Posted on by Fraser Cain

Rover’s Wheels Acting Up

Engineers on NASA’s Mars Exploration Rover team are investigating possible causes and remedies for a problem affecting the steering on Spirit.

The relay for steering actuators on Spirit’s right-front and left-rear wheels did not operate as commanded on Oct. 1. Each of the front and rear wheels on the rover has a steering actuator, or motor, that adjusts the direction in which the wheels are headed independently from the motor that makes the wheels roll. When the actuators are not in use, electric relays are closed and the motor acts as a brake to prevent unintended changes in direction.

Engineers received results from Spirit today from a first set of diagnostic tests on the relay. “We are interpreting the data and planning additional tests,” said Rick Welch, rover mission manager at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “We hope to determine the best work-around if the problem does persist.”

Spirit and its twin, Opportunity, successfully completed their three-month primary missions in April and five-month mission extensions in September. They began second extensions of their missions on Oct. 1. Spirit has driven more than 3.6 kilometers (2.2 miles), six times the distance set as a goal for mission success. It is climbing into uplands called the “Columbia Hills.”

JPL’s Jim Erickson, rover project manager, said, “If we do not identify other remedies, the brakes could be released by a command to blow the fuse controlling the relay, though that would make those two brakes unavailable for the rest of the mission.” Without the steering-actuator brakes, small bumps or dips that a wheel hits during a drive might twist the wheel away from the intended drive direction.

“If we do need to disable the brakes, errors in drive direction could increase. However, the errors might be minimized by continuing to use the brakes on the left-front and right-rear wheels, by driving in smaller segments, and by adding a software patch to reset the direction periodically during a drive,” Erickson said. Engineers believe the steering-brake issue is not related to excessive friction detected during the summer in the drive motor for Spirit’s right-front wheel, because the steering actuator is a different motor.

Meanwhile, the team continues to use Spirit’s robotic arm and camera mast to study rocks and soils around the rover, without moving the vehicle until the cause of the anomaly is understood and corrective measures can be implemented.

JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover project for NASA’s Science Mission Directorate, Washington. Additional information about the project is available from JPL at http://marsrovers.jpl.nasa.gov/ and from Cornell University, Ithaca, N.Y., at http://athena.cornell.edu.

Original Source: NASA/JPL News Release

Posted on by Fraser Cain

The Great Observatories Examine Kepler’s Supernova

Four hundred years ago, sky watchers, including the famous astronomer Johannes Kepler, best known as the discoverer of the laws of planetary motion, were startled by the sudden appearance of a “new star” in the western sky, rivaling the brilliance of the nearby planets.

Modern astronomers, using NASA’s three orbiting Great Observatories, are unraveling the mysteries of the expanding remains of Kepler’s supernova, the last such object seen to explode in our Milky Way galaxy.

When a new star appeared Oct. 9, 1604, observers could use only their eyes to study it. The telescope would not be invented for another four years. A team of modern astronomers has the combined abilities of NASA’s Great Observatories, the Spitzer Space Telescope, Hubble Space Telescope and Chandra X-ray Observatory, to analyze the remains in infrared radiation, visible light, and X-rays. Ravi Sankrit and William Blair of the Johns Hopkins University in Baltimore lead the team.

The combined image unveils a bubble-shaped shroud of gas and dust, 14 light-years wide and expanding at 6 million kilometers per hour (4 million mph). Observations from each telescope highlight distinct features of the supernova, a fast-moving shell of iron-rich material, surrounded by an expanding shock wave sweeping up interstellar gas and dust.

“Multi-wavelength studies are absolutely essential for putting together a complete picture of how supernova remnants evolve,” Sankrit said. Sankrit is an associate research scientist, Center for Astrophysical Sciences at Hopkins and lead for Hubble astronomer observations.

“For instance, the infrared data are dominated by heated interstellar dust, while optical and X-ray observations sample different temperatures of gas,” Blair added. Blair is a research professor, Physics and Astronomy Department at Hopkins and lead astronomer for Spitzer observations. “A range of observations is needed to help us understand the complex relationship that exists among the various components,” Blair said.

