JPL News: Bright Areas on Ceres Suggest Geologic Activity

By photosearth / December 14, 2017

Ceres

Ceres' lonely mountain, Ahuna Mons, is seen in this simulated perspective viewMap shows locations of bright material on dwarf planet CeresBright areas of Occator Crater Oxo Crater is unique because of the relatively largeHaulani Crater in Enhanced Color The bright areas of Occator Crater — Cerealia Facula in the center and Vinalia Faculae to the side — are examples of bright material found on crater floors on Ceres. This is a simulated perspective view.
Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI

If you could fly aboard NASA’s Dawn spacecraft, the surface of dwarf planet Ceres would generally look quite dark, but with notable exceptions. These exceptions are the hundreds of bright areas that stand out in images Dawn has returned. Now, scientists have a better sense of how these reflective areas formed and changed over time — processes indicative of an active, evolving world.

“The mysterious bright spots on Ceres, which have captivated both the Dawn science team and the public, reveal evidence of Ceres’ past subsurface ocean, and indicate that, far from being a dead world, Ceres is surprisingly active. Geological processes created these bright areas and may still be changing the face of Ceres today,” said Carol Raymond, deputy principal investigator of the Dawn mission, based at NASA’s Jet Propulsion Laboratory in Pasadena, California. Raymond and colleagues presented the latest results about the bright areas at the American Geophysical Union meeting in New Orleans on Tuesday, Dec. 12. Their findings were also published in the journal Icarus in a new study led by Nathan Stein, a doctoral researcher at Caltech.

Read the full story from JPL News

Caltech News tagged with “GPS”

A New Spin to Solving Mystery of Stellar Companions

By photosearth / December 4, 2017

Researchers measure the spin rates of bodies thought to be either planets or tiny “failed” stars
News Writer: 
Whitney Clavin

Planetary-mass companion VHS 1256-1257 b

Image of the planetary-mass companion VHS 1256-1257 b (bottom right) and its host star (center).
Credit: Gauza, B. et al 2015, MNRAS, 452, 1677-1683

Taking a picture of an exoplanet—a planet in a solar system beyond our sun—is no easy task. The light of a planet’s parent star far outshines the light from the planet itself, making the planet difficult to see. While taking a picture of a small rocky planet like Earth is still not feasible, researchers have made strides by snapping images of about 20 giant planet-like bodies. These objects, known as planetary-mass companions, are more massive than Jupiter, orbit far from the glare of their stars, and are young enough to still glow with heat from their formation—all traits that make them easier to photograph.

But one big question remains: Are these planetary-mass companions actually planets, or are they instead small “failed” stars called brown dwarfs? Brown dwarfs form like stars do—out of collapsing clouds of gas—but they lack the mass to ignite and shine with starlight. They can be found floating on the their own in space, or they can be found orbiting with other brown dwarfs or stars. The smallest brown dwarfs are similar in size to Jupiter and would look just like a planet when orbiting a star.

Researchers at Caltech have taken a new approach to the mystery: they have measured the spin rates of three of the photographed planetary-mass companions and compared them to spin rates for small brown dwarfs. The results offer a new set of clues that hint at how the companions may have formed.

“These companions with their high masses and wide separations could have formed either as planets or brown dwarfs,” says graduate student Marta Bryan (MS ’14), lead author of a new study describing the findings in the journal Nature Astronomy. “In this study, we wanted to shed light on their origins.”

“These new spin measurements suggest that if these bodies are massive planets located far away from their stars, they have properties that are very similar to those of the smallest brown dwarfs,” says Heather Knutson, professor of planetary science at Caltech and a co-author of the paper.

The astronomers used the W. M. Keck Observatory in Hawaii—which is managed by Caltech, the University of California, and NASA—to measure the spin rate, or the length of a day, of three planetary-mass companions known as ROXs 42B b, GSC 6214-210 b, and VHS 1256-1257 b. They used an instrument at Keck called the Near Infrared Spectrograph (NIRSpec) to dissect the light coming from the companions. As the objects spin on their axes, light from the side that is turning toward us shifts to shorter, bluer wavelengths, while light from the receding side shifts to longer, redder wavelengths. The degree of this shifting indicates the speed of a rotating body. The results showed that the three companions’ spin rates ranged between 6 to 14 kilometers per second, similar to rotation rates of our solar system’s gas giant planets Saturn and Jupiter.

