vendredi 15 novembre 2013

'Murray Ridge' on Rim of Endeavour Crater on Mars












NASA - Mars Science Laboratory (MSL) patch.

Nov. 15, 2013


This scene shows the "Murray Ridge" portion of the western rim of Endeavour Crater on Mars. The ridge is the NASA's Mars Exploration Rover Opportunity's work area for the rover's sixth Martian winter.

The ridge rises about 130 feet (40 meters) above the surrounding plain, between "Solander Point" at the north end of the ridge and "Cape Tribulation," beyond Murray Ridge to the south. This view does not show the entire ridge. The visible ridge line is about 10 meters (33 feet) above the rover's location when the component images were taken.

The scene sweeps from east to south. The planar rocks in the foreground at the base of the hill are part of a layer of rocks laid down around the margins of the crater rim. At this location, Opportunity is sitting at the contact between the Meridiani Planum sandstone plains and the rocks of the Endeavour Crater rim. On the upper left, the view is directed about 22 kilometers (14 miles) across the center of Endeavour crater to the eastern rim.

Opportunity landed on Mars in January 2004 and has been investigating parts of Endeavour's western rim since August 2011.

Artist's view of the Mars Science Laboratory (MSL) "Curiosity" on Mars

The scene combines several images taken by the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity during the 3,446th Martian day, or sol, of the mission's work on Mars (Oct. 3, 2013) and the following three sols. On Sol 3451 (Oct. 8, 2013), Opportunity began climbing the ridge. The slope offers outcrops that contain clay minerals detected from orbit and also gives the rover a northward tilt that provides a solar-energy advantage during the Martian southern hemisphere's autumn and winter.

The rover team chose to call this feature Murray Ridge in tribute to Bruce Murray (1931-2013), an influential advocate for planetary exploration who was a member of the science teams for NASA's earliest missions to Mars and later served as director of NASA's Jet Propulsion Laboratory, in Pasadena.

This view is presented in approximately true color, merging 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).

NASA's Mars Science Laboratory Project is using Curiosity to assess whether areas inside Gale Crater ever offered a habitable environment for microbes. JPL, a division of the California Institute of Technology in Pasadena, manages the project for NASA's Science Mission Directorate in Washington.

More information about Curiosity is online at http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl/ . You can follow the mission on Facebook at: http://www.facebook.com/marscuriosity and on Twitter at: http://www.twitter.com/marscuriosity

Images, Text, Credits: NASA / JPL-Caltech / Cornell / ASU.

Best regards, Orbiter.ch

jeudi 14 novembre 2013

NASA-USGS Landsat Data Yield Best View to Date of Global Forest Losses, Gains












NASA - U.S. Geological Survey Landsat 7 satellite patch.

Nov. 14, 2013

The ravages of deforestation, wildfires, windstorms and insects on global forests during this century are revealed in unprecedented detail in a new study based on data from the NASA-U.S. Geological Survey Landsat 7 satellite.

 Landsat 7 satellite in orbit. Image Credit:  NASA

The maps resulting from the study are the first to document forest loss and gain using a consistent method around the globe, at high resolution. They allow scientists to compare forest changes in different countries and monitor annual deforestation. With each pixel in a Landsat image showing an area about the size of a baseball diamond, researchers see enough detail to tell local, regional and global stories.

“Now, we have 12 years of annual forest loss over the globe,” said Matthew Hansen, whose team at the University of Maryland in College Park, Md., led the new study.


Image above: Using Landsat imagery and cloud computing, researchers mapped forest cover worldwide as well as forest loss and gain. Over 12 years, 888,000 square miles (2.3 million square kilometers) of forest were lost, and 309,000 square miles (800,000 square kilometers) regrew. Image Credit:  NASA Goddard, based on data from Hansen et al., 2013.

Hansen and colleagues analyzed 143 billion pixels in 654,000 Landsat images to compile maps of forest loss and gain between 2000 and 2012. During that period, 888,000 square miles (2.3 million square kilometers) of forest were lost, and 309,000 square miles (800,000 square kilometers) regrew. The researchers, including scientists from the University of Maryland, Google, the State University of New York, Woods Hole Research Center, the U.S. Geological Survey (USGS) and South Dakota State University, published their work in the Nov. 15 issue of the journal Science.

Key to the project was collaboration with team members from Google Earth Engine, who reproduced in the Google Cloud the models developed at the University of Maryland for processing and characterizing the Landsat data.

During the study period, Brazil cut its deforestation rate from approximately 15,400 square miles (40,000 square kilometers) per year to approximately 7,700 square miles (20,000 square kilometers) per year.

"That's the result of a concerted policy effort to reduce deforestation, and it sets a standard for the rest of the world," Hansen said.

The team found that the deforestation rate in other countries increased.  Indonesia's deforestation rate doubled in the study period, from approximately 3,900 square miles (10,000 square kilometers) per year in 2000-2003 to more than 7,700 square miles (20,000 square kilometers) in 2011-2012.


Image above: The border between Malaysia and Indonesia on the island of Borneo stands out in the Landsat-based map of forest disturbance. Red pixels represent forest loss between 2000 and 2012. Image Credit: NASA Goddard, based on data from Hansen et al., 2013.

Prior to this study, country-to-country comparisons of forestry data were not possible at this level of accuracy. Different countries define forests differently, making previous global comparisons difficult with existing inventories.

"When you put together datasets that employ different methods and definitions, it's hard to synthesize," Hansen said. "But with Landsat, as a polar-orbiting instrument that takes the same quality pictures everywhere, we can apply the same algorithm to forests in the Amazon, in the Congo, in Indonesia, and so on. It's a huge improvement in our global monitoring capabilities."

"Since the first Landsat satellite launched 41 years ago, scientists have been improving their land cover analysis as computers have become more powerful," said Jeff Masek, Landsat project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "Projects like Hansen's took a big leap forward once USGS made the data freely available on the Internet in 2008."

