Posted on by Fraser Cain

Online Global Map of Forest Fires

Global map of forest fires. Image credit: ESA. Click to enlarge
ESA satellites have been keeping track of global forest fires for more than 10 years, and now this data is available online through ESA’s ATSR World Fire Atlas. More than 50 million hectares (123 million acres) of forests burn every year, and these fires make a signficant contribution to global pollution. By monitoring these fires, researchers can improve computer models to predict which regions are at greatest risk based on weather patterns.

For a decade now, ESA satellites have been continuously surveying fires burning across the Earth’s surface. Worldwide fire maps based on this data are now available to users online in near-real time through ESA’s ATSR World Fire Atlas.

The ATSR World Fire Atlas (WFA) – the first multi-year global fire atlas ever developed – provides data approximately six hours after acquisition and represents an important scientific resource because fire is a major agent of environmental change.

“The atlas is an excellent resource that provides a glimpse of the world that was not previously possible, and which is certain to allow ecologists to address both new and old questions regarding the role of fire in structuring the natural world,” Matt Fitzpatrick of the University of Tennessee’s Department of Ecology & Evolutionary Biology said.

More than 50 million hectares of forest are burnt annually, and these fires have a significant impact on global atmospheric pollution, with biomass burning contributing to the global budgets of greenhouse gases, like carbon dioxide. In the past decade researchers have realised the importance of monitoring this cycle. In fact, WFA data are currently being accessed mostly for atmospheric studies.

Quantifying fire is important for the ongoing study of climate change. The 1998 El Niño, for example, helped encourage fires across Borneo which emitted up to 2.5 billion tonnes of carbon into the atmosphere, equivalent to Europe’s entire carbon emissions that year.

There are over 200 registered users accessing the WFA. The data are being used in Europe, Asia, North America, South America, Africa and Australia for research in atmospheric chemistry, land use change, global change ecology, fire prevention and management and meteorology.

Harvard University, University of Toronto, National Centre for Atmosphere and NASA, among others, have used the data in research publications. To date, there are more than 100 scientific publications based on WFA data.

In addition to maps, the time, date, longitude and latitude of the hot spots are provided. The database covers 1995 to present, but complete yearly coverage begins from 1997.

The WFA data are based on results from the Along Track Scanning Radiometer (ATSR) on ESA’s ERS-2 satellite, launched in 1995, and the Advanced Along Track Scanning Radiometer (AATSR) on ESA’s Envisat satellite, launched in 2002.

These twin radiometer sensors work like thermometers in the sky, measuring thermal infrared radiation to take the temperature of Earth’s land surfaces. Fires are detected best during local night, when the surrounding land is cooler.

Temperatures exceeding 312º K (38.85 ºC) are classed as burning fires by ATSR/AATSR, which are capable of detecting fires as small as gas flares from industrial sites because of their high temperature.

The WFA is an internal and Data User Programme (DUP) project.

Original Source: ESA News Release

Posted on by Fraser Cain

SOHO Mission Extended Through 2009

Artist illustration of SOHO and the Sun. Image credit: ESA. Click to enlarge
NASA and ESA’s long-running Solar and Heliospheric Observatory (SOHO) has been given another mission extension, this time until December 2009. The spacecraft was launched on December 2, 1995, and it has been steadily observing the Sun ever since. Over the next two years, five additional spacecraft will join SOHO to observe the Sun. ESA is involved in two of these spacecraft: Solar B, and Proba-2. NASA will launch the STEREO pair of spacecraft, as well as the Solar Dynamics Orbiter in 2008.

New funding, to extend the mission of ESA’s venerable solar watchdog SOHO, will ensure it plays a leading part in the fleet of solar spacecraft scheduled to be launched over the next few years.

Since its launch on 2 December 1995, The Solar and Heliospheric Observatory (SOHO) has provided an unprecedented view of the Sun – and not just the side facing the Earth. Two teams have now developed techniques for using SOHO to recreate the conditions on the far side of the Sun. The new funding will allow its mission to be extended from April 2007 to December 2009.

Despite being over ten years old now, SOHO just keeps on working, monitoring the activity on the Sun and allowing scientists to see inside the Sun by recording the seismic waves that ripple across the surface of our nearest star.

More than 2300 scientists have used data from the solar observatory to forward their research, publishing over 2400 scientific papers in peer-reviewed journals. During the last two years, at least one SOHO paper has been accepted for publication every working day.

