Monday, June 28, 2010

Center for Space Microelectronics Technology

Future space travel means small spacecraft. In today’s constrained budget environment, large space missions can no longer be afforded. At the Jet Propulsion Laboratory, planners have adjusted the size of missions and spacecraft to be more moderate, primarily by taking more risks and asking the spacecraft to do less. In the future, they will be using very advanced technology in order to reduce the spacecraft size even more, while retaining the functionality of today's spacecraft. The spacecraft of the future will provide world-class science in focused areas for an affordable price, making it possible for many of these microspacecraft to be launched, perhaps as many as one per month.

JPL’s Center for Space Microelectronics Technology (CSMT) concentrates on innovative, high-risk, high-payoff concepts and devices that hold the potential to enable new space missions or to enhance current and planned space missions. The center conducts research and development in microsensors and microinstruments, advanced detectors and high performance computing. Once the concepts are proved through demonstrations, the successes are transferred to mission applications or to industry for commercialization.

The center focuses on areas of microelectronics and advanced computing that are unique to space applications. This includes sensors studying objects in space in portions of the electromagnetic spectrum that can not be readily studied from Earth because of atmospheric interference, as well as high-performance ground computing for mission data analysis and visualization.

In 1987, NASA and several Department of Defense agencies with space responsibilities established CSMT in order to create a program in space microelectronics with world-class facilities, equipment and staff.

Microdevices Laboratory Much of CSMT's research and development work takes place in the Microdevices Laboratory, a unique 38,000-squarefoot facility at JPL.

It includes clean rooms for thin-film material deposition, lithography, device processing and optical characterization. Work at the Microdevices Laboratory encompasses a wide range of sensors designed for use on future spacecraft, including passive optical instruments, dust detectors and a variety of spectrometer instruments. A mass spectrometer, for instance, is used to identify and measure gases. An X-ray fluorescence spectrometer would be used to measure the absolute abundance of elements at the surface of an airless body, such as an asteroid. The center also is developing new micro instruments for Earth remote sensing.

Other sensors measure infrared radiation. The intensity of infrared radiation in our environment is second only to that of visible light. All objects produce radiation, most of which is emitted in the
infrared waveband of the electromagnetic spectrum.

Infrared extends from just beyond red light to the beginning of microwaves. NASA has a significant interest in space instruments that map in the infrared.

The agency is developing instruments that look upward into the universe as well as downward to observe Earth.The center has developed a gallium arsenide-based quantum well infrared photodetector (QWIP) that has been made into large arrays and packaged into camcorder sized portable cameras. QWIP detectors have a narrow bandwidth (~1μm) and have been made in various wavelength responses from 6 μm to 22 μm. Because gallium arsenide is a mature and producible technology, 256 by 256 and 640 by 480 element arrays can be routinely made.

In addition, scientists are currently working to improve spacecraft “eyes.” Wireless digital imaging cameras the size of two sugar cubes are being developed which can operate in the ultraviolet, visible and near-infrared realms. The active pixel sensor, a compact, solid-state image sensor technology, makes possible a veritable “camera on a chip.” In many imaging applications, such sensors may ultimately replace charge-coupled devices (CCDs), which measure light digitally and are used in many still and video cameras.

An active pixel sensor camera uses 100 times less power than the standard CCD camera, has superior resolution, is less susceptible to radiation damage in space, and can be made in a standard semiconductor factory. The camera features automatic exposure control and electronic pan and zoom. In addition, it comes with a built-in transmitter that can send images more than a mile. These “cameras-on-a chip” will be used in orbiters, landers and rovers.

Still, CCDs will be used on many future space missions, and a new process has been developed at
the center to build CCDs to image at ultraviolet wavelengths.That enhancement will allow a new set of NASA space instruments for ultraviolet astronomy and other remote sensing projects. In the area of microinstruments, scientists are developing highly sensitive, light, compact, obust, low-power microaccelerometers and seismometers for planetary, cometary, microgravity and terrestrial applications. Conventional seismometers are ill-suited for space applications; despite good sensitivity, they require careful deployment and are delicate, heavy and power-hungry. The miniature seismometer weights less than 200 grams (about 7 ounces); normal seismometers are about the size of an overnight bag and weigh about 50 times more.

To understand if Mars has a molten core, scientists want to measure Mars quakes with seismometers capable of measuring one billionth the acceleration of gravity, all within a package the size of a message pager. A prototype of a microseismometer has successfully measured earthquakes in laboratory demonstrations. Several microdevices needed for future space missions have been developed by the center, including instruments for a microweather station that may go to Mars. Imagine fleets of nearly autonomous microlanders dispersed by one small spacecraft, each with a weatherstation aboard. A network of these stations could be established to supply information about the humidity and wind and the composition and temperature of the planetary atmosphere. Because of the importance of water to the atmospheric science of both Earth and Mars, the microhygrometer is the most scientifically important component of the micro weather station. A microhygrometer for direct dewpoint measurements has been developed and successfully tested on NASA’s DC8 for upper troposphere measurements of humidity. It has demonstrated superior performance compared to conventional, large, chilled-mirror hygrometers. Other instruments being developed in the program include micromachined silicon sensors for wind, pressure and air temperature, a radiation densitometer to measure radiation and a micro laser Doppler anemometer to measure wind speed and direction. Surface micro weather stations also have applications in military tactical situations as tools for gathering critical information on surface conditions on land or sea.

This effort has resulted in the world's first demonstration of single mode lasers suitable for spectroscopy applications that operate at ambient temperatures. To enable scientists to learn more about the role water played in Mars’ past and its impact on the planet today, the Microdevices Laboratory has developed and delivered space-qualified tunable diode lasers to detect water, as well as a variety of other gases.

Measurement of water in the martian atmosphere will be done by near-infrared diode lasers the size of pencil points. These lasers can be assembled with their electronics into instruments the size of a roll of pennies. Any data attained could help answer questions regarding the possibility of life on the planet. One of the most innovative projects at the Microdevices Laboratory has been the development of the ballistic electron emission microscope

(BEEM). Scientists working in solid-state physics must know the conditions existing at the interface of two separate materials. The BEEM method uses a scanning tunneling microscope to inject an electron tunnel current into a structure with one or more buried interfaces between different materials. Electrons injected into the structure are sent ballistically -- that is, without scattering or loss of energy -- for distances as small as tens of billionths of a meter (nanometers).

The stabilized microscope tip is scanned over the surface as the electron current is detected crossing the buried interface. The transmission of ballistic electrons gives information on the material and interface quality. High Performance Computing High-performance computers are needed onboard spacecraft to enable spacecraft autonomy and to analyze and compress scientific data prior to transmission to Earth. High-performance computers are also needed on the ground to analyze and visualize data as part of the process of turning data into knowledge.

Ground-based computers are also used for space mission and spacecraft design and simulation, and for theoretical studies and modeling of physical phenomena. The center’s activities in on-board computing have focused on developing a miniature flight computer using advanced technologies, including multichip modules and three-dimensional chip and module

Although the initial emphasis has been on system miniaturization, the limited power onboard deep space missions has made low-power consumption a major new R&D direction. Under NASA’s High Performance Computing and Communications program, the center is developing a scalable, low-power flight computer architecture that relies on commercial microprocessors and implements the fault tolerance needed for space applications in software.

