vendredi 1 mai 2015

GPS Data Show How Nepal Quake Disturbed Earth’s Upper Atmosphere












NAVSTAR - Global Positioning System (GPS) patch.

May 1, 2015

GPS Data Show How Nepal Quake Disturbed Earth’s Upper Atmosphere

The April 25, 2015, magnitude 7.8 Gorkha earthquake in Nepal created waves of energy that penetrated into Earth's upper atmosphere in the vicinity of Nepal, disturbing the distribution of electrons in the ionosphere. The ionosphere is a region of Earth's upper atmosphere located from about 37 miles (60 kilometers) to 621 miles (1,000 kilometers) above Earth’s surface. These disturbances were monitored using signals transmitted by the Global Positioning System (GPS) that were received by a science-quality GPS receiver located in a neighboring region to Nepal.

The disturbance measurements, known as vertical total electron content (VTEC) (depicted in blue in the upper panel), have been filtered using processing software developed by NASA’s Jet Propulsion Laboratory, Pasadena, California, to show wave-like disturbances (circled in red) in the distribution of electrons in the ionosphere. The waves have periods of between two and eight minutes in length. The disturbance measurements following the earthquake rupture are circled in black in the lower panel. The colors represent the relative strengths of the earthquake-induced ionospheric disturbances as captured by the GPS signals, with red being high and blue being low.

GPS Satellites Constellation

The data show that after the initial earthquake rupture (indicated by the vertical black line) it took about 21 minutes for the earthquake-generated ionospheric disturbance to reach a GPS station (LHAZ), located about 400 miles (640 kilometers) away from the epicenter in Lhasa, Tibet, China. The station is hosted at the Tibet Autonomous Regional Bureau of Surveying and Mapping Institute. The site collects both GPS and GLONASS (the Russian global navigation satellite system) data at a rate of 1 Hertz and is part of an international scientific collaboration known as the International GPS Service (IGS) (http://igs.org/igsnetwork/network_by_site.php?site=lhaz).

Scientists study ionosphere-based measurements caused by natural hazards such as earthquakes, volcanic eruptions and tsunamis to better understand wave propagation in the upper atmosphere. The disturbances caused by earthquakes help scientists develop new first-principle-based wave propagation models. These models may become part of future early warning systems for tsunamis and other difficult-to-detect natural hazards.

The data may be accessed at: ftp://cddis.gsfc.nasa.gov/gps/data/highrate/2015/115/15d/06/.

For more information about Global Positioning System (GPS), visit: http://www.gps.gov/

Images, Text, Credits: NASA/JPL/Ionosphere Natural Hazards Team/Tony Greicius.

Greetings, Orbiter.ch

jeudi 30 avril 2015

Science Continues on the International Space Station












ISS - Expedition 43 Mission patch.

April 30, 2015


Image above: One-Year crew members Scott Kelly (left) and Mikhail Kornienko (right) took a few minutes out of their day to speak to media. Credit: NASA.

The Expedition 43 crew continued their work on Wednesday with a variety of research and technology demonstration activities.

One-Year Space Station Crew Members Discuss Life in Space with the Media

NASA astronauts Scott Kelly and Terry Virts studied the effects of microgravity on living organisms for the Rodent Research experiment. They are looking at mice and how their body systems change in space. The results may promote the development of new drugs tackling the effects of aging and disease on Earth.

Meanwhile, ESA (European Space Agency) astronaut Samantha Cristoforetti continued operations with the Triplelux-A experiment and adjusted imaging equipment on the Electromagnetic Levitation study.


Image above: The unpiloted Russian ISS Progress 50 (50P) resupply ship seen shortly after undocking. Progress is an unmanned cargo craft used to resupply the International Space Station. Image Credit: NASA.

Attempts by Russian ground controllers to regain control of the Progress have been unsuccessful, and they have said they will not be able to regain propulsive control of it. As a result, the Progress currently is expected to reenter Earth’s atmosphere within the next two weeks. Russian ballistics specialists, working in conjunction with flight controllers in Mission Control Houston and ESA, are continuing to track the vehicle’s path and will provide updates on its anticipated reentry date.

The United States Air Force Joint Functional Component Command for Space’s Joint Space Operations Center is also tracking Progress, performing conjunction analysis, and providing warning of any potential collisions in space to ensure spaceflight safety. The break up and reenty of the Progress poses no threat to the ISS crew.

Related links:

Rodent Research experiment: http://www.nasa.gov/mission_pages/station/research/experiments/1824.html

Triplelux-A experiment: http://www.nasa.gov/mission_pages/station/research/experiments/382.html

Electromagnetic Levitation study: http://www.nasa.gov/mission_pages/station/research/news/eml/#.VUDomGO4is8

For more information about the International Space Station (ISS), visit: http://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Video, Text, Credits: NASA/NASA TV.

Best regards, Orbiter.ch

SPoRT Satellite Image of the Post Kathmandu Earthquake






NASA - Short-term Prediction Research and Transition (SPoRT) logo.

April 30, 2015

SPoRT Satellite Image as Detected by the Visible Infrared Imaging Radiometer Suite Sensor of the Post Kathmandu Earthquake.