The explosion of a star is a catastrophic event. The blast rips the star apart and unleashes a roughly spherical shock wave that expands outward at more than 35 million kilometers per hour (22 million mph) like an interstellar tsunami. The shock wave spreads out into surrounding space, sweeping up any tenuous interstellar gas and dust into an expanding shell. The stellar ejecta from the explosion initially trail behind the shock wave. It eventually catches up with the inner edge of the shell and is heated to X-ray temperatures.

Visible-light images from Hubble’s Advanced Camera for Surveys reveal where the supernova shock wave is slamming into the densest regions of surrounding gas. The bright glowing knots are dense clumps that form behind the shock wave. Sankrit and Blair compared their Hubble observations with those taken with ground-based telescopes to obtain a more accurate distance to the supernova remnant of about 13,000 light-years.

The astronomers used Spitzer to probe for material that radiates in infrared light, which shows heated microscopic dust particles that have been swept up by the supernova shock wave. Spitzer is sensitive enough to detect both the densest regions seen by Hubble and the entire expanding shock wave, a spherical cloud of material. Instruments on Spitzer also reveal information about the chemical composition and physical environment of the expanding clouds of gas and dust ejected into space. This dust is similar to dust which was part of the cloud of dust and gas that formed the Sun and planets in our solar system.

The Chandra X-ray data show regions of very hot gas. The hottest gas, higher-energy X-rays, is located primarily in the regions directly behind the shock front. These regions also show up in the Hubble observations and also align with the faint rim of material seen in the Spitzer data. Cooler X-ray gas, lower-energy X-rays, resides in a thick interior shell and marks the location of the material expelled from the exploded star.

There have been six known supernovas in our Milky Way over the past 1,000 years. Kepler’s is the only one for which astronomers do not know what type of star exploded. By combining information from all three Great Observatories, astronomers may find the clues they need. “It’s really a situation where the total is greater than the sum of the parts,” Blair said. “When the analysis is complete, we will be able to answer several questions about this enigmatic object.”

Images and additional information are available at http://www.nasa.gov, http://hubblesite.org/news/2004/29, http://chandra.harvard.edu , http://spitzer.caltech.edu ,http://www.jhu.edu/news_info/news/, http://heritage.stsci.edu/2004/29 and http://www.nasa.gov/vision/universe/starsgalaxies/kepler.html.

Original Source: NASA/JPL News Release

Posted on by Fraser Cain

Rocket Will Launch 50 Nanosatellites

Image credit: Arianespace
During this year’s International Astronautical Federation (IAF) Congress in Vancouver, Canada, Arianespace, the Russian Space Agency with the support of the Russian space industry and IAF, in partnership with the leading space agencies from around the world, are proposing to commemorate the first satellite launch in 1957, by orbiting a cluster of 50 nanosatellites, each representing a different country.

Each nanosat will weigh about one kilogram, and will be dedicated to a scientific experiment under the responsibility of researchers at universities or other organizations. Each nanosat will offer a design life of about two years. All 50 will be launched on a single Arianespace mission.

“Arianespace is very proud to be participating in this commemoration,” said Jean-Yves Le Gall, the company’s Chief Executive Officer. “Supporting science and research is an integral part of our assigned mission. We have already orbited some 40 auxiliary payloads of the same type we will launch in 2007. Just like 50 years ago, when the first man-made Earth satellite was launched, these nanosatellites will signal a new era for scientists worldwide.”

Original Source: Arianespace News Release

Posted on by Mark Mortimer

Book Review: New Moon Rising

In an easy to read style, the book, for the most part, follows a chronological list of relevant events from about the year 2000 to the present. The main ones are Goldin’s last days, finding his replacement, the appointment of Sean O’Keefe, the loss of Columbia and the fabrication of NASA’s new vision which President Bush provided in early 2004. Names predominate throughout. Large quantities of people, projects, programs, companies and foundations appear in what sometimes seems to be a never ending parade. As quickly as these come, they go again. So, it is difficult to find a common thread or reason for their inclusion. Perhaps these names and/or offices are essential contributors, but this is not apparent. Nevertheless, the discussed events all directly contribute to the making of NASA’s new vision.

