Institute for Planets and Exoplanets
UCLA Professor An Yin has been named a Fellow of the American Geophysical Union (AGU). A Fellow of AGU must be a scientist who has attained acknowledged eminence in the geophysical sciences. Fellowship is granted to only 1 of every 1000 members in each year. Click here to find out more about An’s research.
When Raquel Nuno isn’t hunting for atmospheric water vapor on Mars, she’s constructing a massive super computer in the basement of UCLA’s Geology building. Nuno, a recent UCLA graduate with an interest in planetary science, analyzes data collected by NASA’s two Viking spacecraft that orbited Mars from 1976-1980. She hopes to pinpoint areas where excess water vapor in the Martian atmosphere might trigger the formation of Recurring Slope Lineae, mysterious dark streaks that appear on crater rims and canyon walls during the warmest Martian seasons. These features, first observed by NASA’s Mars Reconnaissance Orbiter in 2010, may indicate the presence of flowing liquid water beneath Mars’ surface. “We think Recurring Slope Lineae could mean there is current hydrological activity on Mars,” said Nuno. “The question we are trying to answer is: where is this water coming from?” To locate potential water sources, Nuno and her advisor, Professor David Paige, have been looking for areas on Mars where the water content in the air is higher than average. Nuno presented her results during a talk at the American Astronomical Society’s Division of Planetary Science meeting in Reno, NV in October of 2012.
Nuno, who moved to the United States from Portugal at age eleven, is the first person in her family to earn a college degree. Her unlikely path to planetary science began when she joined the United States Air Force out of high school, working as a medical laboratory technologist. While in the military, Nuno took classes at six different colleges and universities before enrolling as an undergraduate student at UCLA, her “favorite so far.” Nuno hopes to pursue a career in academia and she hopes to inspire the next generation of scientists and researchers through teaching. “Teachers were very important in shaping my interests and career goals,” she said. “I would like to have that sort of positive impact on other students.”
Professor Jonathan Mitchell with joint appointments in UCLA’s Departments of Earth, Planetary, and Space Sciences (EPSS) and Atmospheric and Oceanic Sciences (AOS) has been awarded a the American Geophysical Union’s (AGU) Ronald Greely Early Career Award in Planetary Science. As the name indicates, this award is given to individuals ” in recognition of significant early career contributions to planetary science.” To learn more about Jonathan’s award-winning research, visit his website here.
On July 13th, 2013, the Institute for Planets and Exoplanets participated in the 3rd annual TwentyWonder, an event to benefit the Down’s Syndrome Association of Los Angeles (DSALA). The iPLEX booth, which showcased a sampling of the UCLA Meteorite Gallery Collection and an informational hands-on DIY comet-building activity, was one of dozens of science, art, and performance acts featured at the event held at the L.A. Derby Dolls Doll Factory in Echo Park. Over 1500 people attended the event that the L.A. Times has called “Awesome! An Event PICK!” Overall, it was an excellent evening full of education presented in a “passive and enjoyable” way, said the event’s creator and DSALA-director, Jim Hodgson. For more information about the event, please visit the Twentywonder official website.
http://www.youtube.com/watch?v=Fy6MDC58FI0&feature=youtu.be
A combination of dry ice (solid carbon dioxide), karo syrup, ammonia, and dirt simulate what a real comet could be like. Comets with very elliptical orbits remain very cold for most of their orbit, but when passing close to the Sun are warmed enough that some of the ice is removed by a process called sublimation; this results in the characteristic “tail” feature seen on most comets. The dry ice in the video is sublimating away, simulating what happens when a comet (composed of dirt/dust, ice, and some organic materials) passes close to the Sun.
Most planet-hunting astronomers infer the existence of extrasolar planets by monitoring tiny changes in the parent stars. With the recently assembled Gemini Planet Imager (GPI), UCLA Assistant Professor Michael Fitzgerald intends to capture images of these extrasolar planets directly.
Scheduled to go online at the Gemini South Observatory in Chile in late 2013, GPI will be able to detect planets in newly formed systems where traditional detection methods would be likely to fail. Sensitive at infrared wavelengths, GPI targets young planets, which are warmer than their more evolved counterparts in other systems. “When planets form they are initially large and are slowly contracting, releasing their gravitational energy in the form of heat and cooling off as they get older,” Fitzgerald said. “We need to look at young systems because that’s when their planets are warmest and therefore brightest in the infrared.”