In the wake of the April 25, 2015 earthquake in Nepal, NASA’s Short-term Prediction Research and Transition, SPoRT, project at Marshall Space Flight Center has developed satellite imagery to assist decision makers in post disaster analysis and assessment.

The image shows a decrease in emitted light over the city of Kathmandu and surrounding areas as detected by the Visible Infrared Imaging Radiometer Suite (VIIRS) “Day-Night Band” sensor aboard the NASA/NOAA Suomi National Polar-Orbiting Partnership satellite, derived from a comparison of pre-earthquake (22 April 2015) and post-earthquake (26 April 2015) imagery.  In this percent of normal product, the warm colors (red – yellow) indicate the largest reduced light emissions in the post-event image, possibly due to damage to electrical infrastructure.  Towns and suburban areas around Kathmandu show the larger percentage of reduced light emission.  Input satellite data were obtained in collaboration with the NASA Suomi NPP Science Investigator-led Processing System activities at the University of Wisconsin.

This information can help relief operations determine areas that may be affected by electrical outages.

For more information about NASA’s Short-term Prediction Research and Transition (SPoRT), visit: http://weather.msfc.nasa.gov/sport/

Text, Credit: NASA/Images Produced By: The Short-term Prediction Research and Transition (SPoRT) team at NASA’s Marshall Space Flight Center in Huntsville, AL./Jennifer Harbaugh.

Greetings, Orbiter.ch

Hubble Eyes Galactic Refurbishment












NASA - Hubble Space Telescope patch.

April 30, 2015


The smudge of stars at the center of this NASA/ESA Hubble Space Telescope image is a galaxy known as UGC 5797. UGC 5797 is an emission line galaxy, meaning that it is currently undergoing active star formation. The result is a stellar population that is constantly being refurbished as massive bright blue stars form. Galaxies with prolific star formation are not only veiled in a blue tint, but are key to the continuation of a stellar cycle.

In this image UGC 5797 appears in front of a background of spiral galaxies. Spiral galaxies have copious amounts of dust and gas — the main ingredient for stars — and therefore often also belong to the class of emission line galaxies.

video
Hubble orbiting Earth

Spiral galaxies have disk-like shapes that drastically vary in appearance depending on the angle at which they are observed. The collection of spiral galaxies in this frame exhibits this attribute acutely: Some are viewed face-on, revealing the structure of the spiral arms, while the two in the bottom left are seen edge-on, appearing as plain streaks in the sky. There are many spiral galaxies, with varying colors and at different angles, sprinkled across this image — just take a look.

Notes for editors:

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

For more information about Hubble Space Telescope, visit: http://www.spacetelescope.org and http://hubblesite.org

Image, Video, Text, Credits: ESA/Hubble & NASA, Acknowledgement: Luca Limatola/Karl Hille.

Cheers, Orbiter.ch

NASA's Chandra Suggests Black Holes Gorging at Excessive Rates












NASA - Chandra X-ray Observatory patch.

April 30, 2015

A group of unusual giant black holes may be consuming excessive amounts of matter, according to a new study using NASA’s Chandra X-ray Observatory. This finding may help astronomers understand how the largest black holes were able to grow so rapidly in the early Universe.

Astronomers have known for some time that supermassive black holes − with masses ranging from millions to billions of times the mass of the Sun and residing at the centers of galaxies − can gobble up huge quantities of gas and dust that have fallen into their gravitational pull. As the matter falls towards these black holes, it glows with such brilliance that they can be seen billions of light years away. Astronomers call these extremely ravenous black holes “quasars.”

Black holes “quasars”

This new result suggests that some quasars are even more adept at devouring material than scientists previously knew.

“Even for famously prodigious consumers of material, these huge black holes appear to be dining at enormous rates, at least five to ten times faster than typical quasars,” said Bin Luo of Penn State University in State College, Pennsylvania, who led the study.

Luo and his colleagues examined data from Chandra for 51 quasars that are located at a distance between about 5 billion and 11.5 billion light years from Earth. These quasars were selected because they had unusually weak emission from certain atoms, especially carbon, at ultraviolet wavelengths. About 65% of the quasars in this new study were found to be much fainter in X-rays, by about 40 times on average, than typical quasars.

The weak ultraviolet atomic emission and X-ray fluxes from these objects could be an important clue to the question of how a supermassive black hole pulls in matter. Computer simulations show that, at low inflow rates, matter swirls toward the black hole in a thin disk. However, if the rate of inflow is high, the disk can puff up dramatically, because of pressure from the high radiation, into a torus or donut that surrounds the inner part of the disk.

“This picture fits with our data,” said co-author Jianfeng Wu of the Harvard-Smithsonian Center for Astrophysics, in Cambridge, Massachusetts. "If a quasar is embedded in a thick donut-shaped structure of gas and dust, the donut will absorb much of the radiation produced closer to the black hole and prevent it from striking gas located further out, resulting in weaker ultraviolet atomic emission and X-ray emission."

The usual balance between the inward pull of gravity and the outward pressure of radiation would also be affected.

"More radiation would be emitted in a direction perpendicular to the thick disk, rather than along the disk, allowing material to fall in at higher rates," said co-author Niel Brandt, also of Penn State University.

Chandra X-ray Observatory

The important implication is that these “thick-disk” quasars may harbor black holes growing at an extraordinarily rapid rate. The current study and previous ones by different teams suggest that such quasars might have been more common in the early Universe, only about a billion years after the Big Bang. Such rapid growth might also explain the existence of huge black holes at even earlier times.

