News and Updates

11/21/2014

In becoming a partner in the Murchison Widefield Array radio telescope, scientists from ASU's School of Earth and Space Exploration will be using it to explore the beginning of the universe. 

Arizona State University has joined with 14 other institutions in Australia, India, New Zealand, and the United States in a radio telescope project that focuses on the early universe and the birth and formation of the first galaxies.

The radio telescope is the Murchison Widefield Array (MWA), located in the Shire of Murchison, Western Australia. The Shire, isolated and sparsely populated, has no villages or towns, and consists of only about 30 cattle and sheep stations (ranches), with a combined population of around 100. These are spread over about 20,000 square miles (50,000 square kilometers).

The telescope is constructed of 2048 dipole antennas, grouped into 4 x 4 arrays called tiles. Each dipole antenna spans about 30 inches (74 centimeters). Most of the tiles (112) scatter across a core section one mile (1.5 kilometer) in diameter, with the remaining 16 tiles placed outside the core, yielding baseline distances of about two miles (3 km).

The antennas and receivers operate at low radio frequencies and are optimized for radio waves in the 80-300 Megahertz range — the same frequencies used for FM radio and broadcast TV. Hence Murchison's geographic isolation provides great advantages.

"A dense-core-plus-outliers arrangement gives sensitive, wide-field views from the central tiles," says Judd Bowman, associate professor of astronomy in the School of Earth and Space Exploration (SESE) and project scientist for the telescope array. "And the outliers provide high-reolution imaging for solar outbursts and extragalactic sources, other areas of focus in the telescope's scientific program."

Research opportunities for ASU astronomers

The telescope program will provide many opportunities for scientists, researchers, and students in SESE, Bowman says. "As a partner institution in the telescope, any faculty member at ASU can join the project and receive access to observing data."

Three ASU undergraduates traveled with Bowman to Australia to help with the construction and commissioning of the telescope and related experiments at the site. The telescope is already being used by graduate students and two postdoctoral scholars at ASU for their research. For example, ASU researchers are currently using the telescope to search for traces of relic radio waves from primordial gas surrounding the first stars and galaxies at a time, more than 13 billion years ago, when the Universe less than a billion years old.

Bowman says, “This telescope complements very well the observational cosmology efforts already underway at ASU to observe the oldest galaxies in the Universe. With the MWA, while we won’t see the galaxies themselves, we hope to detect the cosmic fingerprints those galaxies left in the intergalactic gas around them.”

Danny Jacobs, NSF Postdoctoral Fellow in SESE, is helping to coordinate the analysis of more than a thousand terabytes of data already acquired by the telescope. “The MWA is fixed to the ground and sees the entire sky," he explains. To unpack the signals and extract the data requires powerful computer processing. "To an unprecedented degree, the MWA is a software telescope. We’re really pushing the limits of what our computers can do.”

The Murchison Widefield Array has four elements or research avenues that make up its scientific program. These are: (1) exploration of the Cosmic Dawn and epoch of reionization, the period when the first stars and galaxies formed in the early Universe; (2) radio emission from the Milky Way Galaxy and extragalactic sources, which is both a complicating foreground "fog" for observations and an interesting scientific target of its own; (3) searching for transient and variable radio events that are rare and faint, and which occur on timescales from seconds to months; and (4) space weather, the study of solar outbursts as they travel from the Sun's surface to Earth.

Along with ASU's new role in the project, Bowman notes, SESE is hosting an international scientific conference in December 2014. It will be based around the Murchison Widefield Array and the initial science results from both it and other low-frequency radio telescopes.

The School of Earth and Space Exploration is an academic unit of ASU's College of Liberal Arts and Sciences.

 

11/20/2014

A longstanding controversy over a purported rare form of diamond called lonsdaleite is now settled. It is diamond that has been formed by impact shock, but which lacks the three-dimensional regularity of ordinary diamond.

Scientists have argued for half a century about the existence of a form of diamond called lonsdaleite, which is associated with impacts by meteorites and asteroids. A group of scientists based mostly at Arizona State University now show that what has been called lonsdaleite is in fact a structurally disordered form of ordinary diamond.