For the study, the researchers also included the two planetary-mass companions for which spin rates had already been measured. One, β Pictoris b, has a rotation rate of 25 kilometers per second—the fastest rotation rate of any planetary-mass body measured so far.

The researchers compared the spin rates for the five companions to those measured previously for small free-floating brown dwarfs. The ranges of rotation rates for the two populations were indistinguishable. In other words, the companions are whirling about their own axes at about the same speeds as their free-floating brown-dwarf counterparts.

The results suggest two possibilities. One is that the planetary-mass companions are actually brown dwarfs. The second possibility is that the companions looked at in this study are planets that formed, just as planets do, out of disks of material swirling around their stars, but for reasons not yet understood, the objects ended up with spin rates similar to those of brown dwarfs. Some researchers think that both newly forming planets and brown dwarfs are encircled by miniature gas disks that might be helping to slow their spin rates. In other words, similar physical processes may leave planets and brown dwarfs with similar spin rates.

“It’s a question of nature versus nurture,” says Knutson. “Were the planetary companions born like brown dwarfs, or did they just end up behaving like them with similar spins?”

The team also says that the companions are spinning more slowly than expected. Growing planets tend to be spun up by the material they pull in from a surrounding gas disk, in the same way that spinning ice skaters increase their speed, or angular momentum, when they pull their arms in. The relatively slow rotation rates observed for these objects indicate that they were able to effectively put the brakes on this spin-up process, perhaps by transferring some of this angular momentum back to encircling gas disks. The researchers are planning future studies of spin rates to further investigate the matter.

“Spin rates of planetary-mass bodies outside our solar system have not been fully explored,” says Bryan. “We are just now beginning to use this as a tool for understanding formation histories of planetary-mass objects.”

The study, titled, “Constraints on the Spin Evolution of Young Planetary-Mass Companions,” was funded by NASA and the Sloan Research Fellowship Program. Other authors include Caltech’s Konstantin Batygin (MS ’10, PhD ’12), assistant professor of planetary science and Van Nuys Page Scholar; Björn Benneke, formerly of Caltech and now of the Institute for research on exoplanets at the University of Montreal; and Brendan Bowler of the University of Texas at Austin.

 

 

 

 

 

 

 

 

 

 

Caltech News tagged with “GPS”

Undersea Topography Generates Hot Spots of Ocean Mixing

By photosearth / December 2, 2017

The finding has bearing on models of heat transport toward Antarctica and the ocean's role in the carbon cycle
News Writer: 
Robert Perkins

Ocean ice

A view of Antarctica, as seen by the researchers from the deck of the Antarctic Research Support Vessel Laurence Gould
Credit: Andrew Thompson/Caltech

Using underwater robots in the waters surrounding Antarctica, scientists at Caltech have shown that the intersection of strong currents with the slope of landmasses rising from the ocean floor makes a significant contribution to the mixing of different waters in the Southern Ocean. A study on the research was published online in the journal Nature Geoscience on October 30.

To understand the important role of the seafloor in mixing ocean water, imagine a liquid in a blender. Mixing of the liquid does not occur evenly throughout the blender; rather, the liquid blends more rapidly closer to the spinning blades at the bottom than it does at the top.  Nevertheless, the strength and speed of the blades determines the degree to which material is mixed throughout the container.

Similarly, in the ocean, global water properties may depend on very localized mixing processes.  Researchers are interested in understanding where and how this mixing occurs, as it governs the large-scale circulation of the ocean and its ability to sequester carbon dioxide. (The ocean stores atmospheric carbon dioxide by absorbing it in the surface waters and then, pushing it into the deep ocean at a rate controlled by ocean mixing. The carbon remains in the deep ocean for hundreds to thousands of years before it returns to the surface again.)