"This is the first time somebody has been able to do a wall-to-wall, global Landsat analysis of all the world's forests -- where they're being cleared, where they're regrowing, and where they're subject to natural disturbances," Masek said, noting that the maps could be routinely updated to aid in carbon accounting and other studies of land cover change.

The maps also illustrate the impact of politics on land cover. On the island of Borneo, the maps clearly show the border between Malaysia and Indonesia. Malaysia's heavy logging along forest roads is visible right up to the Indonesian border, where forests were still largely intact as of 2012. In Côte d'Ivoire, a civil war in 2002 corresponded with intense deforestation of several previously protected nature reserves.


Image above: Civil unrest in Côte d'Ivoire was associated with widespread deforestation in national parks, including Marahoué National Park. Other protected areas, such as Tai National Park, remained intact. Image Credit: NASA Goddard, based on data from Hansen et al., 2013.

A different pattern of change appears in the southeastern U.S., where landowners harvest trees for timber and quickly plant their replacements.

"Of this eco-region in the southeast, 30 percent of the forest land was regrown or lost during this period," Hansen said. "It's incredibly intensive. Trees are really treated like a crop in this region."


Image above: The forest cover maps also capture natural disturbances such as this 2011 tornado path in Alabama. In this map, the colors represent forest loss by year, with yellows representing loss closer to 2000 and reds representing later forest loss, up to 2012. Image Credit: NASA Goddard, based on data from Hansen et al., 2013.

In Alabama, Landsat also detected miles-long streaks of destroyed forest. When the researchers examined the year-by-year record, they found the damage occurred in 2011 after a violent tornado season.

Since 1972, the Landsat program has played a critical role in monitoring, understanding and managing the resources needed to sustain human life such as food, water and forests. Landsat 8 was launched Feb. 11 and is managed jointly by NASA and USGS to continue the 40-plus years of Earth observations.

To view the forest cover maps in Google Earth Engine, visit: http://earthenginepartners.appspot.com/google.com/science-2013-global-forest

For more information about the Landsat satellites, visit: http://www.nasa.gov/landsat

Images (mentioned), Text, Credit: NASA's Goddard Space Flight Center / Kate Ramsayer.

Greetings, Orbiter.ch

Hubble Reveals First Pictures of Milky Way's Formative Years












NASA - Hubble Space Telescope patch.

Nov. 14, 2013


NASA's / ESA's Hubble Space Telescope has revealed the first visual evidence of how our home galaxy, the Milky Way, assembled itself into the majestic pinwheel of stars we see today.

Astronomers used Hubble's deep-sky surveys to study the evolution of 400 galaxies similar to the Milky Way and noted their appearance at various stages of development over a time span of 11 billion years. Judging from images of these far-flung galaxies, they found the Milky Way likely began as faint, blue, low-mass object containing lots of gas. Gas is the fuel for star birth and the blue color is an indicator of rapid star formation.

They also found the Milky Way probably was a flat disk with a bulge in the middle, both of which grew simultaneously into the majestic spiral seen today. The sun and Earth reside in the disk and the bulge is both full of older stars and home to a supermassive black hole that probably grew along with the galaxy.

Galaxies Similar to the Milky Way

"For the first time, we have direct images of what the Milky Way looked like in the past," said study co-leader Pieter G. van Dokkum of Yale University in New Haven, Conn. "Of course, we can't see the Milky Way itself in the past. We selected galaxies billions of light-years away that will evolve into galaxies like the Milky Way. By tracing the Milky Way's siblings, we find that our galaxy built up 90 percent of its stars between 11 billion and 7 billion years ago, which is something that has not been measured directly before."

The Hubble telescope's superior resolving power, with which it can see extremely fine details, allowed the researchers to study how the structure of the Milky Way changed over time. At the peak of star formation, when the universe was about 4 billion years old, the Milky Way-like galaxies were pumping out about 15 stars a year. By comparison, the Milky Way today is creating only one star a year.

Artist's Illustration of the Present Milky Way

"You can see that these galaxies are fluffy and spread out," said study co-leader Shannon Patel of Leiden University in The Netherlands. "There is no evidence of a bulge without a disk, around which the disk formed later." Team member Erica Nelson, of Yale University, added: "These galaxies show us the whole Milky Way grew at the same time, unlike more massive elliptical galaxies, in which the central bulge forms first."

To identify the far-flung galaxies and study them in detail, the research team used three of the largest Hubble programs, the 3D-HST survey, the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey and the Great Observatories Origins Deep Survey. These surveys combined spectroscopy with visible and near-infrared imaging by Hubble's Wide Field Camera 3 and Advanced Camera for Surveys.

Artist's Illustration of the Early Milky Way

The research team's analysis involved measuring the distances and sizes of the galaxies. The astronomers calculated the mass of each galaxy from its brightness and colors. They selected the galaxies in their census from a catalog they compiled of more than 100,000 galaxies. The survey galaxies are consistent with computer models, which show at early stages, a majority of the bulges of spiral galaxies were built up at the same time as their corresponding disks.

"In these observations, we're capturing most of the evolution of the Milky Way," explained team member Joel Leja of Yale University. "These deep surveys allow us to see the smaller galaxies. In previous observations we could only see the most luminous galaxies in the distant past, and now we can look at more normal galaxies. Hubble gives us the shapes and colors of these spirals as well as their distances from Earth. We also can measure the rates at which each part of the galaxies grew. All of this is difficult to do from the ground."

The team’s results were published July 10 in The Astrophysical Journal Letters. A second paper appears in the Nov. 11 online edition of The Astrophysical Journal.

Notes for editors:

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

For images and more information about the Milky Way’s formative years, visit: http://hubblesite.org/news/2013/45 and http://www.nasa.gov/hubble and http://www.spacetelescope.org/

Images, Text, Credits: NASA, ESA, and Z. Levay (STScI/AURA)/P. van Dokkum (Yale University), S. Patel (Leiden University), and the 3D-HST Team.