A single mode of the computer could be used for a simple microlander application, whereas a 50-processor parallel machine can do onboard processing of hyperspectral science imagery. Other scientists at the center are developing innovative magnetic and optical data storage techniques and optical processing. A major thrust is directed toward electronic neural networks modelled on the human brain, capable of pattern recognition and vehicle control in real time.

JPL and the California Institute of Technology have been pioneers in developing technologies for
massively parallel computing. A dozen years ago, the Center was building parallel supercomputers because there was no industry. Caltech/JPL partnerships with Intel, Cray Research and, most recently, Hewlett Packard have been instrumental in turning high performance parallel supercomputing into the industry known today.

The center concentrates on software and applications of high performance parallel supercomputers for NASA and Defense Department applications. These include ocean modeling, data visualization, mission design and radar processing. The new 256-processor Hewlett Packard Exemplar system has a peak performance of 184 billion operations per second, with a memory of 64 gigabytes. This is 700 times faster than the JPL’s CRAY X-MP supercomputer of a decade ago. The memory is 4,000 times larger than that of a typical desktop system. The large memory allows huge problems to be tackled. For example, all the data NASA has from previous missions can fit into the machine’s memory and can be processed and visualized in real time.

In the future, we will be using more and more very advanced technology in order to reduce spacecraft size, all the while retaining the functionality of today's spacecraft. By the year 2010, second-generation microspacecraft the size of toaster ovens that weigh 5-1/2 kilograms (about 12 pounds) and use 5 watts of power will travel a billion miles away and send data back to Earth. They will be able to figure out their location and navigate autonomously, all by the position of the

These microspacecraft will be enabled by advances in space technology. Many of the key technologies will be derived from those in such commercial products as cell phones, low-power palm top computers and pagers. Others are being developed specifically for space. These include a micromachined gyro, accelerometer and other micro-electro-mechani- cal systems, microthrusters, neural networks and spacecraft autonomy software.

The center is developing ground-based microspacecraft prototypes that include many of the above components to begin to investigate the systems issues that will arise when building these new miniature spacecraft.
Dr. Carl Kukkonen is director of the Center for Space Microelectronics Technology. Policy guidance and program oversight are provided by a board of governors. Board members include the major sponsors of the center, together with the JPL director, Caltech president and Caltech provost.

The center’s scientific advisory board, composed of seven world-renowned scientists, reviews the technical program and provides advice to the board of governors and the center’s director. Programs Many of the center’s technologies have commercial as well as government mission applications. The U.S. Department of Commerce joined the center in 1991 and urged the center and its sponsors to emphasize technology applications for business. As a result, the center has initiated programs with a strong emphasis on dual-use technologies and partnerships with industry.

Currently there are 39 cooperative agreements with U.S. industry in the areas of electronics, computing, communications, automotive and health care. Those collaborations are with companies both large and small, as well as minority- and women-owned

  • Key programs under the center include:
  • Low- and high-temperature superconductors
  • Semiconductor lasers
  • Microsensors and microinstruments
  • Microelectro-mechanical systems
  • Infrared, visible and ultraviolet detectors
  • Submillimeter receivers
  • Advanced flight computer
  • High-performance computing
  • Advanced networking
  • Neural networks
  • Vertical Bloch line memory
For more information, visit the CSMT web site at .

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Friday, June 25, 2010

NASA Chief Technology Officer for IT Honored by CIO Magazine

Chris  KempChris C. Kemp, NASA’s chief technology officer for Information Technology and ‘super star’ of IT innovation for the agency, has been recognized with CIO Magazine’s “CIO 100” award for his work done while he was chief information officer for NASA’s Ames Research Center in Moffett Field, Calif., in 2009. Every year, CIO Magazine identifies and honors 100 organizations that have distinguished themselves through the effective and innovative use of information technology.

“I am honored to be recognized by CIO Magazine and to be the first honoree from Ames is truly humbling. The work that I did there in 2009 was meaningful to me and makes me extremely proud. I am inspired by NASA’s mission, and it’s been an honor to be a member of the team ” said Kemp.

The combination of Kemps’ enthusiasm for NASA and information technology has made him extremely successful at his job.

"This year's CIO 100 awards draws well-deserved attention to companies that are not only innovating with IT but creating genuine business value as well," said Maryfran Johnson, editor in chief of CIO Magazine. "These winning companies and their IT organizations are an inspiration to businesses everywhere."

Kemp is not afraid to venture into unchartered territory. In 2008, he began the Nebula Cloud Computing project (now a NASA-wide program) which uses open source software components to create a robust cloud environment where scientists can process and share data. Kemp also implemented an agency-wide IT Security Operations Center at Ames.

“The Nebula Platform allows scientists to focus on their research and spend less time and money on IT infrastructure. These researchers are doing amazing things, and it’s rewarding to create a platform that enables this innovation,” said Kemp.

Kemp is NASA’s first chief technology officer for IT, a new position established to lead IT innovation across the agency. "This move will leverage Chris’ creative talents and energies," said NASA Chief Information Officer Linda Cureton.

“I’m extremely excited about my new position. I’m thrilled to be involved in supporting many of the ground-breaking IT innovations happening here” Kemp said.

Kemp joined Ames as a successful entrepreneur, having helped create several companies including the third largest online community, He also helped create the leading web-based vacation rental platform Escapia, and the first online grocery shopping platform for Kroger, the world’s largest grocery store chain.

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Thursday, June 24, 2010

NASA Rover Finds Clue to Mars' Past and Environment for Life

Lengthy detective work with data NASA's Mars Exploration Rover   Spirit collected in late 2005 has confirmed that an outcrop called   'Comanche'
Lengthy detective work with data NASA's Mars Exploration Rover Spirit collected in late 2005 has confirmed that an outcrop called "Comanche" contains a mineral indicating that a past environment was wet and non-acidic, possibly favorable to life.
› Full image and caption
Rocks examined by NASA's Spirit Mars Rover hold evidence of a wet, non-acidic ancient environment that may have been favorable for life. Confirming this mineral clue took four years of analysis by several scientists.

An outcrop that Spirit examined in late 2005 revealed high concentrations of carbonate, which originates in wet, near-neutral conditions, but dissolves in acid. The ancient water indicated by this find was not acidic.

NASA's rovers have found other evidence of formerly wet Martian environments. However the data for those environments indicate conditions that may have been acidic. In other cases, the conditions were definitely acidic, and therefore less favorable as habitats for life.

Laboratory tests helped confirm the carbonate identification. The findings were published online Thursday, June 3 by the journal Science.

"This is one of the most significant findings by the rovers," said Steve Squyres of Cornell University in Ithaca, N.Y. Squyres is principal investigator for the Mars twin rovers, Spirit and Opportunity, and a co-author of the new report. "A substantial carbonate deposit in a Mars outcrop tells us that conditions that could have been quite favorable for life were present at one time in that place. "

Spirit inspected rock outcrops, including one scientists called Comanche, along the rover's route from the top of Husband Hill to the vicinity of the Home Plate plateau which Spirit has studied since 2006. Magnesium iron carbonate makes up about one-fourth of the measured volume in Comanche. That is a tenfold higher concentration than any previously identified for carbonate in a Martian rock.

