JPL

NASA Satellites Spot Young Star in Growth Spurt

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Calla Cofield
Jet Propulsion Laboratory, Pasadena, Calif.

 

This illustration shows a young star undergoing a type of growth spurt. Left panel: Material from the dusty and gas-rich disk (orange) plus hot gas (blue) mildly flows onto the star, creating a hot spot. Middle panel: The outburst begins – the inner disk is heated, more material flows to the star, and the disk creeps inward. Right panel: The outburst is in full throttle, with the inner disk merging into the star and gas flowing outward (green). Credit: Caltech/T. Pyle (IPAC)

 

An adolescent star in the midst of a dramatic growth phase has been observed with the help of two NASA space telescopes. The youngster belongs to a class of stars that gain mass when matter swirling around the star falls onto its surface. The in-falling matter causes the star to appear about 100 times brighter. Astronomers have found only 25 stars in this class, and only about half of those have been observed during an outburst. 


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The Mars InSight Landing Site Is Just Plain Perfect

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This artist’s concept depicts the smooth, flat ground that dominates InSight’s landing ellipse in the Elysium Planitia region of Mars. Credits: NASA/JPL-Caltech

No doubt about it, NASA explores some of the most awe-inspiring locations in our solar system and beyond. Once seen, who can forget the majesty of astronaut Jim Irwin standing before the stark beauty of the Moon’s Hadley Apennine mountain range, of the Hubble Space Telescope’s gorgeous “Pillars of Creation” or Cassini’s magnificent mosaic of Saturn?

 Mars also plays a part in this visually compelling equation, with the high-definition imagery from the Curiosity rover of the ridges and rounded buttes at the base of Mount Sharp bringing to mind the majesty of the American Southwest. That said, Elysium Planitia – the site chosen for the Nov. 26 landing of NASA’s InSight mission to Mars – will more than likely never be mentioned with those above because it is, well, plain. 

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NASA’s Juno Spacecraft Set for Fifth Jupiter Flyby

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DC Agle
Jet Propulsion Laboratory, Pasadena, Calif.

Dwayne Brown / Laurie Cantillo
NASA Headquarters, Washington

 

This enhanced-color image of a mysterious dark spot on Jupiter seems to reveal a Jovian “galaxy” of swirling storms. Credits: NASA/JPL-Caltech/SwRI/MSSS/Roman Tkachenko

 

NASA’s Juno spacecraft will make its fifth flyby over Jupiter’s mysterious cloud tops on Monday, March 27, at 1:52 a.m. PDT (4:52 a.m. EDT, 8:52 UTC).

At the time of closest approach (called perijove), Juno will be about 2,700 miles (4,400 kilometers) above the planet’s cloud tops, traveling at a speed of about 129,000 miles per hour (57.8 kilometers per second) relative to the gas-giant planet. All of Juno’s eight science instruments will be on and collecting data during the flyby.


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NASA to Release New Pluto Images, Science Findings at July 17 NASA TV Briefing

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July 16, 2015
MEDIA ADVISORY M15-109

New image of an area on Pluto's largest moon Charon
This new image of an area on Pluto’s largest moon Charon has a captivating feature — a depression with a peak in the middle, shown here in the upper left corner of the inset. The image shows an area approximately 240 miles (390 kilometers) from top to bottom, including few visible craters. The image was taken at approximately 6:30 a.m. EDT on July 14, 2015, about 1.5 hours before closest approach to Pluto, from a range of 49,000 miles (79,000 kilometers). Credits: NASA-JHUAPL-SwRI

NASA will hold a media briefing at 1 p.m. EDT Friday, July 17, to reveal new images of Pluto and discuss new science findings from Tuesday’s historic flyby.

The briefing will be held in James E. Webb Auditorium at NASA Headquarters, located at 300 E St. SW in Washington. NASA Television and the agency’s website will carry the briefing live.

Participants in the briefing will be:

  • Jim Green, director of Planetary Science at NASA Headquarters in Washington
  • Alan Stern, New Horizons principal investigator at Southwest Research Institute (SwRI) in Boulder, Colorado
  • Randy Gladstone, New Horizons co-investigator at SwRI in San Antonio
  • Jeffrey Moore, New Horizons co-investigator at NASA’s Ames Research Center in Moffett Field, California
  • Fran Bagenal, New Horizons co-investigator, University of Colorado, Boulder

Media may participate by phone. To join the briefing by phone, reporters must email their name, affiliation and telephone number to Karen Northon at karen.northon by noon Friday.

