No spacecraft had ever imaged the collision zone, which occurs in a region known as the heliosheath, because it emits no light. But the two detectors on IBEX are designed to “see” what the human eye cannot. The interaction of the solar wind and interstellar medium creates energetic neutral atoms of hydrogen, called ENAs, that zip away from the heliosheath in all directions. Some of these atoms pass near Earth, where IBEX records their arrival direction and energy. As the spacecraft slowly spins, the detectors gradually build up pictures of the ENAs as they arrive from all over the sky.
Mission scientists got their first surprise six months after launch, once the spacecraft had scanned enough overlapping strips of sky to create a complete 360° map. Instead of recording a relatively even distribution all the way around, as expected, IBEX found that the counts of ENAs — and thus the strength of the interaction in the heliosheath — varied dramatically from place to place. The detectors even discovered a long, enhanced “ribbon,” accentuated by an especially intense hotspot or “knot,” arcing across the sky. (IBEX Explores Galactic Frontier, Releases First-Ever All-Sky Map)
Now scientists have finished assembling a second complete sweep around the sky, and IBEX has again delivered an unexpected result: the map has changed significantly. Overall, the intensity of ENAs has dropped 10% to 15%, and the hotspot has diminished and spread out along the ribbon. Details of these findings appear in the September 27th issue of Journal of Geophysical Research (Space Physics).
“We thought we might detect small changes occurring gradually throughout the Sun’s 11-year-long activity cycle, but not over just 6 months,” notes David McComas (Southwest Research Institute), principal investigator for the IBEX mission and the paper’s lead author. “These observations show that the interaction of the Sun with the interstellar medium is far more dynamic and variable than anyone envisioned.”
In the past, space physicists had little notion of what to expect along the boundary where the Sun’s own magnetic bubble, the heliosphere, meets interstellar space. Even though the solar wind travels outward at roughly a million miles per hour, it still takes about a year to reach the heliosphere’s edge. Also, the encounter zone within the heliosheath is believed to be several billion miles thick (roughly Pluto’s distance from the Sun). Finally, the ENAs take another six months to many years to complete the return trip back to Earth, depending on their direction and energy.
With ENAs starting out from such a wide range of distances and traveling back toward Earth at different speeds, IBEX mission scientists had expected that any highs and lows in intensity arising within the heliosheath would be hopelessly smeared out in the spacecraft’s all-sky maps. So they’re elated by the variations and changes seen so far by IBEX. These early results hint that the solar wind and the interstellar flow might be interacting in a thinner layer than many researchers had imagined possible.
McComas says the dropoff in intensity between the two all-sky maps perhaps makes sense, because the Sun is only now emerging from an unusually long period of very low activity and a correspondingly weak solar wind. The fewer the solar-wind particles that reached the heliosheath in recent years, the fewer the ENAs that got created. “We didn’t plan it this way,” says McComas, “but it’s an almost perfect situation, in that we’re seeing the interaction in its simplest state — before trying to interpret what turns out to be a much more complicated interaction than anticipated.”
If IBEX remains healthy, and if the team gets approval to continue well past its planned two-year mission, then the changes it’s seeing in the distant heliosheath should become more dramatic as solar activity ramps up later in this decade.
“The surprising results from IBEX show that there is still exciting science that can be done with small missions,” comments Eric Christian, a member of the spacecraft’s research team and the program’s Deputy Mission Scientist at the Goddard Space Flight Center. “This is clearly a huge success for the Explorer program.” IBEX is one of a dozen Explorer-class missions operated by NASA’s Science Mission Directorate.
“The public might think that scientists make measurements and instantly know what’s going on, but that is not how science really works,” McComas observes. “We thought the outer heliosphere would be stable over time — and IBEX is showing us that it’s not. This is changing the game completely.”
For more information visit http://www.nasa.gov/mission_pages/ibex/news/solar-boundary.html
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Earlier today, navigators and mission controllers for NASA's EPOXI mission watched their computer screens as 23.6 million kilometers (14.7 million miles) away, their spacecraft successfully performed its 20th trajectory correction maneuver. The maneuver refined the spacecraft's orbit, setting the stage for its flyby of comet Hartley 2 on Nov. 4. Time of closest approach to the comet was expected to be about 10: 02 a.m. EDT (7:02 a.m. PDT).
Today's trajectory correction maneuver began at 2 p.m. EDT (11 a.m. PDT) today, when the spacecraft fired its engines for 60 seconds, changing the spacecraft's velocity by 1.53 meters per second (3.4 mph).
"We are about 23 million miles and 36 days away from our comet," said EPOXI project manager Tim Larson of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "I can't wait to see what Hartley 2 looks like."
On Nov. 4, the spacecraft will fly past the comet at a distance of about 700 kilometers (435 miles). It will be only the fifth time in history that a spacecraft has been close enough to image a comet's nucleus, and the first time in history that two comets have been imaged with the same instruments and same spatial resolution.
"We are imaging the comet every day, and Hartley 2 is proving to be a worthy target for exploration," said Mike A'Hearn, EPOXI principal investigator from the University of Maryland, College Park.
EPOXI is an extended mission that utilizes the already "in flight" Deep Impact spacecraft to explore distinct celestial targets of opportunity. The name EPOXI itself is a combination of the names for the two extended mission components: the extrasolar planet observations, called Extrasolar Planet Observations and Characterization (EPOCh), and the flyby of comet Hartley 2, called the Deep Impact Extended Investigation (DIXI). The spacecraft will continue to be referred to as "Deep Impact."
NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the EPOXI mission for NASA's Science Mission Directorate, Washington. The University of Maryland, College Park, is home to the mission's principal investigator, Michael A'Hearn. Drake Deming of NASA's Goddard Space Flight Center, Greenbelt, Md., is the science lead for the mission's extrasolar planet observations. The spacecraft was built for NASA by Ball Aerospace & Technologies Corp., Boulder, Colo.
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-317
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Ice currently covers more than 10 percent of our watery planet, yet its volume is continuing to decline at a staggering pace in response to our warming world. A new NASA interactive tool lets you take a close-up tour of some of the places around our planet where climate change is taking a toll on Earth’s ice cover, including:
• Greenland, where the massive Ilulissat Glacier is depositing 35 to 50 cubic kilometers of icebergs into the ocean each year, raising sea level (a cubic kilometer is about 264.2 billion gallons, enough to fill 400,000 Olympic-size pools)
• The Arctic, where sea ice continues to decline in both area and volume
• Antarctica, where massive ice shelves the size of some small U.S. states have collapsed in recent years
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-315
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“For some decades we’ve known that the large amount of greenhouse gases in the atmosphere of Venus cause the extreme heat we observe presently,” explains Lena Noack from the German Aerospace Center (DLR) in Berlin, lead author of the study.
“The carbon dioxide and other greenhouse gases that are responsible for the high temperatures were blown into the atmosphere by thousands of volcanoes in the past. The permanent heat -- today we measure almost 470 degrees Celsius globally on Venus -- might even have been much higher in the past and, in a runaway cycle, led to even more volcanism. But at a certain point this process turned on its head -- the high temperatures caused a partial mobilization of the Venusian crust, leading to an efficient cooling of the mantle, and the volcanism strongly decreased. This resulted in lower surface temperatures, rather comparable to today’s temperature on Venus, and the mobilization of the surface stopped.”
The source of the magma, or molten rocky material, and the volcanic gases lies deep in the mantle of Venus. The decay of radioactive elements, inherited from the building blocks of the Solar System’s planets, and the heat stored in the interior from planet formation produce enough heat to generate partial melts of silicate-, iron- and magnesium-rich magma in the upper mantle. Molten rock has more volume and is lighter than the surrounding solid rock of identical composition. The magma therefore can rise upwards and eventually penetrate through the rigid crust in volcanic vents, spreading lava over the surface and blowing gases into the atmosphere, mostly greenhouse gases like carbon dioxide (CO2), water vapor (H2O) and sulphur dioxide (SO2).