A paper describing these results appears in an upcoming issue of The Astrophysical Journal and is available online. NASA's Marshall Space Flight Center in Huntsville, Alabama, manages the Chandra program for the agency’s Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory in Cambridge, Massachusetts, controls Chandra's science and flight operations.

Read More from NASA's Chandra X-ray Observatory: http://chandra.harvard.edu/ and http://www.nasa.gov/mission_pages/chandra/main/index.html

Images, Text, Credits: Illustration: CXC/M. Weiss/X-ray images: NASA/CXC/Penn State/B. Luo et al./Jennifer Harbaugh.

Greetings, Orbiter.ch

New Horizons Sees Pluto and Charon












NASA - New Horizons Mission logo.

April 30, 2015


This series of New Horizons images of Pluto and its largest moon, Charon, was taken at 13 different times spanning 6.5 days, starting on April 12 and ending on April 18, 2015. During that time, the NASA spacecraft's distance from Pluto decreased from about 69 million miles (111 million kilometers) to 64 million miles (104 million kilometers).

The pictures were taken with the New Horizons Long Range Reconnaissance Imager, or LORRI. Pluto and Charon rotate around a center-of-mass (also called the "barycenter") once every 6.4 Earth days, and these LORRI images capture one complete rotation of the system.

Artist's view of New Horizons spacecraft orbiting Pluto and Charon

In the annotated version, a 3x-magnified view of Pluto is displayed in the inset to the lower right, highlighting the changing brightness across the disk of Pluto as it rotates. Because Pluto is tipped on its side (like Uranus), when observing Pluto from the New Horizons spacecraft, one primarily sees one pole of Pluto, which appears to be brighter than the rest of the disk in all the images. Scientists suggest this brightening in Pluto's polar region might be caused by a "cap" of highly reflective snow on the surface. The "snow" in this case is likely to be frozen molecular nitrogen ice. New Horizons observations in July will determine definitively whether or not this hypothesis is correct.


In addition to the polar cap, these images reveal changing brightness patterns from place to place as Pluto rotates, presumably caused by large-scale dark and bright patches at different longitudes on Pluto's surface. In all of these images, a mathematical technique called "deconvolution" is used to improve the resolution of the raw LORRI images, restoring nearly the full resolution allowed by the camera's optics and detector.

Related article:

NASA’s New Horizons Detects Surface Features, Possible Polar Cap on Pluto: http://orbiterchspacenews.blogspot.ch/2015/04/nasas-new-horizons-detects-surface.html

To view images from New Horizons and learn more about the mission, visit:
http://www.nasa.gov/newhorizons

Animations, Image, Text, Credits: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Jim Wilson.

Best regards, Orbiter.ch

Rock Spire in 'Spirit of St. Louis Crater' on Mars











NASA - Mars Exploration Rover "Opportunity" (MER-B) patch.

April 30, 2015

An elongated crater called "Spirit of St. Louis," with a rock spire in it, dominates a recent scene from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity.


Image above: An elongated crater called "Spirit of St. Louis," with a rock spire in it, dominates a recent scene from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity. Image Credits: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.

Opportunity completed its 4,000th Martian day, or sol, of work on Mars on April 26, 2015. The rover has been exploring Mars since early 2004.

Artist's view of Opportunity rover. Image Credit: NASA/JPL-Caltech

This scene from late March 2015 shows a shallow crater called Spirit of St. Louis, about 110 feet (34 meters) long and about 80 feet (24 meters) wide, with a floor slightly darker than surrounding terrain. The rocky feature toward the far end of the crater is about 7 to 10 feet (2 to 3 meters) tall, rising higher than the crater's rim.

The component images of this mosaic view were taken on March 29 and 30, 2015, during Sol 3973 and Sol 3974 of the mission. This version of the image is presented in approximate true color by combing exposures taken through three of the Pancam's color filters, centered on wavelengths of 753 nanometers (near-infrared), 535 nanometers (green) and 432 nanometers (violet).


Image above: An elongated crater called "Spirit of St. Louis," with a rock spire in it, dominates this stereo view from NASA's Mars Exploration Rover Opportunity. Image Credits: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.

The unusually shaped Spirit of St. Louis Crater lies on the outer portion of the western rim of Endeavour Crater. Endeavour spans about 14 miles (22 kilometers) in diameter, and Opportunity has been exploring its western rim for about one-third of the rover's mission, which has lasted more than 11 years.  Endeavour's elevated western rim extends northward to the left from Spirit of St. Louis Crater in this scene. A glimpse of the far side of Endeavour is visible on either side of the rock spire.

For more about Opportunity's mission, see: http://mars.nasa.gov/mer

Images (mentioned), Text, Credits: NASA/JPL/Guy Webster/Tony Greicius.

Greetings, Orbiter.ch

NASA Completes MESSENGER Mission with Expected Impact on Mercury's Surface












NASA - MESSENGER Mission patch.

April 30, 2015

A NASA planetary exploration mission came to a planned, but nonetheless dramatic, end Thursday when it slammed into Mercury’s surface at about 8,750 mph and created a new crater on the planet’s surface.