During Goldin’s time as administrator, NASA had many mandates and insufficient resources. The Challenger accident left the space shuttle program with a blemish and an even greater launch cost than originally estimated. The orbiting space station went through innumerable configurations and designs in an effort to please as many potential users as possible. Even NASA’s various field offices seemed more focussed on their own agendas than on a ‘corporate’ vision. Sean O’Keefe, Goldin’s replacement, had recent experience in financial auditing including a recent review of NASA’s finances. As the new administrator, his main assignment was to reassert fiscal realism. But to do this he needed priorities. And to set priorities he needed an achievable and specific vision. Thus, as much as O’Keefe replaced Goldin, so did O’Keefe need a vision to replace and rebuild from the current situation.

The premise of this book is that the creation of NASA’s vision was by the spontaneous and surreptitious meetings of a cadre of very junior hill staffers during coffee break and lunch. This seems difficult to believe, but the authors weave a very reasonable and continuous thread from this ‘rump’ group as they were called, through to more senior groups, senators and agencies and then up to the president. Again, names are liberally included, so this thread may be authentic, but still it seems a bit far fetched. Perhaps the most intriguing element is that NASA was apparently not part of this process until very late in the formulation. So in one sense it does seem a bit too fanciful to have junior staffers making a vision for an agency with an annual budget of $16 billion (can you imagine this happening for foreign policy?!). But, as they had nothing to lose and probably no alternate agendas, there is a ring of truth to this premise.

Perhaps equally fanciful is the claim that this new vision will get humans operating in space. Having a vision and a supporting budget is critical. Equally critical is the support of the elected politicians, who regularly change, as well as the support of other nations and their respective space agencies. But all of these will be needed for the duration. The authors rightly point out that this will be challenging. They even provide an excellent perspective on what to expect should either of this year’s presidential candidates win. Sadly, neither candidate seems solidly behind NASA and perhaps with this, the authors unknowingly provide more evidence contrary to their expectations than for it.

In their writing, the authors show they are non-partisan but very supportive of NASA’s new space vision. They acknowledge that senior NASA leadership provided access to information and verified personal communications, but they are also quick to point out that the contents is their own. The included DVD has memorable video footage of President Bush’s introduction of this vision, as well as Sean O’Keefe’s comments. This all lends authenticity to the contents and claim.

This book is good but it has its weaknesses. One item lacking is an index. Retracing people and events is almost impossible. Further, though the names and events may be very applicable today (the fall of the year 2004), expect them to become quickly very dated. With retirements and re-appointments, the parade of people just changes too quickly to make this book a useful reference in the long term. Also, perhaps the weakest element of the book is the lack of justification for spending nearly $100 billion for a program to send people to the Moon, Mars and beyond. Though more effort could have remedied these, the book is still a good read.

As the authors say in New Moon Rising, NASA needed and obtained a new space vision to direct its efforts. The authors provide a detailed and broad overview of the very large supporting cast that contributed to the vision that was initiated with President Bush’s speech early in the year 2004. Now, in the authors viewpoint, NASA and its new administrator, Sean O’Keefe, have what they need to ensure this vision becomes reality.

To read more reviews, or order the book online, visit Amazon.com.

Review by Mark Mortimer

Posted on by Fraser Cain

Astronaut Gordon Cooper Dies

Gordon Cooper Jr., the astronaut who piloted the sixth and last flight of the Mercury program and later commanded Gemini 5, died earlier today at his home in Ventura, Calif. He was 77 years old.

“As one of the original seven Mercury astronauts, Gordon Cooper was one of the faces of America’s fledgling space program. He truly portrayed the right stuff, and he helped gain the backing and enthusiasm of the American public, so critical for the spirit of exploration. My thoughts and prayers are with Gordon’s family during this difficult time,” said NASA Administrator Sean O’Keefe.

“Cooper’s efforts and those of his fellow Mercury astronauts, Alan Shepard, Gus Grissom, John Glenn, Scott Carpenter, Wally Schirra and Deke Slayton, serve as reminders of what drives us to explore. They also remind us that to succeed any vision for exploration needs the support of the American people.”

“Gordo was one of the most straightforward people I have ever known. What you saw was what you got,” said fellow Mercury astronaut and former U.S. Senator John Glenn, in a statement released by the Astronaut Scholarship Foundation.