However, the more greenhouse gases, the hotter the atmosphere -- possibly leading to even more volcanism. To find out if this runaway process would end in a red-hot Venus, Lena Noack and Doris Breuer, co-author of the study, calculated for the first time a model where the hot atmosphere is ‘coupled’ to a 3D model of the planet’s interior. Unlike here on Earth, the high temperatures have a much bigger effect at the interface with the rocky surface, heating it up to a large extent.
“Interestingly, due to the rising surface temperatures, the surface is mobilized and the insulating effect of the crust diminishes,” says Noack. “The mantle of Venus loses much of its thermal energy to the outside. It’s a little bit like lifting the lid on the mantle: the interior of Venus suddenly cools very efficiently and the rate of volcanism ceases. Our model shows that after that ‘hot’ era of volcanism, the slow-down of volcanism leads to a strong decrease of the temperatures in the atmosphere.”
The calculations of the geophysicists yield another interesting result: the process of volcanic resurfacing takes place at different places at different times. When the atmosphere cools, the mobilization of the surface stops. However, there are still a few active volcanoes which resurface some spots with lava flows. Some volcanoes might be active even today, which fits recent results from the European Space Agency’s Venus Express mission. This detected ‘hot spots’, or unusual high surface temperatures at volcanoes previously thought to be extinct. So far no ‘smoking gun’, or active volcano has been identified on Venus -- but it seems not unlikely that Venus Express or future space probes will detect the first active volcano on Earth’s next neighbor.
Venus and Earth: Twins in the Solar System with Quite Different Characters
Earth and its inner neighbor Venus are sometimes called ‘sister planets’ in the solar system: they are about the same size and mass, and both planets orbit at a somewhat comparable distance to the Sun.
However, scientists have been wondering for decades why both planets developed quite differently:
* Here, our ‘blue marble,’ the Earth, has a treasure of water harboring life. The molecule H2O is very bond-friendly to ions of other atoms or molecules.
* There, a hellish Venus has no liquid water at the surface, where it is just too hot. Venus is shrouded with thick, hot and dynamical skies of carbon dioxide where clouds of sulphuric acid prevent any glimpse of the surface from outside. It was Venus where we learned how the greenhouse effect works: solar energy reemitted from the surface is absorbed by greenhouse gases like CO2, raising the atmosphere’s temperature. Though the same process takes place on Earth, it has a much smaller dimension here than on Venus.
The fact that on Venus there is no liquid water present at all shows that something happened differently when these apparent twins formed about 4.5 billion years ago. From radar observations we have a complete survey of the surface features of Venus. They show us that thousands of volcanoes seem to have reshaped most of the surface of the planet, which is on average about 500 million years old.
For more information visit http://www.astrobio.net/pressrelease/3625/venus-hot-outside-cool-inside
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The Soyuz TMA-18 spacecraft is seen as it lands with Expedition 24 Commander Alexander Skvortsov and Flight Engineers Tracy Caldwell Dyson and Mikhail Kornienko near the town of Arkalyk, Kazakhstan on Saturday, Sept. 25, 2010. Russian Cosmonauts Skvortsov and Kornienko and NASA Astronaut Caldwell Dyson, are returning from six months onboard the International Space Station where they served as members of the Expedition 23 and 24 crews.
For more information visit http://www.nasa.gov/multimedia/imagegallery/image_feature_1767.html
A new movie and images showing Saturn's shimmering aurora over a two-day period are helping scientists understand what drives some of the solar system's most impressive light shows.
The movie and images are part of a new study that, for the first time, extracts auroral information from the entire catalogue of Saturn images taken by the visual and infrared mapping spectrometer instrument (VIMS) aboard NASA's Cassini spacecraft. These images and preliminary results are being presented by Tom Stallard, lead scientist on a joint VIMS and Cassini magnetometer collaboration, at the European Planetary Science Congress in Rome on Friday, Sept. 24.
In the movie, the aurora phenomenon clearly varies significantly over the course of a Saturnian day, which lasts around 10 hours 47 minutes. On the noon and midnight sides (left and right sides of the images, respectively), the aurora can be seen to brighten significantly for periods of several hours, suggesting the brightening is connected with the angle of the sun. Other features can be seen to rotate with the planet, reappearing at the same time and the same place on the second day, suggesting that these are directly controlled by the orientation of Saturn's magnetic field.
"Saturn's auroras are very complex and we are only just beginning to understand all the factors involved," Stallard said. "This study will provide a broader view of the wide variety of different auroral features that can be seen, and will allow us to better understand what controls these changes in appearance."
Auroras on Saturn occur in a process similar to Earth's northern and southern lights. Particles from the solar wind are channeled by Saturn's magnetic field toward the planet's poles, where they interact with electrically charged gas (plasma) in the upper atmosphere and emit light. At Saturn, however, auroral features can also be caused by electromagnetic waves generated when the planet's moons move through the plasma that fills Saturn's magnetosphere.
Previous data from Cassini have contributed to a number of detailed snapshots of the aurora. But understanding the overall nature of the auroral region requires a huge number of observations, which can be difficult because Cassini observation time close to Saturn is in high demand, Stallard said.
However, VIMS observations of numerous other scientific targets also include auroral information. Sometimes the aurora can be clearly seen, but sometimes Stallard and colleagues add multiple images together to produce a signal. This wide set of observations allows Cassini scientists to understand the aurora in general, rather than the beautiful specific cases that dedicated auroral observations allow, Stallard said.
Stallard and his colleagues have investigated about 1,000 images from the 7,000 that VIMS has taken to date of Saturn's auroral region.
The new, false-color images show Saturn's aurora glowing in green around the planet's south pole. The auroral information in the two images was extracted from VIMS data taken on May 24, 2007, and Nov. 1, 2008. The video covers about 20 Earth hours of VIMS observations, from Sept. 22 and 23, 2007.
"Detailed studies like this of Saturn's aurora help us understand how they are generated on Earth and the nature of the interactions between the magnetosphere and the uppermost regions of Saturn's atmosphere," said Linda Spilker, Cassini project scientist, based at NASA's Jet Propulsion Laboratory, Pasadena, Calif.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The visual and infrared mapping spectrometer team is based at the University of Arizona, Tucson. Stallard's work on Saturn's auroras is funded by the Science and Technologies Facilities Council, Swindon, U.K.
For more information visit http://www.nasa.gov/mission_pages/cassini/whycassini/cassini20100923.html
Karl had maximum sustained winds of 115 mph when it made landfall on Friday afternoon, Sept. 17. That made Karl a Category three hurricane on the Saffir-Simpson scale, and a major hurricane to boot.
On that day, NASA's Genesis and Rapid Intensification Processes (GRIP) aircraft were flying over Karl and taking readings of the storm's winds, temperature, pressure and more. The DC-8 aircraft was one of the planes that flew into Karl at an altitude of 37,000 feet on the afternoon of Friday, Sept. 17, about 3 hours after Hurricane Karl made landfall in Mexico. The DC-8 aircraft took off from its base in Fort Lauderdale, Fla. All nine instruments installed on the DC-8 collected data during its flight over the storm system, and dropsondes were launched successfully to aid the other instruments in gauging wind profiles and moisture content.
Meanwhile, NASA's WB-57 took off from its base in Houston, Texas and joined the DC-8 for flights over Hurricane Karl in mid-afternoon on Sept. 17. The WB-57 flew higher than the DC-8 aircraft, at an altitude between 56,000 and 58.000 feet. The WB-57 has two instruments aboard to study tropical cyclones: the Advanced Microwave Precipitation Radiometer (AMPR) and the HIRAD (Hurricane Imaging Radiometer). AMPR studies rain cloud systems, but are also useful to studies of various ocean and land surface processes. The HIRAD measures strong ocean surface winds through heavy rain, providing information on both rain rate and wind speed. For more information on the NASA GRIP Mission, visit: www.nasa.gov/grip.