Media and the public also may ask questions during the briefing on Twitter using the hashtag #askNASA.

For NASA TV streaming video, scheduling and downlink information, visit:

http://www.nasa.gov/nasatv

For more information on the New Horizons mission, including fact sheets, schedules, video and images, visit:

http://www.nasa.gov/newhorizons

Traffic Around Mars Gets Busy

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This graphic depicts the relative shapes and distances from Mars for five active orbiter missions plus the planet’s two natural satellites. It illustrates the potential for intersections of the spacecraft orbits. Image Credit: NASA/JPL-Caltech



Fast Facts:

  • Five active spacecraft are orbiting Mars, an increase of two since last summer
  • An enhanced system warns if two orbiters may approach each other too closely

NASA has beefed up a process of traffic monitoring, communication and maneuver planning to ensure that Mars orbiters do not approach each other too closely. 

Last year’s addition of two new spacecraft orbiting Mars brought the census of active Mars orbiters to five, the most ever. NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) and India’s Mars Orbiter Mission joined the 2003 Mars Express from ESA (the European Space Agency) and two from NASA: the 2001 Mars Odyssey and the 2006 Mars Reconnaissance Orbiter (MRO). The newly enhanced collision-avoidance process also tracks the approximate location of NASA’s Mars Global Surveyor, a 1997 orbiter that is no longer working.

It’s not just the total number that matters, but also the types of orbits missions use for achieving their science goals. MAVEN, which reached Mars on Sept. 21, 2014, studies the upper atmosphere. It flies an elongated orbit, sometimes farther from Mars than NASA’s other orbiters and sometimes closer to Mars, so it crosses altitudes occupied by those orbiters. For safety, NASA also monitors positions of ESA’s and India’s orbiters, which both fly elongated orbits.

“Previously, collision avoidance was coordinated between the Odyssey and MRO navigation teams,” said Robert Shotwell, Mars Program chief engineer at NASA’s Jet Propulsion Laboratory, Pasadena, California. “There was less of a possibility of an issue. MAVEN’s highly elliptical orbit, crossing the altitudes of other orbits, changes the probability that someone will need to do a collision-avoidance maneuver. We track all the orbiters much more closely now. There’s still a low probability of needing a maneuver, but it’s something we need to manage.”

Traffic management at Mars is much less complex than in Earth orbit, where more than 1,000 active orbiters plus additional pieces of inactive hardware add to hazards. As Mars exploration intensifies, though, and will continue to do so with future missions, precautions are increasing. The new process was established to manage this growth as new members are added to the Mars orbital community in years to come.

All five active Mars orbiters use the communication and tracking services of NASA’s Deep Space Network, which is managed at JPL. This brings trajectory information together, and engineers can run computer projections of future trajectories out to a few weeks ahead for comparisons.

“It’s a monitoring function to anticipate when traffic will get heavy,” said Joseph Guinn, manager of JPL’s Mission Design and Navigation Section. “When two spacecraft are predicted to come too close to one another, we give people a heads-up in advance so the project teams can start coordinating about whether any maneuvers are needed.”

The amount of uncertainty in the predicted location of a Mars orbiter a few days ahead is more than a mile (more than two kilometers). Calculating projections for weeks ahead multiplies the uncertainty to dozens of miles, or kilometers. In most cases when a collision cannot be ruled out from projections two weeks ahead, improved precision in the forecasting as the date gets closer will rule out a collision with no need for avoidance action. Mission teams for the relevant orbiters are notified in advance when projections indicate a collision is possible, even if the possibility will likely disappear in subsequent projections. This situation occurred on New Year’s weekend, 2015.

On Jan. 3, automated monitoring determined that two weeks later, MAVEN and MRO could come within about two miles (three kilometers) of each other, with large uncertainties remaining in the exact passing distance. Although that was a Saturday, automatic messages went out to the teams operating the orbiters.

“In this case, before the timeline got short enough to need to plan an avoidance maneuver, the uncertainties shrank, and that ruled out the chance of the two spacecraft coming too near each other,” Guinn said. This is expected to be the usual pattern, with the advance warning kicking off higher-level monitoring and initial discussions about options.