“This mission extension will allow SOHO to cement its position as the most important spacecraft in the history of solar physics,” says Bernhard Fleck, SOHO’s project scientist, “There is a lot of valuable work for this spacecraft still to do.”

During the next two years, five new solar spacecraft will join SOHO in orbit. ESA is involved in two of these spacecraft. The Japan Aerospace Exploration Agency (ISAS/JAXA) has built Solar B and will launch it later this year. ESA will supply the use of a ground station at Svalbard, Norway in exchange for access to the data.

Next year, ESA will launch Proba-2, a technology demonstration satellite that carries solar instruments. In particular, it will carry a complementary instrument to SOHO’s EIT camera. Whilst EIT concentrates on the origin and early development of solar eruptions, Proba-2’s camera will be able to track them into space.

NASA plans to launch the STEREO pair of spacecraft later this year, and the Solar Dynamics Orbiter in 2008. Far from making SOHO obsolete, these newer solar satellites embrace it as a crucial member of the team. SOHO will provide a critical third point of view to assist the analysis of STEREO’s observations. Also, SOHO’s coronagraph will remain unique. The instrument is capable of blotting out the glare from the Sun so that the tenuous outer atmosphere of the Sun is visible for study.

“By next year, we will have a fleet of spacecraft studying the Sun,” says Hermann Opgenoorth, Head of Solar System Missions Division at ESA. This will advance the International Living With a Star programme (ILWS), an international collaboration of scientists dedicated to a long-term study of the Sun and its effects on Earth and the other solar system planets.

ILWS will possibly culminate in the launch of the advanced ESA satellite, Solar Orbiter, around 2015. It is designed to travel close to the Sun, to gain a close-up look at the powerful processes at the heart of our Solar System.

Original Source: ESA News Release

Posted on by Fraser Cain

Infrared Sensor Could Be Useful on Earth Too

Infrared image of a NASA researcher. Image credit: NASA. Click to enlarge
The development of infrared detectors has been a boon to astronomy. Many objects in the Universe only reveal themselves when seen in the infrared spectrum; like planets forming within clouds of dust. NASA has developed an inexpensive alternative to previous infrared detectors, which could find many uses here on Earth. The detector is called a Quantum Well Infrared Photodetector (QWIP) array, and it could quickly spot forest fires, detect gas leaks, and have many other commercial uses.

An inexpensive detector developed by a NASA-led team can now see invisible infrared light in a range of “colors,” or wavelengths.

The detector, called a Quantum Well Infrared Photodetector (QWIP) array, was the world’s largest (one million-pixel) infrared array when the project was announced in March 2003. It was a low-cost alternative to conventional infrared detector technology for a wide range of scientific and commercial applications. However, at the time it could only detect a narrow range of infrared colors, equivalent to making a conventional photograph in just black and white. The new QWIP array is the same size but can now sense infrared over a broad range.

“The ability to see a range of infrared wavelengths is an important advance that will greatly increase the potential uses of the QWIP technology,” said Dr. Murzy Jhabvala of NASA’s Goddard Space Flight Center, Greenbelt, Md., Principal Investigator for the project.

Infrared light is invisible to the human eye, but some types are generated by and perceived as heat. A conventional infrared detector has a number of cells (pixels) that interact with an incoming particle of infrared light (an infrared photon) and convert it to an electric current that can be measured and recorded. They are similar in principle to the detectors that convert visible light in a digital camera. The more pixels that can be placed on a detector of a given size, the greater the resolution, and NASA’s QWIP arrays are a significant advance over earlier 300,000-pixel QWIP arrays, previously the largest available.

NASA’s QWIP detector is a Gallium Arsenide (GaAs) semiconductor chip with over 100 layers of detector material on top. Each layer is extremely thin, ranging from 10 to 700 atoms thick, and the layers are designed to act as quantum wells.

Quantum wells employ the bizarre physics of the microscopic world, called quantum mechanics, to trap electrons, the fundamental particles that carry electric current, so that only light with a specific energy can release them. If light with the correct energy hits one of the quantum wells in the array, the freed electron flows through a separate chip above the array, called the silicon readout, where it is recorded. A computer uses this information to create an image of the infrared source.

