Exploring the Carina Nebula by Touch
Max Mutchler, a research and instrument scientist at the Space Telescope Science Institute in Baltimore, and Noreen Grice, president of You Can Do Astronomy LLC and author of several tactile astronomy books, have created a touchable image of the Carina Nebula that is engaging for everyone, regardless of their visual ability.
The 17-by-11-inch color image is embossed with lines, slashes, and other markings that correspond to objects in the giant cloud, allowing visually impaired people to feel what they cannot see and form a picture of the nebula in their minds. The image's design is also useful and intriguing for sighted people who have different learning styles.
"The Hubble image of the Carina Nebula is so beautiful, and it illustrates the entire life cycle of stars," says Mutchler, who, along with Grice, unveiled the tactile Carina image in January 2010, at the American Astronomical Society meeting in Washington, D.C. "I thought that people who are visually impaired should be able to explore it and learn from it, too."
Located 7,500 light-years from Earth, the nebula is a 3-million-year-old gigantic cloud where thousands of stars are cycling through the stages of stellar life and death. The nebula is 300 light-years wide, but Hubble captured a 50-light-year-wide view of its central region.
A Hubble education and public outreach grant allowed Mutchler to produce the special image. The grant is part of his Hubble archival research project to create complete mosaics of a huge collection of individual Carina Nebula images taken by Hubble (http://archive.stsci.edu/prepds/carina/). Mutchler made 300 copies of the tactile image and will distribute them to organizations that serve the visually impaired, including state schools and libraries for the blind and the National Federation of the Blind in Baltimore, Md.
When Mutchler decided to make a tactile Carina Nebula image last year, he immediately called his friend Grice, who is a pioneer in designing tactile astronomy images for the blind.
But Grice says the nebula image is so visually rich, it posed a challenge to design a textured image that conveys its beauty and complexity.
"When I first looked at the image, I didn't know what to focus on," she recalls. "In order to translate the image into a tactile image, I had to make certain that I understood the individual features that make up the image. There was so much to see."
She spent a couple of hours on the telephone with Mutchler, who gave her a guided tour of the nebula. Then she parsed astronomy books, looking for other views of the nebula. One feature, in particular, gave her some trouble. It was the Keyhole Nebula. Grice couldn't see how the shape in the image resembled a keyhole. Finally, she came across a 1950s image of Carina, and suddenly, she got it. The name referred to the shape of an old-fashioned "skeleton" key. Some visually impaired children who have touched the image say the feature actually resembles a foot, Grice says.
Choosing which features to show on the textured image also posed a challenge. Grice says she relied on a lesson she learned from her first NASA tactile astronomy book of Hubble images called "Touch the Universe": less is more.
"Convey just enough to get the idea," she says. "Then provide some Braille text that explains the science and describes the scene. A picture that is jammed with too many tactile details is very overwhelming for the mind's eye."
Grice used the Keyhole Nebula as the focal point and added other important features suggested by Mutchler to tell the story of stellar life and death, such as pillars of gas and dust that harbor infant stars, a cluster of young stars called Trumpler 14, and a massive, unstable star, Eta Carinae, that is near the end of its life.
The pair then developed a tactile code identifying the raised features and wrote a short guided tour that provides more information on the highlighted on the features. The guide and an audio tour of the nebula are on a special Web page called "The Tactile Carina Nebula" (http://amazing-space.stsci.edu/tactile-carina/), on Amazing Space, the Space Telescope Science Institute's education Web site.
A stable of seasoned tactile astronomy evaluators, including Vivian Hoette, the education outreach coordinator of the University of Chicago's Yerkes Observatory in Williams Bay, Wis., and Ben Wentworth, a retired teacher from the Colorado School for the Blind in Colorado Springs, Colo., helped test several prototypes of the image. One such evaluation place was the Youth Slam, held in the summer of 2009 in College Park, Md. The National Federation of the Blind coordinated the event to promote careers in math, engineering, and science.
One of the biggest surprises from their testing was the image size. Grice and Mutchler originally thought that a large (almost 6-foot-wide) or medium-sized (3-foot-wide) tactile image would be appropriate for students. The children who sampled the image, however, preferred the much smaller 11-by-17-inch image.
"Many students felt lost with the larger prototype versions because certain objects were separated by empty spaces," Grice says. "However, the smaller version allowed hands to easily track from one object to another."
Adds Hoette, one of the evaluators: "The smaller size gives them enough details so they can get the big picture, and then they can read the science behind it in Braille text, or they can listen to the audio tour on 'The Tactile Carina' Web page while they are touching the image."
The Grice-Mutchler partnership has worked so well that the duo hopes to produce more tactile Hubble images. "It would be great to build up a catalogue of these images for the visually impaired," Mutchler says.
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute conducts Hubble science operations. The institute is operated for NASA by the Association of Universities for Research in Astronomy, Inc. in Washington, D.C.
High Schools Battle It Out at Robotic Match
The teams from Hope Chapel Academy High School, Hermosa Beach, Calif.; Windward School Robotics and A & S Youth Organization, Los Angeles; and Dos Pueblos High School Engineering Academy, Goleta, Calif., won the overall regional competition. Beverly Hills High School in Beverly Hills, Calif., won the competition's highest award, the Regional Chairman's Award.