Mission controllers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, have confirmed NASA’s MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft impacted the surface of Mercury, as anticipated, at 3:26 p.m. EDT.

Overview of MESSENGER Spacecraft's Impact Region on Mercury

Mission control confirmed end of operations just a few minutes later, at 3:40 p.m., when no signal was detected by NASA’s Deep Space Network (DSN) station in Goldstone, California, at the time the spacecraft would have emerged from behind the planet. This conclusion was independently confirmed by the DSN’s Radio Science team, which also was monitoring for a signal from MESSENGER.

“Going out with a bang as it impacts the surface of Mercury, we are celebrating MESSENGER as more than a successful mission,” said John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “The MESSENGER mission will continue to provide scientists with a bonanza of new results as we begin the next phase of this mission--analyzing the exciting data already in the archives, and unravelling the mysteries of Mercury.”

Prior to impact, MESSENGER’s mission design team predicted the spacecraft would pass a few miles over a lava-filled basin on the planet before striking the surface and creating a crater estimated to be as wide as 50 feet.

MESSENGER’s lonely demise on the small, scorched planet closest to the sun went unobserved because the probe hit the side of the planet facing away from Earth, so ground-based telescopes were not able to capture the moment of impact. Space-based telescopes also were unable to view the impact, as Mercury’s proximity to the sun would damage optics.

Artist's view of MESSENGER spacecraft

MESSENGER’s last day of real-time flight operations began at 11:15 a.m., with initiation of the final delivery of data and images from Mercury via a 230-foot (70-meter) DSN antenna located in Madrid, Spain. After a planned transition to a 111-foot (34-meter) DSN antenna in California, at 2:40 p.m., mission operators later confirmed the switch to a beacon-only communication signal at 3:04 p.m.

The mood in the Mission Operations Center at APL was both somber and celebratory as team members watched MESSENGER’s telemetry drop out for the last time, after more than four years and 4,105 orbits around Mercury.

“We monitored MESSENGER’s beacon signal for about 20 additional minutes,” said mission operations manager Andy Calloway of APL. “It was strange to think during that time MESSENGER had already impacted, but we could not confirm it immediately due to the vast distance across space between Mercury and Earth.”

MESSENGER was launched on Aug. 3, 2004, and began orbiting Mercury on March 17, 2011. Although it completed its primary science objectives by March 2012, the spacecraft’s mission was extended two times, allowing it to capture images and information about the planet in unprecedented detail.

During a final extension of the mission in March, referred to as XM2, the team began a hover campaign that allowed the spacecraft to operate within a narrow band of altitudes from five to 35 kilometers from the planet’s surface.

 MESSENGER's Final Image

On Tuesday, the team successfully executed the last of seven daring orbit correction maneuvers that kept MESSENGER aloft long enough for the spacecraft’s instruments to collect critical information on Mercury’s crustal magnetic anomalies and ice-filled polar craters, among other features. After running out of fuel, and with no way to increase its altitude, MESSENGER was finally unable to resist the sun’s gravitational pull on its orbit. 

“Today we bid a fond farewell to one of the most resilient and accomplished spacecraft to ever explore our neighboring planets,” said Sean Solomon, MESSENGER’s principal investigator and director of Columbia University’s Lamont-Doherty Earth Observatory in Palisades, New York. “A resourceful and committed team of engineers, mission operators, scientists, and managers can be extremely proud that the MESSENGER mission has surpassed all expectations and delivered a stunningly long list of discoveries that have changed our views--not only of one of Earth’s sibling planets, but of the entire inner solar system.”

Among its many accomplishments, the MESSENGER mission determined Mercury’s surface composition, revealed its geological history, discovered its internal magnetic field is offset from the planet’s center, and verified its polar deposits are dominantly water ice.

APL built and operated the MESSENGER spacecraft and managed the mission for NASA’s Science Mission Directorate in Washington.

Learn more about the accomplishments of NASA’s MESSENGER mission at: https://www.youtube.com/watch?v=ENwD31EDFjc and http://www.nasa.gov/messenger

Images, Text, Credits: NASA/Dwayne Brown/Johns Hopkins University Applied Physics Laboratory/Paulette Campbell/Carnegie Institution of Washington/Karen Northon.

Cheers, Orbiter.ch

The Pillars of Creation Revealed in 3D












ESO - European Southern Observatory logo.

30 April 2015

New study suggests that iconic structures more aptly named the Pillars of Destruction

3D data visualisation of the Pillars of Creation

Using the MUSE instrument on ESO’s Very Large Telescope (VLT), astronomers have produced the first complete three-dimensional view of the famous Pillars of Creation in the Eagle Nebula, Messier 16. The new observations demonstrate how the different dusty pillars of this iconic object are distributed in space and reveal many new details — including a previously unseen jet from a young star. Intense radiation and stellar winds from the cluster’s brilliant stars have sculpted the dusty Pillars of Creation over time and should fully evaporate them in about three million years.

Colour composite view of the Pillars of Creation from MUSE data

The original NASA/ESA Hubble Space Telescope image of the famous Pillars of Creation was taken two decades ago and immediately became one of its most famous and evocative pictures. Since then, these billowing clouds, which extend over a few light-years [1], have awed scientists and the public alike.