Greetings, Orbiter.ch

Ariane 6 moves to next stage of development











ESA - European Space Agency patch.

14 November 2013

Ariane 6

The preliminary requirements for Europe’s next-generation Ariane 6 launcher have been agreed and the project is set to move on to the next stage.

In November 2012, the ESA Council at Ministerial level, meeting in Naples, Italy, approved the start of preparatory activities for Europe’s next-generation Ariane 6 launch vehicle.

The objective of Ariane 6 is to guarantee autonomous access to space for Europe, serving European institutional missions, without requiring public support to exploit.

The performance requested for the new vehicle is up to 6.5 tonnes in equivalent geostationary transfer orbit, to cover both institutional and commercial needs. The configuration retained was ‘PPH’ – indicating the sequence of stages: a first and a second stage using solid propulsion (P) and a third stage using cryogenic propulsion (H).

Ministers also requested that the new vehicle exploits maximum commonalities with the cryogenic reignitable upper stage of Ariane 5 ME.

In early July, seven months after ESA’s Ministerial Council decision, the concept for the Ariane 6 vehicle was selected.

video
Ariane 6 animation

On 1 October the Preliminary Requirements Review of the launch system began. The management plans and the preliminary specifications together with the technical and programmatic files of the concept were submitted for review.

The review was concluded by the board on 6 November. The review involved European experts from Arianespace, Italy’s ASI space agency, France’s CNES space agency, the DLR German Aerospace Center and ESA. European customers also participated and contributed to the consolidation of the Mission Requirement Document, which will drive the development.

The next step for the Ariane 6 project is the completion of a first Design Analysis Cycle, which is planned for the end of February, and which includes trade-offs for several subsystems. A second Design Analysis Cycle will start in March. The results of the second loop will feed the next ESA review: the System Requirements Review, planned for October–November 2014.

In parallel, ESA has consulted industry to gather competing ideas on key launcher elements. More than 160 responses were received, and ESA is completing their evaluation. This will allow the progressive setting up of the industrial organisation, awarding contracts to subcontractors for the second Design Analysis Cycle and receiving an industry proposal for the full development of Ariane 6 in preparation for the next ESA Ministerial Council meeting.

“Decisions taken by the ESA Council at Ministerial level in November 2012 are being implemented strictly and timely,” noted Antonio Fabrizi, ESA’s Director of Launchers.

For more information about the European launchers, visit: http://www.esa.int/Our_Activities/Launchers/

Image, Video, Text, Credits: ESA / D. Ducros.

Cheers, Orbiter.ch

Hubble views an old and mysterious cluster












ESA - Hubble Space Telescope logo.

14 November 2013

New Hubble image of star cluster Messier 15

The NASA/ESA Hubble Space Telescope has captured the best ever image of the globular cluster Messier 15, a gathering of very old stars that orbits the centre of the Milky Way. This glittering cluster contains over 100 000 stars, and could also hide a rare type of black hole at its centre.

Wide field image of star cluster Messier 15 (ground-based view)

This multi-coloured firework display is a cluster of stars known as Messier 15, located some 35 000 light-years away in the constellation of Pegasus (The Winged Horse). It is one of the oldest globular clusters [1] known, with an age of around 12 billion years.

Very hot blue stars and cooler golden stars are seen swarming together in this image, becoming more concentrated towards the cluster's bright centre. Messier 15 is one of the densest globular clusters known, with most of its mass concentrated at its core.

video
A rare and exotic intermediate-mass black hole (artist’s impression)

However, this sparkling bauble has hidden secrets. Astronomers studying the cluster with Hubble in 2002 found there to be something dark and mysterious lurking at its heart. It could either be a collection of dark neutron stars [2], or an intermediate-mass black hole. Of the two possibilities it is more likely that Messier 15 harbours a black hole at its centre, as does the massive globular cluster Mayall II.

video
View of a globular cluster (artist’s impression)

Intermediate-mass black holes are thought to form either from the merging of several smaller, stellar-mass black holes, or as a result of a collision between massive stars in dense clusters. A third possibility is that they were formed during the Big Bang. In terms of mass they lie between the more commonly found stellar-mass and supermassive types of black hole [3], and could tell us about how black holes grow and evolve within clusters like Messier 15, and within galaxies.

video
View of a Sun-like star within an open cluster (artist’s impression)

As well as this black hole, Messier 15 is known to house a planetary nebula, Pease 1 [4] — and it was the first globular known to contain one of these objects [5]. This nebula is visible as the bright blue object just to the left of the cluster's centre.

video
Zooming on star cluster Messier 15

This new image is made up of observations from Hubble's Wide Field Camera 3 and Advanced Camera for Surveys in the ultraviolet, infrared and optical parts of the spectrum.

video
Panning across star cluster Messier 15

Notes:

[1] A globular cluster is a roughly spherical group of stars that orbits the core of a galaxy. The Milky Way has over 150 of these starry satellites — including Messier 15. However, other galaxies have many more than this; a staggering 160 000 were recently discovered by Hubble in the galaxy cluster Abell 1689 (heic1317). Globular clusters contain some of the most ancient stars in the Universe.

[2] A neutron star is formed from the collapse of a massive star. They are very hot and very dense, with an average mass of around two solar masses contained within a radius of tens of kilometres.

[3] Stellar-mass black holes have masses of a few to a few tens of times the mass of the Sun. Supermassive black holes have masses ranging from hundreds of thousands to billions of times the mass of the Sun.

[4] Pease 1 is also known as PN Ku 648, or Kürster 648.

[5] Since the discovery of Pease 1, only three other globular clusters have been found to host planetary nebulae: Messier 22, NGC 6441, and Palomar 6. This number is so low because planetary nebulae are a very brief, short-lived phase at the end of the lives of low to moderate mass stars — which are not common within globular clusters.