Another of the “Original Seven,” Wally Schirra added, “We seven were bonded like brothers, maybe even closer if that’s possible.”

“He never said ‘you can’t do it.’ He was gung ho on everything,” said Norris Gray, the NASA Fire Chief and Emergency Preparedness Officier during the Mercury days. Sam Beddingfield, then Mechanical Engineer for Project Mercury added, “He knew what he was doing and could always make things work.”

“Gordon Cooper’s legacy is permanently woven into the fabric of the Kennedy Space Center as a Mercury Seven astronaut,” said Kennedy Space Center director Jim Kennedy. “His achievements helped build the foundation of success for human space flight that NASA and KSC have benefited from for the past four decades.

“While the KSC family mourns the loss of this space pioneer, we honor his contributions and rest easy knowing his imprint on KSC will last forever. I consider it a privilege to have known Gordon Cooper. On behalf of the KSC family, I extend condolences to the Cooper family and our prayers are with them in their trying days ahead. ”

The youngest of the original seven astronauts, Cooper’s flight in his Faith 7 capsule stretched the capabilities of the Mercury spacecraft to the limits. The mission, May 15 and 16, 1963, lasted more than 34 hours and 22 orbits. That was more than three times the longest U.S. human space flight until that time, and far exceeded the initial design capability of the capsule. During his flight, Cooper also became the first astronaut to sleep in space.

“NASA’s astronauts extend their deepest sympathies to Gordon Cooper’s family,” said Kent Rominger, chief of the astronaut office at NASA’s Johnson Space Center in Houston. “He was among the first pioneers in space and his achievements inspired many of us to pursue our dreams of exploring our universe. We salute his many accomplishments as an astronaut and as a husband and father. He will be truly missed.”

Cooper and Charles “Pete” Conrad Jr. flew the troubled and suspenseful third flight of the Gemini program in August 1965. The goal of the mission was to prove astronauts could survive in space long enough to perform a lunar mission, which takes eight days.

During their eight-day mission, they experienced a number of problems with power systems, thruster fuel, venting gas that caused the spacecraft to roll, and more in a seemingly unending series. But they stayed in orbit for almost 191 hours, 122 orbits in nearly eight days, and got themselves and their spacecraft back intact. In orbit, they accomplished a “shadow rendezvous” with an imaginary spacecraft, an exercise demonstrating it could be done.

The Gemini 5 mission established a new space endurance record at the time, travelling 3,312,993 miles in 190 hours and 56 minutes. Cooper also became the first man to make a second orbital flight and thus won for the United States the lead in man-hours in space by accumulating a total of 225 hours and 15 minutes.

A Life of Service
Leroy Gordon Cooper Jr. was born on March 6, 1927, in Shawnee, Okla. He served in the Marine Corps in 1945 and 1946, then attended the University of Hawaii where he was commissioned a second lieutenant in the U.S. Army.

In 1949 he was called to active duty and completed pilot training in the U.S. Air Force. From 1950 to 1954 he was a fighter pilot in Germany.

Cooper earned a bachelor’s degree at the Air Force Institute of Technology in 1956, then completed test pilot school at Edwards Air Force Base, Calif. He served as a test pilot there until he was selected as a Mercury astronaut.

In addition to his two flights, Cooper was backup command pilot of Gemini 12, launched in November 1965. He also served as backup command pilot for Apollo 10, which flew in May 1969. He left NASA and retired from the Air Force as a colonel on July 31, 1970.

He founded Gordon Cooper and Associates that year and served as president of the consulting firm that specialized in activities ranging from aerospace to hotel and land development projects. Cooper was a director of a number of other organizations, most specializing in energy, advanced electronics systems, efficient homes, boats and marine systems and equipment.

In 1975, he became vice president for research and development for Walter E. Disney Enterprises Inc. of Glendale, Calif., the research and development subsidiary of Walt Disney Productions.

Throughout his life, Cooper pursued a wide range of activities, both professionally and as hobbies. A NASA biography lists his hobbies as treasure hunting, archaeology, racing, flying, skiing, boating, hunting and fishing. Among his numerous awards were the Air Force Legion of Merit, the Distinguished Flying Cross with cluster, NASA’s Exceptional Service Medal, the Collier Trophy and the Harmon Trophy.