NASA’s original QWIP array could detect infrared light with a wavelength between 8.4 and 9.0 micrometers. The new version can see infrared between 8 to 12 micrometers. The advance was possible because quantum wells can be designed to detect light with different energy levels by varying the composition and thickness of the detector material layers.

“The broad response of this array, particularly in the far infrared — 8 to12 micrometers — is crucial for infrared spectroscopy,” said Jhabvala. Spectroscopy is an analysis of the intensity of light at different colors from an object. Unlike a simple photograph that just shows the appearance of an object, spectroscopy is used to gather more detailed information like the object’s chemical composition, speed, and direction of motion. Spectroscopy is used in criminal investigations; for example, to tell if a chemical found on a suspect’s clothing matches that at a crime scene, and it’s how astronomers determine what stars are made of even though there’s no way to take a sample directly, with the stars many trillions of miles away.

Other applications for QWIP arrays are numerous. At NASA Goddard, some of these applications include: studying troposphere and stratosphere temperatures and identifying trace chemicals; tree canopy energy balance measurements; measuring cloud layer emissivities, droplet/particle size, composition and height; SO2 and aerosol emissions from volcanic eruptions; tracking dust particles (from the Sahara Desert, e.g.); CO2 absorption; coastal erosion; ocean/river thermal gradients and pollution; analyzing radiometers and other scientific equipment used in obtaining ground truthing and atmospheric data acquisition; ground based astronomy; and temperature sounding.

The potential commercial applications are quite diverse. The utility of QWIP arrays in medical instrumentation is well documented (OmniCorder, Inc. in N.Y.) and may become one of the most significant QWIP technology drivers. The success of OmniCorder Technologies use of 256 x 256 narrow band QWIP arrays for aiding in the detection of malignant tumors is quite remarkable.

Other potential commercial applications for QWIP arrays include: location of forest fires and residual warm spots; location of unwanted vegetation encroachment; monitoring crop health; monitoring food processing contamination, ripeness, and spoilage; locating power line transformer failures in remote areas; monitoring effluents from industrial operations such as paper mills, mining sites, and power plants; infrared microscopy; searching for a wide variety of thermal leaks, and locating new sources of spring water.

The QWIP arrays are relatively inexpensive because they can be fabricated using standard semiconductor technology that produces the silicon chips used in computers everywhere. They can also be made very large, because GaAs can be grown in large ingots, just like silicon.

The development effort was led by the Instrument Systems and Technology Center at NASA Goddard. The Army Research Laboratory (ARL), Adelphi, Md., was instrumental in the theory, design, and fabrication of the QWIP array, and L3/Cincinnati Electronics of Mason, Ohio, provided the silicon readout and hybridization. This work was conceived for, and funded by, the Earth Science Technology Office as an Advanced Component Technology development project.

Original Source: NASA News Release

Posted on by Fraser Cain

Janus and Saturn

Janus in front of Saturn. Image credit: NASA/JPL/SSI. Click to enlarge
Tiny Janus – only 181 km (113 miles) across – hovers in front of Saturn in this photograph taken by Cassini. The giant planet’s rings are seen nearly edge-on, and cast large shadows against the northern hemisphere. Cassini took this photo on April 21 when it was approximately 2.9 million kilometers (1.8 million miles) from Saturn.

The small, dark form of Janus cruises along in front of bright Saturn. The edge-on rings cast dramatic shadows onto the northern hemisphere.

Janus is 181 kilometers (113 miles) across.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on April 21, 2006, at a distance of approximately 2.9 million kilometers (1.8 million miles) from Saturn. The image scale is 17 kilometers (11 miles) per pixel on Janus.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visithttp://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .

Original Source: NASA/JPL/SSI News Release

Posted on by Fraser Cain

Discovery Prepares for Launch

Discovery at the launch pad. Image credit: NASA. Click to enlarge
After another long delay, NASA’s space shuttle fleet is nearly ready to get flying again. Discovery rolled out to the launch pad on Friday to prepare for its upcoming launch, returning the fleet to service, and continuing the construction of the International Space Station. Discovery’s launch window opens up on July 1, and extends until July 19. If all goes well, the shuttle will spend 12 days in space, testing new hardware and safety techniques, and delivering supplies to the station.

The Space Shuttle Discovery stands at its launch pad at NASA’s Kennedy Space Center, Fla. The shuttle arrived at 8:30 p.m. EDT Friday on top of a giant vehicle known as the crawler transporter.