From its vantage point in space, NASA's Aqua satellite captured a much wider view of Hurricane Karl after it made landfall on Sept. 17. The Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on Aqua captured a visible image at 19:35 UTC (3:35 p.m. EDT) and showed that two-thirds of Karl was already over land.
Karl's heavy rainfall was responsible for inland flooding and evacuations. Reports indicated that almost half a million people were without electricity, and over 20,000 homes were damaged or flooded. Over 40,000 people were evacuated from the municipalities of Jamapa, La Antigua, Medellin de Bravo, Cotaxtla and Actopanm. Reports indicated eight people missing and seven dead from Karl's rampage.
By Saturday morning, Sept. 18, Karl's maximum sustained winds were down to 25 mph. By Sunday, Sept. 19, the National Hurricane Center in Miami, Fla. proclaimed that Karl had dissipated over inland Mexico.
For more information visit http://www.nasa.gov/mission_pages/hurricanes/missions/grip/news/NASAStudiedKarl.html
Images that NASA's Mars Exploration Rover Opportunity took at the end of an 81-meter (266-foot) drive on Sept. 16 reveal a dark rock about 31 meters (102 feet) away. The rover's science team has decided to go get a closer look at the toaster-sized rock and determine whether it is an iron meteorite.
"The dark color, rounded texture and the way it is perched on the surface all make it look like an iron meteorite," said science-team member Matt Golombek of NASA's Jet Propulsion Laboratory, Pasadena, Calif. Opportunity has found four iron meteorites during the rover's exploration of the Meridiani Planum region of Mars since early 2004. Examination of these rocks has provided information about the Martian atmosphere, as well as the meteorites themselves.
The newfound rock has been given the informal name "Oileán Ruaidh" (pronounced ay-lan ruah), which is the Gaelic name for an island off the coast of northwestern Ireland. The rock is about 45 centimeters (18 inches) wide from the angle at which it was first seen.
Opportunity has driven 23.3 kilometers (14.5 miles) on Mars. The drive to this rock will take the total combined distance driven by Opportunity and its twin, Spirit, to more than 31 kilometers (19.26 miles).
JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover mission for the NASA Science Mission Directorate, Washington. Opportunity landed on Mars in January 2004 for what was planned as a three-month mission.
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-309
NASA's Mars Reconnaissance Orbiter resumed observing Mars with its science instruments on Sept. 18, recovering from an unplanned reboot of its computer three days earlier.
The reboot put the orbiter into a precautionary standby called "safe mode" on Sept. 15. The event appears to have been similar to one the orbiter last experienced on Aug. 26, 2009. For 10 months prior to this latest reboot, the spacecraft operated normally, making science observations and returning data.
The Mars Reconnaissance Orbiter, at Mars since 2006, has met the mission's science goals and returned more data than all other Mars missions combined. It completed its primary science phase of operations in November 2008, but continues to observe Mars both for science and for support of future missions that will land on Mars.
The Mars Reconnaissance Orbiter mission is managed by NASA's Jet Propulsion Laboratory in Pasadena, Calif. Caltech manages JPL for NASA.
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-307
NASA has announced the awards for the NASA Launch Services (NLS) II Contract. The award will provide a broad range of launch services for NASA’s planetary, Earth-observing, exploration and scientific satellites.
NASA has the ability to order a maximum of 70 launch services missions with a maximum cumulative potential contract value of $15 billion. The NLS II contracts are multiple award indefinite delivery/indefinite quantity, spanning a 10-year period.
NASA selected four companies for awards: Lockheed Martin Space Systems Company of Denver; Orbital Sciences Corporation of Dulles, Va.; Space Exploration Technologies of Hawthorne, Calif.; and United Launch Services, LLC of Littleton, Colo.
The NLS contracts provide for a minimum capability of delivering agency payloads weighing approximately 550 pounds or more to a minimum 124-mile-high circular orbit with a launch inclination of 28.5 degrees. The launch service provider also may offer a range of vehicles to NASA to meet higher payload weight and orbit requirements. In addition, there is an annual opportunity for additional providers and incumbents to submit proposals introducing launch services not available at the time of award, if they meet the minimum contract requirements.
The NLS II contracts support the goals and objectives of the agency's Science Mission Directorate, Space Operations Mission Directorate and Exploration Systems Mission Directorate. Under the contract, NASA also will provide launch services to other government agencies, such as the National Oceanic and Atmospheric Administration.
NASA's Launch Services Program Office at the Kennedy Space Center in Florida is responsible for program management.
For more information visit http://www.nasa.gov/home/hqnews/2010/sep/C10-053_Launch_Services_Contract.html
The moon was bombarded by two distinct populations of asteroids or comets in its youth, and its surface is more complex than previously thought, according to new results from NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft featured in three papers appearing in the Sept. 17 issue of Science.
In the first paper, lead author James Head of Brown University in Providence, R.I., describes results obtained from a detailed global topographic map of the moon created using LRO's Lunar Orbiter Laser Altimeter (LOLA). "Our new LRO LOLA dataset shows that the older highland impactor population can be clearly distinguished from the younger population in the lunar 'maria' -- giant impact basins filled with solidified lava flows," says Head. "The highlands have a greater density of large craters compared to smaller ones, implying that the earlier population of impactors had a proportionally greater number of large fragments than the population that characterized later lunar history."
Meteorite impacts can radically alter the history of a planet. The moon, Mars, and Mercury all bear scars of ancient craters hundreds or even thousands of miles across. If Earth was subjected to this assault as well -- and there's no reason to assume our planet was spared -- these enormous impacts could have disrupted the initial origin of life. Large impacts that occurred later appear to have altered life's evolution. The approximately 110-mile-diameter, partially buried crater at Chicxulub, in the Yucatan Peninsula of Mexico, is from an impact about 65 million years ago that is now widely believed to have led or contributed to the demise of the dinosaurs and many other lifeforms.
Scientists trying to reconstruct the meteorite bombardment history of Earth face difficulty because impact craters are eroded by wind and water, or destroyed by the action of plate tectonics, the gradual movement and recycling of the Earth's crust. However, a rich record of craters is preserved on the moon, because it has only an extremely thin atmosphere – a vacuum better than those typically used for experiments in laboratories on Earth. The moon’s surface has no liquid water and no plate tectonics. The only source of significant erosion is other impacts.
"The moon is thus analogous to a Rosetta stone for understanding the bombardment history of the Earth," said Head. "Like the Rosetta stone, the lunar record can be used to translate the 'hieroglyphics' of the poorly preserved impact record on Earth."
Even so, previous lunar maps had different resolutions, viewing angles, and lighting conditions, which made it hard to consistently identify and count craters. Head and his team used the LOLA instrument on board LRO to build a map that highlights lunar craters with unprecedented clarity. The instrument sends laser pulses to the lunar surface, measures the time that it takes for them to reflect back to the spacecraft, and then with a very precise knowledge of the orbit of the LRO spacecraft, scientists can convert this information to a detailed topographic map of the moon, according to Head.
Objects hitting the moon can be categorized in different “impactor populations,” where each population has its own set of characteristics. Head also used the LOLA maps to determine the time when the impactor population changed. "Using the crater counts from the different impact basins and examining the populations making up the superposed craters, we can look back in time to discover when this transition in impactor populations occurred. The LRO LOLA impact crater database shows that the transition occurred about the time of the Orientale impact basin, about 3.8 billion years ago. The implication is that this change in populations occurred around the same time as the large impact basins stopped forming, and raises the question of whether or not these factors might be related. The answers to these questions have implications for the earliest history of all the planets in the inner solar system, including Earth," says Head.