Notes for editors:

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

Links:

Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/

For more information about NASA / ESA Hubble Space Telescope: http://www.nasa.gov/hubble and http://www.spacetelescope.org/

Images, Text, Credit: NASA / ESA / Digitized Sky Survey 2 / Videos: NASA, ESA, and M. Kornmesser /  Digitized Sky Survey 2, Nick Risinger (skysurvey.org). Music: movetwo.

Best regards, Orbiter.ch

Mars - Deep freeze












ESA - Mars Express Mission patch.

Nov. 14, 2013

Ismeniae Fossae

This scene shows a section of Ismeniae Fossae that straddles the southern highlands–northern lowlands of Mars. The 2 km-wide curvilinear trough that runs through this image contains numerous parallel grooves and ridges comprising material from the trough walls and material that has been dragged along the floor by ancient glaciers and ice-rich flows.

In the left portion of the scene the channel truncates a roughly 25 km-wide crater. Material in the crater walls has slumped down into the channel, smoothing over the grooved floor.

Around this crater, and elsewhere in Ismeniae Fossae, clusters of circular to elliptical, partially interconnected depressions are observed. These may be either secondary impact craters from debris flung out by larger impact craters, or collapse pits caused by the sublimation of subsurface ice.

The western portion of the 138 km-wide Moreux Crater is seen in the bottom right of the image. Numerous small dendritic valley systems west of the crater provide further evidence of water flowing in this region at some point in the Red Planet’s past, perhaps as water melting from the ice thought to have once covered this region.

The image was taken by the High Resolution Stereo Camera on ESA’s Mars Express on 16 June 2013 (orbit 11709), with a ground resolution of about 20 m per pixel. The image centre is at approximately 40°N / 42°E.

Ismeniae Fossae topography

This colour-coded topography map shows the heights and depths of features within Ismeniae Fossae. White and red show the highest terrains, while blue and purple show the deepest. The edge of Moreux crater is seen in the lower right as the deepest feature in this scene.

The region was imaged by the High Resolution Stereo Camera on ESA’s Mars Express on 16 June 2013 (orbit 11709), with a ground resolution.

Ismeniae Fossae perspective

Branches in the 2 km-wide trough of Ismeniae Fossae are seen in close-up detail in this scene. Material in the channels likely derived from the walls subsequently transported by glaciers or water flowing through the region. Smaller dendritic valley systems formed by water – possibly from melting ice – are seen at the bottom left and in the upper right portion of the image. The clusters of circular to elliptical depressions in the bottom left may be either secondary impact craters from debris flung out by larger impact craters, or collapse pits caused by the sublimation of subsurface ice.

This region was imaged by the High Resolution Stereo Camera on ESA’s Mars Express on 16 June 2013 (orbit 11709), with a ground resolution of about 20 m per pixel. The scene is located at approximately 40°N / 42°E.

Ismeniae Fossae 3D

Data from the nadir channel and one stereo channel of the High Resolution Stereo Camera on ESA’s Mars Express have been combined to produce this anaglyph 3D image of Ismeniae Fossae, which can be viewed using stereoscopic glasses with red–green or red–blue filters.

This region was imaged on 16 June 2013 (orbit 11709), with a ground resolution of about 20 m per pixel. The image centre is located at approximately 40°N / 42°E.

For more information about Mars Express Mission, visit: http://www.esa.int/Our_Activities/Space_Science/Mars_Express

Images, Text, Credits: ESA / DLR / FU Berlin (G. Neukum).

Greetings, Orbiter.ch

mercredi 13 novembre 2013

Black hole boasts heavyweight jets












ESA - XMM-Newton Mission patch.

13 November 2013

Black hole with disc and jets

Astronomers studying a black hole in our Galaxy with ESA’s XMM-Newton observatory have made a surprising discovery about the cocktail of particles that are ejected from its surroundings.

Stellar-mass black holes are often found feasting on material from a companion star. Matter flows from the star towards the black hole, circling in a disc around it with a temperature so high that it emits X-rays.

The black hole can be a fussy eater: instead of swallowing all of the material, it sometimes pushes a fraction of it away in the form of two powerful jets of particles. Because these jets release mass and energy into the surroundings, the black hole has less material to feed on.

By studying the composition of the jets, we can learn more about the feeding habits of black holes.

Observations at radio wavelengths have already found that black hole jets contain electrons moving at close to the speed of light. But, until now, it was not clear whether the negative charge of the electrons is complemented by their anti-particles, positrons, or rather by heavier positively-charged particles in the jets, like protons or atomic nuclei.

In a new study, astronomers have used XMM-Newton to study a black hole binary system called 4U1630–47, well known to show outbursts of X-rays over periods of months and years.

“In our observations, we found signs of highly ionised nuclei of two heavy elements, iron and nickel,” says María Díaz Trigo of the European Southern Observatory in Munich, Germany, lead author of the paper published in the journal Nature.

“The discovery came as a surprise – and a good one, since it shows beyond doubt that the composition of black hole jets is much richer than just electrons.”

The team of astronomers observed 4U1630–47 with XMM-Newton on two occasions in September 2012, and compared the results with near-simultaneous radio observations from the Australia Telescope Compact Array.

Although the two sets of observations described by Dr Díaz Trigo and collaborators were separated by only a couple of weeks, the results were surprisingly different.

In the first set of observations, the astronomers detected X-rays from the accretion disc, but did not see anything in radio waves – a sign that the jets were not active.

But in the second set, they detected the source both in X-rays and radio waves, so they knew the jets had been reactivated in the meantime.

ESA's XMM-Newton spacecraft

When scrutinising the X-ray data from the second batch of observations, the astronomers also found tell-tale signs of iron nuclei moving both towards and away from XMM-Newton, providing confirmation that the ions belong to the two jets, pointing in opposite directions.

The astronomers also found evidence of nickel nuclei in the jet pointing towards XMM-Newton.