“Rollout of Space Shuttle Discovery signifies the last major processing milestone in preparation for our next mission, STS-121,” said Space Shuttle Program Manager Wayne Hale. “The entire team has worked tremendously hard to ensure we were prepared to move to the pad, and we are excited to continue moving toward a July launch.”

The crawler transporter began carrying Discovery out of Kennedy’s Vehicle Assembly Building at 12:45 p.m. Friday. The crawler’s maximum speed during the 4.2-mile journey was less than 1 mph.

While at the pad, the shuttle will undergo final testing and hardware integration prior to launch, as well as a “hot fire” test of the auxiliary power units to ensure they are properly functioning. The rotating service structure then will be moved back around the vehicle to protect it from potential damage and the elements.

Discovery’s launch to the International Space Station is targeted for July 1, with a launch window that extends until July 19. During the 12-day mission, Discovery’s crew will test new hardware and techniques to improve shuttle safety, as well as deliver supplies and make repairs to the station.

Another upcoming milestone is the terminal countdown demonstration test, set for June 12 through 15. This countdown dress rehearsal provides each shuttle crew with the opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency evacuation training.

Audio clips of additional comments from Wayne Hale are available at:
http://www.nasa.gov/formedia

For information about the STS-121 mission and its crew, visit:
http://www.nasa.gov/shuttle

Original Source: NASA News Release

Posted on by Fraser Cain

Prospecting the Moon and Mars for Supplies

Artist illustration of a robotic ice miner. Image credit: NASA/John Frassanito & Associates. Click to enlarge
NASA’s new vision for space exploration hopes to send humans back to the Moon and then onto Mars over the next decades. The Chief Scientist for NASA’s Mars Program, David Beaty, has spent more than 20 years searching the Earth for metals and oil, and this makes the right man to help future astronauts survive off-Earth. Astronauts will become more like prospectors, searching the Moon and Mars for reserves of water to make air and rocket fuel. The more they can live off the land, the less they have to bring from Earth.

Long before David Beaty became associate Chief Scientist for NASA’s Mars Program, he was a prospector. Beaty spent 10 years surveying remote parts of Earth for precious metals and another 12 years hunting for oil.

And this qualifies him to work for NASA? Precisely.

Beaty has the kind of experience NASA needs as the agency prepares to implement the Vision for Space Exploration. “Mining and prospecting are going to be key skills for settlers on the Moon and Mars,” he explains. “We can send them air and water and fuel from Earth, but eventually, they’ll have to learn to live off the land, using local resources to meet their needs.”

On the Moon, for instance, mission planners hope to find water frozen in the dark recesses of polar craters. Water can be split into hydrogen for rocket fuel and oxygen for breathing. Water is also good for drinking and as a bonus it is one of the best known radiation shields. “In many ways,” notes Beaty, “water is key to a sustained human presence.” Ice mining on the Moon could become a big industry.

Beaty has learned a lot from his long career prospecting, exploring and mining on Earth. Now, with an eye on other worlds, he has distilled four pieces of wisdom he calls “Dave’s Postulates” for prospectors working anywhere in the solar system:

Postulate #1: “Wishful thinking is no substitute for scientific evidence.”

“On Earth, banks won’t lend money for less than proven reserves. From a bank’s viewpoint, anything less than proven is not really there. This lesson has been learned the hard way by many a prospector,” he laughs.

For NASA the stakes are higher than profit. The lives of astronauts could hang in the balance. “Proven reserves on the Moon can perhaps be thought of as having enough confidence to risk the lives of astronauts to go after it.”

What does it take to “prove” a reserve?that is, to know with confidence that a resource exists in high enough concentration to be produced?

“That depends on the nature of the deposit,” explains Beaty. “Searching for oil on Earth, you can drill one hole, measure the pressure and calculate how much oil is there. You know that oil probably exists 100 feet away because liquids flow. However, for gold you must drill holes 100 feet apart, and assay the concentration of gold every five feet down each hole. That’s because the solid earth is heterogenous. 100 feet away the rocks may be completely different.”

Deposits on the Moon aren’t so well understood. Is lunar ice widespread or patchy, deep or shallow? Does it even exist? “We don’t know,” says Beaty. “We still have a lot to learn.”

Postulate #2: “You cannot define a reserve without specifying how it can be extracted. If it can’t be mined, it’s of no use.” Enough said.