In the other two Science papers, researchers describe how data from the Diviner Lunar Radiometer Experiment instrument on LRO are showing that the geologic processes that forged the lunar surface were complex as well. The data have revealed previously unseen compositional differences in the crustal highlands, and have confirmed the presence of anomalously silica-rich material in five distinct regions.
Every mineral, and therefore every rock, absorbs and emits energy with a unique spectral signature that can be measured to reveal its identity and formation mechanisms. For the first time ever, LRO's Diviner instrument is providing scientists with global, high-resolution infrared maps of the moon, which are enabling them to make a definitive identification of silicate minerals commonly found within its crust. "Diviner is literally viewing the moon in a whole new light," says Benjamin Greenhagen of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., lead author of one of the Diviner Science papers.
Lunar geology can be roughly broken down into two categories – the anorthositic highlands, rich in calcium and aluminium, and the basaltic maria, which are abundant in iron and magnesium. Both of these crustal rocks are what’s deemed by geologists as 'primitive'; that is, they are the direct result of crystallization from lunar mantle material, the partially molten layer beneath the crust.
Diviner’s observations have confirmed that most lunar terrains have spectral signatures consistent with compositions that fall into these two broad categories. However they have also revealed that the lunar highlands may be less homogenous than previously thought.
In a wide range of terrains, Diviner revealed the presence of lunar soils with compositions more sodium rich than that of the typical anorthosite crust. The widespread nature of these soils reveals that there may have been variations in the chemistry and cooling rate of the magma ocean which formed the early lunar crust, or they could be the result of secondary processing of the early lunar crust.
Most impressively, in several locations around the moon, Diviner has detected the presence of highly silicic minerals such as quartz, potassium-rich, and sodium-rich feldspar - minerals that are only ever found in association with highly evolved lithologies (rocks that have undergone extensive magmatic processing).
The detection of silicic minerals at these locations is a significant finding for scientists, as they occur in areas previously shown to exhibit anomalously high abundances of the element thorium, another proxy for highly evolved lithologies.
"The silicic features we've found on the moon are fundamentally different from the more typical basaltic mare and anorthositic highlands," says Timothy Glotch of Stony Brook University in Stony Brook, N.Y., lead author of the second Diviner Science paper. "The fact that we see this composition in multiple geologic settings suggests that there may have been multiple processes producing these rocks."
One thing not apparent in the data is evidence for pristine lunar mantle material, which previous studies have suggested may be exposed at some places on the lunar surface. Such material, rich in iron and magnesium, would be readily detected by Diviner.
However, even in the South Pole Aitken Basin (SPA), the largest, oldest, and deepest impact crater on the moon -- deep enough to have penetrated through the crust and into the mantle -- there is no evidence of mantle material.
The implications of this are as yet unknown. Perhaps there are no such exposures of mantle material, or maybe they occur in areas too small for Diviner to detect.
However it's likely that if the impact that formed this crater did excavate any mantle material, it has since been mixed with crustal material from later impacts inside and outside SPA. "The new Diviner data will help in selecting the appropriate landing sites for potential future robotic missions to return samples from SPA. We want to use these samples to date the SPA-forming impact and potentially study the lunar mantle, so it's important to use Diviner data to identify areas with minimal mixing," says Greenhagen.
The research was funded by NASA's Exploration Systems Missions Directorate at NASA Headquarters in Washington. LRO was built and is managed by NASA's Goddard Space Flight Center in Greenbelt, Md. LOLA was built by NASA Goddard. David E. Smith from the Massachusetts Institute of Technology and NASA Goddard is the LOLA principal investigator. The Diviner instrument was built and is managed by NASA’s Jet Propulsion Laboratory in Pasadena, Calif. UCLA is the home institution of Diviner’s principal investigator, David Paige.
For more information visit http://www.nasa.gov/mission_pages/LRO/news/turbulent-youth.html
Mars Science Laboratory, aka Curiosity, is part of NASA's Mars Exploration Program, a long-term program of robotic exploration of the Red Planet. The mission is scheduled to launch from Cape Canaveral, Fla., in late 2011, and arrive at an intriguing region of Mars in August 2012. The goal of Curiosity, a rolling laboratory, is to assess whether Mars ever had an environment capable of supporting microbial life and conditions favorable for preserving clues about life, if it existed. This will help us better understand whether life could have existed on the Red Planet and, if so, where we might look for it in the future.
- How Big Is It?: The Mini Cooper-sized rover is much bigger than its rover predecessors, Spirit, Opportunity and Pathfinder. Curiosity is twice as long (about 2.8 meters, or 9 feet) and four times as heavy as Spirit and Opportunity, which landed in 2004. Pathfinder, about the size of a microwave oven, landed in 1997.
- Landing--Where and How: In November 2008, possible landing sites were narrowed to four finalists, all linked to ancient wet conditions. NASA will select a site believed to be among the most likely places to hold a geological record of a favorable environment for life. The site must also meet safe-landing criteria. The landing system is similar to a sky crane heavy-lift helicopter. After a parachute slows the rover's descent toward Mars, a rocket-powered backpack will lower the rover on a tether during the final moments before landing. This method allows landing a very large, heavy rover on Mars (instead of the airbag landing systems of previous Mars rovers). Other innovations enable a landing within a smaller target area than previous Mars missions.
- Toolkit: Curiosity will use 10 science instruments to examine rocks, soil and the atmosphere. A laser will vaporize patches of rock from a distance, and another instrument will search for organic compounds. Other instruments include mast-mounted cameras to study targets from a distance, arm-mounted instruments to study targets they touch, and deck-mounted analytical instruments to determine the composition of rock and soil samples acquired with a powdering drill and a scoop.
- Big Wheels: Each of Curiosity's six wheels has an independent drive motor. The two front and two rear wheels also have individual steering motors. This steering allows the rover to make 360-degree turns in-place on the Mars surface. The wheels' diameter is double the wheel diameter on Spirit and Opportunity, which will help Curiosity roll over obstacles up to 75 centimeters (30 inches) high.
- Rover Power: A nuclear battery will enable Curiosity to operate year-round and farther from the equator than would be possible with only solar power.
For more information visit http://www.nasa.gov/mission_pages/msl/msl5things20100916.html
Data from the Multi-angle Imaging Spectroradiometer (MISR) instrument on NASA's Terra spacecraft have been used in a groundbreaking new university study that examines the concentration, distribution and composition of aerosol pollution over the Indian subcontinent. The study documents the region's very high levels of natural and human-produced pollutants, and uncovered surprising seasonal shifts in the source of the pollution.
Larry Di Girolamo and postdoctoral scientist Sagnik Dey of the University of Illinois, Champaign, used a decade's worth of MISR data to comprehensively analyze aerosol pollution over the Indian subcontinent. This densely populated region has poor air quality and lacks on-the-ground pollution monitoring sites. The study was published recently in the Journal of Geophysical Research.
Aerosols - tiny particles suspended in the air - are produced both by natural sources, such as dust and pollen carried on the wind, and by human activities, such as soot and other hydrocarbons released from the burning of fossil fuels. They can affect the environment and human health, causing a range of respiratory problems. Aerosol pollution levels can be measured on the ground, but only the most developed countries have widespread sensor data.
Since standard satellite imaging cannot measure aerosols over land, Di Girolamo and Dey used NASA's MISR, developed and managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif. MISR's unique multi-view design allows researchers to differentiate surface variability from the atmosphere so they can observe and quantitatively measure particles in the air. MISR not only measures the amount of aerosols, but can also distinguish between natural and human-produced particles.
The scientists found very high levels of both natural and human-produced aerosol pollutants. The level of atmospheric pollution across most of the country was two to five times higher than World Health Organization guidelines.