Using a method based on pioneering work by UCLA Professor Ben Zuckerman, the GPI Exoplanet Survey Team has identified and catalogued over 900 nearby young stars that are promising candidates for planet imaging. They hope to image 600 of these stars and expect to find roughly fifty new planets. The type of planets most likely to be revealed by GPI are Jupiter-sized gas giants that formed less than one hundred million years ago and are located many Earth-Sun distances away from their parent star.
But the search won’t be easy. “Stars are a million times brighter than the planets we are looking for, and these are the biggest and brightest planets that we expect to see,” Fitzgerald said. The GPI experiment utilizes several state-of-the-art innovations to image these elusive planets including a special coronograph that blocks out light from the parent star in order to make the planet more easily visible, and a unique deformable mirror that helps to compensate for atmospheric distortion.
The best picture astronomers can hope for will show an extrasolar gas giant as a single point of light. “The planet will not be spatially resolved,” Fitzgerald said. “We’ll see a dot.” Yet the GPI instrument can glean a surprising amount of information from a tiny speck of light. Fitzgerald and his colleagues will be able to analyze the composition of these far-off planets using a spectrograph built by UCLA Professor James Larkin, and perhaps even more importantly, they’ll be able to directly image their associated circumstellar disks.
“A lot of these systems are young – the planets have only recently formed and there are a lot of leftover planetesimals which collide and produce debris disks,” Fitzgerald said. Scattered light from the dusty cloud surrounding the star has a distinct polarization signature that can be separated from the unpolarized starlight by using special filters. “If we just look at the intensity of the polarized light, the dust jumps out,” Fitzgerald said. The shape and position of stellar disks around new stars may help scientists like Fitzgerald better understand the formation of our own solar system. “There is a lot of diversity in the debris disks we see. Some of them are rings, some are very extended, a few show interesting asymmetry, and some are even offset from the star due to gravitational perturbations from a planet,” Fitzgerald said. The structure of dusty disks may also provide clues about the orbital dynamics of distant planets. “The highlight for the Gemini Planet Imager will be looking at the systems where you have both a disk and a planet, because you can immediately put constraints on the orbit of the planet,” Fitzgerald said. “If you see a nice, symmetric disk, you wouldn’t expect a planet to be plowing through it.”
Fitzgerald, who came to UCLA in 2010, is also collaborating with scientists at NASA’s Jet Propulsion Laboratory in Pasadena, California to develop a way to make precision radial velocity measurements using infrared rather than visible light. He hopes the technique will help to find planets around young, energetic stars that are too active to yield accurate results in optical wavelengths, and low mass stars which are optically faint. Fitzgerald has enjoyed forming new interdisciplinary collaborations in his search for extrasolar planets as a member of iPLEX. “Having iPLEX and integrating all of the departments in terms of exoplanet studies is definitely the way of the future,” he said.
Over two dozen scientists from thirteen different institutions and four countries visited UCLA June 26-28, 2013 for a hands-on workshop entitled “Connecting Theory to Experiments in Geophysical and Astrophysical Fluid Dynamics (GAFD).” The three-day interdisciplinary workshop, sponsored by the UCLA Institute for Planets and Exoplanets (iPLEX) and Professor Jonathan Aurnou’s SPINLab, brought theorists and experimentalists together to discuss how to integrate their respective techniques and answer key questions in the field of fluid dynamics.
Researchers discussed fluid flow in oceans, atmospheres, and the metallic cores of planets. These topics have applications ranging from weather and climate on Earth and other planets to magnetism in planets and stars.
UCLA scientists showcased the unique fluid dynamics experiments underway at SPINLAB through interactive lab tutorial sessions. Workshop attendees examined SPINLab’s rotating magnetic convection device (RoMag) and conducted basic experiments on spinning fluids with tanks mounted on turntables.
Learn more about UCLA fluid dynamics research on the SPINLab website.
Research at the SPINLab was recently featured in the annual iPLEX magazine. Read the story here.
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Professor Dave Paige of UCLA’s Department of Earth and Space Sciences has been awarded a NASA Exceptional Scientific Achievement Medal. This award is NASA’s top scientific honor and is given to individuals “for exceptional scientific contributions (specific, concrete scientific achievements) toward achievement of the NASA mission.” Dave is honored for his “Breakthrough discoveries in the thermal stability of volatiles on the Moon and Mercury”. To learn more about Dave’s work, visit his website here.
