samedi 15 octobre 2011
NASA - Chandra X-ray Observatory patch.
Oct. 15, 2011
The Carina Nebula is a star-forming region in the Sagittarius-Carina arm of the Milky Way that is 7,500 light years from Earth and the Chandra X-Ray Observatory has detected more than 14,000 stars in the region.
Chandra's X-ray vision provides strong evidence that massive stars have self-destructed in this nearby star-forming region. Firstly, there is an observed deficit of bright X-ray sources in the area known as Trumpler 15, suggesting that some of the massive stars in this cluster were already destroyed in supernova explosions. Trumpler 15 is located in the northern part of the image and is one of ten star clusters in the Carina complex.
The detection of six possible neutron stars, the dense cores often left behind after stars explode in supernovas, provides additional evidence that supernova activity is increasing up in Carina. Previous observations had only detected one neutron star in Carina.
For more information about Chandra X-ray Observatory, visit: http://chandra.si.edu/
Image, Text, Credit: NASA / CXC / Penn State / L. Townsley et al.
Publié par Orbiter.ch à 15:11
jeudi 13 octobre 2011
CNSA - China National Space Agency logo.
Oct. 13, 2011
Launch of Shenzhou 8 and docking between Tiangong-1 & Shenzhou-8:
Launch date: 1 November 2011 (launch time: hours not reported).
Launch vehicle: Long March 2F
Payload: Shenzhou 8
Launch time: TBD
Launch site: Jiuquan, China
A Chinese Long March 2F rocket launch Shenzhou 8 Will we have n Conduct unmanned flight to the country's first docking spacecraft in orbit Between Two. Shenzhou 8 Will rendezvous and dock with the Tiangong 1 module Launched in September 2011.
Shenzhou 8 in thermal vacuum chamber test
The space module Tiangong-1 dock Shenzhou-8 to November 3. Tiangong-1 entered the designated orbit to await Shenzhou-8, a ship without a crew.
Once the two spacecraft have made their rendezvous in space, they dock with 340 km above the earth. According to the chief engineer of the project, the operation will take place two days after the launch of Shenzhou-8. Then Tiangong-1 will change to a higher orbit for the arrival of Shenzhou-9 and Shenzhou-10.
Docking between Tiangong-1 & Shenzhou-8 (Artist's view)
During the mission, experiments will be conducted with, among others, the University of Zurich in Switzerland:
- Project “Innate Immunity in microgravity”, SHENZHOU-8 Space Ship Mission, PI: Prof. Dr. Dr. Oliver Ullrich. German Aerospace Center DLR and China Manned Space Engineering Office (CMSEO).
University of Zurich (Switzerland): http://www.anatom.uzh.ch/research/Appliedanatomy-1/DivisionUllrich-1.html
China Space Administration: http://www.cnsa.gov.cn/n615709/cindex.html
Images, Text, Credits: CNSA / CASC / CMSEO / Orbiter.ch.
Publié par Orbiter.ch à 15:42
ESA - Hubble Space Telescope logo.
13 October 2011
Hubble image of galaxy cluster MACS
The NASA/ESA Hubble Space Telescope has been used to make an image of galaxy cluster MACS J1206.2-0847. The apparently distorted shapes of distant galaxies in the background is caused by an invisible substance called dark matter, whose gravity bends and distorts their light rays. MACS 1206 has been observed as part of a new survey of galaxy clusters using Hubble.
Cluster MACS J1206.2-0847 (or MACS 1206 for short) is one of the first targets in a Hubble survey that will allow astronomers to construct the highly detailed dark matter maps of more galaxy clusters than ever before. These maps are being used to test previous but surprising results that suggest that dark matter is more densely packed inside clusters than some models predict. This might mean that galaxy cluster assembly began earlier than commonly thought.
Wide field view of MACS 1206 (ground-based image)
The Cluster Lensing And Supernova survey with Hubble (CLASH) probes, with unparalleled precision, the distribution of dark matter in 25 massive clusters of galaxies. So far, the CLASH team has observed six of the 25 clusters.
Dark matter makes up the bulk of the Universe’s mass, yet it can only be detected by measuring how its gravity tugs on visible matter and warps the fabric of space-time like a fairground mirror so that the light from distant objects is distorted.