He was the first active-duty military man to address joint sessions of Congress twice.

Cooper continued to design and test new aircraft in Southern California, never giving up his passion for pushing the envelope. Cooper told a reporter when he was 71, “I get cranky if I don’t fly at least three times a month.”

Original Source: NASA News Release

Posted on by Fraser Cain

Giant Infrared Space Observatory Considered by NASA

A NASA-led team is studying the construction of a railway in space for a pair of telescopes that will provide views of planet, star, and galaxy formation in unprecedented detail. The proposed Space Infrared Interferometric Telescope (SPIRIT) mission will also examine the atmospheric chemistry of giant planets around other stars.

SPIRIT will consist of two telescopes at opposite ends of a 120-foot (40-meter) beam. The telescopes will move along the beam like cars on a railway, combing their images using the techniques of interferometry to achieve the resolving power of a single giant telescope 120 feet across.

NASA’s Goddard Space Flight Center, Greenbelt, Md., will lead a NASA/university/industry team to develop a preliminary design for SPIRIT. The team will evaluate various mission concepts, create a roadmap of the technology development required for the mission, and generate independent cost assessments.

The study was commissioned in July 2004 by NASA Headquarters, Washington, D.C., as one of nine proposals that will help strategic planning for NASA’s Origins Space Science research theme. NASA’s Origins program seeks to answer the fundamental questions about the universe, such as where we came from and whether or not we are alone. The team will report to the Origins Roadmap Committee in early January, 2005, and a final report is due three months later.

“I’m delighted that SPIRIT was chosen for study,” said Dr. David Leisawitz of NASA Goddard, Principal Investigator for the proposed mission. “We’re going to give NASA a chance to build a telescope that will dazzle the world with crisp, clear infrared pictures of the universe.”

“These images will help us to answer some very profound questions. How did we living critters wind up on a rocky planet bathed in light from the Sun, one of a hundred billion stellar denizens of the magnificently spiral-shaped Milky Way galaxy? Perhaps even more tantalizing, we should expect the unexpected, as that’s what we find whenever a big step is taken to improve the scientific community’s tools. SPIRIT will use techniques pioneered a century ago by Nobel Laureate Albert A. Michelson, so we know it can be done, and I think it’s an excellent match to the Origins mission class envisioned in NASA’s call for proposals,” said Leisawitz.

SPIRIT will examine the universe in the far-infrared and sub-millimeter wavelengths of light. This light is invisible to the human eye, but some types of infrared light are perceived as heat.

The processes that build planets, stars, and galaxies are most readily visible in these kinds of light. For example, stars are born when massive interstellar clouds collapse under their own gravity. The collapse generates heat, causing the central star-forming region of the cloud to glow in infrared. Newborn stars are frequently surrounded by disks of dust and gas, which also collapse under their own gravity to form planets. While the planets are too small to be seen directly, their gravity disturbs the dust disk, forming ripples and lumps. Warmed by the central star, the dust glows in infrared light, revealing the dusty structures to SPIRIT and divulging the locations and sizes of previously unknown planets.

Looking farther into space is equivalent to seeing back in time, because the speed of light is finite, and it takes light a significant amount of time to traverse immense cosmic distances. We see the nearest large galaxy (Andromeda) as it appeared about two million years ago, because that’s how long it took for its light to reach us. We cast our gaze back billions of years by looking toward the limit of the observable universe, and thus can watch galaxies as they evolve. However, since the universe is expanding, light emitted by remote galaxies has been stretched by the expansion of space to infrared and sub-millimeter wavelengths, so we need telescopes highly sensitive to these types of light to observe distant galaxy formation.

Many of these objects appear too small, or shine too faintly at their remote distances for existing telescopes to observe in great detail. To accomplish such ambitious observations, SPIRIT will have 100 times the angular resolution (ability to see fine detail) than existing infrared telescopes, complemented with a matching improvement in sensitivity.