Postulate #3: “Perfect knowledge is not possible. Exploration costs money, and we can’t afford to buy all the information we want. We have to make choices, deciding what information is critical and what’s not.”

He offers the following hypothetical example:

“Suppose we decide to send a robot with a little drill and an onboard laboratory into Shackleton Crater, a place on the Moon with suspected ice deposits. We’re going to have to think pretty carefully about that lab. Maybe it can contain only two instruments. What are the two things we most need to know?”

“Suppose further that someone on Earth has invented a machine that can extract water from lunar soil. But it only works if the ice is close to the surface and if the ice is not too salty.” The choice is made. “We’d better equip the robot with instruments to measure the saltiness of the ice and its depth in the drill hole.”

Finally, Postulate #4: “Don’t underestimate the potential effects of heterogeneity. All parts of the Moon are not alike, just as all parts of Earth are not alike. So where you land matters.”

Ultimately, says Beaty, if geologists and engineers work together applying these rules as they go, living off the land on alien worlds might not be so hard after all.

Original Source: Science@NASA Article

Posted on by Fraser Cain

Hubble’s Best Gravitational Lens

Quintuple quasar gravitational lens. Image credit: Hubble. Click to enlarge
The most powerful telescopes in the Universe are relatively nearby galaxies, which warp and focus the light of more distant objects. Called gravitation lenses, which occur randomly, are a boon for astronomers as they allow powerful telescopes, like Hubble, to look even further out into the Universe. This Hubble image is the first “quintuple quasar” ever seen, where an entire galaxy perfectly focuses a more distant quasar – located 12 billion light-years away.

NASA’s Hubble Space Telescope has captured the first-ever picture of a group of five star-like images of a single distant quasar.

The multiple-image effect seen in the Hubble picture is produced by a process called gravitational lensing, in which the gravitational field of a massive object — in this case, a cluster of galaxies — bends and amplifies light from an object — in this case, a quasar — farther behind it.

Although many examples of gravitational lensing have been observed, this “quintuple quasar” is the only case so far in which multiple quasar images are produced by an entire galaxy cluster acting as a gravitational lens.

The background quasar is the brilliant core of a galaxy. It is powered by a black hole, which is devouring gas and dust and creating a gusher of light in the process. When the quasar’s light passes through the gravity field of the galaxy cluster that lies between us and the quasar, the light is bent by the space-warping gravity field in such a way that five separate images of the object are produced surrounding the cluster’s center. The fifth quasar image is embedded to the right of the core of the central galaxy in the cluster. The cluster also creates a cobweb of images of other distant galaxies gravitationally lensed into arcs.

The galaxy cluster creating the lens is known as SDSS J1004+4112 and was discovered in the Sloan Digital Sky Survey. It is one of the more distant clusters known (seven billion light-years away), and is seen as it appeared when the universe was half its present age.

Spectral data taken with the Keck I 10-meter telescope show that these are images of the same galaxy. The spectral results match those inferred by a lens model based only on the image positions and measurements of the light emitted from the quasar.

A gravitational lens will always produce an odd number of lensed images, but one image is usually very weak and embedded deep within the light of the lensing object itself. Though previous observations of SDSS J1004+4112 have revealed four of the images of this system, Hubble’s sharp vision and the high magnification of this gravitational lens combine to place a fifth image far enough from the core of the central imaging galaxy to make it visible as well.

The galaxy hosting the background quasar is at a distance of 10 billion light-years. The quasar host galaxy can be seen in the image as multiple faint red arcs. This is the most highly magnified quasar host galaxy ever seen.

The Hubble picture also shows a large number of stretched arcs that are more distant galaxies lying behind the cluster, each of which is split into multiple distorted images. The most distant galaxy identified and confirmed so far is 12 billion light-years away (corresponding to only 1.8 billion years after the Big Bang).

By comparing this image to a picture of the cluster obtained with Hubble a year earlier, the researchers discovered a rare event — a supernova exploding in one of the cluster galaxies. The supernova exploded seven billion years ago, and the data, together with other supernova observations, are being used to try to reconstruct how the universe was enriched by heavy elements through these explosions.