The scientists' report is published in Nature Communications, Nov. 20, 2014, by Péter Németh, a former ASU visiting researcher (now with the Research Centre of Natural Sciences of the Hungarian Academy of Sciences), together with ASU's Laurence Garvie, Toshihiro Aoki, and Peter Buseck, plus Natalia Dubrovinskaia and Leonid Dubrovinsky from the University of Bayreuth in Germany. Buseck and Garvie are with ASU's School of Earth and Space Exploration, while Aoki is with ASU's LeRoy Eyring Center for Solid State Science.

"So-called lonsdaleite is actually the long-familiar cubic form of diamond, but it's full of defects," says Péter Németh. These can occur, he explains, due to shock metamorphism, plastic deformation, or unequilibrated crystal growth.

The lonsdaleite story began almost 50 years ago. Scientists reported that a large meteorite, called Canyon Diablo after the crater it formed on impact in northern Arizona, contained a new form of diamond with a hexagonal structure. They described it as an impact-related mineral and called it lonsdaleite, after Dame Kathleen Lonsdale, a famous crystallographer.

Since then, "lonsdaleite" has been widely used by scientists as an indicator of ancient asteroidal impacts on Earth, including those linked to mass extinctions. In addition, it has been thought to have mechanical properties superior to ordinary diamond, giving it high potential industrial significance. All this focused much interest on the mineral, although pure crystals of it, even tiny ones, have never been found or synthesized. That posed a long-standing puzzle.

The ASU scientists approached the question by re-examining Canyon Diablo diamonds and investigating laboratory samples prepared under conditions in which lonsdaleite has been reported.

Using the advanced electron microscopes in ASU's Center for Solid State Science, the team discovered, both in the Canyon Diablo and the synthetic samples, new types of diamond twins and nanometer-scale structural complexity. These give rise to features attributed to lonsdaleite.

"Most crystals have regular repeating structures, much like the bricks in a well-built wall," says Peter Buseck. However, interruptions can occur in the regularity, and these are called defects. "Defects are intermixed with the normal diamond structure, just as if the wall had an occasional half-brick or longer brick or row of bricks that's slightly displaced to one side or another."

The outcome of the new work is that so-called lonsdaleite is the same as the regular cubic form of diamond, but it has been subjected to shock or pressure that caused defects within the crystal structure.

One consequence of the new work is that many scientific studies based on the presumption that lonsdaleite is a separate type of diamond need to be re-examined. The study implies that both shock and static compression can produce an intensely defective diamond structure.

The new discovery also suggests that the observed structural complexity of the Canyon Diablo diamond results in interesting mechanical properties. It could be a candidate for a product with exceptional hardness.

The School of Earth and Space Exploration is an academic unit of ASU's College of Liberal Arts and Sciences. 

 

11/18/2014

Using robots to explore extreme enviroments is the theme of the Earth and Space open house.

Need to explore a place where even sophisticated robots can't go? It's a tough job, but something's got to do it. This semester's final ASU public Earth & Space open house is all about "Extreme Robotic Exploration." Find out what's involved, Nov. 21, from 7 to 10 p.m., at the Interdisciplinary Science and Technology Building IV (ISTB 4) on ASU’s Tempe campus.

Robots explore lunar cave or lava tubeVisitors to the free event can attend a public lecture by the School of Earth and Space Exploration's Jekan Thanga. His topic is "Exploring Extreme Environments on the Moon and Mars using a Flying Network of Ball Robots." The talk discusses the feasibility of using small robots to explore environments on the Moon and Mars where larger and more expensive robotic spacecraft can't safely go. Small robots, however, could be deployed from landers or rovers, making accessible such locations as canyons, lava tubes, and caves that would otherwise be out of reach. The talk will be given at 8:15 p.m. in room 240.

Besides the public lecture, this Open House will feature the inaugural appearance of the Icarus Rocketry team, ASU's high-power rocketry competition team.

In addition, there will be two 3D planetarium shows titled "Measuring Distances in the Universe" in the Marston Exploration Theater, at 7:15 and 8:45 p.m. All seating is on a first-come basis.