This year's "Breakaway" challenge closely resembled a robotic soccer match. In each two-minute-15-second match, two alliances of three teams competed on a 27-by-54-foot field with bumps. The object of the game was to attain the highest score by shooting balls into a goal, climbing on the alliance tower or platform, or by lifting an alliance robot off the playing surface.
The students designed and built their robots with the help of engineers from JPL, aerospace and other companies and institutions of higher education.
These students are among the more than 38,000 students in 1,500 teams from around the world vying to compete in the FIRST championships. FIRST is part of NASA's Robotics Alliance Project, which aims to expand the number of robotics systems experts available to NASA.
2010 Los Angeles Regional FIRST Robotics Awards
* Denotes JPL-mentored team
Regional Chairman's Award
"MorTorq," Beverly Hills High School, Beverly Hills
Engineering Inspiration Award
"D'Penguineers," Dos Pueblos High School Engineering Academy, Goleta
Regional Winners
*"Beach Bots," Hope Chapel Academy High School, Hermosa Beach "D'Penguineers," Dos Pueblos High School Engineering Academy, Goleta "Wildcats," Windward School Robotics and A & S, Los Angeles
Regional Finalists
"Beach Cities Robotics," Redondo Union and Mira Costa High School, Redondo Beach "RAWC," West Covina High School, West Covina *"ThunderBots," John Burroughs High School, Burbank
Cooperation Award
"Gompei and the H.E.R.D.," Massachusetts Academy of Math and Science, Hawthorne, Mass.
Xerox Creativity Award
"TorBots," South High School, North High School, West High School and Torrance High School, Torrance
Delphi Engineering Excellence Award
"Gompei and the H.E.R.D.," Massachusetts Academy of Match and Science, Worcester, Mass.
Kleiner Perkins Caufield and Byers Entrepreneurship Award
"The Nerd Herd," California Academy of Mathematics and Science, Carson
AutoDesk Excellence in Design Award
"DOC," Buchanan High School, Clovis
Johnson & Johnson Gracious Professionalism Award
"DOC," Buchanan High School, Clovis
Highest Rookie Seed Award
"Dragonbots," Foothill Technology High School, Ventura
Imagery Award in honor of Jack Kamen
"The Pink Team," Rockledge High School, Cocoa Beach High School and Viera High School, Florida
General Motors Industrial Design Award
*"Beach Bots," Hope Chapel Academy High School, Hermosa Beach
Underwriters Laboratory Industrial Safety Award
*"Wolverines," Foshay Learning Center, Los Angeles
Rockwell Automation Innovation in Control Award
"Beach Cities Robotics," Redondo Union and Mira Costa High School, Redondo Beach
Judges Award
"Metalcrafters," Centinela Valley Union High School District, Hawthorne
Motorola Quality Award
"RAWC," West Covina High School, West Covina
Rookie All-Star Award
"Dragonbots," Foothill Technology High School, Ventura
Rookie Inspiration Award
"NohoRobo," North Hollywood High School, North Hollywood
Chrysler Team Spirit Award
"Iron Eagles," Verbum Dei High School, Watts
Website Award
*"Wolverines," Foshay Learning Center, Los Angeles
Extreme Weather Impacts Migratory Birds
While this may not seem like a revelation, the researchers were surprised to find that migratory bird species located as far as 60 miles (100 kilometers) from a hurricane’s path had experienced a long-term loss in population. Those populations took up to five years to rebound from the damage to their forest environments.
At the same time, researchers found that some migratory bird species could experience population losses as high as 13 percent when rainfall levels fall dramatically and cause drought in plains regions. The studies appear in the March edition of Global Change Biology.
"These studies suggest that whether a hurricane or a drought batters an area, migratory habits -- whether birds migrate south or stay put after breeding season -- are a strong predictor of how birds will fare," said Anna Pidgeon, an avian ecologist at the University of Wisconsin-Madison and a NASA-funded co-author of both studies.
"We believe changes in weather and climate are fundamental drivers of migration but, until now, we’ve known little of how changes in climate compel changes in migratory patterns," said Woody Turner, manager of the biodiversity program at NASA’s Headquarters in Washington. "The correlations don’t necessarily mean the environment alone is forcing migratory changes, but they offer a good place to start looking."
Wings of Change
Turner and other researchers see birds as excellent indicators of overall environmental health. Birds can give advance notice of ecosystem changes that will affect humans in time, while also telling us about the broader impacts of our actions.
Pidgeon, along with colleagues from NASA, the U.S. Department of Agriculture's Forest Service, the University of Maryland-College Park, and the University of Wisconsin-Madison, grouped 77 bird species into "migratory guilds." The guilds were based on similar migratory habits: birds that migrate long distances (to the tropics or subtropics), short distances, or reside solely in one location; breeding habitats: urban, semi-arid, or water-based habitats; the type of nests they construct; and whether they nest on or close to the ground or in tree canopies.
At the outset, researchers believed intuitively that hurricanes would cause losses among tree nesters due to a wipe-out of habitat from downed trees. That would bring gains for ground- and shrub nesters because of the increase in ground vegetation and nesting resources.