“Most global ocean observations acquire measurements in the open ocean or in the top layers of the water, while our research shows that important mixing processes may be occurring in the deep ocean in thin layers over sloping topography,” says senior author Andrew Thompson, professor of environmental science and engineering at Caltech.

Thompson and his colleagues deployed two autonomous underwater drones, or “gliders,” for a period of eight months over the course of a year and a half in the Southern Ocean, which encircles Antarctica. The team concentrated on the region around Drake Passage, the 1,000-kilometer-wide waterway between Antarctica and South America.

The gliders were able to reach depths of 1,000 meters—nearly scraping the bottom at times. They carry instruments to measure temperature, salinity, the quantity of various nutrients like nitrogen and iron, and other variables. When the gliders come to the surface, they regularly relay this data back to Thompson and his colleagues. In this way, they were able to document strong mixing occurring in thin layers in the waters near the “edges” of the coastline, where ocean currents rub up against the rising continental mass of Antarctica.

“There is growing evidence that topography plays a bigger role in oceanographic mixing than we had previously suspected,” says lead author Xiaozhou Ruan, a Caltech graduate student. “While this boundary region represents a small fraction of the ocean, the interaction between water and continental topography plays an outsized role in mixing.”

Such mixing has been predicted by high-resolution ocean circulation models, but this is the first time it has been observed directly over a period of many months. Documenting these physical processes and improving our understanding of where and how they arise may improve our ability to simulate the changes in ocean circulation and in Earth’s climate in the past and in the future, Thompson and his colleagues say.

Next, the team plans to deploy multiple gliders in the Bellingshausen Sea, located to the west of the Antarctic Peninsula, where ocean processes contribute to the high melting rates of the floating Antarctic ice shelves that buttress the West Antarctic Ice Sheet. 

The study is titled “Contribution of topographically generated submesoscale turbulence to Southern Ocean overturning.” Co-authors include Mar Flexas, senior research scientist at Caltech, and Janet Sprintall of Scripps Institute of Oceanography at UC San Diego. This research was supported by the National Science Foundation and the David and Lucile Packard Foundation.

Caltech News tagged with “GPS”

The Neutron Dance

By photosearth / November 7, 2017

Caltech geochemist John Eiler aims to reveal “the genetics of everything”

Caltech geochemist John Eiler

Caltech geochemist John Eiler
Credit: Caltech

Caltech geochemist John Eiler aims to reveal “the genetics of everything”—the history of each molecule in the natural world as written in its isotopic structure. What he finds out could have implications for ventures ranging from the study of meteorites to medical diagnosis and treatment.

Read more on the Break Through campaign website.

Caltech News tagged with “GPS”

The Grand Tour: Watson Lecture Preview

By photosearth / November 3, 2017

In the November 15 Watson Lecture, Professor of Planetary Science Heather Knutson will discuss how to characterize planets outside of our solar system.
News Writer: 
Lori Dajose

Heather Knutson

Heather Knutson
Credit: Caltech

The past decade has marked a period of great progress in our quest to discover and characterize the properties of the planets outside of our own solar system, called exoplanets. Observations of eclipsing systems—in which a planet periodically passes in front of and then behind its star as seen from Earth—have given us new insights into the nature of these alien worlds. On November 15, Professor of Planetary Science Heather Knutson will give a Watson Lecture to discuss ongoing efforts, using a combination of both ground- and space-based telescopes, to investigate the diverse properties of exoplanetary systems. This Watson Lecture begins at 8 p.m. in Beckman Auditorium and is free and open to the public.

What do you do?

I study the properties of planets orbiting nearby stars. We’re currently very good at finding these systems—the astronomy community has found over 5,000 planets and planet candidates so far—but for the vast majority of them, all we know is the size and orbital period of the planet. My group is working to answer questions like: What is the planet made of? Does it have an atmosphere and, if so, what kind? What is the weather like on the planet—is it hot, cold, cloudy, windy?