Technical challenges to overcome include keeping the telescope mirrors extremely cold (about 4 degrees Kelvin or minus 452 degrees Fahrenheit) so their own heat does not obscure the faint infrared light they are trying to collect. The detectors also need to have greater sensitivity and more pixels. The Goddard/industry team is up to the challenge: “Our engineers love working on this project; there’s a lot of room for creative thought, and everyone understands that this is an opportunity to take a giant leap forward scientifically while inspiring the next generation of explorers.” says Leisawitz.

If approved, SPIRIT could be ready for launch in 2014, on board a large expendable rocket. SPIRIT would travel to the L2 libration point one million miles from Earth where it will automatically unfold its beam and deploy the telescopes. The Goddard-led team includes collaborators from Caltech, Cornell, the Harvard-Smithsonian Center for Astrophysics, the University of Maryland, the Massachusetts Institute of Technology, the Naval Research Laboratory, Princeton, the University of California, Los Angeles, the University of Wisconsin, and NASA’s Jet Propulsion Laboratory and Marshall Space Flight Center. The industry team includes Ball Aerospace, Boeing, Lockheed-Martin, and Northrop-Grumman.

Original Source: NASA News Release

Posted on by Fraser Cain

Study Predicts Quakes Nearly Perfectly

A NASA-funded earthquake forecast program has an amazing track record. Published in 2002, the Rundle-Tiampo Forecast has accurately forecast the locations of 15 of California’s 16 largest earthquakes this decade, including last week’s tremors.

The 10-year forecast was developed by researchers at the University of Colorado (now at the University of California, Davis) and from NASA’s Jet Propulsion Laboratory, Pasadena, Calif. NASA and the U.S. Department of Energy funded it.

“We’re elated our computer modeling technique has revealed a relationship between past and future earthquake locations,” said Dr. John Rundle, director of the Computational Science and Engineering initiative at the University of California, Davis. He leads the group that developed the forecast scorecard. “We’re nearly batting a thousand, and that’s a powerful validation of the promise this forecasting technique holds.”

Of 16 earthquakes of magnitude 5 and higher since Jan. 1, 2000, 15 fall on “hotspots” identified by the forecasting approach. Twelve of the 16 quakes occurred after the paper was published in Proceedings of the National Academy of Sciences in Feb. 2002. The scorecard uses records of earthquakes from 1932 onward to predict locations most likely to have quakes of magnitude 5 or greater between 2000 and 2010. According to Rundle, small earthquakes of magnitude 3 and above may indicate stress is building up along a fault. While activity continues on most faults, some of those faults will show increasing numbers of small quakes, building up to a big quake, while some faults will appear to shut down. Both effects may herald the possible occurrence of large events.

The scorecard is one component of NASA’s QuakeSim project. “QuakeSim seeks to develop tools for quake forecasting. It integrates high-precision, space-based measurements from global positioning system satellites and interferometric synthetic aperture radar (InSAR) with numerical simulations and pattern recognition techniques,” said JPL’s Dr. Andrea Donnellan, QuakeSim principal investigator. “It includes historical data, geological information and satellite data to make updated forecasts of quakes, similar to a weather forecast.”

JPL software engineer Jay Parker said, “QuakeSim aims to accelerate the efforts of the international earthquake science community to better understand earthquake sources and develop innovative forecasting methods. We expect adding more types of data and analyses will lead to forecasts with substantially better precision than we have today.”

The scorecard forecast generated a map of California from the San Francisco Bay area to the Mexican border, divided into approximately 4,000 boxes, or “tiles.” For each tile, researchers calculated the seismic potential and assigned color-coding to show the areas most likely to experience quakes over a 10-year period.

“Essentially, we look at past data and perform math operations on it,” said James Holliday, a University of California, Davis graduate student working on the project. Instrumental earthquake records are available for Southern California since 1932 and for Northern California since 1967. The scorecard gives more precision than a simple look at where quakes have occurred in the past, Rundle said.

“In California, quake activity happens at some level almost everywhere. This method narrows the locations of the largest future events to about six percent of the state,” Rundle said. “This information will help engineers and government decision makers prioritize areas for further testing and seismic retrofits.”

So far, the technique has missed only one earthquake — a magnitude of 5.2 — on June 15, 2004, under the ocean near San Clemente Island. Rundle believes this “miss” may be due to larger uncertainties in locating earthquakes in this offshore region of the state. San Clemente Island is at the edge of the coverage area for Southern California’s seismograph network. Rundle and Holliday are working to refine the method and find new ways to visualize the data.