Pidgeon’s research team examined five Gulf and Atlantic Coast areas affected by hurricanes between 1984 and 2005. They used population and diversity data from the North American Breeding Bird Survey, tracks of hurricanes, and a time-series of digital images from the NASA-built Landsat remote sensing satellite. When matched to data on breeding seasons, the scientists found that destruction of habitat correlated with varying degrees of distress on the bird species. Habitat destruction caused losses in abundance and diversity across all species in the season following hurricanes, which persisted as long as five years.
Hurricanes pose no immediate danger to bird conservation, Pidgeon believes, provided there remains ample and suitable forest habitat to which birds can shift in the aftermath of a major storm.
Grass Not Always Greener for Birds
In a separate study, Pidgeon and colleagues identified periods of drought and their subsequent impact on bird species. They started with a measure of the amount and quality of refuge for birds -- the Normalized Difference Vegetation Index (NDVI), which assesses the seasonal "greenness" of the landscape. The method involves using data from a satellite-based radiometer that measures the color of the landscape in different wavelengths according to a plant’s ability to absorb radiation. The stronger the reflectance of wavelengths off Earth’s surface, the greater density of green leaves on the ground.
When they compared this "greenness" against 15 years of precipitation data from 1,600 weather stations across the plains of North America, the team found that precipitation is a better means of forecasting bird survival during drought. "Rows of corn may be a sign of vegetation when viewed in a satellite image, but they don’t help protect birds during a drought because they’re not essential habitat," Pidgeon explained.
Whether researchers considered bird species together or in groups, according to whether they stay in an area all year versus spending the winter to the south, they always found that precipitation, rather than "greenness," was more strongly associated with species diversity and abundance.
"Satellite remote sensing is helping us see and analyze the ecological impact of these events on bird populations, as well as marine species and mammals," says climatologist Bill Patzert of NASA’s Jet Propulsion Laboratory in Pasadena, Calif. "Ultimately, however, hurricanes, drought, and other influences act as part of natural selection."
Related Links:
> About Anna Pidgeon
> About Woody Turner
> Measuring Vegetation with NDVI
> Butterflies Reeling From Impacts of Climate and Development
> Scientists Find Climate Change to Have Paradoxical Effects on Coastal Wetlands
Ashes to Ashes, Dust to Dust: Chandra/Spitzer Image
"Scientists think the stars in the image are part of a stellar cluster in which a supernova exploded," said Tea Temin of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass., who led the study. "The material ejected in the explosion is now blowing past these stars at high velocities."
The composite image of G54.1+0.3 is online at http://photojournal.jpl.nasa.gov/catalog/?IDNumber=pia12982 . It shows the Chandra X-ray Observatory data in blue, and data from the Spitzer Space Telescope in green (shorter wavelength) and red-yellow (longer). The white source near the center of the image is a dense, rapidly rotating neutron star, or pulsar, left behind after a core-collapse supernova explosion. The pulsar generates a wind of high-energy particles -- seen in the Chandra data -- that expands into the surrounding environment, illuminating the material ejected in the supernova explosion.
The infrared shell that surrounds the pulsar wind is made up of gas and dust that condensed out of debris from the supernova. As the cold dust expands into the surroundings, it is heated and lit up by the stars in the cluster so that it is observable in infrared. The dust closest to the stars is the hottest and is seen glowing in yellow in the image. Some of the dust is also being heated by the expanding pulsar wind as it overtakes the material in the shell.
The unique environment into which this supernova exploded makes it possible for astronomers to observe the condensed dust from the supernova that is usually too cold to emit in infrared. Without the presence of the stellar cluster, it would not be possible to observe this dust until it becomes energized and heated by a shock wave from the supernova. However, the very action of such shock heating would destroy many of the smaller dust particles. In G54.1+0.3, astronomers are observing pristine dust before any such destruction.
G54.1+0.3 provides an exciting opportunity for astronomers to study the freshly formed supernova dust before it becomes altered and destroyed by shocks. The nature and quantity of dust produced in supernova explosions is a long-standing mystery, and G54.1+0.3 supplies an important piece to the puzzle.
NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.
The Spitzer observations were made before the telescope ran out of its coolant in May 2009 and began its "warm" mission. NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages Spitzer for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.
More information on the Spitzer Space Telescope is online at: http://www.spitzer.caltech.edu/spitzer and http://www.nasa.gov/spitzer . More information on the Chandra X-ray Observatory is at: http://chandra.harvard.edu and http://chandra.nasa.gov .
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1980s Video Icon Glows on Saturn Moon
"Other moons usually grab the spotlight, but it turns out Mimas is more bizarre than we thought it was," said Linda Spilker, Cassini project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "It has certainly given us some new puzzles."
Cassini collected the data on Feb. 13, during its closest flyby of the moon, which is marked by an enormous scar called Herschel Crater and resembles the Death Star from "Star Wars."
Scientists working with the composite infrared spectrometer, which mapped Mimas' temperatures, expected smoothly varying temperatures peaking in the early afternoon near the equator. Instead, the warmest region was in the morning, along one edge of the moon's disk, making a sharply defined Pac-Man shape, with temperatures around 92 Kelvin (minus 294 degrees Fahrenheit). The rest of the moon was much colder, around 77 Kelvin (minus 320 degrees Fahrenheit). A smaller warm spot - the dot in Pac-Man's mouth - showed up around Herschel, with a temperature around 84 Kelvin (minus 310 degrees Fahrenheit).