As usual, there will be telescope sky viewing outdoors next to the James Turrell Skyscape art installation from 8 to 10 p.m. (weather permitting). Don't miss the many exciting demonstrations and activities in the state-of-the-art ISTB4 Gallery of Scientific Exploration by experts in astrobiology, geology, cosmology, planetary science — and don't leave without picking up your free poster.

To get to the open house, go to the main entrance of ISTB 4, located on the building’s north side.

The monthly open house is sponsored by the School of Earth and Space Exploration, GeoClub, and AstroDevils: ASU Astronomy Club, Icarus Rocketry, Students for the Exploration and Development of Space (SEDS), and the Center for Meteorite Studies (CMS). For more information, visit http://earthspaceopenhouse.weebly.com or visit the School's Facebook event page. The next open houses will be on February 20, March 27, and April 24, 2015.

The School of Earth and Space Exploration is an academic unit of the College of Liberal Arts and Sciences.

 

11/17/2014

A SESE-led project to map the impact sequence on the asteroid Vesta is helping scientists compare its history to other solar system objects.

A team of 14 scientists led by David Williams of Arizona State University's School of Earth and Space Exploration has completed the first global geologic and tectonic map of the asteroid Vesta. The work reveals that Vesta's history has been dominated by impacts from large meteorites.

The mapping was carried out using images from NASA's Dawn spacecraft, which orbited Vesta between June 2011 and September 2012. The images let scientists create high-resolution geological maps, revealing the variety of Vesta’s surface features in unprecedented detail.

"The geologic mapping campaign at Vesta took about two and a half years to complete," says Williams. "The resulting maps enabled us to construct a geologic time scale of Vesta for comparison to other planets and moons."

The geologic map and timescale appear in a paper by Williams and others in the December 2014 issue of the journal Icarus. The issue also has 10 other papers reporting on Dawn's investigation of Vesta. In addition to Williams, the mapping effort was also led by R. Aileen Yingst of the Planetary Science Institute, Tucson, Arizona, and W. Brent Garry of NASA's Goddard Spaceflight Center, Greenbelt, Maryland.

The mappers found that Vesta’s geologic time scale has been shaped by a sequence of large impact events. The biggest of these were the impacts that blasted the large Veneneia and Rheasilvia craters early in Vesta's history and the Marcia crater late in its history.

In mapping an extraterrestrial object, scientists begin by studying its surface features to develop a relative chronology of events. They look to see which feature interrupts or disturbs other features, thereby placing them in a relative time sequence. Then, crater by crater, fracture by fracture, scientists build up a chronology of events.

But how long ago did specific events happen? An age in years is quite difficult to determine because the samples scientists have from Vesta — a family of basaltic meteorites called HEDs, for howardite-eucrite-diogenite — do not show a clear formation age (as dated by laboratory methods) that can be linked to specific features on the asteroid.

"So figuring out an actual date in years is a step-by-step-by-step process," explains Williams. "We work with rock samples from the Moon, mostly from Apollo missions decades ago. These give actual dates for large lunar impacts." The tricky part, he says, lies in creating a model that links the lunar impact time scale to the rest of the solar system.

In the case of Vesta, scientists have developed two different models to estimate surface ages. One is based on the lunar impact rate, the other on the frequency of asteroid impacts. Thus scientists can use two approaches with crater statistics to date Vesta's surface, but these yield two different age ranges.

Applying the models to Vesta, Williams' team concluded that the oldest surviving crust on Vesta predates the Veneneia impact, which has an age of 2.1 billion years (asteroid system) or 3.7 billion years (lunar system). The Rheasilvia impact likely has an age of around 1 billion years (asteroids) or 3.5 billion years (lunar).

"Vesta's last big event, the Marcia impact, has an age that's still uncertain," says Williams. "But our current best estimates suggest an age between roughly 120 and 390 million years." The difference, he explains, comes from which cratering model is used.

The geologic mapping relied on images taken by the framing camera provided by the Max Planck Institute for Solar System Research of the German Max Planck Society and the German Aerospace Center (DLR). This camera takes panchromatic images and seven bands of color filtered images. Overlapping images provide stereoscopic views that create topographic models of the surface to help the geologic interpretation.