Original Source: Hubble News Release

Posted on by Fraser Cain

First Light from Japan’s AKARI

Reflection nebula IC4954. Image credit: ESA. Click to enlarge
Japan’s newly launched AKARI spacecraft took its first images on April 13, 2006, testing out its scientific instruments. AKARI (formally known as ASTRO-F) used its Far Infrared Surveyor and near-mid-infrared camera to make a survey of the entire sky in 6 infrared wavebands. It was then pointed towards the reflection nebula IC4954, and was able to distinguish newly born stars. The space observatory is now entering its first mission phase, which will last about 6 months.

AKARI, the new Japanese infrared sky surveyor mission in which ESA is participating, saw ‘first light’ on 13 April 2006 (UT) and delivered its first images of the cosmos. The images were taken towards the end of a successful checkout of the spacecraft in orbit.

The mission, formerly known as ASTRO-F, was launched on 21 February 2006 (UT) from the Uchinoura Space Centre in Japan. Two weeks after launch the satellite reached its final destination in space – a polar orbit around Earth located at an altitude of approximately 700 kilometres.

On 13 April, during the second month of the system checkout and verification of the overall satellite performance, the AKARI telescope’s aperture lid was opened and the on-board two instruments commenced their operation. These instruments – the Far Infrared Surveyor (FIS) and the near-mid-infrared camera (IRC) – make possible an all-sky survey in six infrared wavebands. The first beautiful images from the mission have confirmed the excellent performance of the scientific equipment beyond any doubt.

AKARI’s two instruments were pointed toward the reflection nebula IC4954, a region situated about 6000 light years away, and extending more than 10 light years across space. Reflection nebulae are clouds of dust which reflect the light of nearby stars. In these infrared images of IC4954 ? a region of intense star formation active for several million years – it is possible to pick out individual stars that have only recently been born. They are embedded in gas and dust and could not be seen in visible light. It is also possible to see the gas clouds from which these stars were actually created.

“These beautiful views already show how, thanks to the better sensitivity and improved spatial resolution of AKARI, we will be able to discover and study fainter sources and more distant objects which escaped detection by the previous infrared sky-surveyor, IRAS, twenty years ago,” says Pedro García-Lario, responsible for ‘pointing reconstruction’ – a vital part of the AKARI data processing – at ESA’s European Space Astronomy Centre (ESAC), Spain. “With the help of the new infrared maps of the whole sky provided by AKARI we will be able to resolve for the first time heavily obscured sources in crowded stellar fields like the centre of our Galaxy,” he continued.

With its near-mid-infrared camera, AKARI also imaged the galaxy M81 at six different wavelengths. M81 is a spiral galaxy located about 12 million light years away. The images taken at 3 and 4 microns show the distribution of stars in the inner part of the galaxy, without any obscuration from the intervening dust clouds. At 7 and 11 microns the images show the radiation from organic materials (carbon-bearing molecules) in the interstellar gas of the galaxy. The distribution of the dust heated by young hot stars is shown in the images at 15 and 24 microns, showing that the star forming regions sit along the spiral arms of the galaxy.

“It’s a feeling of tremendous accomplishment for all of us involved in the AKARI project to finally see the fruits of the long years of labour in these amazing new infrared images of our Universe,” said Chris Pearson, ESA astronomer located at ISAS and involved with AKARI since 1997, “We are now eagerly waiting for the next ‘infrared revelation’ about the origin and evolution of stars, galaxies and planetary systems.”

Having concluded all in-orbit checks, AKARI is now entering the first mission phase. This will last about six months and is aimed at performing a complete survey of the entire infrared sky. This part of the mission will then be followed by a phase during which thousands of selected astronomical targets will be observed in detail. During this second phase, as well as in the following third phase in which only the infrared camera will be at work, European astronomers will have access to ten percent of the overall pointed observation opportunity.

“The user support team at ESAC are enthusiastic about the first images. They show that we can expect a highly satisfactory return for the European observing programme,” said Alberto Salama, ESA Project Scientist for AKARI. “Furthermore, the new data will be of enormous value to plan follow-up observations of the most interesting celestial objects with ESA’s future infrared observatory, Herschel,” he concluded.

Original Source: ESA News Release

Posted on by Fraser Cain

Six New Candidates for Earth Observation

Artist illustration of the GOCE mission. Image credit: ESA. Click to enlarge
The European Space Agency has decided on the shortlist of spacecraft that could launch in less than a decade and contribute to the scientific exploration of our planet. The missions include Biomass, which will measure the Earth’s forests; TRAQ, which will monitor air quality; PREMIER, to watch how gasses change in the atmosphere; FLEX, to observe global photosynthesis; A-SCOPE, to track the global carbon cycle; and CoReH20, which will measure the ice/water/snow cycle. ESA requested proposals more than a year ago, and received 24 from different research groups.