Other forecast collaborators include Kristy Tiampo, the University of Western Ontario, Canada; William Klein, Boston University, Boston; and Jorge S. Sa Martins, Universidad Federal Fluminense, Rio de Janeiro, Brazil.

For images and updated scorecard maps on the Internet, visit http://www.nasa.gov/vision/earth/environment/0930_earthquake.html.

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

Original Source: NASA/JPL News Release

Posted on by Fraser Cain

Infrared View of Mount Saint Helens

NASA scientists took infrared (IR) digital images of Mount Saint Helens’ last week. The images revealed signs of heat below the surface one day before the volcano erupted last Friday in southern Washington. The images may provide valuable clues as to how the volcano erupted.

Scientists flew an IR imaging system aboard a small Cessna Caravan aircraft over the mountain to acquire the data. “Based on the IR signal, the team predicted an imminent eruption,” said Steve Hipskind, acting chief of the Earth Science Division at NASA’s Ames Research Center (ARC), Moffett Field, Calif.

“We were seeing some thermal artifacts in the floor of the Mount Saint Helens’ crater in southern Washington,” said Bruce Coffland, a member of the Airborne Sensor Facility at ARC. ” We flew Thursday and used the 50-channel MODIS/ASTER Airborne Simulator (MASTER) digital imaging system. We are working to create images from the IR data that depict the thermal signatures on the dome,” Coffland added.

MASTER is an airborne simulator instrument similar to the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) high-resolution infrared imager carried on NASA’s Terra Earth observation satellite. Scientists plan to fly the MASTER instrument again over the volcano early this week.

The ARC airborne sensor team was in the area taking data for a United States Geological Survey (USGS) study examining some of the effects of the 1980 Mount Saint Helens’ eruption. “This had been planned for some time, and we were there totally by coincidence,” Coffland said. The science objectives for the USGS study were to outline the boundaries of the lava flows associated with Mt. St. Helens’ previous eruptions in 1980.

“We flew four flight lines over the mountain,” Coffland said. “It’s a continuous scan image, eight miles long (13 kilometers) and about 2.3 miles (3.7 kilometers) wide.” There were four adjoining flight lines flown for Joel Robinson, an investigator at USGS, Menlo Park, Calif.

After the plane landed, technicians downloaded data from a computer hard drive, and began to process the data to produce an image format for use by scientists. NASA will post the pre and post eruption infrared images on the Web.

Sky Research, based in Ashland, Ore. provided the Cessna Caravan, a propeller driven, single-engine airplane that carried the IR imager.

To access images on the Internet as they become available, visit:

Mt. St. Helens and http://masterweb.jpl.nasa.gov/

Original Source: NASA News Release

Posted on by Fraser Cain

Field of Fault Lines on Mars

This image, taken by the High Resolution Stereo Camera (HRSC) on board ESA?s Mars Express spacecraft, shows the Claritas Fossae tectonic grabens and part of the Solis Planum plains.

The image was taken during orbit 508 in June 2004 with a ground resolution of approximately 40 metres per pixel. The displayed region is the eastern part of Claritas Fossae and the western part of Solis Planum at longitude 260? East and latitude of about 28? South.

The diffuse blue-white streaks in the northern parts of the scene are clouds or aerosols.

The Claritas Fossae (?fossa? is Latin for trough) region is characterised by systems of ?grabens? running mainly north-west to south-east. These can be traced several hundred kilometres up to the northern Tharsis shield volcanoes.

A graben forms when a block of the planet?s crust drops down between two faults, due to extension, or pulling, of the crust.

Grabens are often seen together with features called ?horsts?, which are upthrown blocks lying between two steep-angled fault blocks.

A ?horst and graben? system can occur where there are several parallel faults.

Geographically, the grabens separate the eastern volcanic plains of the Solis Planum region from the western Daedalia Planum lava plains.

The lava blankets of the Solis Planum area cover the eastern parts of the older Claritas Fossae ridge and surround some of the higher ground.