Galaxy clusters like MACS 1206 are perfect laboratories for studying dark matter’s gravitational effects because they are the most massive structures in the Universe to be held together by gravity. Because of their immense gravitational pull, the clusters act like giant cosmic lenses, amplifying, distorting and bending any light that passes through them — an effect known as gravitational lensing.
Zoom on MACS 1206
Lensing effects can also produce multiple images of the same distant object, as is evident in this Hubble picture. In particular, the apparent numbers and shapes of the distant galaxies far beyond a galaxy cluster become distorted as the light passes through, yielding a visible measurement of how much mass there is in the intervening cluster, and how it is distributed. The substantial lensing distortions seen are proof that the dominant mass component of the clusters is dark matter. The distortions would be far weaker if the clusters’ gravity came only from visible matter.
MACS 1206 lies four billion light-years from Earth. Hubble’s keen vision helped CLASH astronomers to uncover 47 multiple images of 12 newly identified faraway galaxies. Finding so many multiple images in a cluster is a unique capability of Hubble, and the CLASH survey is optimised to find them. The new observations build on earlier work by Hubble and ground-based telescopes.
Among the observations which complement Hubble’s is a major project using the European Southern Observatory’s Very Large Telescope. Unlike Hubble, which is making images of the clusters, the VLT is carrying out spectroscopic observations, where instruments split up the galaxies’ light into their component colours letting the scientists draw inferences about many of the properties of the cluster galaxies, including their distance and chemical makeup.
Taking advantage of two of Hubble’s powerful cameras, the Advanced Camera for Surveys and the Wide Field Camera 3, the CLASH survey covers a broad wavelength range, from ultraviolet to near-infrared.
Astronomers need the diverse colours to estimate the distances to the lensed galaxies and to study them in more detail. Hubble’s unique capabilities allow astronomers to estimate distances to galaxies that are four times fainter than those that ground-based telescopes can see.
The era when the first clusters formed is not precisely known, but is estimated to be at least nine billion years ago and possibly as far back as twelve billion years ago. If most of the clusters in the CLASH survey are found to have excessively high accumulations of dark matter in their central cores, then it may yield new clues about the early stages of the origin of structure in the Universe.
Future telescopes like the NASA/ESA/CSA James Webb Space Telescope (JWST), a space-based infrared observatory now being built, will be able to study the fainter lensed galaxies in clusters like MACS 1206 in greater detail. JWST will be powerful enough to observe the spectra of some of the magnified galaxies and study their early chemical composition.
The Hubble Space Telescope is a project of international cooperation between ESA and NASA.
Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/
NASA release: http://hubblesite.org/news/2011/25
CLASH survey: http://www.stsci.edu/~postman/CLASH/Home.html
Images, Text, Credits: NASA / ESA / M. Postman (STScI) and the CLASH Survey Team / Digitized Sky Survey 2 (Acknowledgement: Davide De Martin) / Videos: NASA / ESA / Digitzed Sky Survey 2 / M. Postman (STScI) and the CLASH Survey Team / Music: John Dyson (from the album Moonwind).
Publié par Orbiter.ch à 07:21
mercredi 12 octobre 2011
Qu8k Rockets logo / KickSat.org logo.
Oct. 13, 2011
On some points, we saw a really great time!
While the sending of objects beyond our atmosphere was kept the field of companies with huge financial resources, it is now possible for amateurs to send rockets into space, and even to consider the creation of a fleet of small satellites very economical.
The rest of this article may make you want to create a shooting range in your garden!
Qu8k Rocket launch
The project Qu8k was to send a rocket above 30 km altitude, in order to win the award Carmack (link below, in related links section).
Created by John Cramack, creator of the legendary video games Doom and Quake, the competition can win a prize symbol of $ 5 000, and a very good advertising of the project if successful.
I'll let you see the video of rocket launch, as well as his short stay in space:
Qu8k Rocket Launch Highlights - On board GoPro HD at 22 mile
Certainly this kind of tinkering is not for everyone, not least as qualified to determine the ideal design for a rocket of this size, not including the handling of solid fuels (and potentially explosive) ...
Qu8k Rocket (click on the image for enlarge)
However, you can learn more about the site from the creators of this project (Qu8K link below, in related links section).