"We used detective work combining results from three spectrometers to lock this down," said Dick Morris, lead author of the report and a member of a rover science team at NASA's Johnson Space Center in Houston."The instruments gave us multiple, interlocking ways of confirming the magnesium iron carbonate, with a good handle on how much there is."

Massive carbonate deposits on Mars have been sought for years without much success. Numerous channels apparently carved by flows of liquid water on ancient Mars suggest the planet was formerly warmer, thanks to greenhouse warming from a thicker atmosphere than exists now. The ancient, dense Martian atmosphere was probably rich in carbon dioxide, because that gas makes up nearly all the modern, very thin atmosphere.

It is important to determine where most of the carbon dioxide went. Some theorize it departed to space. Others hypothesize that it left the atmosphere by the mixing of carbon dioxide with water under conditions that led to forming carbonate minerals. That possibility, plus finding small amounts of carbonate in meteorites that originated from Mars, led to expectations in the 1990s that carbonate would be abundant on Mars. However, mineral-mapping spectrometers on orbiters since then have found evidence of localized carbonate deposits in only one area, plus small amounts distributed globally in Martian dust.

Morris suspected iron-bearing carbonate at Comanche years ago from inspection of the rock with Spirit's Moessbauerpectrometer, which provides information about iron-containing minerals. Confirming evidence from other instruments emerged slowly. The instrument with the best capability for detecting carbonates, the Miniature Thermal Emission Spectrometer, had its mirror contaminated with dust earlier in 2005, during a wind event that also cleaned Spirit's solar panels.

"It was like looking through dirty glasses," said Steve Ruff of Arizona State University in Tempe, Ariz., another co-author of the report. "We could tell there was something very different about Comanche compared with other outcrops we had seen, but we couldn't tell what it was until we developed a correction method to account for the dust on the mirror."

Spirit's Alpha Particle X-ray Spectrometer instrument detected a high concentration of light elements, a group including carbon and oxygen, that helped quantify the carbonate content.

The rovers landed on Mars in January 2004 for missions originally planned to last three months. Spirit has been out of communication since March 22 and is in a low-power hibernation status during Martian winter. Opportunity is making steady progress toward a large crater, Endeavour, which is about seven miles away.

NASA's Jet Propulsion Laboratory, Pasadena, manages the Mars Exploration Rovers for the agency's Science Mission Directorate in Washington. For more information about the rovers, visit:

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Monday, June 21, 2010

As the Sun Awakens, NASA Keeps a Wary Eye on Space Weather

Earth and space are about to come into contact in a way that's new to human history. To make preparations, authorities in Washington DC are holding a meeting: The Space Weather Enterprise Forum at the National Press Club on June 8th.

Richard Fisher, head of
NASA's Heliophysics Division, explains what it's all about:

"The sun is waking up from a deep slumber, and in the next few years we expect to see much higher levels of solar activity. At the same time, our technological society has developed an unprecedented sensitivity to solar storms. The intersection of these two issues is what we're getting together to discuss."

The National Academy of Sciences framed the problem two years ago in a landmark report entitled "Severe Space Weather Events—Societal and Economic Impacts." It noted how people of the 21st-century rely on high-tech systems for the basics of daily life. Smart power grids, GPS navigation, air travel, financial services and emergency radio communications can all be knocked out by intense solar activity. A century-class solar storm, the Academy warned, could cause twenty times more economic damage than Hurricane Katrina.

Much of the damage can be mitigated if managers know a storm is coming. Putting satellites in 'safe mode' and disconnecting transformers can protect these assets from damaging electrical surges. Preventative action, however, requires accurate forecasting—a job that has been assigned to NOAA.

"Space weather forecasting is still in its infancy, but we're making rapid progress," says Thomas Bogdan, director of NOAA's Space Weather Prediction Center in Boulder, Colorado.

Bogdan sees the collaboration between NASA and NOAA as key. "NASA's fleet of heliophysics research spacecraft provides us with up-to-the-minute information about what's happening on the sun. They are an important complement to our own GOES and POES satellites, which focus more on the near-Earth environment."

Among dozens of NASA spacecraft, he notes three of special significance: STEREO, SDO and ACE.

STEREO (Solar Terrestrial Relations Observatory) is a pair of spacecraft stationed on opposite sides of the sun with a combined view of 90% of the stellar surface. In the past, active sunspots could hide out on the sun's farside, invisible from Earth, and then suddenly emerge over the limb spitting flares and CMEs. STEREO makes such surprise attacks impossible.

SDO (the Solar Dynamics Observatory) is the newest addition to NASA's fleet. Just launched in February, it is able to photograph solar active regions with unprecedented spectral, temporal and spatial resolution. Researchers can now study eruptions in exquisite detail, raising hopes that they will learn how flares work and how to predict them. SDO also monitors the sun's extreme UV output, which controls the response of Earth's atmosphere to solar variability.

Bogdan's favorite NASA satellite, however, is an old one: the Advanced Composition Explorer (ACE) launched in 1997. "Where would we be without it?" he wonders. ACE is a solar wind monitor. It sits upstream between the sun and Earth, detecting solar wind gusts, billion-ton CMEs, and radiation storms as much as 30 minutes before they hit our planet.

"ACE is our best early warning system," says Bogdan. "It allows us to notify utility and satellite operators when a storm is about to hit.”

NASA spacecraft were not originally intended for operational forecasting—"but it turns out that our data have practical economic and civil uses," notes Fisher. "This is a good example of space science supporting modern society."

2010 marks the 4th year in a row that policymakers, researchers, legislators and reporters have gathered in Washington DC to share ideas about space weather. This year, forum organizers plan to sharpen the focus on critical infrastructure protection. The ultimate goal is to improve the nation’s ability to prepare, mitigate, and respond to potentially devastating space weather events.

"I believe we're on the threshold of a new era in which space weather can be as influential in our daily lives as ordinary terrestrial weather." Fisher concludes. "We take this very seriously indeed."

For more information about the meeting, please visit the Space Weather Enterprise Forum home page at

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Friday, June 18, 2010

On Guard

At NASA's Kennedy Space Center in Florida, an adult osprey guards its young in a nest built on a platform in the press site parking lot, backdropped by the 209-foot by 110-foot American flag painted on the side of the Vehicle Assembly Building. The Merritt Island National Wildlife Refuge coexists with Kennedy Space Center and provides a habitat for 330 species of birds, including the osprey, and a variety of other wildlife. Kennedy's press site is located at the turn basin in Launch Complex 39, making it an ideal osprey nesting place.

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Thursday, June 17, 2010

NASA Spacecraft Burns for Home, Then Comet

Artist's concept of Epoxi spacecraft
Artist's concept of Epoxi spacecraft. › Full image and caption

NASA's Deep Impact/Epoxi spacecraft has successfully performed a trajectory correction maneuver to refine its orbit prior to an upcoming Earth flyby June 27. The maneuver, along with the Earth flyby, will place the spacecraft on a trajectory to fly past comet Hartley 2 on Nov. 4.