ESA has announced the shortlist of new Earth Explorer mission proposals within its Living Planet Programme. This is part of the selection procedure that will eventually lead to the launch of the fourth Earth Explorer Core mission during the first half of the next decade.

The six missions cover a range of environmental issues with the aim of furthering our understanding of the Earth system and changing climate:

* BIOMASS – to take global measurements of forest biomass.

* TRAQ (TRopospheric composition and Air Quality) – to monitor air quality and long-range transport of air pollutants.

* PREMIER (PRocess Exploration through Measurements of Infrared and millimetre-wave Emitted Radiation) – to understand processes that link trace gases, radiation, chemistry and climate in the atmosphere.

* FLEX (FLuorescence EXplorer) – to observe global photosynthesis through the measurement of fluorescence.

* A-SCOPE (Advanced Space Carbon and Climate Observation of Planet Earth) – to improve our understanding of the global carbon cycle and regional carbon dioxide fluxes.

* CoReH2O (Cold Regions Hydrology High-resolution Observatory – to make detailed observations of key snow, ice and water cycle characteristics.

The selection of these six mission proposals follows the release of the Call for Earth Explorer Core mission ideas in March 2005. ESA received 24 responses, which covered a broad range of Earth science disciplines, and in particular responded well to the priorities set by the Agency’s Earth Science Advisory Committee (ESAC). These priorities focused on the global carbon and water cycles, atmospheric chemistry and climate, as well as the human element as a cross cutting issue.

The proposals were peer reviewed by scientific teams, and also appraised technically and programmatically. Based on these reviews, the ESAC evaluated the proposals and recommended the list of six mission ideas in order of priority. Following these recommendations, ESA’s Programme Board for Earth Observation on 18-19 May approved the proposal of the Director of Earth Observation Programmes to initiate assessment studies for these six mission candidates.

Earth Explorer Core missions are ESA-led research missions and the budget limit for the current set is 300 M€. The first Earth Explorer Core Missions were selected in 1999: the Earth Gravity field and Ocean Circulation (GOCE) mission and the Atmospheric Dynamics Mission (ADM-Aeolus) to be launched in 2007 and 2008 respectively. The third Core mission, Earth Clouds Aerosols and Radiation Explorer (EarthCARE), was selected in 2004 and will be launched in 2012.

In addition to the Earth Explorer Core missions, three Earth Explorer Opportunity missions are currently under implementation: SMOS for soil moisture and ocean salinity, CryoSat-2 for the study of ice sheets and sea ice, and Swarm, which is a constellation of small satellites to study the dynamics of the Earth’s magnetic field and its interactions with the Earth system, due for launch in 2007, 2009 and 2010, respectively.

The six mission candidates recently selected will significantly extend the scientific disciplines covered by ESA’s Living Planet Programme. When the assessment studies have been completed, a subset of the six candidates will be selected for feasibility study, and the mission finally selected for implementation will be launched during the first half of the next decade.

BIOMASS – the mission aims at global measurements of forest biomass. The measurement is accomplished by a space borne P-band synthetic aperture polarimetric radar. The technique is mainly based on the measurement of the cross-polar backscattering coefficient, from which forest biomass is directly retrieved. Use of multi-polarization measurements and of interferometry is also proposed to enhance the estimates. In line with the ESAC recommendations, the analysis for this mission will include comparative studies to measure terrestrial biomass using P- or L-band and consideration of alternative implementations using L-band.

TRAQ – the mission focuses on monitoring air quality and long-range transport of air pollutants. A new synergistic sensor concept allows for process studies, particularly with respect to aerosol-cloud interactions. The main issues are the rate of air quality change on regional and global scales, the strength and distribution of sources and sinks of tropospheric trace gases and aerosols influencing air quality, and the role of tropospheric composition in global change. The instrumentation consists of imaging spectrometers in the range from ultraviolet to short-wave infrared.

PREMIER – Many of the most important processes for prediction of climate change occur in the upper troposphere and lower stratosphere (UTLS). The objective is to understand the many processes that link trace gases, radiation, chemistry and climate in the atmosphere – concentrating on the processes in the UTLS region. By linking with MetOp/ National Polar-orbiting Operational Environmental Satellite System (NPOESS) data, the mission also aims to provide useful insights into processes occurring in the lower troposphere. The instrumentation consists of an infrared and a microwave radiometer.