The three-dimensional view of the Pillars of Creation from MUSE

The jutting structures, along with the nearby star cluster, NGC 6611, are parts of a star formation region called the Eagle Nebula, also known as Messier 16 or M16. The nebula and its associated objects are located about 7000 light-years away in the constellation of Serpens (The Serpent).

Messier 16 in the constellation of Serpens Cauda (The Tail of the Serpent)

The Pillars of Creation are a classic example of the column-like shapes that develop in the giant clouds of gas and dust that are the birthplaces of new stars. The columns arise when immense, freshly formed blue–white O and B stars give off intense ultraviolet radiation and stellar winds that blow away less dense materials from their vicinity.

Digitized Sky Survey Image of the Eagle Nebula

Denser pockets of gas and dust, however, can resist this erosion for longer. Behind such thicker dust pockets, material is shielded from the harsh, withering glare of O and B stars. This shielding creates dark "tails" or “elephant trunks”, which we see as the dusky body of a pillar, that point away from the brilliant stars.

ESO's MUSE instrument on the Very Large Telescope has now helped illustrate the ongoing evaporation of the Pillars of Creation in unprecedented detail, revealing their orientation.

video
3D data visualisation of the Pillars of Creation

MUSE has shown that the tip of the left pillar is facing us, atop a pillar that is is actually situated behind NGC 6611, unlike the other pillars. This tip is bearing the brunt of the radiation from NGC 6611’s stars, and as a result looks brighter to our eyes than the bottom left, middle and right pillars, whose tips are all pointed away from our view.

Astronomers hope to better understand how young O and B stars like those in NGC 6611 influence the formation of subsequent stars. Numerous studies have identified protostars forming in these clouds — they are indeed Pillars of Creation. The new study also reports fresh evidence for two gestating stars in the left and middle pillars as well as a jet from a young star that had escaped attention up to now.

video
3D data visualisation of the Pillars of Creation

For more stars to form in environments like the Pillars of Creation, it is a race against time as intense radiation from the powerful stars that are already shining continues to grind away at the pillars.

By measuring the Pillars of Creation’s rate of evaporation, MUSE has given astronomers a time frame for when the pillars will be no more. They shed about 70 times the mass of the Sun every million years or so. Based on the their present mass of about 200 times that of the Sun, the Pillars of Creation have an expected lifetime of perhaps three million more years — an eyeblink in cosmic time. It seems that an equally apt name for these iconic cosmic columns might be the Pillars of Destruction.

Notes:

[1] The left pillar, considered as a complete object from top to bottom, is estimated to be about four light-years in length. It is the longest pillar and about twice the height of the right pillar.

More information:

This research was presented in a paper entitled "The Pillars of Creation revisited with MUSE: gas kinematics and high-mass stellar feedback traced by optical spectroscopy" by A. F. McLeod et al., to appear in the journal Monthly Notices of the Royal Astronomical Society on 30 April 2015.

The team is composed of A. F. Mc Leod (ESO, Garching, Germany), J. E. Dale (Universitäts-Sternwarte München, München, Germany; Excellence Cluster Universe, Garching bei München, Germany), A. Ginsburg (ESO), B. Ercolano (Universitats-Sternwarte München,; Excellence Cluster Universe), M. Gritschneder (Universitats-Sternwarte München), S. Ramsay (ESO) and L. Testi (ESO; INAF/Osservatorio Astrofisico di Arcetri, Firenze, Italy).

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Links:

Research paper: http://www.eso.org/public/archives/releases/sciencepapers/eso1518/eso1518a.pdf

Photos of the VLT: http://www.eso.org/public/images/archive/category/paranal/

Photos of MUSE: http://www.eso.org/public/images/archive/search/?adv=&subject_name=MUSE

Images, Videos, Text, Credits: ESO/M. Kornmesser/IAU and Sky & Telescope/Digitized Sky Survey 2. Acknowledgment: Davide De Martin.

Greetings, Orbiter.ch

NASA’s New Horizons Detects Surface Features, Possible Polar Cap on Pluto












NASA - New Horizons Mission logo.

April 30, 2015

For the first time, images from NASA’s New Horizons spacecraft are revealing bright and dark regions on the surface of faraway Pluto – the primary target of the New Horizons close flyby in mid-July.

Artist's view of New Horizons spacecraft on Pluto orbit. Image Credits: NASA

The images were captured in early to mid-April from within 70 million miles (113 million kilometers), using the telescopic Long-Range Reconnaissance Imager (LORRI) camera on New Horizons. A technique called image deconvolution sharpens the raw, unprocessed images beamed back to Earth. New Horizons scientists interpreted the data to reveal the dwarf planet has broad surface markings – some bright, some dark – including a bright area at one pole that may be a polar cap.

“As we approach the Pluto system we are starting to see intriguing features such as a bright region near Pluto’s visible pole, starting the great scientific adventure to understand this enigmatic celestial object,” says John Grunsfeld, associate administrator for NASA’s Science Mission Directorate in Washington. “As we get closer, the excitement is building in our quest to unravel the mysteries of Pluto using data from New Horizons."

Also captured in the images is Pluto’s largest moon, Charon, rotating in its 6.4-day long orbit. The exposure times used to create this image set – a tenth of a second – were too short for the camera to detect Pluto’s four much smaller and fainter moons.