The maneuver began at 2 p.m. EST (11 a.m. PST) today, when the spacecraft fired its engines for 11.3 seconds. While the burn changed the spacecraft's velocity by only 0.1 meters per second (less than a quarter mile per hour), that was all the mission's navigators requested to set the stage for an Earth gravity assist on June 27.

"While it was a small burn, it was a big step in getting us to Hartley 2," said Tim Larson, project manager of NASA's Epoxi mission. "Humanity's fifth close-up view of a comet is less than five months away."

Epoxi is an extended mission of the Deep Impact spacecraft. Its name is derived from its two tasked science investigations -- the Deep Impact Extended Investigation (DIXI) and the Extrasolar Planet Observation and Characterization (EPOCh).

The University of Maryland is the Principal Investigator institution. JPL manages Epoxi for NASA's Science Mission Directorate, Washington. The spacecraft was built for NASA by Ball Aerospace & Technologies Corp., Boulder, Colo.

For information about Epoxi, visit

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Wednesday, June 16, 2010

NASA Sensor Completes Initial Gulf Oil Spill Flights

AVIRIS airborne measurement
AVIRIS airborne measurement acquired May 17, 2010, over the site of the Deepwater Horizon BP oil rig disaster. The oil appears orange to brown. › Full image and caption › View related images
NASA's Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) instrument collected an image over the site of the Deepwater Horizon BP oil rig disaster on May 17, 2010. Crude oil on the surface appears orange to brown. Scientists are using spectroscopic methods to analyze measurements for each point in images like this one to detail the characteristics of the oil on the surface.

AVIRIS extensively mapped the region affected by the spill during 11 flights conducted between May 6 and May 25, 2010, at the request of the National Oceanic and Atmospheric Administration. In total, AVIRIS measured more than 100,000 square kilometers (38,610 square miles) in support of the national oil spill response. The instrument flew at altitudes of up to 19,800 meters (65,000 feet) aboard a NASA ER-2 aircraft from NASA's Dryden Flight Research Center, Edwards, Calif.

AVIRIS is using imaging spectroscopy to map the occurrence and condition of oil on the surface of the Gulf, and to estimate the amount of oil on the surface to help scientists and responding agencies better understand the spill and how to address its effects. In addition, coastline maps created from the AVIRIS overflights will be used to provide a baseline of ecosystems and habitats that can be compared with data from future AVIRIS flights to assess the oil spill's impacts.

Figure 1 depicts AVIRIS imaging spectrometer measurements along the Gulf coast to measure the characteristics and condition of the ecosystem and habitat prior to possible oil contamination and impact. The location is near Johnson's Bayou and along the Gulf Beach Highway, between Port Arthur, La., to the west and Cameron, La., to the east. The west corner of the image includes part of the Texas Point National Wildlife Refuge. The 224 wavelengths of light measured by AVIRIS from visible to infrared are depicted in the top and left panels. The spectrum measured for each point in the image will be used to help assess the characteristics and conditions of the coastal ecosystems and habitats.

AVIRIS data provide scientists with many different types of information about the spill. Researchers at the U.S. Geological Survey's Spectroscopy Laboratory in Golden, Colo., are working to determine the characteristics of the oil based upon the AVIRIS measured spectral signature. As shown in Figure 2, acquired May 17, 2010, the signature of the oil measured in the infrared portion of the spectrum allows scientists to measure the occurrence and condition of oil and estimate the thickness of oil on the water's surface, Figure 3 depicts AVIRIS oil spill flight line measurements acquired on May 17, 2010, superimposed on a background regional image.

For more information on AVIRIS, visit

To read more and see related images, visit:

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Tuesday, June 15, 2010

NASA Takes to the Air With New 'Earth Venture' Research Projects

JPL's Carbon in Arctic Reservoirs Vulnerability Experiment
JPL's Carbon in Arctic Reservoirs Vulnerability Experiment will bridge critical gaps in our knowledge and understanding of Arctic ecosystems, links between the Arctic water and terrestrial carbon cycles, and the effects of fires and thawing permafrost. › Larger view
Hurricanes, air quality and Arctic ecosystems are among the research areas to be investigated during the next five years by new NASA airborne science missions announced today.

The five competitively-selected proposals, including one from NASA's Jet Propulsion Laboratory, Pasadena, Calif., are the first investigations in the new Venture-class series of low-to-moderate-cost projects established last year.

The Earth Venture missions are part of NASA's Earth System Science Pathfinder program. The small, targeted science investigations complement NASA's larger research missions. In 2007, the National Research Council recommended that NASA undertake these types of regularly solicited, quick-turnaround projects.

This year's selections are all airborne investigations. Future Venture proposals may include small, dedicated spacecraft and instruments flown on other spacecraft.

"I'm thrilled to be able to welcome these new principal investigators into NASA's Earth Venture series," said Edward Weiler, associate administrator of the agency's Science Mission Directorate in Washington. "These missions are considered a 'tier 1' priority in the National Research Council's Earth Science decadal survey. With this selection, NASA moves ahead into this exciting type of scientific endeavor."

The missions will be funded during the next five years at a total cost of not more than $30 million each. The cost includes initial development and deployment through analysis of data. Approximately $10 million was provided through the American Recovery and Reinvestment Act toward the maximum $150 million funding ceiling for the missions.

Six NASA centers, 22 educational institutions, nine U.S. or international government agencies and three industrial partners are involved in these missions. The five missions were selected from 35 proposals.

The selected missions are:

1. Carbon in Arctic Reservoirs Vulnerability Experiment. Principal Investigator Charles Miller, NASA's Jet Propulsion Laboratory in Pasadena, Calif.

The release and absorption of carbon from Arctic ecosystems and its response to climate change are not well known because of a lack of detailed measurements. This investigation will collect an integrated set of data that will provide unprecedented experimental insights into Arctic carbon cycling, especially the release of important greenhouse gases such as carbon dioxide and methane. Instruments will be flown on a Twin Otter aircraft to produce the first simultaneous measurements of surface characteristics that control carbon emissions and key atmospheric gases.

2. Airborne Microwave Observatory of Subcanopy and Subsurface. Principal Investigator Mahta Moghaddam, University of Michigan

North American ecosystems are critical components of the global exchange of the greenhouse gas carbon dioxide and other gases within the atmosphere. To better understand the size of this exchange on a continental scale, this investigation addresses the uncertainties in existing estimates by measuring soil moisture in the root zone of representative regions of major North American ecosystems. Investigators will use NASA's Gulfstream-III aircraft to fly synthetic aperture radar that can penetrate vegetation and soil to depths of several feet.

3. Airborne Tropical Tropopause Experiment. Principal Investigator Eric Jensen, NASA's Ames Research Center in Moffett Field, Calif.