“Geological mapping was crucial for resolving Vesta’s geologic history, as well as providing geologic context to understand compositional information from Dawn's Visible and Infrared (VIR) spectrometer and Gamma Ray and Neutron Detector (GRaND),” says Carol Raymond, Dawn’s deputy principal investigator.

The objective of NASA's Dawn mission, launched in 2007, is to characterize the two most massive objects in the main asteroid belt between Mars and Jupiter. Vesta was thought to be the source of a unique set of basaltic meteorites (the HEDs), and Dawn confirmed the Vesta-HED connection. The Dawn spacecraft is currently on its way to the dwarf planet Ceres, the largest object in the asteroid belt. The spacecraft will arrive at Ceres in March 2015. The Dawn mission is managed by the NASA Jet Propulsion Laboratory in Pasadena, California.

The School of Earth and Space Exploration is an academic unit of ASU's College of Liberal Arts and Sciences.  

11/13/2014

Astrophysicist Steve Desch of ASU's School of Earth and Space Exploration says that magnetic clues in a meteorite outline the earliest steps in the formation of the solar system and Earth-like planets.

 The most accurate laboratory measurements yet made of magnetic fields trapped in grains within a primitive meteorite are providing important clues to how the early solar system evolved. The measurements point to shock waves traveling through the cloud of dusty gas around the newborn Sun as a major factor in solar system formation. 

The results appear in a paper published November 13, 2014, in the journal Science. The lead author is graduate student Roger Fu of MIT, working under Benjamin Weiss; Steve Desch of Arizona State University's School of Earth and Space Exploration is a co-author of the paper.
 
"The measurements made by Fu and Weiss are astounding and unprecedented," says Desch. "Not only have they measured tiny magnetic fields thousands of times weaker than a compass feels, they have mapped the magnetic fields' variation recorded by the meteorite, millimeter by millimeter."
 
Construction debris
 
It may seem all but impossible to determine how the solar system formed, given it happened about 4.5 billion years ago. But making the solar system was a messy process, leaving lots of construction debris behind for scientists to study.
 
Among the most useful pieces of debris are the oldest, most primitive and least altered type of meteorites, called the chondrites (KON-drites). Chondrite meteorites are pieces of asteroids, broken off by collisions, that have remained relatively unmodified since they formed at the birth of the solar system. They are built mostly of small stony grains, called chondrules, barely a millimeter in diameter.
 
Chondrules themselves formed through quick melting events in the dusty gas cloud – the solar nebula – that surrounded the young sun. Patches of the solar nebula must have been heated above the melting point of rock for hours to days. Dustballs caught in these events made droplets of molten rock, which then cooled and crystallized into chondrules. 
 
Tiny magnets
 
As chondrules cooled, iron-bearing minerals within them became magnetized like bits on a hard drive by the local magnetic field in the gas. These magnetic fields are preserved in the chondrules even down to the present day.
 
The chondrule grains whose magnetic fields were mapped in the new study came from a meteorite named Semarkona, after the place in India where it fell in 1940. It weighed 691 grams, or about a pound and a half.
 
The scientists focused specifically on the embedded magnetic fields captured by "dusty" olivine grains that contain abundant iron-bearing minerals. These had a magnetic field of about 54 microtesla, similar to the magnetic field at Earth’s surface, which ranges from 25 to 65 microtesla.
 
Coincidentally, many previous measurements of meteorites also implied similar field strengths. But it is now understood that those measurements detected magnetic minerals contaminated by Earth’s magnetic field, or even from hand magnets used by meteorite collectors.
 
"The new experiments," Desch says, "probe magnetic minerals in chondrules never measured before. They also show that each chondrule is magnetized like a little bar magnet, but with 'north' pointing in random directions."
 
This shows, he says, they became magnetized before they were built into the meteorite, and not while sitting on Earth’s surface.
 
Shocks and more shocks
 
"My modeling for the heating events shows that shock waves passing through the solar nebula is what melted most chondrules," Desch explains. Depending on the strength and size of the shock wave, the background magnetic field could be amplified by up to 30 times.
 
He says, "Given the measured magnetic field strength of about 54 microtesla, this shows the background field in the nebula was probably in the range of 5 to 50 microtesla."
 