“From these ‘fingerprints’ of iron and nickel, we could show that the speed of the jet is very high, about two-thirds of the speed of light,” says co-author James Miller-Jones from the Curtin University node of the International Centre for Radio Astronomy Research in Perth, Australia.

“Moreover, the presence of heavy atomic nuclei in black hole jets means that mass and energy are being carried away from the black hole in much larger amounts than we previously thought, which may have an impact on the mechanism and rate by which the black hole accretes matter,” adds co-author Simone Migliari from the University of Barcelona, Spain.

This is the first time that heavy nuclei have been detected in the jets of a relatively typical stellar-mass black hole.

There is only one other X-ray binary that shows similar signatures from atomic nuclei in its jets – a source known as SS 433. This black hole system, however, is characterised by an unusually high accretion rate, which makes it difficult to compare its properties to those of more ordinary black holes.

The new observations of 4U1630–47 will help astronomers learn more about the physical mechanism that launches jets from a black hole’s accretion disc.

“While we now know a great deal about black holes and what happens around them, the formation of jets is still a big puzzle, so this observation is a major step forward in understanding this fascinating phenomenon,” says Norbert Schartel, ESA's XMM-Newton Project Scientist.

“Baryons in the relativistic jets of the stellar-mass black hole candidate 4U1630–47,” by M. Díaz Trigo et al. is published in Nature, 14 November 2013.

For more information about XMM-Newton Mission, visit: http://sci.esa.int/xmm-newton/

Images, Text, Credits: ESA, Markus Bauer / ESO, María Díaz Trigo / XMM-Newton Project Scientist, Norbert Schartel / ATG medialab.

Best regards, Orbiter.ch

Hubble Catches Stellar Explosions in NGC 6984











NASA - Hubble Space Telescope patch.

Nov. 13, 2013

Spiral galaxy NGC 6984

Supernovae are intensely bright objects. They are formed when a star reaches the end of its life with a dramatic explosion, expelling most of its material out into space. The subject of this new Hubble image, spiral galaxy NGC 6984, played host to one of these explosions back in 2012, known as SN 2012im. Now, another star has exploded, forming supernova SN 2013ek — visible in this image as the prominent, star-like bright object just slightly above and to the right of the galaxy's center.

SN 2012im is known as a Type Ic supernova, while the more recent SN 2013ek is a Type Ib. Both of these types are caused by the core collapse of massive stars that have shed — or lost — their outer layers of hydrogen. Type Ic supernovae are thought to have lost more of their outer envelope than Type Ib, including a layer of helium.

The observations that make up this new image were taken on August 19,  2013, and aimed to pinpoint the location of this new explosion more precisely. It is so close to where SN 2012im was spotted that the two events are thought to be linked; the chance of two completely independent supernovae so close together and of the same class exploding within one year of one another is a very unlikely event. It was initially suggested that SN 2013ek may in fact be SN 2012im flaring up again, but further observations support the idea that they are separate supernovae — although they may be closely related in some as-yet-unknown way.

Notes:

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, Text, Credit: NASA / ESA / Hubble.

Greetings, Orbiter.ch

Young Stars Paint Spectacular Stellar Landscape












ESO - European Southern Observatory logo.

13 November 2013

The star cluster NGC 3572 and its dramatic surroundings

Astronomers at ESO have captured the best image so far of the curious clouds around the star cluster NGC 3572. This new image shows how these clouds of gas and dust have been sculpted into whimsical bubbles, arcs and the odd features known as elephant trunks by the stellar winds flowing from this gathering of hot young stars. The brightest of these cluster stars are much heavier than the Sun and will end their short lives as supernova explosions.

Most stars do not form alone, but with many siblings that are created at about the same time from a single cloud of gas and dust. NGC 3572, in the southern constellation of Carina (The Keel), is one of these clusters. It contains many hot young blue-white stars that shine brightly and generate powerful stellar winds that tend to gradually disperse the remaining gas and dust from their surroundings. The glowing gas clouds and accompanying cluster of stars are the subjects of a new picture from the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile [1].

The star cluster NGC 3572 in the constellation of Carina

In the lower part of the image a big chunk of the molecular cloud that gave birth to these stellar youngsters still can be seen. It has been dramatically affected by the powerful radiation coming from its smoldering offspring. The radiation not only makes it glow with a characteristic hue, but also sculpts the clouds into amazingly convoluted shapes, including bubbles, arcs and the dark columns that astronomers call elephant trunks [2].

A strange feature captured in this image is the tiny ring-like nebula located slightly above the centre of the image. Astronomers still are a little uncertain about the origin of this curious feature. It is probably a dense leftover from the molecular cloud that formed the cluster, perhaps a bubble created around a very bright hot star. But some authors have considered that it may be some kind of oddly shaped planetary nebula — the remnants of a dying star [3].

Wide-field view of the sky around the star cluster NGC 3572

Stars born inside a cluster may be siblings, but they are not twins. They have almost the same age, but differ in size, mass, temperature, and colour. The course of a star's life is determined largely by its mass, so a given cluster will contain stars in various stages of their lives, giving astronomers a perfect laboratory in which they can study how stars evolve [4].

video
Zooming in on the star cluster NGC 3572

These gangs of young stars stick together for a relatively short time, typically tens or hundreds of millions of years. They are gradually disbanded by gravitational interactions, but also because the most massive stars are short-lived, burning through their fuel quickly and ultimately ending their lives in violent supernova explosions, thus contributing to the dispersion of the remaining gas and stars in the cluster.

video
A close look at the star cluster NGC 3572 and its dramatic surroundings

Notes:

[1] The data used to create this picture were obtained by a team led by ESO astronomer Giacomo Beccari. They used the power of the Wide Field Imager to study the physics of protoplanetary discs in the young stars in NGC 3572. They were surprised to find that this cluster contains stars older than ten million years that are still unambiguously undergoing mass accretion and, therefore, must still be surrounded by discs. This proves that the star formation in NGC 3572 has been ongoing for at least 10–20 million years and would imply that the planet formation process could proceed on much longer timescales than previously thought.