The Simulated Planetary Interiors Laboratory, known more fondly as the SPINLab, is a state-of-the-art fluid dynamics research facility among only a handful of such unique labs in the world. Funded by the National Science Foundation, the group is led by Associate Professor Jonathan Aurnou, who has dedicated over ten years of his life to building functional models of planetary cores and atmospheres.
The daily routine for Jon, his graduate students, post-doctoral scholars and researchers involves spinning large, heat-driven containers of water or liquid metal in order to understand the fundamental physics of rotating bodies. “We are interested in explaining how strongly turbulent systems, like planetary cores and planetary atmospheres, organize into planetary-scale magnetic fields, jet systems, and vortices,” said Aurnou.
The primary device used in the lab, a rotating magnetic convection device (RoMag), is a fluid-filled cylinder that to Aurnou represents “a parcel of fluid inside a planetary core.” “The idea is to study all the ingredients that are involved in planetary core convection and dynamo generation in their simplified state,” said Jonathan Cheng, a fourth-year graduate student with Aurnou. Dynamos, large-scale magnetic fields generated from the motions of an electrically conducting fluid, are known to exist within planets, stars and even galaxies. Yet the detailed physics of these natural dynamos remain largely mysterious.
The Earth has a very organized magnetic field, created by convective motions in its rapidly rotating molten metal core, but other bodies such as Uranus and Neptune, the ice giants, and Jupiter and Neptune, the gas giants, have much “messier” dynamos, Aurnou said. In his lab, however, Aurnou is more concerned with studying the underlying dynamics of fluid systems than reproducing these dynamos. “I know there are dynamos. There are dynamos all over the solar system and on just about every star,” Aurnou said. “I’m interested not so much in building a dynamo in my laboratory, but instead in building experiments that allow me to better understand the fundamental physics that underlie dynamo processes.”
And fundamentals have proved successful so far for the SPINLab. Using RoMag, the team has been able to show drastic differences in rotating convection systems that are metal versus those that are water. In water experiments, rapidly rotating systems become turbulent much faster than numerical models had predicted. The interpretation is that planets with deep-water layers can easily break down into turbulent systems that create disordered dynamos, like those we see on the ice giants.
Marie-Curie fellow Michael Le Bars, has been working in the SPINLab for a year, taking part in a long-standing relationship between the lab and French researchers. Le Bars investigates mixed systems that are partially convecting and partially layered, like those in our atmosphere, oceans, and stars. These systems were thought to be well understood, but when Le Bars decided to ship his experiments all the way from France to Los Angeles and try rotating them in the SPINLab, the results were surprising. “Rotation changes everything,” said Le Bars. One interesting result was the production of “inverse cascades” that create columns of spinning fluid that cut across stratified layers similar to the Great Red Spot on Jupiter.
The fluid dynamics of most turbulent systems studied in the SPINLab are simply too complex for even the most advanced supercomputers to model or predict, but Aurnou and his team realize the importance of combining the two approaches. They hope to build bridges between experimental and computational methods in order to determine “how to make models that better describe the examples we see in nature.”
Learn more about SPINLab on their website. Watch the SPINLab educational film project here.
For third-year UCLA graduate student Jessica Watkins, the “big picture goal” has always been to travel to space as an astronaut. To achieve her dream meant intense physical training (she was part of Stanford’s 2008 international collegiate rugby championship team) and earning a Ph.D. in a research area relevant to space. Beginning her education as a mechanical engineer, she soon realized it wasn’t for her. Turning to a course bulletin for inspiration, she found classes about planets and atmospheres in Stanford’s Geological and Environmental Sciences department that would prove to suit her well.
Presently, Watkins works with her advisor, UCLA Professor An Yin, to understand massive landslides in Mars’ Valles Marineris, a network of canyons the size of the continental United States. Using images and data from NASA’s Mars Reconnaissance Orbiter and satellite images of Earth for comparison, she attempts to determine whether the cause of Martian landslides is tectonic activity, flowing water, glaciers, or something else. Accordingly, Watkins is trying to determine if any of the minerals in her landslides are hydrated, or wet. Although she is not studying the astrobiological aspects of the minerals, she said her work is “one small study that could tell us a lot,” including information about the habitability of Mars.
Watkins also examines landslides up close to understand how to best interpret images of Mars’ landslides. During a recent field investigation of a Mars-like landslide in Death Valley National Park, Watkins was surprised that some of her preliminary image interpretations were incorrect. “There are many things about other planets that we might not be able to truly understand just from images,” she said. “Being able to walk around and get your hands on it really makes a difference.”