Why is this important?

There are two reasons why this is important. First, we are looking for clues that tell us about how these planetary systems formed and evolved. Many of them have architectures that look very different than our own—for instance, a large gas giant planet orbiting closer to its star than Mercury is to our sun. We’d like to understand why our solar system went down a different path. The second reason is related to life: we’d like to know whether Earth-like planets are common or rare in the universe and eventually we’d like to search for signs of life on these planets. Of course, life might not necessarily be limited to Earth-like planets, but it’s the obvious place to start!

How did you get into this line of work?

I have always loved science, and picked physics as my major when I was an undergrad at Johns Hopkins because it was interesting and also practical. However, my interests took a decidedly non-practical turn when I found my way across the street to the Space Telescope Science Institute, home of the Hubble Space Telescope, and located immediately adjacent to the Johns Hopkins campus, for a summer internship. The presence of so many professional astronomers in one spot convinced me that, yes, you could earn a living doing really cool astronomy research, and I ultimately ended up going to Harvard to earn my PhD in astronomy.

 

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

Caltech News tagged with “GPS”

Caltech Launches New Autonomous Systems Research Center

By photosearth / October 24, 2017

The Center for Autonomous Systems and Technologies (CAST) will unite engineers and scientists from many disciplines to advance research on robotics, drones, driverless cars, and machine learning
News Writer: 
Robert Perkins

Ambulance

A scale model of the Autonomous Flying Ambulance being developed at CAST hovers in front of the wall of fans.
Credit: Caltech

On October 24, Caltech will officially open the new Center for Autonomous Systems and Technologies (CAST), a 10,000-square-foot facility where machines and researchers will work together and learn from one another.

At CAST, researchers from Caltech’s Division of Engineering and Applied Science (EAS), Division of Geological and Planetary Sciences (GPS), and the Jet Propulsion Laboratory (JPL) will collaborate to create the next generation of autonomous systems, advancing the fields of drone research, autonomous exploration, and bio-inspired systems. Researchers will continue pioneering work on technologies ranging from prosthetic legs that use machine learning to automatically adjust to a wearer’s gait to a flying, self-driven ambulance.

“The goal is to teach autonomous systems to think independently and react accordingly, preparing them for the rigors of the world outside of the lab,” says CAST Director Mory Gharib, Hans W. Liepmann Professor of Aeronautics and Bioinspired Engineering.

The facility will be a living experiment. While engineers construct and test drones, robots within CAST itself will learn to help run the facility—all while being observed by 46 cameras that provide complete coverage of the interior, tracking each robot’s motion down to within 100 microns (about the thickness of a human hair).

The CAST team includes more than two dozen engineers and scientists. Instead of developing autonomous systems simply for the sake of advancing the technology, the work will be guided in part by scientists and other stakeholders who would benefit tremendously from autonomous systems. For example, by collaborating with seismologists and first responders, engineers could develop a swarm of flying sentinel drones that automatically activate during an earthquake, rapidly scan damaged areas, and relay information about where there are likely to be injured people in need of medical attention. “The CAST team will also work on the next generation of drones and robots to explore the solar system, including submersible vehicles designed to operate in the ice-covered oceans of Europa, a moon of Jupiter,” says CAST steering committee member Woody Fischer, Professor of Geobiology.

The facility will include an assembly room with an 85-foot-long oval track for walking robots and an aerospace robotics control lab with high-precision flat floor that allows researchers to fly “spacecraft” that have been engineered to hover through high-pressure jets (like a reverse air hockey table) and simulate the frictionless motion of space flight. But CAST’s centerpiece is a three-story-tall, wholly enclosed aerodrome—the tallest of its kind—in which to test flying drones. To simulate the ever-shifting environmental conditions that drones face in the real world, the aerodrome includes a 10-foot-by-10-foot wall of 1,296 fans capable of generating wind speeds of up to 44 mph, with a side wall of 324 fans to create a crosswind. The wall is capable of creating a nearly infinite variety of wind conditions for drones to learn to react to—everything from a light gust to a stormy vortex. It can also be tilted 90 degrees to simulate vertical take offs and landings.