If preparations for an avoidance maneuver were called for, spacecraft commands would be written, tested and approved for readiness, but such commands would not be sent to a spacecraft unless projections a day or two ahead showed probability of a hazardous conjunction. The amount of uncertainty about each spacecraft’s exact location varies, so the proximity considered unsafe also varies. For some situations, a day-ahead projection of two craft coming within about 100 yards (100 meters) of each other could trigger a maneuver.

The new formal collision-avoidance process for Mars is part of NASA’s Multi-Mission Automated Deep-Space Conjunction Assessment Process. A side benefit of it is that information about when two orbiters will be near each other — though safely apart — could be used for planning coordinated science observations. The pair could look at some part of Mars or its atmosphere from essentially the same point of view simultaneously with complementary instruments.

Odyssey, MRO and MAVEN — together with NASA’s two active Mars rovers, Opportunity and Spirit — are part of NASA’s robotic exploration of Mars that is preparing the way for human-crewed missions there in the 2030s and later, in NASA’s Journey to Mars strategy.

NASA’s Goddard Space Flight Center manages the MAVEN project for the NASA Science Mission Directorate, Washington. MAVEN’s principal investigator is based at the University of Colorado’s Laboratory for Atmospheric and Space Physics. JPL, a division of the California Institute of Technology in Pasadena, manages NASA’s Mars Exploration Program and the Odyssey and MRO projects for the Science Mission Directorate. Lockheed Martin Space Systems, Denver, built all three NASA Mars orbiters.

For more about NASA’s Mars Exploration Program, visit:  http://mars.jpl.nasa.gov or http://www.nasa.gov/mars.

 

New Pages Available: NASA Apps for the Public and News Feed Links, Fact Sheets

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I have created a number of pages available that will provide you with additional information, links to news feeds, and iPad and Android Apps by NASA for a variety of missions and news.

The new pages (all pages are available when you click the three bars on the upper right hand side of the page) that have been added are:

• Mobile Apps – Connect and Collaborate With NASA Projects

A comprehensive list of both NASA’s main or featured Apps available for mobile users. Along with the featured apps, NASA also has numerous apps for everything from other facilities to current space exploration projects, live views of the Sun, ISS and Mars rover.

NASA RSS Feeds (Links)

Here this page provides the news feed (RSS) links to many of NASA’s missions, centers, science and technology, general and topical feeds. You will need to copy the links into your News or an RSS App or computer programs (Microsoft Exchange suppports RSS feeds within the mail program, for example).

NASA  Fact Sheets – NASA Centers

Each NASA center creates and updates Fact Sheets covering its mission, facilities and projects. Click on a center’s name to go its Fact Sheet index. Click on the links to veiw any fact sheet you wish to know about.

• News Feeds/Links to Other Cosmology News Sources

This page is the main page for all the RSS and XML feeds that other websites provide, such as Space.com. As we find more sites providing news stories related to Cosmology and Space Exploration, I will add it here.

As I gather more links together, I will update this message (which will stick to the top for at least seven days every time it changes) with the new links. For example, I am working on a Fact Sheet page that will provide links to every mission NASA has performed. It will at least have current missions, however, I am also going to add all missions going back to the beginning of the US space program.

George.

NASA’s Spitzer Spots Planet Deep Within Our Galaxy

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This artist’s map of the Milky Way shows the location of one of the farthest known exoplanets, lying 13,000 light-years away. Image credit: NASA/JPL-Caltech
 


NASA’s Spitzer Space Telescope has teamed up with a telescope on the ground to find a remote gas planet about 13,000 light-years away, making it one of the most distant planets known.

The discovery demonstrates that Spitzer — from its unique perch in space — can be used to help solve the puzzle of how planets are distributed throughout our flat, spiral-shaped Milky Way galaxy. Are they concentrated heavily in its central hub, or more evenly spread throughout its suburbs?

“We don’t know if planets are more common in our galaxy’s central bulge or the disk of the galaxy, which is why these observations are so important,” said Jennifer Yee of the Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, and a NASA Sagan fellow. Yee is the lead author of one of three new studies that appeared recently in the Astrophysical Journal describing a collaboration between astronomers using Spitzer and the Polish Optical Gravitational Lensing Experiment, or OGLE. 

OGLE’s Warsaw Telescope at the Las Campanas Observatory in Chile scans the skies for planets using a method called microlensing. A microlensing event occurs when one star happens to pass in front of another, and its gravity acts as a lens to magnify and brighten the more distant star’s light. If that foreground star happens to have a planet in orbit around it, the planet might cause a blip in the magnification. 