Image above: This image of Pluto and it largest moon, Charon, was taken by the Long Range Reconnaissance Imager (LORRI) on NASA’s New Horizons spacecraft on April 15, 2015. The image is part of several taken between April 12-18, as the spacecraft’s distance from Pluto decreased from about 69 million miles (111 million kilometers) to 64 million miles (104 million kilometers). Image Credits: NASA/JHU-APL/SwRI.

Since it was discovered in 1930, Pluto has remained an enigma. It orbits our sun more than 3 billion miles (about 5 billion kilometers) from Earth, and researchers have struggled to discern any details about its surface. These latest New Horizons images allow the mission science team to detect clear differences in brightness across Pluto’s surface as it rotates.

“After traveling more than nine years through space, it’s stunning to see Pluto, literally a dot of light as seen from Earth, becoming a real place right before our eyes,” said Alan Stern, New Horizons principal investigator at Southwest Research Institute in Boulder, Colorado. “These incredible images are the first in which we can begin to see detail on Pluto, and they are already showing us that Pluto has a complex surface.”

The images the spacecraft returns will dramatically improve as New Horizons speeds closer to its July rendezvous with Pluto.

“We can only imagine what surprises will be revealed when New Horizons passes approximately 7,800 miles (12,500 kilometers) above Pluto’s surface this summer,” said Hal Weaver, the mission’s project scientist at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland.

APL designed, built, and operates the New Horizons spacecraft, and manages the mission for NASA’s Science Mission Directorate. SwRI leads the science team, payload operations and encounter science planning. New Horizons is part of the New Frontiers Program managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama.

To view images from New Horizons and learn more about the mission, visit: http://www.nasa.gov/newhorizons

Images (mentioned), Text, Credits: NASA/Dwayne Brown/Johns Hopkins University Applied Physics Laboratory/Michael Buckley.

Best regards, Orbiter.ch

mercredi 29 avril 2015

Tracking Japan’s asteroid impact mission








ESA logo.

29 April 2015

ESA is set to support Japan’s ‘touch-and-go’ Hayabusa-2 spacecraft, now en route to a little-known asteroid, helping to boost the scientific return from this audacious mission.

A flawless launch last December marked the start of a six-year round-trip for Japan’s Hayabusa-2, which is on course to arrive at the carbon-rich asteroid 1999 JU3 in June 2018.

Hayabusa-2 dispatches European Mascot lander

Once there, it will study the surface in detail in preparation for dispatching three diminutive landing drones. It will also deliver the Mascot lander, developed by the DLR German Aerospace Center in cooperation with France’s CNES space agency and equipped with a ‘hopper’ mechanism to enable it to explore the tiny world from multiple locations.

Hayabusa will also use explosives to fire a copper impactor into the 980 m-diameter asteroid, then scoop up the debris fragments in a complex touch-and-go manoeuvre. The fragments will be returned to Earth in 2020.

Tracking deep in space

In the first such support provided to a Japanese deep-space mission, ESA’s 35 m-diameter dish at Malargüe, Argentina, will provide up to 400 hours of tracking, establishing radio contact as the asteroid arcs through the Solar System between 135 million to 210 million km from the Sun. 

Telecommands from mission controllers at the Japan Aerospace and Exploration Agency (JAXA) will be fed to the station via ESOC, ESA’s European Space Operations Centre, Germany.

Malargüe station

 The sophisticated technology and location of ESA’s station will enable Hayabusa-2 to deliver significantly more science data and provide coverage when Japanese stations are out of visibility.

In the past, ESOC has supported JAXA’s Earth and astronomy missions, including Oicets and Astro-F.

“This is the first time we’ve supported a Japanese deep-space mission, so we’ve been working closely with JAXA in the past months to establish technical links between the ground station and the Hayabusa mission systems,” said Maite Arza, ESA’s Service Manager for Hayabusa at ESOC.

World-class tracking technology

Together with similar stations in Spain and Australia, the Malargüe site comprises the deep-space tracking capability of ESA’s Estrack network.

Estrack’s global system of ground stations provides links between spacecraft in orbit and control teams on Earth. The network is controlled from ESOC, and provides tracking support to ESA and partner agency missions 24 hours/day, 365 days/year. The network will celebrate its 40th anniversary this year.

Tracking network control room

“On 22 April, we completed a live, inflight compatibility test, linking Malargüe with the Japanese spacecraft, demonstrating that we're ready to provide tracking for the incredible Hayabusa-2 mission,” says Maite.

“We look forward to helping our Japanese colleagues explore asteroid 1999 JU3, demonstrate advanced technology and achieve some excellent scientific results.”

Related link:

ESA’s Estrack network: http://www.esa.int/Our_Activities/Operations/Estrack_tracking_stations

ESOC - European Space Operations Centre: http://www.esa.int/About_Us/ESOC

JAXA: http://global.jaxa.jp/

Hayabusa-2: http://b612.jspec.jaxa.jp/hayabusa2/e/hayabusa2_e.html

Images, Text, Credits: ESA/J. Mai/JAXA.

Greetings, Orbiter.ch

NASA's NuSTAR Captures Possible 'Screams' from Zombie Stars














NASA - Nuclear Spectroscopic Telescope Array (NuSTAR) patch.