There are other ideas for how chondrules might have formed, some involving magnetic flares above the solar nebula, or passage through the sun’s magnetic field. But those mechanisms require stronger magnetic fields than what is measured in the Semarkona samples.
 
This reinforces the idea that shocks melted the chondrules in the solar nebula at about the location of today's asteroid belt, which lies some two to four times farther from the sun than Earth now orbits.
 
Desch says, "This is the first really accurate and reliable measurement of the magnetic field in the gas from which our planets formed."
 
The School of Earth and Space Exploration is an academic unit of ASU's College of Liberal Arts and Sciences. 
10/27/2014

Ominous Comets, Spooky Things in Space, and Nefarious Nebulas are all on the program at the next Earth and Space Open House, October 31.

SESE's next Earth & Space Open House is set to take place from 7 to 10 p.m., October 31, at the Interdisciplinary Science and Technology Building IV (ISTB 4) on ASU’s Tempe campus.

Visitors to the free event can attend a pair of public lectures, take in a planetarium show, gaze at the sky through telescopes, watch science demonstrations and explore the interactive displays in ISTB 4, which is located at the corner of McAllister and Terrace. (There's also a family-friendly Halloween Costume Contest.)

The theme for this Open House, appropriately, is Strange Things in the Sky. There will be two public lectures and two showings of a planetarium show in the Marston Exploration Theater. All seating is on a first-come basis.

The first public talk, given at 7:30 p.m. in Room 240, is "Spooky Things in the Universe," by Teresa Ashcraft, School of Earth and Space Exploration graduate student.

The second public talk, at 8:15 p.m. in Room 240, is "Ominous Comets," by Vincenzo Cataldo, School of Earth and Space Exploration graduate student.

The planetarium show is titled "Nefarious Nebulas" and is given at 7:15 p.m. and again at 8:45 p.m. in the Marston Exploration Theater.

In addition, there will be a family-friendly Halloween Costume Contest (prize: a small telescope) and an opportunity to get your picture taken on Mars. Sky viewing telescopes will be set up from 8 to 10 p.m. outdoors next to the Skyscape art installation.

To get to the open house, go to the main entrance of ISTB 4, located on the building’s north side.

The monthly open house is partially sponsored by the School of Earth and Space Exploration, GeoClub and AstroDevils: ASU Astronomy Club. For more information, visit http://earthspaceopenhouse.weebly.com or https://www.facebook.com/events/666877276760169. The next Open Houses will be on November 21, 2014 and February 20, March 27, and April 24, 2015.

The School of Earth and Space Exploration is an academic unit of the College of Liberal Arts and Sciences.

10/20/2014

Everyone of all ages is invited to a whole day of hands-on science fun at ASU.

The public is invited to spend a day exploring Earth and space with ASU scientists from 9 a.m. to 3 p.m., Oct. 25, at the Interdisciplinary Science and Technology Building IV (ISTB 4), at Arizona State University’s Tempe campus. The daylong event is designed to inspire the many local kids, parents, educators and other community members that are intrigued by science.

Earth and Space Exploration Day provides a variety of science-related interactive activities for children ages five and up and anyone interested in exploring Earth and space alongside real scientists.

This will be the 17th year that faculty and students in the School of Earth and Space Exploration in ASU’s College of Liberal Arts and Sciences have sponsored the event and used it as a means of connecting the community with science.

Together, families can experience a variety of activities, including digging for meteorites and creating impact craters, manipulating robotic arms and driving remote controlled underwater robots, and learning the science of rockets by making a soda straw rocket, to name a few. For a complete listing of activities, visit http://sese.asu.edu/earth-and-space-exploration-day.

In addition to the tabletop activities and interactive demonstrations, there will be lab tours, lectures and opportunities to engage with the kiosk-style exhibits in the Gallery of Scientific Exploration.

Space lovers can look through telescopes at solar spots and visit a replica of Curiosity Rover, matching the dimensions of the real rover currently on Mars. Several 3-D astronomy shows will be offered at various times in the building’s state-of-the-art, high-definition Marston Exploration Theater.

Meteorite enthusiasts can visit the meteorite display on the second floor, drawn from the extensive collection of ASU’s Center for Meteorite Studies. Visitors can examine touchable samples, engage with interactive displays and ask staff to inspect potential meteorite specimens.