But the study also revealed some surprising trends. For example, the researchers noticed consistent seasonal shifts in human-produced versus natural aerosols. Before monsoon season begins, the winds over the Indian subcontinent shift, blowing inland instead of out to sea. These winds carry immense amounts of dust from Africa and the Arabian Peninsula to India, degrading air quality.
"Just before the rains come, the air gets really polluted, and for a long time everyone blamed the dust," Di Girolamo said, "but MISR has shown that not only is there an influx of dust, there's also a massive buildup of man-made pollutants that's hidden within the dust."
During monsoon season, rains wash some of the dust and soot from the air, but other human-produced pollutants continue to build up. After monsoon season, dust transport is reduced, but human-produced pollutant levels skyrocket, as biomass burning and the use of diesel-fueled transportation soar. During winter, seaward-blowing breezes disperse all the pollutants across the subcontinent and out to sea, where they remain until the pre-monsoon winds blow again.
"We desperately needed these observations to help validate our atmospheric models," said Di Girolamo. "We're finding that in a complex area like India, we have a long way to go. But these observations help give us some guidance."
As MISR continues to collect worldwide aerosol data, Di Girolamo says atmospheric scientists will continue to refine models for India and other areas and begin to propose new regulatory measures. The MISR data may also reveal trends in aerosol concentration over time, which can be compared with climate and health data.
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-299
Giant planet GJ 436b in the constellation Leo is missing something--and that something is swamp gas.
To the surprise of astronomers who have been studying the Neptune-sized planet using NASA's Spitzer Space Telescope, GJ 436b has very little methane--an ingredient common to many planets in our own solar system. This artist's concept shows the unusual, methane-free world partially eclipsed by its star.
Models of planetary atmospheres indicate that any world with the common mix of hydrogen, carbon and oxygen, and a temperature up to 1,000 Kelvin (1,340 degrees Fahrenheit) should have a large amount of methane and a small amount of carbon monoxide. But at about 800 Kelvin (or 980 degrees Fahrenheit), GJ 436b it does not. The finding demonstrates the diversity of exoplanets and the need for further study.
For more information visit http://www.nasa.gov/multimedia/imagegallery/image_feature_1759.html
The rover Curiosity, which NASA's Mars Science Laboratory mission will place on Mars in August 2012, has been rolling over ramps in a clean room at NASA's Jet Propulsion Laboratory to test its mobility system.
Curiosity uses the same type of six-wheel, rocker-bogie suspension system as previous Mars rovers, for handling uneven terrain during drives. Its wheels are half a meter (20 inches) in diameter, twice the height of the wheels on the Spirit and Opportunity rovers currently on Mars.
Launch of the Mars Science Laboratory is scheduled for 2011 during the period from Nov. 25 to Dec. 18. The mission is designed to operate Curiosity on Mars for a full Martian year, which equals about two Earth years.
A public lecture by Mars Science Laboratory Chief Scientist John Grotzinger, of the California Institute of Technology in Pasadena, will take place at JPL on Thursday, Sept. 16, beginning at 7 p.m. PDT Time (10 p.m. EDT).
JPL, a division of Caltech, manages the Mars Science Laboratory Project for the NASA Science Mission Directorate, Washington.
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-297
As NASA studies possibilities for the next launcher to the stars, a team of engineers from Kennedy Space Center and several other field centers are looking for a system that turns a host of existing cutting-edge technologies into the next giant leap spaceward.
An early proposal has emerged that calls for a wedge-shaped aircraft with scramjets to be launched horizontally on an electrified track or gas-powered sled. The aircraft would fly up to Mach 10, using the scramjets and wings to lift it to the upper reaches of the atmosphere where a small payload canister or capsule similar to a rocket's second stage would fire off the back of the aircraft and into orbit. The aircraft would come back and land on a runway by the launch site.
Engineers also contend the system, with its advanced technologies, will benefit the nation's high-tech industry by perfecting technologies that would make more efficient commuter rail systems, better batteries for cars and trucks, and numerous other spinoffs.
It might read as the latest in a series of science fiction articles, but NASA's Stan Starr, branch chief of the Applied Physics Laboratory at Kennedy, points out that nothing in the design calls for brand-new technology to be developed. However, the system counts on a number of existing technologies to be pushed forward.
"All of these are technology components that have already been developed or studied," Starr said. "We're just proposing to mature these technologies to a useful level, well past the level they've already been taken."
For example, electric tracks catapult rollercoaster riders daily at theme parks. But those tracks call for speeds of a relatively modest 60 mph -- enough to thrill riders, but not nearly fast enough to launch something into space. The launcher would need to reach at least 10 times that speed over the course of two miles in Starr's proposal.
The good news is that NASA and universities already have done significant research in the field, including small-scale tracks at NASA's Marshall Space Flight Center in Huntsville, Ala., and at Kennedy. The Navy also has designed a similar catapult system for its aircraft carriers.
As far as the aircraft that would launch on the rail, there already are real-world tests for designers to draw on. The X-43A, or Hyper-X program, and X-51 have shown that scramjets will work and can achieve remarkable speeds.
The group sees NASA's field centers taking on their traditional roles to develop the Advanced Space Launch System. For instance, Langley Research Center in Virginia, Glenn Research Center in Ohio and Ames Research Center in California would work on different elements of the hypersonic aircraft. Dryden Research Center in California, Goddard Space Flight Center in Maryland and Marshall would join Kennedy in developing the launch rail network. Kennedy also would build a launch test bed, potentially in a two-mile long area parallel to the crawlerway leading to Launch Pad 39A.
Because the system calls for a large role in aeronautic advancement along with rocketry, Starr said, "essentially you bring together parts of NASA that aren't usually brought together. I still see Kennedy's core role as a launch and landing facility."
The Advanced Space Launch System is not meant to replace the space shuttle or other program in the near future, but could be adapted to carry astronauts after unmanned missions rack up successes, Starr said.
The studies and development program could also be used as a basis for a commercial launch program if a company decides to take advantage of the basic research NASA performs along the way. Starr said NASA's fundamental research has long spurred aerospace industry advancement, a trend that the advanced space launch system could continue.
For now, the team proposed a 10-year plan that would start with launching a drone like those the Air Force uses. More advanced models would follow until they are ready to build one that can launch a small satellite into orbit.
A rail launcher study using gas propulsion already is under way, but the team is applying for funding under several areas, including NASA's push for technology innovation, but the engineers know it may not come to pass. The effort is worth it, however, since there is a chance at revolutionizing launches.
"It's not very often you get to work on a major technology revolution," Starr said.
For more information visit http://www.nasa.gov/topics/technology/features/horizontallaunch.html
From farmers to government officials in charge of efficiently managing Earth's precious water and energy resources, people all over the world rely on accurate short-term climate forecasts on timescales ranging from a few weeks to a few years to make more informed decisions. But today's climate forecast systems have limited ability to operate on such timescales. That's because it's difficult to realistically represent the complex interactions between Earth's ocean, atmosphere and land surface in the climate models from which forecasts are developed.
A new report by the National Academy of Sciences looks at the current state of these climate predictions and recommends strategies and best practices for improving them. Duane Waliser, chief Earth scientist at NASA's Jet Propulsion Laboratory, Pasadena, Calif., was on the 12-member panel that conducted the NOAA-requested study.
Among the report's key recommendations:
- Continue research to better understand and use information from key sources of climate predictability, and interactions between the ocean and atmosphere, atmosphere and land, as well as volcanic eruptions, greenhouse gases and land use changes.
- Improve the basic building blocks of climate forecasts through better physical climate models, making more sustained physical observations, better incorporating observations into forecast systems, and increasing collaboration between forecast agencies and stakeholders in developing and implementing forecast strategies.