April 29, 2015


Image above: NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, has captured a new high-energy X-ray view of the bustling center of our Milky Way galaxy. Image Credits: NASA/JPL-Caltech.

Peering into the heart of the Milky Way galaxy, NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) has spotted a mysterious glow of high-energy X-rays that, according to scientists, could be the "howls" of dead stars as they feed on stellar companions.

"We can see a completely new component of the center of our galaxy with NuSTAR's images," said Kerstin Perez of Columbia University in New York, lead author of a new report on the findings in the journal Nature. "We can't definitively explain the X-ray signal yet -- it's a mystery. More work needs to be done."

The center of our Milky Way galaxy is bustling with young and old stars, smaller black holes and other varieties of stellar corpses – all swarming around a supermassive black hole called Sagittarius A*.

NuSTAR, launched into space in 2012, is the first telescope capable of capturing crisp images of this frenzied region in high-energy X-rays. The new images show a region around the supermassive black hole about 40 light-years across. Astronomers were surprised by the pictures, which reveal an unexpected haze of high-energy X-rays dominating the usual stellar activity.

"Almost anything that can emit X-rays is in the galactic center," said Perez. "The area is crowded with low-energy X-ray sources, but their emission is very faint when you examine it at the energies that NuSTAR observes, so the new signal stands out."


Image above: NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, has captured a new high-energy X-ray view (magenta) of the bustling center of our Milky Way galaxy. The smaller circle shows the center of our galaxy where the NuSTAR image was taken. Image Credits: NASA/JPL-Caltech.

Astronomers have four potential theories to explain the baffling X-ray glow, three of which involve different classes of stellar corpses. When stars die, they don't always go quietly into the night. Unlike stars like our sun, collapsed dead stars that belong to stellar pairs, or binaries, can siphon matter from their companions. This zombie-like "feeding" process differs depending on the nature of the normal star, but the result may be an eruption of X-rays.

According to one theory, a type of stellar zombie called a pulsar could be at work. Pulsars are the collapsed remains of stars that exploded in supernova blasts. They can spin extremely fast and send out intense beams of radiation. As the pulsars spin, the beams sweep across the sky, sometimes intercepting the Earth, like lighthouse beacons.

"We may be witnessing the beacons of a hitherto hidden population of pulsars in the galactic center," said co-author Fiona Harrison of the California Institute of Technology (Caltech) in Pasadena, and principal investigator of NuSTAR. "This would mean there is something special about the environment in the very center of our galaxy."

Other possible culprits include heavy-set stellar corpses called white dwarfs, which are the collapsed, burned-out remains of stars not massive enough to explode in supernovae. Our sun is such a star, and is destined to become a white dwarf in about five billion years. Because these white dwarfs are much denser than they were in their youth, they have stronger gravity and can produce higher-energy X-rays than normal. Another theory points to small black holes that slowly feed off their companion stars, radiating X-rays as material plummets down into their bottomless pits.

NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR. Image Credits: NASA/JPL-Caltech

Alternatively, the source of the high-energy X-rays might not be stellar corpses at all, astronomers say, but rather a diffuse haze of charged particles, called cosmic rays. The cosmic rays might originate from the supermassive black hole at the center of the galaxy as it devours material. When the cosmic rays interact with surrounding, dense gas, they emit X-rays.

However, none of these theories match what is known from previous research, leaving the astronomers largely stumped.

"This new result just reminds us that the galactic center is a bizarre place," said co-author Chuck Hailey of Columbia University. "In the same way people behave differently walking on the street instead of jammed on a crowded rush hour subway, stellar objects exhibit weird behavior when crammed in close quarters near the supermassive black hole."

The team says more observations are planned. Until then, theorists will be busy exploring the above scenarios or coming up with new models to explain what could be giving off the puzzling high-energy X-ray glow.

"Every time that we build small telescopes like NuSTAR, which improve our view of the cosmos in a particular wavelength band, we can expect surprises like this," said Paul Hertz, the astrophysics division director at NASA Headquarters in Washington.

NuSTAR is a Small Explorer mission led by Caltech and managed by NASA's Jet Propulsion Laboratory in Pasadena, California, for NASA's Science Mission Directorate in Washington.

More information is online at: http://www.nasa.gov/nustar

Images (mentioned), Text, Credits: NASA/Felicia Chou/JPL/Whitney Clavin/Karen Northon.

Greetings, Orbiter.ch

Nepal earthquake on the radar








ESA - Sentinel-1 Mission logo.

29 April 2015

Sentinel-1

On 25 April, a 7.8-magnitude earthquake struck Nepal, claiming over 5000 lives and affecting millions of people. Satellite images are being used to support emergency aid organisations, while geo-scientists are using satellite measurements to analyse the effects of the earthquake on the land.

Radar imagery from the Sentinel-1A satellite shows that the maximum land deformation is only 17 km from Nepal’s capital, Kathmandu, which explains the extremely high damage experienced in this area.

Nepal earthquake

By combining Sentinel-1A imagery acquired before and after the quake, changes on the ground that occurred between the two acquisition dates lead to rainbow-coloured interference patterns in the combined image, known as an ‘interferogram’, enabling scientists to quantify the ground movement.