The geological history of this region can be reconstructed by analysing the layers of tectonic grabens, impact craters, volcanic features and even small valley networks.

The complexity of this superposition record suggests that some of the events took place at the same time.

The detailed view of the large southern impact crater shows patches of dark material which are located near the central and marginal parts of the impact crater floor. This material may be of volcanic origin.

The HRSC experiment on ESA?s Mars Express mission is led by the Principal Investigator Prof. Gerhard Neukum of the Freie Universit?t Berlin, who also designed the camera. The experiment?s science team consists of 45 Co-Investigators from 10 nations.

The camera was developed at the German Aerospace Centre (DLR) and built in co-operation with industrial partners EADS Astrium, Lewicke Microelectronic GmbH and Jena-Optronic GmbH). The HRSC is operated by DLR Institute of Planetary Research through ESA?s European Space Operations Centre, Darmstadt.

The systematic processing of image data is carried out at DLR. The images shown here were processed by the FU Berlin group in co-operation with DLR, Berlin.

Original Source: ESA News Release

Posted on by Fraser Cain

Centre of the Milky Way Sterilized by Blasts

Life near the center of our galaxy never had a chance. Every 20 million years on average, gas pours into the galactic center and slams together, creating millions of new stars. The more massive stars soon go supernova, exploding violently and blasting the surrounding space with enough energy to sterilize it completely. This scenario is detailed by astronomer Antony Stark (Harvard-Smithsonian Center for Astrophysics) and colleagues in the October 10, 2004, issue of The Astrophysical Journal Letters.

The team’s discovery was made possible using the unique capabilities of the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO). It is the only observatory in the world able to make large-scale maps of the sky at submillimeter wavelengths.

The gas for each starburst comes from a ring of material located about 500 light-years from the center of our galaxy. Gas collects there under the influence of the galactic bar-a stretched oval of stars 6,000 light-years long rotating in the middle of the Milky Way. Tidal forces and interactions with this bar cause the ring of gas to build up to higher and higher densities until it reaches a critical density or “tipping point.” At that point, the gas collapses down into the galactic center and smashes together, fueling a huge burst of star formation.

“A starburst is star formation gone wild,” says Stark.

Astronomers see starbursts in many galaxies, most often colliding galaxies where lots of gas crashes together. But starbursts can happen in isolated galaxies too, including our own galaxy, the Milky Way.

The next starburst in the Milky Way is coming relatively soon, predicts Stark. “It likely will happen within the next 10 million years.”

That assessment is based on the team’s measurements showing that the gas density in the ring is nearing the critical density. Once that threshold is crossed, the ring will collapse and a starburst will blaze forth on an unimaginably huge scale.

Some 30 million solar masses of matter will flood inward, overwhelming the 3 million solar mass black hole at the galactic center. The black hole, massive as it is, will be unable to consume most of the gas.

“It would be like trying to fill a dog dish with a firehose,” says Stark. Instead, most of the gas will form millions of new stars.

The more massive stars will burn their fuel quickly, exhausting it in only a few million years. Then, they will explode as supernovae and irradiate the surrounding space. With so many stars packed so close together as a result of the starburst, the entire galactic center will be impacted dramatically enough to kill any life on an Earth-like planet. Fortunately, the Earth itself lies about 25,000 light-years away, far enough that we are not in danger.

The facility used to make this discovery, AST/RO, is a 1.7-meter-diameter telescope that operates in one of the most challenging environments on the planet-the frigid desert of Antarctica. It is located at the National Science Foundation’s Amundsen-Scott Station at the South Pole. The air at the South Pole is very dry and cold, so radiation that would be absorbed by water vapor at other sites can reach the ground and be detected.

“These observations have helped advance our understanding of star formation in the Milky Way,” says Stark. “We hope to continue those advancements by collaborating with researchers who are working on the Spitzer Space Telescope’s Legacy Science Program. AST/RO’s complementary observations would uniquely contribute to that effort.”

Stark’s co-authors on the paper announcing this finding are Christopher L. Martin, Wilfred M. Walsh, Kecheng Xiao and Adair P. Lane (Harvard-Smithsonian Center for Astrophysics), and Christopher K. Walker (Steward Observatory).

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.

Original Source: CfA News Release