Rock hounds can bring a rock specimen for "Dr. Rock" to analyze and identify, or take part in a family-friendly geology field trip to “A” Mountain (Hayden Butte) to learn about the sedimentary rocks, volcanic rocks and geological structures exposed in Tempe. The ASU GeoClub will also be selling mineral and rock samples, along with snacks.

Lectures are scheduled throughout the day on topics ranging from space exploration to Earth’s climate.

For more information, contact the School of Earth and Space Exploration at (480) 965-5081 or visit http://sese.asu.edu/earth-and-space-exploration-day

 

 

10/17/2014

Three new postdoctoral Exploration Fellows have joined the School of Earth and Space Exploration, starting with the current academic year. Their terms run until 2016.

The three scientists are Sarah B. Cichy, Harmony Colella, and Monica Palta. Two earned their PhD degrees in 2011: Cichy at Leibniz Universität Hannover in Germany, and Colella at the University of California, Riverside. Palta earned her degree in 2012 at Rutgers.

Volcanoes

"My fascination about volcanoes began with a helicopter ride over and into the crater of Mount St. Helens at the age of 9," Sarah B. Cichy says. More than two decades have passed since then and she is still eager and passionate to tackle the questions “How do volcanoes work?” and especially “What causes them to erupt either explosively or effusively?”

“My main research interests are focusing on magma degassing (i.e. bubble formation through volatile exsolution) and microlite crystallization from magma storage conditions to magma ascent dynamics, and beyond”, she says. "I study these processes and their timescales through chemical and textural analyses, comparing natural rock samples with experimental run-products." 

Her interdisciplinary SESE Fellowship project will combine petrology, volcanology and isotope geochemistry to develop an eruption-geospeedometer, and is mentored by SESE professors Christy Till, Amanda Clarke, and Richard Hervig. 

As a member of the EPIC group (Experimental Petrology & Igneous processes Center; http://epic.asu.edu), Cichy is also responsible for reactivating and managing the high-pressure/high-temperature gas vessel lab of retired ASU professor John Holloway. 

She has a personal website at http://scichy.wordpress.com.

Modeling Earthquakes

Harmony Colella says, "Geology and geophysics have played a central role in my life and interests. I experienced my first earthquake at 7 years old, and I have been fascinated by them ever since."

Her current research is driven by a curiosity about earthquake processes in subduction zones, where the largest and most destructive earthquakes occur. In particular, her work focuses on the interactions of different types of slip along the subduction zone interface and their effects on long-term recurrence rates of great megathrust earthquakes.

"Specifically," she says, "I'm interested in the probability that any given slow-slip event triggers a great megathrust earthquake. Recent studies suggest slow-slip events also trigger an increase of smaller earthquakes near the base of the locked section of the megathrust, which raises interesting questions about seismicity rates prior to great earthquakes." 

She also investigates the possible causes of segmentation of the megathrust and its effects on long-term probabilities, and how slip is partitioned between the megathurst and strike-slip faults at a convergent plate boundary.

Like most geologists Colella loves camping and hiking especially on the flanks of volcanoes with her dogs. She volunteers for a local dog rescue. Colella recently began SCUBA diving, which has added a new way to explore some field areas "and piqued my interest in marine life and ecology."

As Rivers Run

For Monica Palta, the draw is the interaction between human society and wetlands.  

"I examine water quality and quantity issues affected by human use of, and development within, floodplain ecosystems," she explains. "Currently, I'm studying nutrient and microbial pollution in the Salt River in Phoenix, and the ability of Salt River wetlands to attenuate this pollution under different climate scenarios."

Wetland systems, specifically those associated with rivers and streams, have been the focus of her professional interest and endeavors for the last 15 years. Her passion for better understanding human-river interactions began during an undergraduate year abroad in India, where she conducted a study on pollution loading in the Ganges River for her Senior Honors Thesis.

"Floodplain and estuarine ecosystems provide important services to human populations, and have often been at the epicenter of both agricultural and urban expansion," Palta says. However, she explains, we know little about how key ecosystem processes such as nutrient and water cycling interact with each other, and with pollutant loading and flood control infrastructure, in urban rivers.