That’s what drew Watkins to planetary geology. “UCLA merges geology and planetary science really well,” she said. “I can use my Earth geology background to study other planets.” This summer, Watkins will collaborate with Mars Science Laboratory (MSL) scientists at the Jet Propulsion Laboratory (JPL) in Pasadena, California in hopes of improving our understanding of Mars’ surface. In retrospect, Watkins realizes she has always been interested in Mars. “My earliest memory of being interested in Mars was in fifth grade,” she said. “We had to make illustrated books – I wrote mine on Marty the Martian.”
Watch a video profile of Jessica Watkins here. Learn more about her research here.
On September 27th, 2007, NASA’s Dawn spacecraft left Earth and began a multi-year journey to two of the largest objects in the solar system’s main asteroid belt. The first stop on its interplanetary roadtrip was the asteroid Vesta. Dawn reached the Arizona-sized chunk of primordial rock in 2011, providing scientists with the first close-up view of the asteroid’s ancient surface.
A leftover remnant from the formation of the solar system over four billion years ago, Vesta may be similar in composition to the larger bits of celestial debris that originally came together to form the inner planets. Scientists studying our planet’s origins hope that Vesta will reveal clues about our past that have long been erased by plate tectonics and weathering on Earth.
“Studying Vesta is like going back to the beginning of the solar system,” said Jennifer Scully, a third-year UCLA graduate student working on the Dawn mission. “It is kind of like a fossil of the sort of bodies that were around that combined to make the Earth,” she said. Scully, the lead mapper for two large areas on Vesta, makes geological maps of the asteroid’s surface in order to interpret the history of different features and formations.
What she has found so far has been surprising. “We discovered a lot of things that were unexpected at Vesta,” she said. Grayscale and color images taken by Dawn’s framing camera show a remarkable range of shades on the surface of Vesta, featuring both very bright and very dark material. “It’s very colorful,” said Scully. “We think the dark material is residue from meteorites called carbonaceous chondrites that have hit the surface.”
Data from Dawn’s instruments including the camera’s seven color filters, a spectrometer, and a neutron detector help scientists characterize surface deposits and divide Vesta into areas depending on age, composition, and morphology. But sometimes this close-up view of Vesta raises more questions than answers.
“We found both straight and sinuous gully features and I’m investigating what sort of flow(s) formed them,” said Scully. Whether or not some of the gully features could have been carved by molten rock is under investigation. “The team has not found any definitive features of volcanism,” Scully said. “There could have been activity early on, but the evidence has been wiped clean by billions of years of impacts.”
Evidence of many of these impacts is preserved on Vesta’s surface in the form of craters. These craters range in size from being so small that Dawn’s camera can barely resolve them to being so large that they have diameters nearly as big as Vesta. The two largest impact basins on the asteroid, named Veneneia and Rheasilvia, are found in Vesta’s southern hemisphere. Scully is one of many Dawn scientists who are working to connect these impact basins with structures in Vesta’s northern hemisphere. “The current understanding is that each of these large impacts sent shock waves through Vesta, which formed large-scale ridges and depressions on the opposite side,” said Scully.
The Dawn spacecraft does not only examine the surface of an asteroid, it can also give scientists clues about its internal structure. “From the way the gravity pulls on the spacecraft you can tell about the internal layers and the size of the core,” said Scully. From examining how Vesta’s gravitational field tugs on Dawn, scientists believe that Vesta has a distinct crust, mantle, and core like Earth.
The same is likely not true for the asteroid Ceres, Vesta’s younger cousin and the next and final stop for the Dawn spacecraft. After remaining in orbit around Vesta for one year, the Dawn spacecraft took its leave in September of 2012 to begin a three-year journey to Texas-sized Ceres, the largest object in the main asteroid belt located between Mars and Jupiter. Unlike Vesta, scientists think Ceres may harbor large amounts of water ice under its surface. Because Ceres is wetter than Vesta, it will present a whole new set of questions. Scully looks forward to directly comparing the data collected from the two asteroids when the spacecraft arrives at Ceres in 2015.
For Scully, the decision to come to UCLA and work with Professor Christopher Russell was a “no brainer.” “Getting to work on an actual active mission is pretty awesome. You get to meet a lot of people and really see how a team works,” she said. In addition to her work on the geology of Vesta, Scully helped create an online system called Asteroid Mappers where citizen scientists can identify features on Vesta using real data collected by Dawn.
Watch a video profile of Jennifer Scully here. Learn more about her research here.