- Adopt best practices such as working more closely with research communities, particularly universities; making data that feed into and come out of forecasts publicly available; minimizing subjective forecast components; and using forecast metrics that better convey to the public the probability aspects of forecasts.
Waliser contributed his expertise in a phenomenon called the Madden-Julian Oscillation that exerts a powerful influence on short-term climate predictions. During this type of climate pattern, unusual variations of clouds, rainfall and large-scale atmospheric circulation move slowly eastward from the tropical Indian Ocean into the Pacific Ocean over the course of weeks, ebbing and flowing like waves in cycles lasting about 40 to 50 days. This climate pattern typically spans more than half the distance around Earth's equator. In the disturbed portion of the "wave," air rises, triggering showers and thunderstorms; in the sinking portion, air subsides, inhibiting clouds and rainfall.
Madden-Julian Oscillation events can strongly influence long-term weather patterns and have widespread impacts around the globe. They can help trigger the beginning and end of the Asian and Indian monsoons and influence the development and evolution of El Niño, hurricanes and weather in Earth's mid-latitudes. Scientists want to incorporate information about the oscillation more accurately into the climate models that agencies around the world use to predict weather and climate.
"Ten years ago, our ability to forecast Madden-Julian Oscillation events was very limited," said Waliser. "Today, numerous operational forecast centers around the world are recognizing the importance of forecasting the MJO and are beginning to provide useful forecast information about it. This information, in turn, can be used to make better forecasts of other weather and climate phenomena.
"This new report highlights the key shortcomings and strategies needed to make more accurate climate forecasts-- not just of the Madden-Julian Oscillation, but of intraseasonal to interannual climate forecasts in general," he added. The full report, called "Assessment of Intraseasonal to Interannual Climate Prediction and Predictability," can be read and downloaded at: http://nationalacademies.org/morenews/20100908.html .
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-295
When NASA's Mars Exploration Rover Opportunity left Victoria Crater two years ago this month, the rover science team chose Endeavour Crater as the rover's next long-term destination. With a drive of 111 meters (364 feet) on Monday, Sept. 8, Opportunity reached the estimated halfway point of the approximately 19-kilometer (11.8-mile) journey from Victoria to the western rim of Endeavour.
Opportunity completed its three-month prime mission on Mars in April 2004. During its bonus extended operations since then, it spent two years exploring in and around Victoria Crater. Victoria is about 800 meters (half a mile) in diameter. At about 22 kilometers (14 miles) in diameter, Endeavour is about 28 times wider. After the rover science team selected Endeavour as a long-term destination, observations of Endeavour's rim by NASA's Mars Reconnaissance Orbiter revealed the presence of clay minerals. This finding makes the site an even more compelling science destination. Clay minerals, which form exclusively under wet conditions, have been found extensively on Mars from orbit, but have not been examined on the surface.
JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover Project for the NASA Science Mission Directorate, Washington.
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-292
We've all heard this announcement on an airplane before: "Uh, folks, we've got some weather around the airport right now. So I expect we'll be circling probably for the next half hour or so." Heather Arneson, a NASA Aeronautics Scholarship recipient and doctoral student at the University of Illinois, spent her summer at NASA working on ways to better control flows of aircraft into airspace impacted by weather.
"Weather conditions in recent years have caused approximately 65 percent of delays," says Arneson. "When weather is present near in an airspace, the number of flight allowed to occupy that airspace becomes lower than normal. Current methods of scheduling and routing flights that might fly through airspace predicted to experience bad weather can excessively delay flights. I'm seeing how mathematical optimization and modeling techniques can help us use that space more efficiently and reduce delays caused by weather."
Heather's solution can react in real-time as the weather and capacity situation changes. At NASA's Ames Research Center in California this summer, she simulated her new traffic strategy to see how well it worked.
Join Heather on Thursday, September 9, at 3:00 p.m. EDT to chat about her experiences at NASA, about applying for the aeronautics scholarship, or even just about being an engineering student in today's competitive environment. To join the chat, simply visit this page on September 9. The chat window will open at the bottom of this page starting at 2:30 p.m. EDT. You can log in and be ready to ask questions at 3:00 p.m.
See you in chat!
More About Heather Arneson
Heather is working on her doctorate in aerospace engineering from the University of Illinois at Urbana-Champaign. She has a masters in that field already and a bachelors degree in mechanical and aerospace engineering from Cornell University. Originally from Rhode Island, Heather also worked for several years as a member of NASA's Mars Exploration Rover Panoramic Camera Team, using her engineering skills to help the team acquire images of the Martian landscape.
For more information visit http://www.nasa.gov/connect/chat/air_traffic_chat.html
Kennedy Space Center's Launch Equipment Test Facility, or LETF, is an engineer's paradise. Take huge fixtures capable of simulating launch conditions and a complex data system then add a machine shop and a welding facility, and you get a testbed up to the task of proving launch support equipment will work right every time.
A four-year comprehensive upgrade recently was completed to make sure the testing ground remains at the top of the support system testing pyramid.
Since 1977, the facility has supported NASA's Launch Services, shuttle, International Space Station, and Constellation programs, as well as commercial providers.
"We were continuing to satisfy customer requirements at the same time that we were doing the upgrades," said Pat Simpkins, the director of Kennedy's Engineering Directorate. "That's what is really fascinating about this facility."
On Aug. 27, a team from NASA, ASRC Aerospace and MTS Engineering Consulting Services celebrated the $35 million worth of upgrades.
"It plays a vital role in proof-of-concept testing, prototype testing and operations support," said Eric Ernst, LETF's upgrade project manager.
Pepper Phillips, director of Kennedy's Constellation Project Office, said the upgrade project is proof that "people can count on the Kennedy Space Center for executing what they promised."
Stepping outside the 40-foot-tall high bay doors is a steel playground, equipped with a 600-ton test fixture used for tension and compression testing, a water flow test loop that tests valves, pumps and flow meters, two launch simulation towers and two 15,000-gallon cryogenic towers.
"People who are experts in different areas of science come here, plan their tests months in advance, and I get to learn from them," said Geoffrey Rowe, an engineer with ASRC Aerospace. "It's much better than doing the same thing day-in-and-day-out."
Perhaps most impressive is the new vehicle motion simulator, or VMS, which simulates all of the movements a vehicle could experience from rollout to launch.
"It's like the Tower of Terror!" said Craig Technologies' Sandi Slaughter as she watched the simulator move up and down, right to left, and then around and around, similar to the amusement park ride at Disney's Hollywood Studios.
According to the engineers who work in the LETF, the possibilities for testing launch equipment are endless.
"We're looking forward to supporting multiple customers for NASA in the future," Ernst said. "Whether it's heavy-lift, horizontal launch systems or commercial providers . . . we really are a multifaceted facility that can support a broad spectrum of customers."
For more information visit http://www.nasa.gov/centers/kennedy/news/letf.html
Experiments prompted by a 2008 surprise from NASA's Phoenix Mars Lander suggest that soil examined by NASA's Viking Mars landers in 1976 may have contained carbon-based chemical building blocks of life.
"This doesn't say anything about the question of whether or not life has existed on Mars, but it could make a big difference in how we look for evidence to answer that question," said Chris McKay of NASA's Ames Research Center, Moffett Field, Calif. McKay coauthored a study published online by the Journal of Geophysical Research - Planets, reanalyzing results of Viking's tests for organic chemicals in Martian soil.
The only organic chemicals identified when the Viking landers heated samples of Martian soil were chloromethane and dichloromethane -- chlorine compounds interpreted at the time as likely contaminants from cleaning fluids. But those chemicals are exactly what the new study found when a little perchlorate -- the surprise finding from Phoenix -- was added to desert soil from Chile containing organics and analyzed in the manner of the Viking tests.