“The current state-of-the-art in autonomous systems is very promising on two divergent fronts,” Gharib says. “The bodies, or machines and sensors, have become more and more sophisticated and capable. Meanwhile, the algorithms that collect and interpret behavior are increasingly fine-tuned. We plan to bring these two together through a series of ‘moonshot’ challenges that we will undertake in the coming years.”

Like their ambitious namesake that challenged Americans to send a human to the moon in the 1960s, CAST’s moonshot goals will require advances in engineering to accomplish feats not yet possible. They include building a robot (guided by a network of flying drone scouts) that can walk from Mexico to Canada without assistance and creating a drone delivery service between Caltech and JPL.

One key goal of CAST is the development of an autonomous flying ambulance for urban applications. Flying vehicles offer significant benefits over their ground-based counterparts: three-dimensional space is easier to navigate safely than two-dimensional space, and there is an advantage to rising above the gridlock that, with 60 percent of the world’s populations expected to live in cities by 2030, will only continue to get worse.

“This isn’t just as simple as creating a UAV big enough to carry a person. You need a fault-tolerant vehicle that can adapt autonomously to shifting weather conditions and navigate through skies without colliding with other UAVs. You need the best in aerospace engineering, machine learning, GPS-free navigation—and all of it scalable,” Gharib says. “It’s a huge challenge, but at CAST, we can and will build it.”

Corporations and industry members will play a key part in the development of CAST technologies and systems. With the lead sponsorship of Raytheon Company as well as the support of corporations such as AeroVironment, industry partnerships will help fund CAST and the development of the next generations of autonomous systems. Through these partnerships and collaborations, industry members will assist CAST researchers in bringing the resulting products to market faster.

This endowed center was established through the generous support of Foster and Coco Stanback. More information about the CAST facility can be found online at http://cast.caltech.edu

Caltech News tagged with “GPS”

Caltech’s Konstantin Batygin Named a Packard Fellow

By photosearth / October 18, 2017

Five-year fellowship offers early career researchers freedom to tackle major challenges
News Writer: 
Robert Perkins

Batygin

Konstantin Batygin
Credit: Caltech

Konstantin Batygin, assistant professor of planetary science and Van Nuys Page Scholar at Caltech, has been named one of the 2017 Packard Fellows in Science and Engineering. The fellowship, awarded by the David and Lucile Packard Foundation, provides each fellow $ 875,000 over five years to pursue their research. Batygin (MS ’10, PhD ’12) is one of 18 early career scientists and engineers to receive the award this year.

“These scientists and engineers are tackling unanswered questions and pushing the boundaries of their fields,” said Frances Arnold, chair of the Packard Fellowships Advisory Panel and former Packard Fellow, in a press release. Arnold is the Linus Pauling Professor of Chemical Engineering, Bioengineering and Biochemistry at Caltech. “Their innovations could lead to breakthroughs in how we live our lives and our understanding of nature.”

Each year, the Packard Foundation invites 50 universities to nominate two faculty members for consideration. The Packard Fellowships Advisory Panel, a group of 12 scientists and engineers, evaluates the nominations and recommends Fellows for approval by the Packard Foundation board of trustees.

Batygin’s research focuses primarily on planetary astrophysics—in particular, the formation and evolution of solar systems throughout their lifespans. He also studies exoplanets and physical processes that occur in planetary interiors and atmospheres. Many exoplanets are so close to their host stars that they are blasted with radiation, making their atmospheres electrically conductive. Batygin studies how the interaction between an exoplanet’s magnetic field and its atmosphere can induce electrical currents that heat the planet’s interior and perturb atmospheric circulation patterns.

In 2015, having already published 21 papers as a first author, Batygin made Forbes‘s “30 Under 30” list in the science category. The magazine’s editors described him as “the next physics rock star” (a nod to the fact that in his spare time, Batygin takes a turn as an actual rock star—he and his band, The Seventh Season, have recorded three studio albums and play throughout the Los Angeles area).