[2] The most famous examples of such elephant trunk features are the Pillars of Creation in the Eagle Nebula, which were captured in exquisite detail by the NASA/ESA Hubble Space Telescope (http://www.spacetelescope.org/images/opo9544a/).

[3] When a Sun-like star uses up all its fuel, it puffs its outer layers off into the surrounding space. The hot remains of the star continue to shine strongly into this material, creating beautiful but short-lived glowing shells of ionised gas and forming a so-called planetary nebula. This historical name is only related to the appearance of the object in a small telescope, not to a physical relation to a planet.

[4] The lifetime of a star depends dramatically on how heavy it is. A star fifty times more massive than the Sun will have a life of only a few million years, the Sun will live for about ten billion years whereas low-mass red dwarf stars can live for trillions of years — much longer than the current age of the Universe.

More information:

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 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. 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 the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning the 39-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Links:

Handback of 2.2-metre telescope: http://www.eso.org/public/announcements/ann13078/

Images taken with the MPG/ESO 2.2-metre telescope: http://www.eso.org/public/images/archive/search/?adv=&facility=15

Images of the MPG/ESO 2.2-metre telescope: http://www.eso.org/public/images/archive/search/?adv=&subject_name=mpg

ESO press releases with results from the MPG/ESO 2.2-metre telescope: http://www.eso.org/public/news/archive/search/?adv=&facility=15

Images, Text, Credits: ESO / G. Beccari / IAU and Sky & Telescope / Digitized Sky Survey 2. Acknowledgement: Davide De Martin / Videos: ESO/G. Beccari / Nick Risinger (skysurvey.org). Music: movetwo.

Best regards, Orbiter.ch

mardi 12 novembre 2013

Cassini Spacecraft Provides New View of Saturn and Earth














Cassini International Mission logo.


Nov. 12, 2013

The Day the Earth Smiled

Image above: On July 19, 2013, in an event celebrated the world over, NASA / ESA Cassini spacecraft slipped into Saturn's shadow and turned to image the planet, seven of its moons, its inner rings -- and, in the background, our home planet, Earth. Image Credit: NASA/JPL-Caltech/SSI.

Story Highlights:

- Natural-color portrait that is first to show Saturn, its moons and rings, plus Earth, Venus and Mars

- Sweeps nearly 405,000 miles across Saturn and its inner rings

NASA has released a natural-color image of Saturn from space, the first in which Saturn, its moons and rings, and Earth, Venus and Mars, all are visible.

The new panoramic mosaic of the majestic Saturn system taken by NASA's Cassini spacecraft, which shows the view as it would be seen by human eyes, was unveiled at the Newseum in Washington on Tuesday.

Cassini's imaging team processed 141 wide-angle images to create the panorama. The image sweeps 404,880 miles (651,591 kilometers) across Saturn and its inner ring system, including all of Saturn's rings out to the E ring, which is Saturn's second outermost ring. For perspective, the distance between Earth and our moon would fit comfortably inside the span of the E ring.

"In this one magnificent view, Cassini has delivered to us a universe of marvels," said Carolyn Porco, Cassini's imaging team lead at the Space Science Institute in Boulder, Colo. "And it did so on a day people all over the world, in unison, smiled in celebration at the sheer joy of being alive on a pale blue dot."

The mosaic is part of Cassini's "Wave at Saturn" campaign, where on July 19, people for the first time had advance notice a spacecraft was taking their picture from planetary distances. NASA invited the public to celebrate by finding Saturn in their part of the sky, waving at the ringed planet and sharing pictures over the Internet.

 The Faces of 'Wave at Saturn'

Image above: This collage includes about 1,600 images submitted by members (myself included) of the public as part of the NASA Cassini mission's "Wave at Saturn" campaign. Image Credit: NASA/JPL-Caltech/SSI.

An annotated version of the Saturn system mosaic labels points of interest. Earth is a bright blue dot to the lower right of Saturn. Venus is a bright dot to Saturn’s upper left. Mars also appears, as a faint red dot, above and to the left of Venus. Seven Saturnian moons are visible, including Enceladus on the left side of the image. Zooming into the image reveals the moon and the icy plume emanating from its south pole, supplying fine, powder-sized icy particles that make up the E ring.

The E ring shines like a halo around Saturn and the inner rings. Because it is so tenuous, it is best seen with light shining from behind it, when the tiny particles are outlined with light because of the phenomenon of diffraction. Scientists who focus on Saturn's rings look for patterns in optical bonanzas like these. They use computers to increase dramatically the contrast of the images and change the color balance, for example, to see evidence for material tracing out the full orbits of the tiny moons Anthe and Methone for the first time.

“This mosaic provides a remarkable amount of high-quality data on Saturn’s diffuse rings, revealing all sorts of intriguing structures we are currently trying to understand," said Matt Hedman, a Cassini participating scientist at the University of Idaho in Moscow. "The E ring in particular shows patterns that likely reflect disturbances from such diverse sources as sunlight and Enceladus’ gravity.”

Cassini does not attempt many images of Earth because the sun is so close to our planet that an unobstructed view would damage the spacecraft's sensitive detectors. Cassini team members looked for an opportunity when the sun would slip behind Saturn from Cassini's point of view. A good opportunity came on July 19, when Cassini was able to capture a picture of Earth and its moon, and this multi-image, backlit panorama of the Saturn system.

Cassini spacecraft. Image Credit: NASA/ESA

"With a long, intricate dance around the Saturn system, Cassini aims to study the Saturn system from as many angles as possible," said Linda Spilker, Cassini project scientist based at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Beyond showing us the beauty of the Ringed Planet, data like these also improve our understanding of the history of the faint rings around Saturn and the way disks around planets form -- clues to how our own solar system formed around the sun."