As a SESE fellow, she will focus on linking fluvial dynamics to processing of pollutants in the Salt River, under the mentorship of SESE professors Hilairy Hartnett and Enrique Vivoni. 

On occasion, she notes, fieldwork in her diverse and unusual field sites has involved dragging ladders and car batteries through swamps to take environmental measurements — while avoiding both carpets of poison ivy and a myriad of poisonous snakes on the ground. In South Carolina, she once had an encounter with shotgun-toting hunters who mistook her rustlings in the brush for a feral hog.

"I never ended up uncovering Jimmy Hoffa’s body from the sediments of my study wetlands in New Jersey," she says. "But I did happen to spot one of my field sites on TV one night — it was the scene of the murder of Vito Corleone’s driver in the first Godfather movie."

Her personal website is at: https://www.researchgate.net/profile/Monica_Palta

 
 

 

10/12/2014

Small lava flows on the Moon's dark plains show volcanic activity occurred as recently as 50 million years ago.

Dark outpourings of lava gave the "Man in the Moon" his face more than three billion years ago. And volcanic activity continued on the  Moon until it halted a billion years ago – or so lunar scientists have long thought.

However, a new discovery by a group of geologists at Arizona State University's School of Earth and Space Exploration shows that the Moon has seen small but widespread eruptions of basaltic lava during the last 50 million years, a geologically recent period.

The discovery was announced in a paper published online Oct. 12 in Nature Geoscience. Sarah Braden, a recent School of Earth and Space Exploration graduate, is the lead author; the others are Julie Stopar, Samuel Lawrence and Mark Robinson, all researchers in the school, and Carolyn van der Bogert and Harald Hiesinger of the Westfälische Wilhelms-Universität Münster in Germany.

The science team identified 70 small volcanic features scattered across the Moon's dark volcanic plains, or maria. The features show as a combination of smooth, low, rounded mounds near patches of rough, blocky terrain. The scientists refer to these unusual areas as irregular mare patches.

"Finding previously unknown geologic features on the lunar surface is extremely exciting," says Braden.

The features are too small to be seen from Earth, averaging less than a third of a mile (500 meters) across their largest dimension. One feature named Ina has been known for a long time, having been imaged from lunar orbit by Apollo 15 astronauts in the 1970s. Several early studies indicated that Ina could be very young (10 million years or less), but only a few irregular mare patches were known then, and their significance was unclear.

It was not until the scientists had high-resolution images showing the entire Moon that the full extent and significance of the small lava features were understood. These images are the product of the two Narrow Angle Cameras that form part of the Lunar Reconnaissance Orbiter Camera system. Co-author Mark Robinson is the principal investigator for the camera, which is on NASA's Lunar Reconnaissance Orbiter spacecraft.

The ages of the irregular mare patch features come from studies of crater sizes and numbers within a given area by Braden, assisted by van der Bogert and Hiesinger. These crater-counting dates are linked to laboratory ages provided by Apollo and Luna samples. The results show that instead of lunar volcanism stopping abruptly about a billion years ago, it ended more gradually, continuing until less than 50 million years ago.

Activity at Ina, the scientists found, ended about 33 million years ago, and at another irregular mare patch, Sosigenes, it stopped only about 18 million years ago. (In contrast, most of the lava flows that make up the dark plains visible by eye from Earth erupted between 3.5 and 1 billion years ago.)

"The existence and young age of the irregular mare patches provides a new constraint for models of the lunar interior's thermal evolution," Braden says. "The lunar mantle had to remain hot enough for long enough to provide magma for the small-volume eruptions."

Robinson notes that the new discovery is hard to reconcile with what's currently thought about the temperature of the Moon's interior. "These young volcanic features are now prime targets for future exploration, both robotic and human."

The discovery gives the Moon's volcanic history a new chapter. As Braden says, "Our understanding of the Moon is drastically changed by the evidence for volcanic eruptions at ages much younger than previously thought possible, and in multiple locations across the lunar maria."