The warm spot around Herschel makes sense because tall crater walls (about 5 kilometers, or 3 miles, high) can trap heat inside the crater. But scientists were completely baffled by the sharp, V-shaped pattern.
"We suspect the temperatures are revealing differences in texture on the surface," said John Spencer, a Cassini composite infrared spectrometer team member based at Southwest Research Institute in Boulder, Colo. "It's maybe something like the difference between old, dense snow and freshly fallen powder."
Denser ice quickly conducts the heat of the sun away from the surface, keeping it cold during the day. Powdery ice is more insulating and traps the sun's heat at the surface, so the surface warms up.
Even if surface texture variations are to blame, scientists are still trying to figure out why there are such sharp boundaries between the regions, Spencer said. It is possible that the impact that created Herschel Crater melted surface ice and spread water across the moon. That liquid may have flash-frozen into a hard surface. But it is hard to understand why this dense top layer would remain intact when meteorites and other space debris should have pulverized it by now, Spencer said.
Icy spray from the E ring, one of Saturn's outer rings, should also keep Mimas relatively light-colored, but the new visible-light images from the flyby paint a picture of surprising contrasts. Cassini imaging team scientists didn't expect to see dark streaks trailing down the bright crater walls or a continuous, narrow pile of concentrated dark debris tracing the foot of each wall.
The pattern may appear because of the way the surface of Mimas ages, said Paul Helfenstein, a Cassini imaging team associate based at Cornell University, Ithaca, N.Y. Over time, the moon's surface appears to accumulate a thin veil of silicate minerals or carbon-rich particles, possibly because of meteor dust falling onto the moon, or impurities already embedded in surface ice.
As the sun's warming rays and the vacuum of space evaporate the brighter ice, the darker material is concentrated and left behind. Gravity pulls the dark material down the crater walls, exposing fresh ice underneath. Although similar effects are seen on other moons of Saturn, the visibility of these contrasts on a moon continually re-paved with small particles from the E ring helps scientists estimate rates of change on other satellites.
"These processes are not unique to Mimas, but the new high-definition images are like Rosetta stones for interpreting them," Helfenstein said.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. The composite infrared spectrometer team is based at NASA's Goddard Space Flight Center, Greenbelt, Md., where the instrument was built.
More information and images are available at http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov.
› View related images
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Houston, We Have an Astronaut
Shannon Walker, born and raised in Houston, will become the city’s first native to fly in space when she launches to the International Space Station in June. Walker, along with astronaut Doug Wheelock and cosmonaut Fyodor Yurchikhin, will launch on June 16 aboard a Russian Soyuz spacecraft from the Baikonur Cosmodrome in Kazahkstan and will spend six months aboard the orbiting outpost.
Walker’s background is filled with unique events – some by chance and some planned – that led her to become an astronaut. After she graduated from Westbury High School in Houston, Walker attended Rice University. She majored in physics, but wasn’t sure what direction that would take her.
“I was having a hard time getting interest from future employers because of my physics background,” she said. “It seemed all anyone wanted was engineers.”
Walker then happened to meet and interview with a man at NASA, and the subsequent conversation would change Walker’s career path for good. That man was former space shuttle flight director and now senior NASA executive Wayne Hale.
“It was a stroke of luck how it happened,” Walker said. She joined NASA in 1987 as a space shuttle flight controller. She took some time to pursue her doctoral degree in space physics and then returned to NASA in 1993. She worked in both Russia and the United States as the International Space Station came into being, all the while thinking about taking yet another leap. In 2004, Walker applied and was accepted into the astronaut corps.
“When I became an astronaut, I knew I wanted to pursue long-duration flight aboard the station,” She said. “I knew it would be a just a tremendous personal challenge, and I looked forward to it.”
Now that she is approaching her flight, Walker is in the process of completing her final training sessions in both Houston and Star City, Russia. Even though she will leave her hometown behind for six months, she’s going to take a little piece of Houston with her up to the station.
“They’ve given me the key to the city to take with me,” Walker said. She’s also planning on taking up some other personal items as well as some Rice University artifacts. Walker also said she plans on taking up some less tangible things with her – some advice she has received from previous station residents.
“They have all told me to take some time – as busy as it gets – to really enjoy the experience and to take it all in,” she said. “I think that’s probably the best advice I’ve gotten.”
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- The Spirit of Pete Conrad Lives on at Innovation S...
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The Spirit of Pete Conrad Lives on at Innovation Summit
The summit is being held April 8-10, 2010 at NASA’s Ames Research Center, Moffett Field, Calif. The "Spirit of Innovation" award is in honor of the late Charles 'Pete' Conrad, a highly decorated naval aviator and astronaut who flew Gemini V, Gemini XI, commanded Apollo XII and was the third person to walk on the moon. Conrad went on to fly Skylab, our first space station. He received a Congressional Space Medal of Honor for his work on Skylab.
Nancy Conrad, wife of the late Pete Conrad, serves as chairman of the Conrad Foundation. She formed the program to provide high school students with an understanding of science and technology and give them an opportunity to solve real world problems through innovation and entrepreneurship.
During the three-day event, 25 teams from all over the U.S. present their ideas to a panel of experts similar to the way start-up entrepreneurs "pitch" to potential investors. The teams create an online portfolio (videos, blog and "company" logo) to present to venture capitalists, entrepreneurs and scientists.