Launched in 1997, Cassini has explored the Saturn system for more than nine years. NASA plans to continue the mission through 2017, with the anticipation of many more images of Saturn, its rings and moons, as well as other scientific data.

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

To view the image, visit: http://photojournal.jpl.nasa.gov/catalog/pia17172 .

A new version of the collage of photos shared by the public, with the Saturn system as backdrop, is available at: http://photojournal.jpl.nasa.gov/catalog/pia17679 .

More information about Cassini is available at: http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov  and http://www.esa.int/Our_Activities/Space_Science/Cassini-Huygens

Images (mentioned), Text, Credits: NASA / Dwayne Brown / JPL / Jia-Rui C. Cook / SSI / Steve Mullins.

Greetings, Orbiter.ch

Spitzer and ALMA Reveal a Star's Bubbly Birth












NASA - Spitzer Space Telescope patch.

Nov. 11, 2013

Bubbly Newborn Star

Image above: Combined observations from NASA's Spitzer Space Telescope and the newly completed Atacama Large Millimeter/submillimeter Array (ALMA) in Chile have revealed the throes of stellar birth, as never before, in the well-studied object known as HH 46/47. Image Credit: NASA/JPL-Caltech/ALMA.

It's a bouncing baby . . . star! Combined observations from NASA's Spitzer Space Telescope and the newly completed Atacama Large Millimeter/submillimeter Array (ALMA) in Chile have revealed the throes of stellar birth as never before in the well-studied object known as HH 46/47.

Herbig-Haro (HH) objects form when jets shot out by newborn stars collide with surrounding material, producing small, bright, nebulous regions. To our eyes, the dynamics within many HH objects are obscured by enveloping gas and dust. But the infrared and submillimeter wavelengths of light seen by Spitzer and ALMA, respectively, pierce the dark cosmic cloud around HH 46/47 to let us in on the action.

The Spitzer observations show twin supersonic jets emanating from the central star that blast away surrounding gas and set it alight into two bubbly lobes. HH 46/47 happens to sit on the edge of its enveloping cloud in such a way that the jets pass through two differing cosmic environments. The rightward jet, heading into the cloud, is plowing through a "wall" of material, while the leftward jet's path out of the cloud is relatively unobstructed, passing through less material. This orientation serves scientists well by offering a handy compare-and-contrast setup for how the outflows from a developing star interact with their surroundings.

Spitzer Space Telescope. Image Credit: NASA/JPL-Caltech

"Young stars like our sun need to remove some of the gas collapsing in on them to become stable, and HH 46/47 is an excellent laboratory for studying this outflow process," said Alberto Noriega-Crespo, a scientist at the Infrared Processing and Analysis Center at the California Institute of Technology, Pasadena, Calif. "Thanks to Spitzer, the HH 46/47 outflow is considered one of the best examples of a jet being present with an expanding bubble-like structure."

Noriega-Crespo led the team that began studying HH 46/47 with Spitzer nearly 10 years ago when the telescope first began observing the heavens. Now, using a new image processing technique developed in the past few years, he and his colleagues have been able to render HH 46/47 in higher resolution.

Meanwhile, the fresh views of HH 46/47 by ALMA have revealed that the gas in the lobes is expanding faster than previously thought. This faster expansion has an influence on the overall amount of turbulence in the gaseous cloud that originally spawned the star. In turn, the extra turbulence could have an impact on whether and how other stars might form in this gaseous, dusty, and thus fertile, ground for star-making.

A team led by Hector Arce at Yale University, New Haven, Conn., carried out the ALMA observations and their analysis was published recently in The Astrophysical Journal.

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Spacecraft operations are based at Lockheed Martin Space Systems Company, Littleton, Colorado. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA. For more information about Spitzer, visit http://spitzer.caltech.edu and http://www.nasa.gov/spitzer.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile.

Images (mentioned), Text, Credits: NASA / JPL / Whitney Clavin.

Cheers, Orbiter.ch

lundi 11 novembre 2013

Proton-M rocket launch with a military satellite












ROSCOSMOS logo.

Nov. 11, 2013

Russian workhorse rocket is delivering a classified communications satellite for the nation's armed forces Tuesday.

Proton-M night launch

The official Russian sources confirmed that the launch of a Proton-M rocket with a Briz-M upper stage took place as scheduled on Nov. 12, 2013, 03:46:00 Moscow Time (6:46 p.m. EST on November 11) from Pad No. 24 at Site 81 in Baikonur.

video
 Liftoff Proton-M with Raduga-1 spacecraft in the interests of the Defense Ministry

Although the nature of the payload is not being disclosed at the time of the launch, industry sources previously indicated that the vehicle would carry a Raduga-1M (Globus-1M) communications satellite for the Russian Ministry of Defense. It is believed to be the third satellite in the Raduga-1M series.

An official depiction of the Raduga-1 satellite

According to the official RIA Novosti news agency, Major General Aleksandr Golovko, the commander of the Russian Air and Space Defense forces, VKO, personally witnessed the launch in Baikonur. The agency then quoted a VKO spokesman Dmitry Zenin as saying that the spacecraft was scheduled to separate from its upper stage at 12:47 Moscow Time on Nov. 12, 2013, (3:47 a.m. EST), or nine hours and one minute after liftoff. The Russian ground control network would then enter communications with the spacecraft at 13:02 Moscow Time (4:02 a.m. EST) on the same day.

The launch with Raduga-1M became the eighth mission of the Proton rocket in 2013.

Images, Video, Text, Credits: ROSCOSMOS / ROSCOSMOS TV / RussianSpaceWeb.com / Anatoly Zak / ISS Reshetnev / Gunter's Space Page.

Best regards, Orbiter.ch

dimanche 10 novembre 2013

Expedition 37 Crew, Olympic Torch Land in Kazakhstan












ROSCOSMOS - Soyuz TMA-09M Mission patch.