In 2016, Batygin and colleague Mike Brown, the Richard and Barbara Rosenberg Professor of Planetary Astronomy, made global headlines with the announcement of the existence of an as-yet-unobserved ninth planet, touching off a worldwide race among astronomers to locate the planet. The discovery led Popular Science to name him one of the “Brilliant 10” researchers later that year.

Batygin is the 32nd researcher from Caltech to be named a Packard Fellow since the program’s beginning in 1988, recently including Mikhail Shapiro (2016), David Hsieh (2015), Andrew Thompson (2014), and Alexei Aravin (2012). “Caltech provides all of us with amazing resources, but this fellowship gives me the incentive to undertake a project that is truly long-term and potentially very high-risk,” he says. “I usually try to think about problems with the goal of accomplishing something within a year or two–something that generates an interesting result essentially right away. Perhaps it’s time to add big-picture, fundamental problems into the mix.”

Batygin often models the motions of celestial bodies using supercomputers; so one key thing this funding could help pay for is computer time. “This is going to lift any restrictions I had previously on computation. If a problem comes up that requires the heaviest numerical calculation, that’s something I could undertake,” he says.

For now, Batygin is not saying exactly which challenges he plans to pursue next–only that “I’ve got a list started. Looking forward, I’m going to keep doing what I’m doing, but I’m going to do it better.”

The full list of 2017 Packard Fellows—which also includes Caltech alumna and Northwestern University assistant professor Magdalena Osburn (PhD ’13)—can be found online

Caltech News tagged with “GPS”

New Provost Starts This Week

By photosearth / October 3, 2017

David Tirrell assumes his new role on campus

Tirrell

Caltech provost David Tirrell
Credit: Alex H. Parker

On October 1, 2017 chemistry professor and Beckman Institute director David Tirrell officially steps into his new position as Caltech’s 10th provost.

A Caltech faculty member since 1998, Tirrell, the Ross McCollum-William H. Corcoran Professor of Chemistry and Chemical Engineering, chaired the division from 1999 to 2009.

Read more about Tirrell and his new role.

Caltech News tagged with “GPS”

Caltech’s New Provost Starts This Week

By photosearth / October 2, 2017

David Tirrell assumes his new role on campus

Tirrell

Caltech provost David Tirrell
Credit: Alex H. Parker

On October 1, 2017 chemistry professor and Beckman Institute director David Tirrell officially steps into his new position as Caltech’s 10th provost.

A Caltech faculty member since 1998, Tirrell, the Ross McCollum-William H. Corcoran Professor of Chemistry and Chemical Engineering, chaired the division from 1999 to 2009.

Read more about Tirrell and his new role.

Caltech News tagged with “GPS”

Scenes from Frosh Camp

By photosearth / September 29, 2017

Each year, Paul Asimow introduces students to geology on the Frosh Camp Hike
News Writer: 
Lori Dajose

Paul Asimow, the Eleanor and John R. McMillan Professor of Geology and Geochemistry, talks to students from atop a stump during the Frosh Camp geology hike.

Paul Asimow, the Eleanor and John R. McMillan Professor of Geology and Geochemistry, talks to students from atop a stump during the Frosh Camp geology hike.
Credit: Caltech

This year, Caltech’s freshman orientation took place on September 18 and 19 in Ventura, California. Over the two days, students from the class of 2021 attended talks about the Honor Code and academics, met deans and resident associates, and participated in elective activities such as a boat design contest and a geology hike.

Paul Asimow, the Eleanor and John R. McMillan Professor of Geology and Geochemistry, has led the annual geology hike for 10 years, with increasing attendance each year. With panoramic views of the Channel Islands, the Ventura River Valley, and the Santa Clara River Valley—weather almost always permitting—the 1.5-mile trail is located in the hills above Ventura and passes through fossil-rich rocks and landforms testifying to the extremely rapid uplift of those hills and the nearly-as-rapid resulting erosion.

Learn more and view the slideshow here.

Caltech News tagged with “GPS”

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