Astronomers are using these blips to find and characterize planets tens of thousands of light-years away in the central bulge of our galaxy, where star crossings are more common. Our sun is located in the suburbs of the galaxy, about two-thirds of the way out from the center. The microlensing technique as a whole has yielded about 30 planet discoveries so far, with the farthest residing about 25,000 light-years away. 

“Microlensing experiments are already detecting planets from the solar neighborhood to almost the center of the Milky Way,” said co-author Andrew Gould of The Ohio State University, Columbus. “And so they can, in principle, tell us the relative efficiency of planet formation across this huge expanse of our galaxy.”

Microlensing complements other planet-hunting tools, such as NASA’s Kepler mission, which has found more than 1,000 planets closer to home. But it faces one key problem: This method can’t always precisely narrow down the distance to the stars and planets being observed. While a passing star may magnify the light of a more distant star, it rarely can be seen itself, making the task of measuring how far away it is challenging. 

Of the approximately 30 planets discovered with microlensing so far, roughly half cannot be pinned down to a precise location. The result is like a planetary treasure map lacking in X’s.

That’s where Spitzer can help out, thanks to its remote Earth-trailing orbit. Spitzer circles our sun, and is currently about 128 million miles (207 million kilometers) away from Earth. That’s father from Earth than Earth is from our sun. When Spitzer watches a microlensing event simultaneously with a telescope on Earth, it sees the star brighten at a different time, due to the large distance between the two telescopes and their unique vantage points. This technique is generally referred to as parallax.

“Spitzer is the first space telescope to make a microlens parallax measurement for a planet,” said Yee. “Traditional parallax techniques that employ ground-based telescopes are not as effective at such great distances.” 

Using space telescopes to observe microlensing events is tricky. Ground telescopes send out alerts to the astronomy community when an event starts, but the activity can quickly fade, lasting on average about 40 days. The Spitzer team has scrambled to start microlensing campaigns as soon as three days after receiving an alert. 

In the case of the newfound planet, the duration of the microlensing event happened to be unusually long, about 150 days. Both Spitzer and OGLE’s telescopes detected the telltale planetary blip in the magnification, with Spitzer seeing it 20 days earlier.

This time delay between viewing of the event by OGLE and Spitzer was used to calculate the distance to the star and its planet. Knowing the distance allowed the scientists also to determine the mass of the planet, which is about half that of Jupiter.

Spitzer has eyed 22 other microlensing events in collaboration with OGLE and several other ground-based telescopes. While these observations have not turned up new planets, the data are essential to learning the population statistics of stars and planets at the heart of our galaxy. Spitzer will watch approximately 120 additional microlensing events this summer.

“We’ve mainly explored our own solar neighborhood so far,” said Sebastiano Calchi Novati, a Visiting Sagan Fellow at NASA’s Exoplanet Science Institute at the California Institute of Technology, Pasadena. “Now we can use these single lenses to do statistics on planets as a whole and learn about their distribution in the galaxy.”

NASA’s Jet Propulsion Laboratory, Pasadena, California, manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA. 


Fast Facts:

  • Space observatory discovers one of the most distant planets known
  • Research helps map whereabouts of exoplanets throughout the Milky Way

For more information about Spitzer, visit:

http://spitzer.caltech.edu

http://www.nasa.gov/spitzer

NASA Releases Tool Enabling Citizen Scientists to Examine Asteroid Vesta

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Vesta Trek’s interface allows explorers to fly around and even skim the surface of Vesta. Image credit: NASA
 


NASA has announced the release of Vesta Trek, a free, web-based application that provides detailed visualizations of Vesta, one of the largest asteroids in our solar system. 

NASA’s Dawn spacecraft studied Vesta from July 2011 to September 2012. Data gathered from multiple instruments aboard Dawn have been compiled into Vesta Trek’s user-friendly set of tools, enabling citizen scientists and students to study the asteroid’s features. The application includes:

— Interactive maps, including the ability to overlay a growing range of data sets including topography, mineralogy, abundance of elements and geology, as well as analysis tools for measuring the diameters, heights and depths of surface features and more

— 3-D printer-exportable topography so users can print physical models of Vesta’s surface 

— Standard keyboard gaming controls to maneuver a first-person visualization of “flying” across the surface of the asteroid

Vesta Trek was developed by NASA’s Lunar Mapping and Modeling Project (LMMP), which provides mission planners, lunar scientists and the public with analysis and data visualization tools for our moon, spanning multiple instruments on multiple missions. Vesta Trek represents the first application of LMMP’s capabilities to another world beyond the moon. LMMP-based portals for other worlds in our Solar System are currently in development.