FLEX – The main aim of the mission is global remote sensing of photosynthesis through the measurement of fluorescence. Photosynthesis by land vegetation is an important component of the global carbon cycle, and is closely linked to the hydrological cycle through transpiration. Currently there are no direct measurements available from satellites of this parameter. The main specification is for instruments to measure high spectral resolution reflectance and temperature, and to provide a multi-angular capability.

A-SCOPE – The mission aims to observe total column carbon dioxide with a nadir-looking pulsed carbon dioxide DIfferential Absorption Lidar (DIAL) for a better understanding of the global carbon cycle and regional carbon dioxide fluxes, as well as for the validation of greenhouse gas emission inventories. It will provide a spatially resolved global carbon budget combined with diagnostic model analysis through global and frequent observation of carbon dioxide. Spin-off products like aerosols, clouds and surface reflectivity are important parameters of the radiation balance of the Earth. A contribution to Numerical Weather Prediction is foreseen in connection with accurate temperature profiles. Investigations on plant stress and vitality will be supported by a fluorescence imaging spectrometer.

CoReH2O – The mission focuses on spatially detailed observations of key snow, ice, and water cycle characteristics necessary for understanding land surface, atmosphere and ocean processes and interactions by using two synthetic aperture radars at 9.6 and 17.2 GHz. It aims at closing the gaps in detailed information on snow glaciers, and surface water, with the objectives of improving modelling and prediction of water balance and streamflow for snow covered and glacierised basins, understanding and modelling the water and energy cycles in high latitudes, assessing and forecasting water supply from snow cover and glaciers, including the relation to climate change variability

Original Source: ESA News Release

Posted on by Fraser Cain

Lava Tubes on Pavonis Mons

Lava tubes down the side of Pavonis Mons. Image credit: ESA. Click to enlarge
This photograph shows one of Mars’ three great shield volcanos: Pavonis Mons. The image was taken by ESA’s Mars Express spacecraft, and shows a top view of the extinct volcano as it rises 12 km (7.5 miles) above the surrounding plains. Scientists believe the linear features are lava tubes that were created when the volcano was active. Similar to here on Earth, lava forms a crust on top while molten rock continues to flow under the surface. The longest tube extends over 59 km (37 miles).

This image, taken by the High Resolution Stereo Camera (HRSC) on board ESA’s Mars Express, shows Pavonis Mons, the central volcano of the three ‘shield’ volcanoes that comprise Tharsis Montes.

ESA’s Mars Express spacecraft obtained this image using the HRSC during orbit 902 with a ground resolution of approximately 14.3 metres per pixel. The image was acquired in the region of Pavonis Mons, at approximately 0.6° South and 246.4° East.

The context map is centred on Pavonis Mons, one of the three volcanoes called Tharsis Montes (the others being Arsia and Ascreus Montes, aligned with Pavonis in a line nearly 1500 km long).

Pavonis Mons, rising roughly 12 km above the surrounding plains, is the central volcano of the three ‘shield’ volcanoes that comprise Tharsis Montes. Gently sloping shield volcanoes are shaped like a flattened dome and are built almost exclusively of lava flows.

The dramatic features visible in the colour image are located on the south-west flank of Pavonis Mons. Researchers believe these are lava tubes, channels originally formed by hot, flowing lava that forms a crust as the surface cools. Lava continues to flow beneath this hardened surface, but when the lava production ends and the tunnels empty, the surface collapses, forming elongated depressions. Similar tubes are well known on Earth and the Moon.
The long, continuous lava tube in the northwest of the colour image extends over 59 km and ranges from approximately 1.9 km to less than 280 m wide.

Pit chains, strings of circular depressions thought to form as the result of collapse of the surface, are also visible within the colour image. In the northeast, there is a clear distinction between the brighter terrain at higher elevations and darker material located down slope. In the southwest, the lava tubes appear to be covered by subsequent lava flows.

By studying Martian volcanoes, scientists can obtain information regarding this intriguing planet. For example, the gradual flank slopes and the flattened, dome-like appearance of Pavonis Mons suggest that low-viscosity lava formed this volcano.

Original Source: ESA News Release