Winning teams receive an opportunity to commercialize the technology and $5,000 in seed money to further develop the product.
"Our goal is to excite students about science, technology and innovation by connecting them with top entrepreneurs, scientists and industry leaders," said Joshua Neubert, executive director for the Conrad Foundation.
Niveditha Jayasekar, a student from Monta Vista High School in Cupertino, Calif., said she became fascinated with nanotechnology as early as the sixth grade. Jayasekar and her four teammates are using a patented nanotechnology developed by NASA scientist Dr. David Loftus to deliver pharmaceuticals in microgravity. The team hopes the product could lead to future breakthroughs in the field of space medicine.
Monta Vista High School teacher Carl Schmidt is the team’s advisor and representative for Future Business Leaders of America. Schmidt said contrary to most science competitions, students in the Conrad Innovation Summit approach projects with an entrepreneurial mindset. "They need to think about who has a problem and will pay to get it solved," Schmidt said. "The goal is to take a technological idea to the commercial market."
Schmidt said the students gain experience working with scientists as well as an understanding of the market. He adds that the competition, which has 30 percent female participation, is a unique way to recruit more females into science and technology fields.
The 25 finalist teams will compete in four categories: aerospace exploration, renewable energy, green schools and space nutrition. Beginning March 29, 2010, the public can visit the Conrad Foundation Web site and vote for their favorite team. Winners for the People’s Choice Awards will be announced on April 10, 2010.
For more information about the Conrad Innovation Summit, visit:
NASA's First Class of Female Astronauts
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NASA Study Finds Atlantic 'Conveyor Belt' Not Slowing
The findings are the result of a new monitoring technique, developed by oceanographer Josh Willis of NASA's Jet Propulsion Laboratory in Pasadena, Calif., using measurements from ocean-observing satellites and profiling floats. The findings are reported in the March 25 issue of Geophysical Research Letters.
The Atlantic overturning circulation is a system of currents, including the Gulf Stream, that bring warm surface waters from the tropics northward into the North Atlantic. There, in the seas surrounding Greenland, the water cools, sinks to great depths and changes direction. What was once warm surface water heading north turns into cold deep water going south. This overturning is one part of the vast conveyor belt of ocean currents that move heat around the globe.
Without the heat carried by this circulation system, the climate around the North Atlantic -- in Europe, North America and North Africa -- would likely be much colder. Scientists hypothesize that rapid cooling 12,000 years ago at the end of the last ice age was triggered when freshwater from melting glaciers altered the ocean's salinity and slowed the overturning rate. That reduced the amount of heat carried northward as a result.
Until recently, the only direct measurements of the circulation's strength have been from ship-based surveys and a set of moorings anchored to the ocean floor in the mid-latitudes. Willis' new technique is based on data from NASA satellite altimeters, which measure changes in the height of the sea surface, as well as data from Argo profiling floats. The international Argo array, supported in part by the National Oceanic and Atmospheric Administration, includes approximately 3,000 robotic floats that measure temperature, salinity and velocity across the world's ocean.
With this new technique, Willis was able to calculate changes in the northward-flowing part of the circulation at about 41 degrees latitude, roughly between New York and northern Portugal. Combining satellite and float measurements, he found no change in the strength of the circulation overturning from 2002 to 2009. Looking further back with satellite altimeter data alone before the float data were available, Willis found evidence that the circulation had sped up about 20 percent from 1993 to 2009. This is the longest direct record of variability in the Atlantic overturning to date and the only one at high latitudes.
The latest climate models predict the overturning circulation will slow down as greenhouse gases warm the planet and melting ice adds freshwater to the ocean. "Warm, freshwater is lighter and sinks less readily than cold, salty water," Willis explained.
For now, however, there are no signs of a slowdown in the circulation. "The changes we're seeing in overturning strength are probably part of a natural cycle," said Willis. "The slight increase in overturning since 1993 coincides with a decades-long natural pattern of Atlantic heating and cooling."
If or when the overturning circulation slows, the results are unlikely to be dramatic. "No one is predicting another ice age as a result of changes in the Atlantic overturning," said Willis. "Even if the overturning was the Godzilla of climate 12,000 years ago, the climate was much colder then. Models of today's warmer conditions suggest that a slowdown would have a much smaller impact now.
"But the Atlantic overturning circulation is still an important player in today's climate," Willis added. "Some have suggested cyclic changes in the overturning may be warming and cooling the whole North Atlantic over the course of several decades and affecting rainfall patterns across the United States and Africa, and even the number of hurricanes in the Atlantic."
With their ability to observe the Atlantic overturning at high latitudes, Willis said, satellite altimeters and the Argo array are an important complement to the mooring and ship-based measurements currently being used to monitor the overturning at lower latitudes. "Nobody imagined that this large-scale circulation could be captured by these global observing systems," said Willis. "Their amazing precision allows us to detect subtle changes in the ocean that could have big impacts on climate."
For more information about NASA and agency programs, visit: http://www.nasa.gov.
JPL is managed for NASA by the California Institute of Technology in Pasadena.
NASA's Grace Sees Rapid Spread in Greenland Ice Loss
"These changes on the Greenland ice sheet are happening fast, and we are definitely losing more mass than we had anticipated," says Velicogna. "We also are seeing this trend in Antarctica, a sign that warming temperatures really are having an effect on ice in Earth's cold regions."