Send rockets into space is fine, but it should also find a more practical interest is not it? And if we sent mini-satellites economic, about $ 300 each?
It's a crazy idea launched on Kickstarter, a site that allows projects to find funding for their launches.
KickSat consist of a simple electronic circuit consisting of solar cells to provide energy to the micro-satellite, a microcontroller to control functions and a radio transmitter.
The first version does that send radio a unique identifier, and the names of contributors associated with the project. In the near future, and if the project succeeds, it is planned to incorporate sensors, allowing these mini-satellites to handle more functions.
For the launch, there are plans to use a program with NASA, which would save the cost of launch to validate the tests of these satellites personal.
When is a combination of these two projects? It may be in the near future, even more objects randomly walking around in space just above our heads ...
The Price Carmack: http://blog.crashspace.org/2011/03/the-carmack-prize/
Qu8K Rocket: http://ddeville.com/derek/Qu8k.html
Images, Videos, Text, Credits: Nikopik / Derek Deville / KickSat.org / Translation: Orbiter.ch, a suggested article by Alexandre Girardot.
Best regards, Orbiter.ch
Publié par Orbiter.ch à 22:21
ISRO - Indian Space Research Organization logo.
Oct. 12, 2011
The 50 hour countdown commenced at 09:00 hours October 10, 2011. India's Polar Satellite Launch Vehicle (PSLV) as launched the Megha-Tropiques research satellite. Jointly managed by India and France, the mission will study the water cycle and climate in the tropics.
PSLV-C18 Take Off
Launched at 0530 GMT (1:30 a.m. EDT).
Launch of Megha-Tropiques Satellite On Indian PSLV
Launch site: Satish Dhawan Space Center, Sriharikota, India.
PSLV-C18 to injected Megha-Tropiques satellite into an orbit of 867 km altitude at an inclination of 20 deg with respect to equator. PSLV will also inject SRMSat from SRM University, Chennai, JUGNU from Indian Institute of Technology, Kanpur and Vesselsat-1 from Luxembourg.
For more information about the launch and payloads (brochure pdf): http://www.isro.org/pslv-c18/pdf/pslv-c18-brochure.pdf
Images, Video, Text, Credits. ISRO / CNES / Orbiter.ch.
Publié par Orbiter.ch à 14:12
NASA - Dawn Mission patch.
Oct. 12, 2011
Scientists with NASA's Dawn mission are sharing with other scientists and the public their early information about the southern hemisphere of the giant asteroid Vesta. The findings were presented today at the annual meeting of the Geological Society of America in Minneapolis, Minn.
Dawn, which has been orbiting Vesta since mid-July, has found that the asteroid's southern hemisphere boasts one of the largest mountains in the solar system. Other findings show that Vesta's surface, viewed by Dawn at different wavelengths, has striking diversity in its composition, particularly around craters. Science findings also include an in-depth analysis of a set of equatorial troughs on Vesta and a closer look at the object's intriguing craters. The surface appears to be much rougher than most asteroids in the main asteroid belt. In addition, preliminary dates from a method that uses the number of craters indicate that areas in the southern hemisphere are as young as 1 billion to 2 billion years old, much younger than areas in the north.
This full view of the giant asteroid Vesta was taken by NASA's Dawn spacecraft, as part of a rotation characterization sequence on July 24, 2011, at a distance of 3,200 miles (5,200 kilometers). Image credit: NASA / JPL-Caltech / UCLA / MPS /DLR / IDA.
Scientists do not yet understand how all the features on Vesta's surface formed, but they did announce today, after analysis of northern and southern troughs, that results are consistent with models of fracture formation due to giant impact.
Since July, the Dawn spacecraft has been spiraling closer and closer to Vesta, moving in to get better and better views of the surface. In early August, the spacecraft reached an orbital altitude of 1,700 miles (2,700 kilometers) and mapped most of the sunlit surface, during survey orbit, with its framing camera and visible and infrared mapping spectrometer.
That phase was completed in late August, and the spacecraft began moving in to what is known as High Altitude Mapping Orbit at about 420 miles (680 kilometers) above Vesta, which it reached on Sept. 29.
An archive of the live news conference is available for viewing at: http://www.ustream.tv/nasajpl2 .