“There’s nothing like seeing something with your own eyes, but these types of detailed data-visualizations are the next best thing,” said Kristen Erickson, Director, Science Engagement and Partnerships at NASA Headquarters in Washington. “We’re thrilled to release Vesta Trek to the citizen science community and the public, not only as a scientific tool, but as a portal to an immersive experience that, just by the nature of it, will allow a deeper understanding of Vesta and asteroids in general.”

NASA’s Dawn spacecraft is continuing its exploration in the asteroid belt, after arriving at the dwarf planet Ceres on March 6. As Dawn conducts its mapping and measurements of Ceres, LMMP will continue to work closely with the Dawn mission.

The Lunar Mapping and Modeling Project is managed by NASA’s Solar System Exploration Research Virtual Institute, headquartered at NASA’s Ames Research Center in Moffett Field, California. LMMP’s development team is based at NASA’s Jet Propulsion Laboratory in Pasadena, California. JPL also manages the Dawn mission for NASA. LMMP is funded by and receives direction from the Planetary Science Division of NASA’s Science Mission Directorate and the Advanced Exploration Systems program in NASA’s Human Exploration and Operations Mission Directorate, at NASA Headquarters in Washington.

To explore Vesta Trek, visit:

http://vestatrek.jpl.nasa.gov

For more information about the Dawn mission, visit:

http://dawn.jpl.nasa.gov

To learn more about the Solar System Exploration Research Virtual Institute, visit:

http://sservi.nasa.gov

Scars on Mars from 2012 Rover Landing Fade — Usually

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This sequence of images shows a blast zone where the sky crane from NASA’s Curiosity rover mission hit the ground after setting the rover down in August 2012, and how that dark scar’s appearance changed over the subsequent 30 months. Image Credit: NASA/JPL-Caltech/Univ. of Arizona
 


A series of observations from Mars orbit show how dark blast zones that were created during the August 2012 landing of NASA’s Curiosity rover have faded inconsistently.

The High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter made the observations on multiple dates from landing to last month. After fading for about two years, the pace of change slowed and some of the scars may have even darkened again.

The images track changes in blast zones at four locations caused by different pieces of Curiosity hardware, such as the heat shield and the descent stage. The four series, each with images from five to seven different dates since landing, are available online at:

http://www.jpl.nasa.gov/spaceimages/details.php?id=PIA19159

“Spacecraft like Curiosity create these dark blast zone patterns where bright dust is blown away by the landing,” said Ingrid Daubar, a HiRISE team scientist at NASA’s Jet Propulsion Laboratory, Pasadena, California, who has used similar blast zones to find fresh meteor impact sites on Mars. “We expected to see them fade as the wind moved the dust around during the months and years after landing, but we’ve been surprised to see that the rate of change doesn’t appear to be consistent.”

One purpose for repeated follow-up imaging of Curiosity’s landing area has been to check whether scientists could model the fading and predict how long it would take for the scars to disappear. Daubar’s work on this aids preparations for NASA’s next Mars lander, InSight, on track for launch in March 2016. The InSight mission will deploy a heat probe that will hammer itself a few yards, or meters, deep into the ground to monitor heat coming from the interior of the planet. The brightness of the ground affects temperature below ground, because a dark surface warms in sunshine more than a bright one does.

HiRISE is one of six instruments with which NASA’s Mars Reconnaissance Orbiter has been studying Mars since 2006.

NASA’s Mars Science Laboratory Project has been using the Curiosity rover to examine ancient Martian environments favorable for microbial life.

With three active NASA Mars orbiters and two Mars rovers, NASA seeks to characterize and understand Mars as a dynamic system, including its present and past environment, climate cycles, geology and biological potential. In parallel on its journey to Mars, NASA is developing the capabilities needed for human missions there.

The University of Arizona, Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp. of Boulder, Colorado. JPL, a division of the California Institute of Technology, Pasadena, manages the Mars Reconnaissance Orbiter Project, the Mars Science Laboratory Project and the InSight Project for NASA’s Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, built the orbiter and collaborates with JPL to operate it.