The NASA/National Science Foundation-funded study was led by Shfaqat Abbas Khan of the Denmark Technical Institute's National Space Institute in Copenhagen. Other participating institutions included the University of Colorado at Boulder and Ohio State University, Columbus.
Link for more information:
- The Sheer Delight of Tackling Shear Stress
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The Sheer Delight of Tackling Shear Stress
Vijay Chandrasekharan is a research associate and doctoral candidate at the University of Florida, where he produced a micro-electronic sensor that measures the amount of shear stress created when turbulent air flows over a surface.
The sensor already has proven its usefulness in improving the basic understanding of turbulent flow in gases and liquids, and in characterizing wind tunnels.
When air flows through a wind tunnel, some air molecules stick to the wall of the tunnel while others flow through at the speed of the wind. The difference in speed exerts a drag force on the wall of the tunnel and causes friction in the air. Drag and friction are related to shear stress.
The new sensor can measure a wider range of shear stress than can any sensor of its type before.
Accurate measurements of shear stress are crucial to NASA's and aircraft manufacturers' research into developing more efficient airplanes. Shear stress affects the amount of drag on an aircraft. The more drag there is on an aircraft, the more fuel that aircraft burns.
Designers can use data from the sensors to design safer and more fuel-efficient aircraft.
There also are potential applications for this sensor in the fields of medical and environmental sciences. In medicine, for example, according to Chandrasekharan, the sensor could measure variations in shear stress along the wall of an artery and help researchers determine the effect those fluctuations have on the development of arteriosclerosis, commonly known as hardening of the arteries.
Chandrasekharan said the shear stress sensor is "one of the most successful efforts on direct shear stress sensors in published literature" and has a real shot at successfully entering the commercial market.
The sensor innovation is the result of a NASA Research Announcement, or NRA, study contract awarded by the Subsonic Fixed Wing Project of NASA's Aeronautics Research Mission Directorate. The directorate awards dozens of contracts for NRA studies to academia each year. This three-year contract with the University of Florida was worth $475,000.
"This collaboration led to an extremely satisfying experience for me as I worked on my dissertation," Chandrasekharan said. "Without NASA’s involvement my Ph.D. could have been strictly an academic pursuit, without subsequent practical, real-world importance."
Experts outside NASA and the aeronautics community already have taken notice of the sensor, its potential, and its inventor. Chandrasekharan recently received one of 13 national postdoctoral entrepreneurial fellowships awarded by the Kauffman Foundation.
"The work done by Vijay and this NRA's principal investigator, Mark Sheplak, is a great example of how NASA can work with a university to overcome fundamental challenges and lead to the improved safety and efficiency of our nation's aircraft," said Project Scientist Richard Wahls.
Chandrasekharan, Sheplak and two associates have filed a provisional patent application for the sensor.
Even as the original effort is lauded, a sequel to the story already is in work. As part of NASA's Graduate Student Researchers Program one student is working to further develop the sensor's electronic interface, while another is working on the wireless version of the sensor and recently performed tests with the sensor in a wind tunnel at NASA's Langley Research Center in Hampton, Va.
"It's good to see that our initial work has lead to synergistic outcomes at different levels through this NRA and other NASA programs," Chandrasekharan said.
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- GOES Satellite Movie Captures Record-Setting Febru...
- NASA Astrobiology Institute ‘Removes Walls’ for Vi...
- Middle School Science Students Prove Visit to NASA...
GOES Satellite Movie Captures Record-Setting February Blizzards in Washington
Washington, D.C. normally averages only 16 inches of snow per year, but this year most of the season's snowfall arrived over several days and the Geostationary Operational Environmental Satellite called GOES-12 captured the storms.
NASA's GOES Project created a movie of GOES satellite data from February 1-16, 2010 when two blizzards hit the Baltimore, Md. and Washington areas. The GOES-12 operated by the National Oceanic and Atmospheric Administration (NOAA) captures images of U.S. East Coast weather continuously. Those images were compiled into a movie by the NASA GOES Project at NASA's Goddard Space Flight Center, Greenbelt, Md.
"It is a pleasure to see the fruits of the hard work and commitment from the NASA and NOAA team," said Andre Dress, GOES N-P NASA Deputy Project Manager, at NASA Goddard. "These images are very impressive and I am excited to think that these were taken with the older satellites. NOAA plans to put into service the newer GOES N-P design, this April. I know we will be seeing better and more exhilarating images this year," Dress said.
During the first two weeks of February, heavy, wet snows semi-paralyzed Washington. Five inches fell on February 3, 24 inches fell on February 6, and 12 inches on February 10. A second storm followed on February 16 that dumped 10 inches on Philadelphia and New York, but spared Washington and Baltimore.
These storms are called "Nor'easters" because the counter-clockwise circulation around a low pressure system on the Atlantic coast pushes moist sea air from the north-east into arctic air over the land. This windy mixture creates a very efficient snow-making machine from Boston to Washington. "The GOES movie illustrates how succeeding storms form along the Gulf coast, travel up the Atlantic coast, pause over the mid-Atlantic states, and finally slide out to sea," said Dennis Chesters of the NASA GOES Project.