The Dawn scientists also shared their findings at the recent European Planetary Science Congress and the Division of Planetary Sciences Joint Meeting 2011 in Nantes, France.
Dawn launched in September 2007 and arrived at Vesta on July 15, 2011. Following a year at Vesta, the spacecraft will depart in July 2012 for the dwarf planet Ceres, where it will arrive in 2015.
Dawn's mission to Vesta and Ceres is managed by the Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. in Dulles, Va., designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team.
For more information about the Dawn mission, visit: http://www.nasa.gov/dawn and http://dawn.jpl.nasa.gov .To follow the mission on Twitter, visit:http://www.twitter.com/NASA_Dawn
Image (mentioned), Text, Credits: NASA / JPL / Priscilla Vega.
Publié par Orbiter.ch à 13:15
ESO - European Southern Observatory logo.
12 October 2011
New VLT observations chart timeline of reionisation
Artist’s impression of galaxies at the end of the era of reionisation
Scientists have used ESO’s Very Large Telescope to probe the early Universe at several different times as it was becoming transparent to ultraviolet light. This brief but dramatic phase in cosmic history — known as reionisation — occurred around 13 billion years ago. By carefully studying some of the most distant galaxies ever detected, the team has been able to establish a timeline for reionisation for the first time. They have also demonstrated that this phase must have happened quicker than astronomers previously thought.
An international team of astronomers used the VLT as a time machine, to look back into the early Universe and observe several of the most distant galaxies ever detected. They have been able to measure their distances accurately and find that we are seeing them as they were between 780 million and a billion years after the Big Bang .
The new observations have allowed astronomers to establish a timeline for what is known as the age of reionisation  for the first time. During this phase the fog of hydrogen gas in the early Universe was clearing, allowing ultraviolet light to pass unhindered for the first time.
A galaxy seen when the Universe was only 820 million years old
The new results, which will appear in the Astrophysical Journal, build on a long and systematic search for distant galaxies that the team has carried out with the VLT over the last three years.
“Archaeologists can reconstruct a timeline of the past from the artifacts they find in different layers of soil. Astronomers can go one better: we can look directly into the remote past and observe the faint light from different galaxies at different stages in cosmic evolution,” explains Adriano Fontana, of INAF Rome Astronomical Observatory who led this project. “The differences between the galaxies tell us about the changing conditions in the Universe over this important period, and how quickly these changes were occurring.”
Different chemical elements glow brightly at characteristic colours. These spikes in brightness are known as emission lines. One of the strongest ultraviolet emission lines is the Lyman-alpha line, which comes from hydrogen gas . It is bright and recognisable enough to be seen even in observations of very faint and faraway galaxies.
Spotting the Lyman-alpha line for five very distant galaxies  allowed the team to do two key things: first, by observing how far the line had been shifted toward the red end of the spectrum, they were able to determine the galaxies’ distances, and hence how soon after the Big Bang they could see them . This let them place them in order, creating a timeline which shows how the galaxies’ light evolved over time. Secondly, they were able to see the extent to which the Lyman-alpha emission — which comes from glowing hydrogen within the galaxies — was reabsorbed by the neutral hydrogen fog in intergalactic space at different points in time.
A galaxy seen when the Universe was only 840 million years old
“We see a dramatic difference in the amount of ultraviolet light that was blocked between the earliest and latest galaxies in our sample,” says lead author Laura Pentericci of INAF Rome Astronomical Observatory. “When the Universe was only 780 million years old this neutral hydrogen was quite abundant, filling from 10 to 50% of the Universe’ volume. But only 200 million years later the amount of neutral hydrogen had dropped to a very low level, similar to what we see today. It seems that reionisation must have happened quicker than astronomers previously thought.”
As well as probing the rate at which the primordial fog cleared, the team’s observations also hint at the likely source of the ultraviolet light which provided the energy necessary for reionisation to occur. There are several competing theories for where this light came from — two leading candidates are the Universe’s first generation of stars , and the intense radiation emitted by matter as it falls towards black holes.
"The detailed analysis of the faint light from two of the most distant galaxies we found suggests that the very first generation of stars may have contributed to the energy output observed," says Eros Vanzella of the INAF Trieste Observatory, a member of the research team. "These would have been very young and massive stars, about five thousand times younger and one hundred times more massive than the Sun, and they may have been able to dissolve the primordial fog and make it transparent."
