Cassini contains 12-gathering instruments that can give scientists access to insurmountable amount of data. The spacecraft's primary mission was supposed to end in 2008, but because it was so successful, NASA extended it several times. It is now scheduled to end next year. The research team will be calculating the energy budget for Jupiter, Saturn and Saturn's moon Titan, because it will impact our understanding of planetary evolution and climate. The energy budget accounts for the amount of energy from the sun that comes into a planet's climate system and how much energy is emitted. On Earth, Li said the incoming energy is approximately equal to the outgoing energy. The temperature does not dramatically change, even with the effects of greenhouse gases. On the other hand, Saturn and Jupiter emit more energy than the energy they absorb, thus generating internal heat. Titan and Earth are similar, Li said, because they do not have significant internal heat. Li said scientists believe that the atmosphere in Titan is like the ancient atmosphere on our own planet. By studying the Saturn satellite's atmosphere, we can learn what occurred in the past to Earth's atmosphere. Each year in Saturn is approximately equivalent to 30 Earth years. Li said this meant that long-term observations are needed to learn about the ringed planet's seasons. "Fortunately, Cassini is a long-term mission, gathering data for more than 10 years," said Li. "Every year, every day, we are getting beautiful data from the spacecraft." According to Li, Saturn's atmospheric systems vary as seasons change. In summer and spring, there are giant storms. Scientists have even observed the largest storm in our solar system through Cassini. "It was 100,000 kilometers wide, which is more than 62,000 miles," said Li. "That is much bigger than a storm on Earth and, actually, bigger than Earth." Why is it so important? It's because atmospheric scientists will have the chance to look at climate change in a short-term scale. With data from Cassini beginning in 2004 up until 2017, the observations will cover changes within two to three seasons. Since our planet and Saturn have almost the same rotation angle, it is likely that they have some similar changes in seasons. Before this mission, however, the team did not have any data to help them study the ringed planet's seasons, so Cassini's findings are quite remarkable. Li began his career in meteorology in China and concerned himself with weather conditions on our own planet. He came to the United States for his Ph.D. and became interested in planetary science, studying meteorology in other planets. The physics associate professor has been actively involved in ongoing space missions that explore giant planets in our solar system. He said the weather system in other planets is completely different from our own. "By studying the weather systems on planets, we can get a wide perspective for how the climate changes on Earth," added Li.
News Article | February 19, 2017
"Juno is healthy, its science instruments are fully operational, and the data and images we've received are nothing short of amazing," said Thomas Zurbuchen, associate administrator for NASA's Science Mission Directorate in Washington. "The decision to forego the burn is the right thing to do—preserving a valuable asset so that Juno can continue its exciting journey of discovery." Juno has successfully orbited Jupiter four times since arriving at the giant planet, with the most recent orbit completed on Feb. 2. Its next close flyby of Jupiter will be March 27. The orbital period does not affect the quality of the science collected by Juno on each flyby, since the altitude over Jupiter will be the same at the time of closest approach. In fact, the longer orbit provides new opportunities that allow further exploration of the far reaches of space dominated by Jupiter's magnetic field, increasing the value of Juno's research. During each orbit, Juno soars low over Jupiter's cloud tops—as close as about 2,600 miles (4,100 kilometers). During these flybys, Juno probes beneath the obscuring cloud cover and studies Jupiter's auroras to learn more about the planet's origins, structure, atmosphere and magnetosphere. The original Juno flight plan envisioned the spacecraft looping around Jupiter twice in 53-day orbits, then reducing its orbital period to 14 days for the remainder of the mission. However, two helium check valves that are part of the plumbing for the spacecraft's main engine did not operate as expected when the propulsion system was pressurized in October. Telemetry from the spacecraft indicated that it took several minutes for the valves to open, while it took only a few seconds during past main engine firings. "During a thorough review, we looked at multiple scenarios that would place Juno in a shorter-period orbit, but there was concern that another main engine burn could result in a less-than-desirable orbit," said Rick Nybakken, Juno project manager at NASA's Jet Propulsion Laboratory in Pasadena, California. "The bottom line is a burn represented a risk to completion of Juno's science objectives." Juno's larger 53-day orbit allows for "bonus science" that wasn't part of the original mission design. Juno will further explore the far reaches of the Jovian magnetosphere—the region of space dominated by Jupiter's magnetic field—including the far magnetotail, the southern magnetosphere, and the magnetospheric boundary region called the magnetopause. Understanding magnetospheres and how they interact with the solar wind are key science goals of NASA's Heliophysics Science Division. "Another key advantage of the longer orbit is that Juno will spend less time within the strong radiation belts on each orbit," said Scott Bolton, Juno principal investigator from Southwest Research Institute in San Antonio. "This is significant because radiation has been the main life-limiting factor for Juno." Juno will continue to operate within the current budget plan through July 2018, for a total of 12 science orbits. The team can then propose to extend the mission during the next science review cycle. The review process evaluates proposed mission extensions on the merit and value of previous and anticipated science returns. The Juno science team continues to analyze returns from previous flybys. Revelations include that Jupiter's magnetic fields and aurora are bigger and more powerful than originally thought and that the belts and zones that give the gas giant's cloud top its distinctive look extend deep into the planet's interior. Peer-reviewed papers with more in-depth science results from Juno's first three flybys are expected to be published within the next few months. In addition, the mission's JunoCam—the first interplanetary outreach camera—is now being guided with assistance from the public. People can participate by voting on which features on Jupiter should be imaged during each flyby. "Juno is providing spectacular results, and we are rewriting our ideas of how giant planets work," said Bolton. "The science will be just as spectacular as with our original plan." Explore further: NASA's Juno spacecraft to make its fourth flyby over Jupiter
Burrows N.,Science Division |
McCaw L.,Science Division
Frontiers in Ecology and the Environment | Year: 2013
Prescribed burning is an important but often controversial fire-management tool in fire-prone regions of the world. Here, we explore the complex challenges of prescribing fire for multiple objectives in the eucalypt forests of southwestern Australia, which could be regarded as a model for temperate landscapes elsewhere. Prescribed fire has been used in a coordinated manner to manage fuels in Australia's eucalypt forests since the 1950s and continues to be an important tool for mitigating the impacts of unplanned wildfires on human society and on a broad range of ecosystem services. Prescribed fire is increasingly being used to manage fire regimes at the local and landscape scales to achieve biodiversity outcomes through maintenance of spatial and temporal patterns of post-fire seral stages. The prescribed burning program in southwestern eucalypt forests has been informed by a long-term program of applied research into fire behavior and fire ecology. To remain successful in the future, the prescribed burning program in this region will need to adapt to changing expectations of government and the community, emerging land-use issues, resource limitations, and a drying climate. © The Ecological Society of America.