Sentinel-1A’s swath width of 250 km over land surfaces has allowed for an unprecedented area size to be analysed from a single scan. The entire area will be covered under the same geometry every 12 days, allowing for the wider region to be regularly monitored and fully analysed for land deformation with the powerful ‘interferometry’ technique.

Earthquake deformation

Products ensuring a full coverage of the affected area prior to the earthquake were available to all scientists under the Copernicus free and open data policy, and will continue to be available.

Sentinel-1A is the first satellite for the Copernicus environment-monitoring programme led by the European Commission. Its all-weather, day-or-night radar imagery is particularly suited to support impact assessment for many types of geohazards. The satellite is planned to provide systematic observations of tectonic and volcanic areas at global level.

Kathmandu fringes

Imagery from the Sentinels and other Copernicus contributing missions are coordinated by ESA to be used by the Copernicus Emergency Management Service (EMS), which supports all phases of the emergency management cycle.

The Copernicus EMS was activated on the day the earthquake struck, prompting ESA to begin collecting satellite imagery, which is being made available to support relief efforts.

Grading map (Click on the image for enlarge)

In parallel, the International Charter Space and Major Disasters was activated by India, China and the UN. Partner Agencies of this initiative have been providing data and products over the area to relief organisations.

Related links:

Sentinel-1: http://www.esa.int/Our_Activities/Observing_the_Earth/Copernicus/Sentinel-1

INSARAP: http://insarap.org/

SERTIT: http://sertit.u-strasbg.fr/

DLR ZKI: http://www.dlr.de/

Geohazards TEP: https://geohazards-tep.eo.esa.int/#!

Copernicus EMS: Nepal: http://emergency.copernicus.eu/mapping/list-of-components/EMSR125

International Charter Space and Major Disasters: http://www.disasterscharter.org/

European Commission Copernicus site: http://www.copernicus.eu/

Images, text, Credits: ESA/Contains Copernicus data (2015)/Norut/PPO.labs/INGV–ESA COMET–ESA SEOM INSARAP study/DLR Microwaves and Radar Institute/GFZ/e-GEOS/R. Grandin/IPGP/CNRS/DigitalGlobe/European Commission.

Best regards, Orbiter.ch

Progress M-27M began its fall to Earth ...











ROSCOSMOS - Russian Vehicles patch.

April 29, 2015

A Russian cargo ship adrift in space

Progress M cargo spacecraft

Russia has lost control of the unmanned Russian space freighter was to supply the ISS (International Space Station) and the machine that initiated his fall to Earth. "He started his fall," said on condition of anonymity responsible in the Russian space complex, adding that "totally uncontrollable reactions had begun."

Until then, the Russian control center had spoken only transmission problems for Progress. "The ship reached orbit, but the telemetry data is not transmitted in full," he had said Tuesday a spokesman for the Russian control center. NASA had also communicated his side on Twitter about the problem encountered by the ship.

NASA Tweet screen capture

The spacecraft was not carrying any supplies critical for the United States Operating Segment (USOS) of the station. Both the Russian and USOS segments of the station continue to operate normally and are adequately supplied well beyond the next planned resupply flight. The next mission scheduled to deliver cargo to the station is the seventh SpaceX commercial resupply services mission targeted for launch no earlier than June 19. It will carry about 5,000 pounds of science investigations and supplies.

The cargo of Progress 59 includes more than three tons of food, fuel, and supplies for the space station crew, including 1,940 pounds of propellant, 110 pounds of oxygen, 926 pounds of water, and 3,128 pounds of spare parts, supplies and scientific experiment hardware. Among the U.S. supplies on board are spare parts for the station’s environmental control and life support system, backup spacewalk hardware, and crew clothing, all of which are replaceable and his potential loss would not create a problem for the six crew members of the ISS that have several months of reserves.

video
 Progress M-27M Visibly Spinning Out of Control

A failure of the launcher?

NASA confirmed "carries no vital lifeline for the operation of the American part of the ISS" and confirmed that the vessel did not meet this deadline, and for docking was due to "repair appointment system -you "with the ISS.

According to the Russian news agency Tass, citing a source in the aerospace industry, the freighter Progress M-27M was launched Tuesday morning by a Soyuz rocket from Baikonur, had not managed to position itself on desired orbit "because of a failure of the launcher."

video
  Russian Space Station Freighter Launches

A replica of the Soviet flag 1945

Roscosmos, the Russian space agency, has also specified that the cargo contained a replica of the Soviet flag hoisted by the Red Army in Berlin in 1945.

The flag, symbolizing the Soviet victory over Nazi on the Second World War, should be used by Russian cosmonauts on the ISS to send their wishes to the Russians on May 9, on the occasion of the celebrations of the Allied victory in the Second World War.

In 2011, a Soyuz rocket carrying a similar cargo ship had failed and crashed in the Altai region (Mongolian and Chinese borders), shortly after its launch. Three to four Progress cargo ships are launched every year, providing materials and supplies necessary for life on the ISS. After their mission they fall and burn up in the atmosphere above the Pacific Ocean.

As teams continue to monitor the spacecraft, additional updates and more information about the International Space Station will be available online at: http://www.nasa.gov/mission_pages/station/main/index.html

Images, Videos, Text, Credits: NASA/NASA TV/ROSCOSMOS TV/AFP/Orbiter.ch Aerospace.

Greetings, Orbiter.ch