This movie was created by overlaying the clouds observed several times per hour by NOAA's GOES Imager onto a true-color map previously derived from NASA's MODIS land-mapping instrument. The infrared channels on GOES detect clouds day and night, which are portrayed as grey for low clouds and white for high clouds. During the day, the visible channel on GOES adds shadow-texture to the clouds and illuminates the snow on the ground.
The movie compresses 16 days into 2 minutes. It illustrates how continental-scale land/sea/air phenomena come together to make large winter storms. NOAA's ground/space-based observing system and numerical weather models did an excellent job of accurately forecasting the location and depth of each East Coast blizzard in this series.
Related Links:
> GOES Blizzard movie
> GOES Programs
> GOES-15
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NASA Astrobiology Institute ‘Removes Walls’ for Virtual Conference
Entitled "The Organic Continuum from the Interstellar Medium to the Early Earth," the two-day workshop held March 11-12, 2010 was organized by George Cody, leader of the NAI's Carnegie Institution of Washington team and Doug Whittet, leader of the NAI’s team at the Rensselaer Polytechnic Institute, Troy, New York.
Among the countries represented at the workshop were Canada, Mexico, six western European nations, Ukraine, India, South Korea, Japan, Australia, Brazil, Colombia, and Uruguay.
"The Workshop was in many ways a realization of the original vision of the virtual institute,"said Carl Pilcher, director of the NAI. "When the NAI began 12 years ago, we envisioned scientists interacting seamlessly at a distance. But the technology and the culture weren't ready. Today the technology works beautifully, and people have come to see this as the wave of the future. This workshop demonstrated that the future has arrived."
A total of 33 scientific talks were presented during the workshop, with interactive question and answer capability provided for the participants at eight sites equipped with high definition video and audio, and streaming with real-time question submission through the Adobe Connect web interface.
"The advances in technology that made this meeting possible have been paralleled by remarkable developments in the research that drives the science," Whittet said. "The benefit in terms of scientific knowledge gained and dollars expended by participants is likely unprecedented," added Cody.
According to Cody, the conference was "an experiment." Most participants categorized their experience level with remote collaborative technologies as beginner or intermediate, and a few had no prior experience at all.
Despite this, participants reported the experiment was a great success. "I was not expecting to have the same intellectual experience as I normally do at conferences…but after this conference, I do have that same sense of having been to a "real" conference,” adding, "this was very fulfilling for me professionally," said one participant.
Locations of participants ranged from a conference room in a major city with high-speed connectivity and professional videoconferencing equipment, to a home office in a small town with a laptop and home-based Internet connection.
"Over the course of the conference, I actually came to be unaware of the conference as being at multiple venues,"Cody said, "…the difference that high definition, high band-width videoconferencing makes is remarkable. Clear face-to-face contact with no time lag in either visual or audio was the essential part. Evidently the difference between 100 feet and 3000 miles is not all that great."
NAI is preparing guidelines for those in the community who are interested in hosting such an event in the future. Information will be available shortly, but interested parties can contact Marco Boldt at NAI Central at any time, marco.boldt@nasa.gov
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- Middle School Science Students Prove Visit to NASA...
- Astronaut Buzz Aldrin Trades in Moonwalking Boots ...
- A Burst of Spring
Middle School Science Students Prove Visit to NASA Ames Was Anything But a “Drag”
"I sort of slept. I was really excited," Ramesh recalled.
The sleepy-eyed students were prepared to conduct an experiment studying the effects of airflow resistance or "drag" of automobiles for the Santa Clara Valley Science Engineering Fair – 2010 Synopsys Championship held recently.
Ramesh called the education office at NASA Ames and was surprised when he got a phone call back that his visit had been approved. Both Ramesh and his best friend, Aiyaswamy, were invited to visit the Fluid Mechanics Laboratory at NASA Ames to perform their project.
"This is NASA and they called me back. I was surprised. We weren’t expecting them to call back," Ramesh said.
"I don’t think that they will ever forget this. This is a once in a lifetime experience for them," ventured his father, Ramesh Nagar.
The boys were fortunate to request their visit when the Fluid Mechanics Laboratory was uniquely set up to accommodate their request. Kurtis Long, test engineer at the Fluid Mechanics Lab got permission from Rabindra Mehta, chief of the Experimental Aero-Physics Branch, for the boys to visit and Long donated his time during his lunch hour when the boys performed their test.
"This is the perfect age at which we can effectively help, inspire and guide the next generation towards a future with NASA," said Mehta.
"These boys just happened to ask at the right time. If you don’t ask, you’ll never get what you want. It’s a scary thing to call NASA and ask for help with an experiment,” said Long. “These boys are really amazing and showing great initiative." Aiyaswamy’s life science teacher, Leslie Schafer, said that Aiyaswamy "is very motivated and talks a lot about his experience at Ames."
The two young students both showed up for their experiment with a half dozen toy cars they found at home. "Our project is to find the best design shape that has the least amount of drag," said Aiyaswamy. "As we began the experiment, we realized that cars with a sloping shape perform better."
The boys placed the cars in a pool of water. Dye was added to the water and photos were taken of the dye flowing around the toy cars. "Air and water have the same flow characteristics, but by using water we can slow down time and see the flow more clearly," explained Long. With these photos, the boys could measure the drag of each car. "These are real, no kidding, NASA photos," smiled Long.