Water vapor in the stratosphere has a large impact on Earth's climate, the ozone layer and how much solar energy Earth retains. To improve our understanding of the processes that control the flow of atmospheric gases into this region, investigators will launch four airborne campaigns with NASA's Global Hawk remotely piloted aerial systems. The flights will study chemical and physical processes at different times of year from bases in California, Guam, Hawaii and Australia.

4. Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality. Principal Investigator James Crawford, NASA's Langley Research Center in Hampton, Va.

Satellites can measure air quality factors like aerosols and ozone-producing gases in an entire column of atmosphere below the spacecraft, but distinguishing the concentrations at the level where people live is a challenge. This investigation will provide integrated data of airborne, surface and satellite observations, taken at the same time, to study air quality as it evolves throughout the day. NASA's B-200 and P-3B research aircraft will fly together to sample a column of the atmosphere over instrumented ground stations.

5. Hurricane and Severe Storm Sentinel. Principal Investigator Scott Braun, NASA's Goddard Space Flight Center in Greenbelt, Md.

The prediction of the intensity of hurricanes is not as reliable as predictions of the location of hurricane landfall, in large part because of our poor understanding of the processes involved in intensity change. This investigation focuses on studying hurricanes in the Atlantic Ocean basin using two NASA Global Hawks flying high above the storms for up to 30 hours. The Hawks will deploy from NASA's Wallops Flight Facility in Virginia during the 2012 to 2014 Atlantic hurricane seasons.

"These new investigations, in concert with NASA's Earth-observing satellite capabilities, will provide unique new data sets that identify and characterize important phenomena, detect changes in the Earth system and lead to improvements in computer modeling of the Earth system," said Jack Kaye, associate director for research of NASA's Earth Science Division in the Science Mission Directorate.

Langley manages the Earth System Pathfinder program for the Science Mission Directorate. The missions in this program provide an innovative approach to address Earth science research with periodic windows of opportunity to accommodate new scientific priorities.

For information about NASA and agency programs, visit: .

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Monday, June 14, 2010

Small Near-Earth Object Probably a Rocket Part

Graphic depicting the trajectory of near-Earth object 2010 KQ
Graphic depicting the trajectory of near-Earth object 2010 KQ.
› Larger view
Scientists at NASA's Near-Earth Object Program Office at NASA's Jet Propulsion Laboratory in Pasadena, Calif., have determined that a small object that safely passed Earth on May 21 is more than likely an upper-stage of a rocket that carried a spacecraft on an interplanetary trajectory.

"The orbit of this object is very similar to that of the Earth, and one would not expect an object to remain in this type of orbit for very long," said Paul Chodas, a scientist at NASA's Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, Calif.

Observations by astronomer S.J. Bus, using the NASA-sponsored Infrared Telescope Facility in Mauna Kea, Hawaii, indicate that 2010 KQ's spectral characteristics do not match any of the known asteroid types, and the object's absolute magnitude (28.9) suggests it is only a few meters in size.

2010 KQ was discovered by astronomer Richard Kowalski at the NASA-sponsored Catalina Sky Survey in the mountains just north of Tucson, Ariz., on May 16. Five days later, it made its closest approach to Earth at a distance just beyond the moon's orbit. The object is departing Earth's neighborhood but will be returning in 2036.

"At present, there is a 6 percent probability that 2010 KQ will enter our atmosphere over a 30-year period starting in 2036," said Chodas. "More than likely, additional observations of the object will refine its orbit and impact possibilities. Even in the unlikely event that this object is headed for impact with Earth, whether it is an asteroid or rocket body, it is so small that it would disintegrate in the atmosphere and not cause harm on the ground."

NASA detects, tracks and characterizes asteroids and comets passing close to Earth using both ground- and space-based telescopes. The Near-Earth Object Observations Program, commonly called "Spaceguard," discovers these objects, characterizes a subset of them, and plots their orbits to determine if any could be potentially hazardous to our planet.

JPL manages the Near-Earth Object Program Office for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena.

More information about asteroids and near-Earth objects is at:

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Friday, June 11, 2010

Spinoffs Reveal Earth Benefits of NASA Technologies

Congressional staffers in the Rayburn House Office Building on May 20 were wondering why a robot was roaming the halls. Those who followed the robot were led to further surprises: an igloo-shaped life raft, long socks full of fine powder, an inflatable antenna shaped like an enormous beach ball -- all NASA technologies that, through commercial partnerships between NASA and industry, are improving life on Earth.

The second annual Spinoff Day on the Hill, hosted by Representative Suzanne Kosmas of Florida, featured seven companies who have partnered with NASA to bring innovations to market that are saving lives, protecting the environment, and enriching how we experience our planet.

The 1958 Space Act that created NASA mandated that the Agency transfer as much of its technology as possible for the benefit of the public. To date, NASA has documented more than 1662 of these technologies, called spinoffs, in its annual Spinoff publication (, launched in 1976.

"We invest in technologies for what they will bring to NASA in terms of future missions of science and of exploration, but we can never forget that we also invest in these things because of what they do for us right here on Earth," said NASA chief technologist Bobby Braun, who presented remarks at the event.

The products on show at Spinoff Day on the Hill all trace their origins back to space. The igloo-shaped life raft? Engineers at Johnson Space Center originally developed the self-righting raft design to prevent life rafts holding astronauts from capsizing from the downdraft of helicopters after Apollo-era splashdown landings. Now manufactured by Givens Marine Survival Co. Inc. of Tiverton, Rhode Island, the raft is credited with saving the lives of over 450 sailors.

Unirem Inc., managed by Summit International/Rasstech Industries, of Houston, exhibited its Petroleum Remediation Product, or PRP, developed through the collaboration of industry scientists and NASA researchers. The powder technology, which absorbs and captures oil as it floats on the water's surface, may soon play a role in the cleanup of the catastrophic oil spill currently endangering the nation's Gulf coast.

GATR Technologies of Huntsville, Alabama, displayed one of its inflatable antennas, developed under NASA's Small Business Innovation Research program. Quickly deployable from two suitcase-size containers, GATR's antennas enabled communications during wild fires in southern California, after Hurricane Katrina, and following the earthquake in Haiti.

Airocide, a unique air purifier that helps preserve perishable foods and destroys airborne pathogens, was presented by KES Science and Technology Inc. of Kennesaw, Georgia, and Akida Holdings of Jacksonville, Florida. Originally developed by NASA-funded researchers to help preserve plants grown in space, the technology is improving food storage and distribution in remote regions of the world, as well as helping sanitize operating rooms and doctors' offices.

Also on display was Menlo Park, California-based Allocade Inc.'s OnCue scheduling software. The technology was invented by a former Ames Research Center computer scientist who helped design scheduling software for the Hubble Space Telescope. OnCue now helps hospitals operate more efficiently by optimizing constantly changing schedules for imaging procedures.

Gigapan photographic technology, derived from the panoramic camera mast assemblies on the Mars Exploration Rovers, awed attendees with its ultra-high resolution imagery, while the Webby Award-winning NASA@Home and City interactive Web site ( shared information about spinoff technologies that can be found in homes and hometowns across the Nation.