The Lunar Reconnaissance Orbiter spacecraft is managed by NASA's Goddard Space Flight Center in Greenbelt, Maryland, and the Lunar Reconnaissance Orbiter Camera's Science Operations Center is located on ASU's Tempe campus.

The School of Earth and Space Exploration is an academic unit of ASU's College of Liberal Arts and Sciences.

 
10/01/2014

An innovative online course, successfully developed and deployed at Arizona State University, is the basis of a far-reaching online science education project that is a finalist for a major grant from the Bill & Melinda Gates Foundation.

The Gates Foundation announced September 30 that a team led by Smart Sparrow, a Sydney, Australia-based educational technology company – partnered with ASU – is a finalist for a $20-million pool of funding in the Next Generation Courseware Challenge Competition.

The group will establish the Smart Science Network, a digital teaching network that will develop and deploy innovative online courseware to improve the learning outcomes of low-income and disadvantaged college students in high-enrollment introductory science courses across the United States.

“We are excited about this project because it exemplifies key design aspirations of ASU as a New American University,” said ASU President Michael Crow. “It seeks to transform society, enable student success and fuse intellectual disciplines. We look forward to joining with our technology partners to invest in new ways to educate through exploration.”

Dror Ben-Naim, CEO and founder of Smart Sparrow, said the project represented "an opportunity to bring together the nation's top science educators and empower them with the best tools we've got, in order to solve a systemic national problem. ASU spearheading this effort is a natural fit.”

Smart Sparrow was one of three ASU technology partners to be included in the Gates Foundation’s list of finalists. The others are: Acrobatiq, a Carnegie Mellon company that designs customizable, adaptive courseware; and CogBooks, which is designing a project to provide top-quality courseware to U.S. college students at affordable prices.

“The whole learning experience will be designed in collaboration with ASU, drawing on their extensive experience in online learning, flipped classroom models and innovative teaching methods,” CogBooks said in announcing its recognition by the Gates Foundation.

The proposed courseware for the Smart Science Network will follow the design principles of Habitable Worlds, a fully online course offered through ASU Online that teaches science through exploration of the question “Are we alone?”

Key principles include: organizing curriculum around “big questions” at the frontiers of knowledge that cut across traditional disciplines; teaching concepts through rich, game-like interactive, adaptive online lessons and simulations; and deepening and evaluating concept mastery by applying knowledge in project-based learning.

Ariel Anbar, an ASU President’s Professor, will play a pivotal role as the academic lead of the Smart Science Network consortium. Anbar and Lev Horodyskyj, both in the School of Earth and Space Exploration, created Habitable Worlds, which has been offered to more than 1,500 ASU students since 2011. The ongoing development and evaluation of Habitable Worlds is supported by NASA’s Astrobiology Program and the Directorate for Education and Human Resources of the National Science Foundation.

“We developed Habitable Worlds to address some common, critical problems in introductory science education that are especially challenging for disadvantaged students,” said Anbar. “For example, many students tune out in large lectures because they teach science as passive acceptance of what is known, rather than active exploration of the unknown. Also, we tend to teach as though knowledge is organized into distinct disciplinary ‘silos,’ even though the cutting-edge questions that motivate both students and scientists cut across those silos. The Smart Science Network will apply the lessons we’ve learned in developing and teaching Habitable Worlds.”

The Smart Science Network will leverage Smart Sparrow’s adaptive digital learning and analytics technologies to develop two online “Smart Courses” that will improve student engagement and success in introductory college science courses with traditionally high levels of failure. Students in a Smart Course will explore a transdisciplinary “big question” to motivate learning of introductory college science concepts in biology, chemistry and physics. The first Smart Course will expand on Habitable Worlds’ exploration of the question “Are we alone?”

“Science is rational exploration of the unknown, not just mastery of what is known,” Anbar explained. “So, Smart Courses will not be about memorizing facts and answers, but about using logic and reasoning to solve problems, to understand uncertainties, and to train and inspire students to tackle big, challenging questions.”

In addition to Smart Sparrow and ASU, the Smart Science Network includes Achieving the Dream, Inc.; 23 additional colleges and universities, many of whom are in the Achieving the Dream network; and a research and evaluation team led by George Siemens, a world leader in learning analytics, at The University of Texas at Arlington.