Nov. 10, 2013

Three Expedition 37 crew members have landed after 166 days in space, completing a 70.3 million mile mission spanning more than 2,600 orbits of the Earth since their launch to the International Space Station in May.


Image above: The Soyuz TMA-9M carrying Expedition 37 Fyodor Yurchikhin and Flight Engineers Karen Nyberg and Luca Parmitano lands in Kazakhstan.

The Soyuz TMA-09M spacecraft carrying Expedition 37 Commander Fyodor Yurchikhin and Flight Engineers Karen Nyberg and Luca Parmitano landed in the steppe of Kazakhstan southeast of Dzhezkazgan at 9:49 p.m. Sunday (8:49 a.m. Monday, Kazakh time). A Russian recovery team and NASA personnel reached the landing site by helicopter shortly afterward to assist the crew and conduct health assessments.

Soyuz Commander Yurchikhin undocked the Soyuz TMA-09M spacecraft from aft end the Zvezda service module at 6:26 p.m. EST Sunday as the station soared 262 miles over northeast Mongolia. The deorbit burn at 8:55 p.m. slowed the Soyuz for its decent into the Earth’s atmosphere and its parachute-assisted landing.

video
 Landing of Soyuz TMA-09M with Olympic Torch & Expedition 37 crew

The undocking marked the end of Expedition 37 and the start of Expedition 38 under the command of Oleg Kotov. Yurchikhin passed the helm of the station over to Kotov during a change of command ceremony Sunday before he, Nyberg and Parmitano boarded their Soyuz and the hatches between the spacecraft were closed at 3:09 p.m.

Returning to Earth along with Yurchikhin, Nyberg and Parmitano was the torch that will be used to light the Olympic flame at the Feb. 7 opening ceremonies of the 2013 Winter Olympic Games in Sochi, Russia.

The Olympic torch arrived at the space station Thursday aboard the Soyuz TMA-11M spacecraft carrying three new crew members – Expedition 38 Flight Engineers Mikhail Tyurin, Rick Mastracchio and Koichi Wakata. To accommodate their arrival, Yurchikhin, Nyberg and Parmitano relocated their Soyuz spacecraft on Nov. 1 from the Rassvet module where it had been docked since May 28 over to Zvezda. The arrival of Mastracchio, Wakata and Tyurin marked the first time since October 2009 that nine people have served together aboard the station without the presence of a space shuttle.

 Expedition 37 Lands, Brings Olympic Torch Back to Earth

Kotov and Flight Engineer Sergey Ryazanskiy relayed the torch outside the station Saturday during a spacewalk to continue setting up a combination extravehicular activity workstation and biaxial pointing platform and deactivate a completed experiment.

Kotov, Ryazanskiy and Flight Engineer Mike Hopkins, who launched and docked to the station aboard the Soyuz TMA-10M vehicle on Sept. 25, will return to Earth on March 12. Their departure will signify the beginning of Expedition 39 under the command of Wakata, the first Japan Aerospace Exploration Agency astronaut entrusted with that position.

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

Images, Video, Text, Credits: NASA / NASA TV / ROSCOSMOS.

Best regards, Orbiter.ch

Expedition 37 Crew, Olympic Torch Returning to Earth












ROSCOSMOS - Soyuz TMA-09M Mission patch.

Nov. 10, 2013

Three Expedition 37 crew members are on their way back to Earth after 166 days aboard the International Space Station.

Soyuz Commander Fyodor Yurchikhin and Flight Engineers Karen Nyberg and Luca Parmitano undocked their Soyuz TMA-09M spacecraft from aft end the Zvezda service module at 6:26 p.m. EST Sunday to begin the journey home.  At the time of the undocking, the complex was orbiting 262 miles over northeast Mongolia.

video
Expedition 37 Crew Heads Back to Earth

A deorbit burn at 8:55 p.m. will put the Soyuz on track for a parachute-assisted landing in the steppe of Kazakhstan southeast of Dzhezkazgan at 9:49 p.m. (8:49 a.m. Monday, Kazakh time).


Image above: The Soyuz TMA-09M spacecraft backs away from the International Space Station shortly after undocking at 6:26 p.m. EST Sunday. Image Credit: NASA TV.

NASA Television will air live coverage of the Soyuz landing activities beginning at 8:30 p.m.: http://www.nasa.gov/multimedia/nasatv/index.html

The undocking  marked the end of Expedition 37 and the start of Expedition 38 under the command of Oleg Kotov. Yurchikhin passed the helm of the station over to Kotov during a change of command ceremony  Sunday.  After making their final farewells, Yurchikhin, Parmitano and Nyberg boarded their Soyuz,  and the crews closed the hatches between the vehicles at 3:09 p.m.

Returning to Earth along with Yurchikhin, Nyberg and Parmitano is the torch that will be used to light the Olympic flame at the Feb. 7 opening ceremonies of the 2013 Winter Olympic Games in Sochi, Russia.

video
Expedition 37 Bids Farewell to Station Crewmates

The Olympic torch arrived at the space station Thursday aboard the Soyuz TMA-11M spacecraft carrying three new crew members – Expedition 38 Flight Engineers Mikhail Tyurin, Rick Mastracchio and Koichi Wakata.  To accommodate their arrival, Yurchikhin, Nyberg and Parmitano relocated their Soyuz spacecraft on Nov. 1 from the Rassvet module where it had been docked since May 28 over to Zvezda. The arrival of Mastracchio, Wakata and Tyurin marked the first time since October 2009 that nine people have served together aboard the station without the presence of a space shuttle.

Kotov and Flight Engineer Sergey Ryazanskiy relayed the torch outside the station Saturday during a spacewalk to continue setting up a combination extravehicular activity workstation and biaxial pointing platform and deactivate a completed experiment.

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

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

Greetings, Orbiter.ch