Braun noted the economic impact NASA’s technological advancements can create, leading to "more Earth-based spinoffs, more technology-oriented jobs, and more business and industries that can compete in the global marketplace." He also highlighted the inspiration such innovation provides to students exploring education and careers in science, technology, engineering, and mathematics.

"What we have here are just a few outstanding examples, but there are so many others to learn about," said Doug Comstock, director of NASA's Innovative Partnerships Program. "The fabric of our everyday lives benefits from these space technologies."

One such example zipped along the halls of the Rayburn building even as Spinoff Day on the Hill came to an end. The Multi-function Agile Remote Control Robot, or MARCbot, was enhanced by NASA engineers and is now manufactured by Applied Geo Technologies Inc. of Choctaw, Mississippi. More than 300 of the robots are now in service overseas, keeping soldiers safer by helping identify possible explosive devices.

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Wednesday, June 9, 2010

NASAs Swift Survey Finds 'Smoking Gun' Of Black Hole Activation

The optical counterparts of many active galactic nuclei (circled)  detected by the Swift BAT Hard X-ray Survey clearly show galaxies in the  process of mergingData from an ongoing survey by NASA's Swift satellite have helped astronomers solve a decades-long mystery about why a small percentage of black holes emit vast amounts of energy.

Only about one percent of supermassive black holes exhibit this behavior. The new findings confirm that black holes "light up" when galaxies collide, and the data may offer insight into the future behavior of the black hole in our own Milky Way galaxy. The study will appear in the June 20 issue of The Astrophysical Journal Letters.

The intense emission from galaxy centers, or nuclei, arises near a supermassive black hole containing between a million and a billion times the sun's mass. Giving off as much as 10 billion times the sun's energy, some of these active galactic nuclei (AGN) are the most luminous objects in the universe. They include quasars and blazars.

"Theorists have shown that the violence in galaxy mergers can feed a galaxy's central black hole," said Michael Koss, the study's lead author and a graduate student at the University of Maryland in College Park. "The study elegantly explains how the black holes switched on."

Until Swift's hard X-ray survey, astronomers never could be sure they had counted the majority of the AGN. Thick clouds of dust and gas surround the black hole in an active galaxy, which can block ultraviolet, optical and low-energy, or soft X-ray, light. Infrared radiation from warm dust near the black hole can pass through the material, but it can be confused with emissions from the galaxy's star-forming regions. Hard X-rays can help scientists directly detect the energetic black hole.

Since 2004, the Burst Alert Telescope (BAT) aboard Swift has been mapping the sky using hard X-rays.

"Building up its exposure year after year, the Swift BAT Hard X-ray Survey is the largest, most sensitive and complete census of the sky at these energies," said Neil Gehrels, Swift's principal investigator at NASA's Goddard Space Flight Center in Greenbelt, Md.

The survey, which is sensitive to AGN as far as 650 million light-years away, uncovered dozens of previously unrecognized systems.

"The Swift BAT survey is giving us a very different picture of AGN," Koss said. The team finds that about a quarter of the BAT galaxies are in mergers or close pairs. "Perhaps 60 percent of these galaxies will completely merge in the next billion years. We think we have the 'smoking gun' for merger-triggered AGN that theorists have predicted."

Other members of the study team include Richard Mushotzky and Sylvain Veilleux at the University of Maryland and Lisa Winter at the Center for Astrophysics and Space Astronomy at the University of Colorado in Boulder.

"We've never seen the onset of AGN activity so clearly," said Joel Bregman, an astronomer at the University Michigan, Ann Arbor, who was not involved in the study. "The Swift team must be identifying an early stage of the process with the Hard X-ray Survey."

Swift, launched in November 2004, is managed by Goddard. It was built and is being operated in collaboration with Penn State, the Los Alamos National Laboratory in New Mexico, and General Dynamics in Falls Church, Va.; the University of Leicester and Mullard Space Sciences Laboratory in the United Kingdom; Brera Observatory and the Italian Space Agency in Italy; plus additional partners in Germany and Japan.

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Monday, June 7, 2010

The Glory Mission's Judith Lean Discusses Solar Variability

Judith LeanThough the sun's brightness was once thought to be constant, NASA has launched a series of satellite instruments that have helped show it actually fluctuates in conjunction with cycles of solar activity.

With a new sun-watching instrument called the Total Irradiance Monitor (TIM) scheduled to launch on NASA's Glory satellite in November, we spoke with Judith Lean, a member of the Glory science team and solar physicist at the United States Naval Research Laboratory, about solar cycles and what scientists have learned about solar variability in the last three decades.

What is a solar cycle and how long does it last?
For more than a century, people have noticed that sunspots become more and less frequent on an 11-year-cycle. That’s the main solar cycle we look at. The 11-year-cycle is really part of a 22-year-cycle of the sun’s magnetic field polarity. The changes are driven by something called the solar dynamo, a process that generates and alters the strength of the magnetic field erupting onto the sun's surface. It's the sun’s magnetic field that produces sunspots as it moves up through the sun's surface.

How much does the brightness of the sun change throughout the cycle?
It's a small amount. Total solar irradiance typically increases by about 0.1 percent during periods of high activity. However, certain wavelengths of sunlight—such as ultraviolet—vary more.

What causes irradiance to change?
It's really the balance of sunspots, which are cooler dark areas of the sun, and faculae, bright areas that appear near sunspots. The faculae overwhelm the sunspots, so the sun is actually brighter when there are more sunspots.

Can changes in the sun affect our climate?
If it wasn’t for the sun, we wouldn’t have a climate. The sun provides the energy to drive our climate, and even small changes in the sun's output can have a direct impact on Earth. There are two ways irradiance changes can alter climate: One is the direct effect from altering the amount of radiation reaching Earth. The second is that solar variability can affect ozone production, which can in turn affect the climate.

Does the 0.1 percent change in irradiance affect Earth's climate much?
Solar irradiance changes are likely connected to dynamic aspects of climate—things like the coupling of the atmosphere and ocean—El Niño being one example—or aspects of atmospheric circulation, such as the Hadley cells that dominate in the tropics.
But we've done a great deal of modeling, and the sun doesn't explain the global warming that's occurred over the last century. We think changes in irradiance account for about 10 percent global warming at most. Of course, there are also longer cycles that may have an impact on climate, but our understanding of them is limited.

There is disagreement about whether the last three cycles have gotten successively brighter. Has that been resolved?
No, it hasn't. The best understanding is that irradiance cycles have been about the same in the last three cycles, but one group reports an increasing trend whereas another group says that current levels are now the lowest of the entire 30-year record. I believe these differences are due to instrumental effects, but we really need continual, highly accurate, and stable long-term measurements to resolve this. The radiometer aboard Glory—the Total Irradiance Monitor (TIM)--will be a big step, quite an exciting advance.

What part of the 11-year cycle will Glory observe?
Glory is going is to observe during the ascending phase of the cycle. The ascending phase is relatively rapid, so we should get to the peak in about three years. Then there will be about two years or more when solar activity is high and stays high. About five years from now, activity will start to come down again so that by, say, 2019 we will be at low levels again.