"Our results suggest that not only organics, but also perchlorate, may have been present in the soil at both Viking landing sites," said the study's lead author, Rafael Navarro-González of the National Autonomous University of Mexico, Mexico City.
Organics can come from non-biological or biological sources. Many meteorites raining onto Mars and Earth for the past 5 billion years contain organics. Even if Mars has never had life, scientists before Viking anticipated that Martian soil would contain organics from meteorites.
"The lack of organics was a big surprise from the Vikings," McKay said. "But for 30 years we were looking at a jigsaw puzzle with a piece missing. Phoenix has provided the missing piece: perchlorate. The perchlorate discovery by Phoenix was one of the most important results from Mars since Viking." Perchlorate, an ion of chlorine and oxygen, becomes a strong oxidant when heated. "It could sit there in the Martian soil with organics around it for billions of years and not break them down, but when you heat the soil to check for organics, the perchlorate destroys them rapidly," McKay said.
This interpretation proposed by Navarro-González and his four co-authors challenges the interpretation by Viking scientists that Martian organic compounds were not present in their samples at the detection limit of the Viking experiment. Instead, the Viking scientists interpreted the chlorine compounds as contaminants. Upcoming missions to Mars and further work on meteorites from Mars are expected to help resolve this question.
The Curiosity rover that NASA's Mars Science Laboratory mission will deliver to Mars in 2012 will carry the Sample Analysis at Mars (SAM) instrument provided by NASA Goddard Space Flight Center, Greenbelt, Md. In contrast to Viking and Phoenix, Curiosity can rove and thus analyze a wider variety of rocks and samples. SAM can check for organics in Martian soil and powdered rocks by baking samples to even higher temperatures than Viking did, and also by using an alternative liquid-extraction method at much lower heat. Combining these methods on a range of samples may enable further testing of the new report's hypothesis that oxidation by heated perchlorates that might have been present in the Viking samples was destroying organics.
One reason the chlorinated organics found by Viking were interpreted as contaminants from Earth was that the ratio of two isotopes of chlorine in them matched the three-to-one ratio for those isotopes on Earth. The ratio for them on Mars has not been clearly determined yet. If it is found to be much different than Earth's, that would support the 1970s interpretation.
If organic compounds can indeed persist in the surface soil of Mars, contrary to the predominant thinking for three decades, one way to search for evidence of life on Mars could be to check for types of large, complex organic molecules, such as DNA, that are indicators of biological activity. "If organics cannot persist at the surface, that approach would not be wise, but if they can, it's a different story," McKay said.
The Phoenix mission was led by Principal Investigator Peter H. Smith of the University of Arizona, Tucson, with project management at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Phoenix finding of perchlorate was reported by JPL's Michael Hecht and co-authors. JPL, a division of the California Institute of Technology, Pasadena, also manages Mars Science Laboratory for the NASA Exploration Missions Directorate, Washington.
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-286
NASA has begun development of a mission to visit and study the sun closer than ever before. The unprecedented project, named Solar Probe Plus, is slated to launch no later than 2018.
The small car-sized spacecraft will plunge directly into the sun's atmosphere approximately 6.4 million kilometers (four million miles) from our star's surface. It will explore a region no other spacecraft ever has encountered. NASA has selected five science investigations that will unlock the sun's biggest mysteries, including one led by a scientist from NASA's Jet Propulsion Laboratory, Pasadena, Calif.
"The experiments selected for Solar Probe Plus are specifically designed to solve two key questions of solar physics -- why is the sun's outer atmosphere so much hotter than the sun's visible surface and what propels the solar wind that affects Earth and our solar
system? " said Dick Fisher, director of NASA's Heliophysics Division in Washington. "We've been struggling with these questions for decades and this mission should finally provide those answers."
As the spacecraft approaches the sun, its revolutionary carbon-composite heat shield must withstand temperatures exceeding about 1,400 degrees Celsius (2,550 degrees Fahrenheit) and blasts of intense radiation. The spacecraft will have an up-close and personal view of the sun, enabling scientists to better understand, characterize and forecast the radiation environment for future space explorers.
NASA invited researchers in 2009 to submit science proposals. Thirteen were reviewed by a panel of NASA and outside scientists. The total dollar amount for the five selected investigations is approximately $180 million for preliminary analysis, design, development and tests.
The selected proposals are:
-- Solar Wind Electrons Alphas and Protons Investigation: principal investigator, Justin C. Kasper, Smithsonian Astrophysical Observatory in Cambridge, Mass.
This investigation will specifically count the most abundant particles in the solar wind -- electrons, protons and helium ions -- and measure their properties. The investigation also is designed to catch some of the particles in a special cup for direct analysis.
-- Wide-field Imager: principal investigator, Russell Howard, Naval Research Laboratory in Washington. This telescope will make 3-D images of the sun's corona, or atmosphere. The experiment actually will see the solar wind and provide 3-D images of clouds and shocks as they approach and pass the spacecraft. This investigation complements instruments on the spacecraft, providing direct measurements by imaging the plasma the other instruments sample.
-- Fields Experiment: principal investigator, Stuart Bale, University of California Space Sciences Laboratory in Berkeley, Calif. This investigation will make direct measurements of electric and magnetic fields, radio emissions, and shock waves that course through the
sun's atmospheric plasma. The experiment also serves as a giant dust detector, registering voltage signatures when specks of space dust hit the spacecraft's antenna.
-- Integrated Science Investigation of the Sun: principal investigator, David McComas of the Southwest Research Institute in San Antonio. This investigation consists of two instruments that will take an inventory of elements in the sun's atmosphere using a mass
spectrometer to weigh and sort ions in the vicinity of the spacecraft.
-- Heliospheric Origins with Solar Probe Plus: principal investigator, Marco Velli of JPL. Velli is the mission's observatory scientist, responsible for serving as a senior scientist on the science working group. He will provide an independent assessment of scientific performance and act as a community advocate for the mission.
"This project allows humanity's ingenuity to go where no spacecraft has ever gone before," said Lika Guhathakurta, Solar Probe Plus program scientist at NASA Headquarters, in Washington. "For the very first time, we'll be able to touch, taste and smell our sun."
The Solar Probe Plus mission is part of NASA's Living with a Star Program. The program is designed to understand aspects of the sun and Earth's space environment that affect life and society. The program is managed by NASA'S Goddard Space Flight Center in Greenbelt, Md., with oversight from NASA's Science Mission Directorate's Heliophysics Division. The Johns Hopkins University Applied Physics Laboratory in
Laurel, Md., is the prime contractor for the spacecraft.
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-284
With the peak of the 2010 Atlantic hurricane season still 10 days away, the relative calm of the first half of the season has quickly evaporated. As of Sept. 1, there were three named tropical cyclones in the Atlantic-Hurricane Earl and Tropical Storms Fiona and Gaston.
NASA satellites, instruments and researchers are hard at work, providing the National Oceanic and Atmospheric Administration and other agencies with many kinds of data used to help forecast and track these monster storms.
The NASA imagery presented here depicts Hurricane Earl, currently a Category Four hurricane on the Saffir-Simpson scale with maximum sustained winds of 115 knots (near 135 miles per hour), with higher gusts. As of 5 p.m. EDT on Sept. 1, Earl was located about 1,010 kilometers (630 miles) south-southeast of Cape Hatteras, N.C., moving to the northwest at 28 kilometers per hour (17 mph). Hurricane and tropical storm warnings and watches currently extend up the U.S. East Coast from North Carolina to Massachusetts. Hurricane force winds extend outward up to 150 kilometers (90 miles) from Earl's center, with tropical storm-force winds extending outward up to 325 kilometers (200 miles).