News Article | March 3, 2017
The Planetary Science Vision 2050 Workshop is happening right now at NASA headquarters in Washington DC. The workshop is meant to discuss ambitious space projects that could be realized, or at least started, by 2050. One of the most enticing ideas came this morning from Jim Green, NASA's Planetary Science Division Director. In a talk titled, "A Future Mars Environment for Science and Exploration," Green discussed launching a "magnetic shield" to a stable orbit between Mars and the sun, called Mars L1, to shield the planet from high-energy solar particles. The shield structure would consist of a large dipole, or a pair of equal and oppositely charged magnets to generate an artificial magnetic field. Such a shield could leave Mars in the relatively protected magnetotail of the magnetic field created by the object, allowing the Red Planet to slowly restore its atmosphere. About 90 percent of Mars's atmosphere was stripped away by solar particles in the lifetime of the planet, which was likely temperate and had surface water about 3.5 billion years ago. According to simulation models, such a shield could help Mars achieve half the atmospheric pressure of Earth in a matter of years. With protection from solar winds, frozen CO2 at Mars's polar ice caps would start to sublimate, or turn directly into gas from a solid. The greenhouse effect would start to fill Mars's thin atmosphere and heat the planet, mainly at the equator, at which point the vast stores of ice under the poles would melt and flood the world with liquid water. "Perhaps one-seventh of the ancient ocean could return to Mars," said Green. This is some truly futuristic stuff, reminiscent of Kim Stanley Robinson's Red Mars trilogy. But it is theoretically possible, and it just might, maybe, be a step toward terraforming Mars for human inhabitation in the next century. You can watch the talk here (it starts at 1:36:00). You Might Also Like
News Article | October 28, 2016
The U.S. Department of Education has awarded the University of La Verne a $6 million grant to increase the number of Latinos graduating with Science, Technology, Engineering, and Mathematics (STEM) degrees. It is the largest government grant the university has received in its 125-year history. The five-year grant for Hispanic Serving Institutions (HSI) will fund new course development, faculty training, classroom technology, advising, and career support. It will also facilitate partnerships to give community college students throughout the region support in pursuing STEM majors at the university. “This is a very exciting project,” said Dr. Kat Weaver, associate professor of biology and co-author of the grant. “It will allow the faculty in the Natural Science Division to continue their work on designing innovative teaching methods and improving learning and retention for STEM students.” The Department of Education has projected a 17 percent increase in STEM occupations between 2010 and 2020, and there are about two science and technology job openings for every qualified job seeker. Studies have shown that diversity in STEM fields leads to better science by bringing many perspectives together in research and problem solving. The grant’s initiatives, called the “Guided Pathway to STEM Success,” are expected to increase the number of Latinos and students from underserved socioeconomic backgrounds completing STEM degrees at the University of La Verne by 10 percent by 2021. Weaver expects the program to boost the number of Latino sophomores continuing in STEM majors into their junior year by 15 percent in the next five years. But the program will help more than just Latino students. About 2,400 students, including 600 traditional undergraduates and 200 transfer students who are Latino and low-income, as well as 1,600 students of all backgrounds and majors, will benefit from the program by 2021. “All students taking college algebra will benefit,” Weaver said. “All students taking physics will benefit. It is broad reaching across campus.” The grant provides opportunities to incorporate more of what educators call high-impact practices, which include learning communities, group-problem solving, and peer instruction – all elements that researchers say improve success in STEM courses. Assistant Professor of Mathematics Dr. Gail Tang said she uses these techniques and will also utilize technology to help students understand various concepts in subjects such as calculus. “There exists technology that allows students to better visualize these three-dimensional objects by plotting and then interacting with them by rotating, shrinking or expanding them,” Tang said. Some elements of the program include: An HSI is defined by federal agencies as an accredited U.S. college or university with at least 25 percent Hispanic full-time student enrollment. The University of La Verne serves a population of about 44 percent Hispanic students and about 40 percent first generation college students, reflecting the diversity of the communities it serves. About the University of La Verne Founded in 1891 and located 35 miles east of Los Angeles, the University of La Verne is a private, nonprofit, comprehensive institution founded on four core values: lifelong learning, ethical reasoning, civic and community engagement, and diversity and inclusivity. The University of La Verne serves nearly 8,400 students at its historic La Verne campus and across 9 other California regional locations.