What do you hope Glory will find?
The Glory TIM has been calibrated more rigorously than previous instruments, so it should help a lot in getting the absolute brightness of the sun. In addition to recording the ever-changing irradiance levels, it should measure irradiance precisely enough that will make it feasible to determine whether solar irradiance is stable or changing, if the measurements continue long enough into the future.

Are there aspects of the solar variability that TIM won't measure?
Yes. The Glory TIM looks at overall irradiance, but it doesn't measure how specific parts of the spectrum—the ultraviolet, visible, or infrared—are changing. Some of the largest changes actually happen at the shortest wavelengths, so it's extremely important that we look at the spectrum. There's an instrument related to TIM called the Solar Irradiance Monitor (SIM) aboard the SORCE satellite that lets us see how individual parts of the spectrum vary, and it's also critical.

The sun has been exceptionally quiet in recent years. Are we entering a prolonged solar minimum?
There was a period from mid-2008 to mid-2009 when the sun was without sunspots for many days. It was probably the quietest period we've seen since the first total solar irradiance measurements. But we didn't go into a prolonged minimum because the sun still had a few active regions – not sunspots, but small bright faculae regions -- and we could see the irradiance continue to fluctuate throughout this very quiet period. Now there are more dark sunspots and more bright faculae on the sun’s surface, so activity is ramping up and a new cycle--solar cycle 24--has started.

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Thursday, June 3, 2010

WISE Telescope has Heart and Soul

Heart and Soul nebulae
The Heart and Soul nebulae are seen in this infrared mosaic from NASA's Wide-field Infrared Survey Explorer, or WISE. › Full image and caption

NASA's Wide-field Infrared Survey Explorer, or WISE, has captured a huge mosaic of two bubbling clouds in space, known as the Heart and Soul nebulae. The space telescope, which has completed about three-fourths of its infrared survey of the entire sky, has already captured nearly one million frames like the ones making up this newly released mosaic.
"This new image demonstrates the power of WISE to capture vast regions," said Ned Wright, the mission's principal investigator at UCLA, who presented the new picture today at the American Astronomical Society meeting in Miami. "We're looking north, south, east and west to map the whole sky."
The picture is online at .
The Heart nebula is named after its resemblance to a human heart; the nearby Soul nebula happens to resemble a heart too, but only the symbolic kind with two lobes. The nebulae, which lie about 6,000 light-years away in the constellation Cassiopeia, are both massive star-making factories, marked by giant bubbles blown into surrounding dust by radiation and winds from the stars. The infrared vision of WISE allows it to see into the cooler and dustier crevices of clouds like these, where gas and dust are just beginning to collect into new stars.
The new image was captured as WISE circled over Earth's poles, scanning strips of the sky. It is stitched together from 1,147 frames, taken with a total exposure time of three-and-a-half hours.
The mission will complete its first map of the sky in July 2010. It will then spend the next three months surveying much of the sky a second time, before the solid-hydrogen coolant needed to chill its infrared detectors runs dry. The first installment of the public WISE catalog will be released in summer 2011.
About 960,000 WISE images have been beamed down from space to date. Some show ethereal star-forming clouds, while others reveal the ancient light of very remote, powerful galaxies. And many are speckled with little dots that are asteroids in our solar system. So far, the mission has observed more than 60,000 asteroids, most of which lie in the main belt, orbiting between Mars and Jupiter. About 11,000 of these objects are newly discovered, and about 50 of them belong to a class of near-Earth objects, which have paths that take them within about 48 million kilometers (30 million miles) of Earth’s orbit.
One goal of the WISE mission is to study asteroids throughout our solar system and to find out more about how they vary in size and composition. Infrared helps with this task because it can get better size measurements of the space rocks than visible light.
"Infrared will help us understand more about the sizes, properties and origins of asteroids near and far," said Amy Mainzer, the principal investigator of NEOWISE, a program to study and catalog asteroids seen by WISE (the acronym comes from combining near-Earth object, or NEO, with WISE).
WISE will also study the Trojans, asteroids that run along with Jupiter in its orbit around the sun in two packs -- one in front of and one behind the gas giant. It has seen more than 800 of these objects, and by the end of the mission, should have observed about half of all 4,500 known Trojans. The results will address dueling theories about how the outer planets evolved.
"WISE is the first survey capable of observing the two clouds in a uniform way, and this will provide valuable insight into the early solar system," said astronomer Tommy Grav of Johns Hopkins University, Baltimore, Md., who presented the information today at the astronomy meeting.
Comets have also made their way into WISE images, with more than 72 observed so far, about a dozen of them new. WISE is taking a census of the types of orbits comets ride in. The data will help explain what kicks comets out of their original, more distant orbits and in toward the sun.
JPL manages WISE for NASA's Science Mission Directorate, Washington. The principal investigator, Edward Wright, is at UCLA. The mission was competitively selected under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory, Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp., Boulder, Colo. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA. More information is online at and .

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Wednesday, June 2, 2010

Out of Whack Planetary System Offers Clues to a Disturbed Past

illustration of the Upsilon Andromedae A planetary system, where  three Jupiter-type planets orbit the yellow-white star Upsilon  Andromedae AAstronomers are reporting today the discovery of a planetary system way out of tilt, where the orbits of two planets are at a steep angle to each other. This surprising finding will impact theories of how multi-planet systems evolve, and it shows that some violent events can happen to disrupt planets' orbits after a planetary system forms, say researchers.

"The findings mean that future studies of exoplanetary systems will be more complicated. Astronomers can no longer assume all planets orbit their parent star in a single plane," says Barbara McArthur of The University of Texas at Austin's McDonald Observatory.

McArthur and her team used data from the Hubble Space Telescope, the giant Hobby-Eberly Telescope, and other ground-based telescopes combined with extensive modeling to unearth a landslide of information about the planetary system surrounding the nearby star Upsilon Andromedae.

McArthur reported these findings in a press conference today at the 216th meeting of the American Astronomical Society in Miami, along with her collaborator Fritz Benedict, also of McDonald Observatory, and team member Rory Barnes of the University of Washington. The work also will be published in the June 1 edition of the Astrophysical Journal.

For just over a decade, astronomers have known that three Jupiter-type planets orbit the yellow-white star Upsilon Andromedae. Similar to our Sun in its properties, Upsilon Andromedae lies about 44 light-years away. It's a little younger, more massive, and brighter than the Sun.

Combining fundamentally different, yet complementary, types of data from Hubble and ground-based telescopes, McArthur's team has determined the exact masses of two of the three known planets, Upsilon Andromedae c and d. Much more startling, though, is their finding that not all planets orbit this star in the same plane. The orbits of planets c and d are inclined by 30 degrees with respect to each other. This research marks the first time that the "mutual inclination" of two planets orbiting another star has been measured. And, the team has uncovered hints that a fourth planet, e, orbits the star much farther out.

"Most probably Upsilon Andromedae had the same formation process as our own solar system, although there could have been differences in the late formation that seeded this divergent evolution," McArthur said. "The premise of planetary evolution so far has been that planetary systems form in the disk and remain relatively co-planar, like our own system, but now we have measured a significant angle between these planets that indicates this isn't always the case."