Links for additional info:

About HiRISE: http://hirise.lpl.arizona.edu

About NASA’s Mars Reconnaissance Orbiter: http://mars.nasa.gov/mro

About Curiosity and NASA’s Mars Science Laboratory Project: http://mars.nasa.gov/msl

About InSight: http://insight.jpl.nasa.gov


 

Space Radar Helps Track Underground Water Pollution Risk

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Urban growth in Milan, Italy. In this region, urbanization has increased the potential for groundwater contamination. Image credit: Wikimedia Commons

Fast Facts:

› Groundwater pollution is a worldwide threat to water availability.

› A new technique uses satellite observations of land use changes to assess a region’s risk of groundwater pollution.

The next time you’re digging for buried treasure, stop when you hit water. That underground resource is more valuable than all legendary hoards combined. Ninety percent of Earth’s available fresh water is beneath the surface at any particular time. We drink it, we grow our food with it, and we power industries with it.

We also pollute it. When pollutants get into groundwater, they can stay there for decades. Cleanup efforts are difficult, expensive and not always successful. It would be better to protect groundwater from contamination in the first place, but risks to groundwater are moving targets. Although unchanging factors such as porous soil or shallow aquifer depth play a role, the greatest risk comes from the source of the pollutants: people. And people are always moving. A growing city, in particular, usually means a growing threat to groundwater quality. To lock on to the moving target of groundwater risk, planners worldwide need up-to-date information on how people are changing the land surface.

Son Nghiem, a research scientist at NASA’s Jet Propulsion Laboratory in Pasadena, California, has devised a new technique to use satellite observations of changes in land use to assess the threat of groundwater pollution by a common group of polluting compounds called nitrates. “To test the method, we successfully conducted the Po Plain Experiment [POPLEX] in northern Italy,” said POPLEX leader Marco Masetti, a professor at the University of Milan, Italy. Combining data from the experiment with satellite data and two other data sets on population and land use, they discovered that in this region, groundwater is more vulnerable in urban than in agricultural areas. The satellite data produced a more accurate map of groundwater risks than either of the other data sets.

Nghiem’s new technique uses data from NASA’s QuikScat scatterometer, a satellite managed by JPL. The method improves the “focus” of the QuikScat image from a pixel size of about 15 miles (25 kilometers) per side to 0.6 mile (1 kilometer) per side, capturing far more detail on how the landscape has changed. Nghiem explained his technique takes advantage of the fact that human-made structures bounce back more of the radar signal than does soil or vegetation. Since large buildings with steel frames are concentrated in cities, the strength of the return signals is a good measure of urbanization.

Lombardy, the region of Italy where the POPLEX experiment took place, “is both one of the most urbanized and one of the most agricultural regions in Italy,” said Stefania Stevenazzi, a doctoral candidate at the University of Milan and lead author of a paperon the research, which appears in the March 19 Hydrogeology Journal. The city of Milan is in the north, and the southern part of the region is mainly farmland. Lombardy’s farmers have usually been blamed for nitrate pollution in the region’s aquifers because nitrates are used as fertilizers, but the compounds also have urban sources, including leaks from sewage systems.

The research team produced three groundwater vulnerability maps based on observed changes from 2000 to 2009. Each map used the same hydrological and geological data, but a different data set representing human factors: census results, a high-resolution aerial photographic survey and the QuikScat observations processed by Nghiem’s method. Statistical techniques were applied to rank the vulnerability of every part of the plain. Water samples from about 200 wells were used to verify the results.

The three maps agreed that in Lombardy, urban sources of nitrate were more important than the rural in polluting groundwater. The QuikScat map, however, proved to match the water samples most accurately. For example, the map using census data indicated that several areas in greater Milan were not at much risk, whereas the satellite data caught the reality that these areas are highly vulnerable. That is because censuses place people at their home addresses, but most of the people in Milan’s labor force are commuters who spend many waking — and polluting — hours at work.

Stevenazzi added, “Our analysis shows how much changes in land use were related to increasing or decreasing contamination in the 2000s. These results are also useful to evaluate how future land-use plans can be developed appropriately to safeguard groundwater quality and human health.”

For more information on the Po Plain Experiment, see:

http://urban.jpl.nasa.gov/poplex/description.html

For more on QuikScat, please visit:

http://winds.jpl.nasa.gov/missions/quikscat

JPL is managed for NASA by the California Institute of Technology in Pasadena.