Earl is expected to continue to move northwest, and then make a gradual turn to the north on Thursday, Sept. 2. The core of Earl is expected to approach the North Carolina coast by late Thursday with hurricane-force winds. Tropical-storm-force winds are likely to reach the East Coast from Virginia northward to New Jersey by early Friday, Sept. 3. Earl is expected to fluctuate in intensity through Thursday, then gradually weaken.
Earl's storm surge will raise water levels by 1 to 1.5 meters (3 to 5 feet) above ground level within the hurricane watch level. Elsewhere, the storm surge will raise water levels by as much as 0.3 to 1 meter (1 to 3 feet) above ground level within the tropical storm warning area. The storm surge will be accompanied by large and destructive waves.
Rainfall accumulations of 5 to 10 centimeters (2 to 4 inches), with isolated amounts up to 15 centimeters (6 inches) are expected over parts of eastern North Carolina. Large surf swells will continue to affect the Bahamas and U.S. East Coast through Friday, bringing dangerous surf conditions and rip currents.
NASA imagery of Earl from various satellites and aircraft reveal many kinds of information about this impressive storm. Click here to view all related multimedia.
In Figure 1, the Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua satellite, built and managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., captured this infrared image of Earl on Sept. 1 at 1:53 p.m. EDT. The AIRS data create an accurate 3-D map of atmospheric temperature, water vapor and clouds, data that are useful to hurricane forecasters. The image shows the temperature of Earl's cloud tops or the surface of Earth in cloud-free regions. The coldest cloud-top temperatures appear in purple, indicating towering cold clouds and heavy precipitation. The infrared signal of AIRS does not penetrate through clouds. Where there are no clouds, AIRS reads the infrared signal from the surface of the ocean waters, revealing warmer temperatures in orange and red.
The view of the storm for AIRS' visible-light camera is seen in Figure 2.
Figure 3 is an animation created from data from NASA's CloudSat spacecraft, which flew over Hurricane Earl on Aug. 31, 2010, at 2:20 a.m. EDT, when the storm had maximum wind speeds of 115 kilometers (approximately 135 mph). At that time, there were three named storms in the Atlantic: Danielle, Earl and Fiona.
The animation begins by depicting global cloud motion for the 72 hours prior to CloudSat's observation of Earl, from NOAA's GOES satellites. It then zooms in to reveal the vertical cross-section of Earl from CloudSat. CloudSat intersected Earl's eastern edge as the hurricane was just beginning an eyewall replacement cycle, during which the outer eyewall band strengthened, while the inner eyewall began to shrink. CloudSat captured Earl's intense cumulonimbus clouds and eye, along with cloud-free regions known as "moats" that contain a thick cirrus cloud canopy between the storm's spiral rain bands. The storm's most intense convection and precipitation are depicted in shades of oranges and reds.
Figure 4 is from the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA's Terra spacecraft, captured at 11 a.m. EDT on Aug. 30, 2010, when Earl was a Category 3 storm on the Saffir-Simpson scale. The image (left panel) extends approximately 1,110 kilometers (690 miles) in the north-south direction and 380 kilometers (236 miles) in the east-west direction. The hurricane's eye is just visible on the right edge of the MISR image swath.
Winds at various altitudes were obtained by processing the data from five of MISR's nine cameras to produce the display shown on the right. The lengths of the arrows indicate the wind speeds, and their orientation shows wind direction. The altitude of a given wind vector is shown in color. Low clouds, less than 4 kilometers (2.5 miles) in altitude (shown in purple), follow the cyclonic (counter-clockwise) flow of air into the hurricane. This warm, moist air is the power source for the hurricane. Mid- and high-level clouds (green and yellow-orange, respectively) move in an anti-cyclonic (clockwise) direction as they flow out from the top of the storm. The very highest clouds, with altitudes around 17 kilometers (10.6 miles), are flowing directly away from the eye of the hurricane.
Figure 5 and Figure 6 were generated with data from NASA's Jason-1 and Ocean Surface Topography Mission (OSTM)/Jason-2 satellites. They depict Earl's wind speeds (top) and wave heights (bottom), respectively. The images were created by compositing three days of data from the two satellites' radar altimeters from Aug. 29 to Sept. 1.
NASA and JPL scientists are currently engaged in the agency's first major U.S.-based hurricane field campaign in nearly a decade. The Genesis and Rapid Intensification Processes mission, or GRIP, is studying hurricanes in the Atlantic and Gulf of Mexico. Three NASA aircraft carrying 15 instruments are being used, including the JPL-developed High-Altitude Monolithic Microwave Integrated Circuit Sounding Radiometer (HAMSR), which is flying aboard NASA's Global Hawk uninhabited aerial vehicle. The instrument infers the 3-D distribution of temperature, water vapor and cloud liquid water in the atmosphere. A second JPL instrument, the Airborne Precipitation Radar (APR-2), is a dual-frequency weather radar that is taking 3-D images of precipitation aboard NASA's DC-8 aircraft. Three NASA satellites are also playing a key role in supplying data about tropical cyclones during the mission, including the JPL- developed and managed CloudSat spacecraft and the Aqua spacecraft, which includes JPL's Atmospheric Infrared Sounder.
The DC-8, with JPL's APR-2 instrument, has already flown over Earl twice, with additional sorties planned for Sept. 1 and 2. NASA's Global Hawk is currently en route to Earl and is expected to fly over Earl for 10 to 12 hours on Sept. 2. The progress of NASA's GRIP aircraft can be followed in near-real-time when they are flying by visiting: http://grip.nsstc.nasa.gov/current_weather.html. "Click to start RTMM Classic" will download a KML file that displays in Google Earth.
Near-real-time images from HAMSR and APR-2 will be displayed on NASA's TC-IDEAS website, available at http://grip.jpl.nasa.gov. The website is a near-real-time tropical cyclone data resource developed by JPL to support the GRIP campaign. In collaboration with other institutions, it integrates data from satellites, models and direct measurements, from many sources, to help researchers quickly locate information about current and recent oceanic and atmospheric conditions. The composite images and data are updated every hour and are displayed using a Google Earth plug-in.
With a few mouse clicks, users can manipulate data and overlay multiple data sets to provide insights on storms that aren't possible by looking at single data sets alone. The data can be animated and downloaded on demand. TC-IDEAS is a component of JPL's Tropical Cyclone Information System (TCIS) website, located at: http://tropicalcyclone.jpl.nasa.gov/hurricane/. Researchers can use the TCIS to better understand hurricane processes, improve hurricane models and plan future satellite missions.
For more information visit http://www.jpl.nasa.gov/news/news.cfm?release=2010-282
My Friend's Blogroll
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- IBEX Finds Surprising Changes at Solar Boundary
- NASA's EPOXI Mission Sets Up for Comet Flyby
- Sentinels of Climate Change
- Venus Hot Outside, Cool Inside
- Expedition 24 Soyuz Landing
- New Views of Saturn's Aurora, Captured by Cassini
- NASA Satellites and Aircraft Studied Hurricane Kar...
- Mars Rover Opportunity Approaching Possible Meteor...
- Orbiter Resumes Science Observations
- NASA Awards Launch Services Contracts
- NASA's LRO Exposes Moon's Complex, Turbulent Youth...
- Five Things About NASA's Mars Curiosity Rover
- NASA Data Track Seasonal Pollution Changes Over In...
- This Planet Smells Funny
- NASA's Next Mars Rover Rolls Over Ramps
- Emerging Technologies May Fuel Revolutionary Launc...
- New Report Seeks to Improve Climate Forecasts
- Opportunity Rover Reaches Halfway Point of Long Tr...
- NASA Chat: Cheating the Weather to Improve On-Time...
- Launch Equipment Test Facility is Ready for New Bu...
- Missing Piece Inspires New Look at Mars Puzzle
- NASA Selects Investigations for First Sun Encounte...
- NASA Images Dissect Hurricane Earl
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