Until now the conventional wisdom has been that a big cloud of gas collapses down to form a star, and planets are a natural byproduct of leftover material that forms a disk. In our solar system, there's a fossil of that creation event because all of the eight major planets orbit in nearly the same plane. The outermost dwarf planets like Pluto are in inclined orbits, but these have been modified by Neptune's gravity and are not embedded deep inside the Sun's gravitational field.

Several different gravitational scenarios could be responsible for the surprisingly inclined orbits in Upsilon Andromedae. "Possibilities include interactions occurring from the inward migration of planets, the ejection of other planets from the system through planet-planet scattering, or disruption from the parent star's binary companion star, Upsilon Andromedae B," McArthur said.

Barnes, an expert in the dynamics of extrasolar planetary systems, added, "Our dynamical analysis shows that the inclined orbits probably resulted from the ejection of an original member of the planetary system. However, we don't know if the distant stellar companion forced that ejection, or if the planetary system itself formed in such a way that some original planets were ejected. Furthermore, we find that the revised configuration still lies right on the precipice of instability: The planets pull on each other so strongly that they are almost able to throw each other out of the system."

The two different types of data combined in this research were astrometry from the Hubble Space Telescope and radial velocity from ground-based telescopes.

Astrometry is the measurement of the positions and motions of celestial bodies. McArthur's group used one of the Fine Guidance Sensors (FGSs) on the Hubble telescope for the task. The FGSs are so precise that they can measure the width of a quarter in Denver from the vantage point of Miami. It was this precision that was used to trace the star's motion on the sky caused by its surrounding - and unseen - planets.

Radial velocity makes measurements of the star's motion on the sky toward and away from Earth. These measurements were made over a period of 14 years using ground-based telescopes, including two at McDonald Observatory and others at Lick, Haute-Provence, and Whipple Observatories. The radial velocity provides a long baseline of foundation observations, which enabled the shorter duration, but more precise and complete, Hubble observations to better define the orbital motions.

The fact that the team determined the orbital inclinations of planets c and d allowed them to calculate the exact masses of the two planets. The new information told us that our view as to which planet is heavier has to be changed. Previous minimum masses for the planets given by radial velocity studies put the minimum mass for planet c at 2 Jupiters and for planet d at 4 Jupiters. The new, exact masses, found by astrometry are 14 Jupiters for planet c and 10 Jupiters for planet d.

"The Hubble data show that radial velocity isn't the whole story," Benedict said. "The fact that the planets actually flipped in mass was really cute."

The 14 years of radial velocity information compiled by the team uncovered hints that a fourth, long-period planet may orbit beyond the three now known. There are only hints about that planet because it's so far out that the signal it creates does not yet reveal the curvature of an orbit. Another missing piece of the puzzle is the inclination of the innermost planet, b, which would require precision astrometry 1,000 times greater than Hubble's, a goal attainable by a space mission optimized for interferometry.

The team's Hubble data also confirmed Upsilon Andromedae's status as a binary star. The companion star is a red dwarf less massive and much dimmer than the Sun.

"We don't have any idea what its orbit is," Benedict said. "It could be very eccentric. Maybe it comes in very close every once in a while. It may take 10,000 years." Such a close pass by the secondary star could gravitationally perturb the orbits of the planets.

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Tuesday, June 1, 2010

Two Peas in an Irregular Pod

A surprisingly large collection of galaxies (red dots in center)   stands out at a remarkably large distance in this composite image   combining infrared and visible-light observations.
New evidence from NASA's Spitzer Space Telescope is showing that tight-knit twin stars might be triggered to form by asymmetrical envelopes like the ones shown in this image.
› Larger image
How Binary Stars May Form
Our sun may be an only child, but most of the stars in the galaxy are actually twins. The sibling stars circle around each other at varying distances, bound by the hands of gravity.
How twin stars form is an ongoing question in astronomy. Do they start out like fraternal twins developing from two separate clouds, or "eggs”? Or do they begin life in one cloud that splits into two, like identical twins born from one egg? Astronomers generally believe that widely spaced twin, or binary, stars grow from two separate clouds, while the closer-knit binary stars start out from one cloud. But how this latter process works has not been clear.
New observations from NASA's Spitzer Space Telescope are acting like sonograms to reveal the early birth process of snug twin stars. The infrared telescope can see the structure of the dense, dusty envelopes surrounding newborn stars in remarkable detail. These envelopes are like wombs feeding stars growing inside -- the material falls onto disks spinning around the stars, and then is pulled farther inward by the fattening stars.
The Spitzer pictures reveal blob-like, asymmetrical envelopes for nearly all of 20 objects studied. According to astronomers, such irregularities might trigger binary stars to form.
"We see asymmetries in the dense material around these proto-stars on scales only a few times larger than the size of the solar system. This means that the disks around them will be fed unevenly, possibly enhancing fragmentation of the disk and triggering binary star formation," said John Tobin of the University of Michigan, Ann Arbor, lead author of a recent paper in the Astrophysical Journal.
All stars, whether they are twins or not, form from collapsing envelopes, or clumps, of gas and dust. The clumps continue to shrink under the force of gravity, until enough pressure is exerted to fuse atoms together and create an explosion of energy.
Theorists have run computer simulations in the past to show that irregular-shaped envelopes may cause the closer twin stars to form. Material falling inward would be concentrated in clumps, not evenly spread out, seeding the formation of two stars instead of one. But, until now, observational evidence for this scenario was inconclusive.
Tobin and his team initially did not set out to test this theory. They were studying the effects of jets and outflows on envelopes around young stars when they happened to notice that almost all the envelopes were asymmetrical. This led them to investigate further -- 17 of 20 envelopes examined were shaped like blobs instead of spheres. The remaining three envelopes were not as irregular as the others, but not perfectly round either. Many of the envelopes were already known to contain embryonic twin stars – possibly caused by the irregular envelopes.
"We were really surprised by the prevalence of asymmetrical envelope structures," said Tobin. "And because we know that most stars are binary, these asymmetries could be indicative of how they form."
Spitzer was able to catch such detailed views of these stellar eggs because it has highly sensitive infrared vision, which can detect the faint infrared glow from our Milky Way galaxy itself. The dusty envelopes around the young stars block background light from the Milky Way, creating the appearance of a shadow in images from Spitzer.
"Traditionally, these envelopes have been observed by looking at longer infrared wavelengths where the cold dust is glowing. However, those observations generally have much lower resolution than the Spitzer images," said Tobin.
Further study of these envelopes, examining the velocity of the material falling onto the forming stars using radio-wavelength telescopes, is already in progress. While the researchers may not yet be able to look at a picture of a stellar envelope and declare "It's twins," their work is offering important clues to help solve the mystery of how twin stars are born.
Other authors of this study include Lee Hartmann of the University of Michigan, Ann Arbor; and Hsin-Fang Chiang and Leslie Looney of the University of Illinois, Urbana-Champaign. The observations were made before Spitzer ran out its liquid coolant in May 2009, beginning its "warm" mission.
NASA's Jet Propulsion Laboratory, Pasadena, Calif., 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. Caltech manages JPL for NASA.
For more information about Spitzer, visit and

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