The boys were assisted by Christina Ngo, an intern from the Foothill / De Anza college program. "I wasn’t surprised the students were allowed to visit. They love kids here," said Ngo.
During their visit, the boys learned about aerodynamic principles that will help them with their project. "We learned about separation points and what principles a car has to have for minimum drag," said Ramesh. The boys walked away from their lunch hour experiment with an entirely different hypothesis regarding their experiment. "This is why we do experiments," explained Long.
"I think the coolest part of this is the way that NASA responded. Top scientists showing an interest in two middle school kids from San Jose. That's more impressive than anything else," Nagar said. The boys enjoyed their time with the scientists. "We really enjoyed the whole NASA experience - the people, as well as the lab. It was like being part of the NASA team for a day," Ramesh added.
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- Astronaut Buzz Aldrin Trades in Moonwalking Boots ...
- A Burst of Spring
- NASA Mars Rover Getting Smarter as it Gets Older
Astronaut Buzz Aldrin Trades in Moonwalking Boots for Dancing Shoes
"My primary motivation for joining the show is to help bring NASA and the U.S. human spaceflight program to the front of popular consciousness. Until there's a spectacular success or failure, the space program is not on everyone's lips," Aldrin says. "’Dancing with the Stars’ has an audience of millions of followers and it would be great if those viewers became supporters of our space program. I’m hoping that all of my old friends and colleagues in the space community can tune in and cast their vote for the octogenarian on the dance floor!"
During the show’s March 22nd season premiere, Aldrin received a surprise message from more than 220 miles above the Earth. Fellow astronauts recorded a message to wish him good luck from aboard the International Space Station.
The International Space Station, a joint project of five space agencies, is the largest and most complicated spacecraft ever built. Upon completion of assembly later this year, the station’s crew and its U.S., European, Japanese and Russian laboratory facilities will expand the pace of space-based research to unprecedented levels. Nearly 150 experiments are currently under way on the station, and more than 400 experiments have been conducted since research began nine years ago. These experiments already are leading to advances in the fight against food poisoning, new methods for delivering medicine to cancer cells and the development of more capable engines and materials for use on Earth and in space.
Learn more about the space station and even learn when it’s flying over your city by visiting the Space Station section.
To learn more about Buzz’s new endeavor, visit his website.
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NASA Mars Rover Getting Smarter as it Gets Older
Software uploaded this winter is the latest example of NASA taking advantage of the twin Mars rovers' unanticipated longevity for real Martian test drives of advances made in robotic autonomy for future missions.
Now, Opportunity's computer can examine images that the rover takes with its wide-angle navigation camera after a drive, and recognize rocks that meet specified criteria, such as rounded shape or light color. It can then center its narrower-angle panoramic camera on the chosen target and take multiple images through color filters.
"It's a way to get some bonus science," said Tara Estlin of NASA's Jet Propulsion Laboratory, Pasadena, Calif. She is a rover driver, a senior member of JPL's Artificial Intelligence Group and leader of development for this new software system.
The new system is called Autonomous Exploration for Gathering Increased Science, or AEGIS. Without it, follow-up observations depend on first transmitting the post-drive navigation camera images to Earth for ground operators to check for targets of interest to examine on a later day. Because of time and data-volume constraints, the rover team may opt to drive the rover again before potential targets are identified or before examining targets that aren't highest priority.
The first images taken by a Mars rover choosing its own target show a rock about the size of a football, tan in color and layered in texture. It appears to be one of the rocks tossed outward onto the surface when an impact dug a nearby crater. Opportunity pointed its panoramic camera at this unnamed rock after analyzing a wider-angle photo taken by the rover's navigation camera at the end of a drive on March 4. Opportunity decided that this particular rock, out of more than 50 in the navigation camera photo, best met the criteria that researchers had set for a target of interest: large and dark.
"It found exactly the target we would want it to find," Estlin said. "This checkout went just as we had planned, thanks to many people's work, but it's still amazing to see Opportunity performing a new autonomous activity after more than six years on Mars."
Opportunity can use the new software at stopping points along a single day's drive or at the end of the day's drive. This enables it to identify and examine targets of interest that might otherwise be missed.
"We spent years developing this capability on research rovers in the Mars Yard here at JPL," said Estlin. "Six years ago, we never expected that we would get a chance to use it on Opportunity."
The developers anticipate that the software will be useful for narrower field-of-view instruments on future rovers.
Other upgrades to software on Opportunity and its twin, Spirit, since the rovers' first year on Mars have improved other capabilities. These include choosing a route around obstacles and calculating how far to reach out a rover's arm to touch a rock. In 2007, both rovers gained the know-how to examine sets of sky images to determine which ones show clouds or dust devils, and then to transmit only the selected images. The newest software upload takes that a step further, enabling Opportunity to make decisions about acquiring new observations.
The AEGIS software lets scientists change the criteria it used for choosing potential targets. In some environments, rocks that are dark and angular could be higher-priority targets than rocks that are light and rounded, for example.
This new software system has been developed with assistance from NASA's Mars Exploration Rover Project and with funding from the New Millennium Program, the Mars Technology Program, the JPL Interplanetary Network Development Program, and the Intelligent Systems Program. The New Millennium Program tests advanced technology in space flight. JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover Project for the NASA Science Mission Directorate, Washington.
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