The highly accurate measurements required to confirm or disprove this hypothesis, and show that the stars can produce the required energy, require observations from space, or from ESO’s planned European Extremely Large Telescope, which will be the world’s largest eye on the sky once completed early next decade.
Animation of artist’s impression of galaxies at the end of the era of reionisation
Studying this early period in cosmic history is technically challenging because accurate observations of extremely distant and faint galaxies are needed, a task which can only be attempted with the most powerful telescopes. For this study, the team used the great light-gathering power of the 8.2-metre VLT to carry out spectroscopic observations, targetting galaxies first identified by the NASA/ESA Hubble Space Telescope and in deep images from the VLT.
 The most distant galaxy that has been reported with a distance measured by spectroscopy is at a redshift of 8.6, placing it 600 million years after the Big Bang (eso1041). There is a candidate galaxy thought to be at a redshift of about 10 (480 million years after the Big Bang) identified by the Hubble Space Telescope, but this is awaiting confirmation. The most distant galaxy in this study is at a redshift of 7.1, placing it 780 million years after the Big Bang. The Universe today is 13.7 billion years old. The new sample of five confirmed galaxies with Lyman-alpha detections (out of 20 candidates) includes half of all galaxies known at z>7.
 At the time the first stars and galaxies formed, the Universe was filled with electrically neutral hydrogen gas, which absorbs ultraviolet light. As the ultraviolet radiation from these early galaxies excited the gas, making it electrically charged (ionised), it gradually became transparent to ultraviolet light. This process is technically known as reionisation, as there is thought to have been a brief period within the first 100 000 years after the Big Bang in which the hydrogen was also ionised.
 The team measured the effects of the hydrogen fog using spectroscopy, a technique which involves splitting and spreading out the light from the galaxy into its component colours, much like a prism splits sunlight into a rainbow.
 The team used the VLT to study the spectra of 20 candidate galaxies at redshifts close to 7. These come from deep imaging studies of three separate fields. Of these 20 targets five were found to have clearly detected Lyman-alpha emission. This is currently the only set of spectroscopically confirmed galaxies around z=7.
 Because the Universe is expanding, the wavelength of light from objects gets stretched as it passes through space. The further light has to travel, the more its wavelength is stretched. As red is the longest wavelength visible to our eyes, the characteristic red colour this gives to extremely distant objects has become known as ‘redshift’. Although it is technically a measure of how the colour of an object’s light has been affected, it is also by extension a measure both of the object’s distance, and of how long after the Big Bang we see it.
 Astronomers classify stars into three categories, known as Population I, Population II and Population III. Population I stars, like our Sun, are rich in heavier elements synthesised in the hearts of older stars and in supernova explosions: as they are made up from the wreckage of previous generations of stars, they only came into existence later in the Universe. Population II stars have fewer heavy elements in them and are predominantly made up of the hydrogen, helium and lithium created during the Big Bang. These are older stars, though there are still many of them in existence in the Universe today. Population III stars have never been directly observed, though they are thought to have existed in the early years of the Universe. As these contained only the material created during the Big Bang, they contained no heavier elements at all. Because of the role of heavier elements in the formation of stars, only very large stars with very short lifespans were able to form at this stage, and so all the Population III stars quickly ended their lives in supernovae in the early years of the Universe. Up to now, no solid evidence of Population III stars has been confirmed even in observations of very distant galaxies.
This research was presented in a paper “Spectroscopic Confirmation of z∼7 LBGs: Probing the Earliest Galaxies and the Epoch of Reionization”, to appear in the Astrophysical Journal.
The team is composed of L.Pentericci (INAF Osservatorio Astronomico di Roma, Rome, Italy [INAF-OAR]), A. Fontana (INAF-OAR), E. Vanzella (INAF Osservatorio Astronomico di Trieste, Trieste, Italy [INAF-OAT]), M. Castellano (INAF-OAR), A. Grazian (INAF-OAR), M. Dijkstra (Max-Planck-Institut für Astrophysik, Garching, Germany), K. Boutsia (INAF-OAR), S. Cristiani (INAF-OAT), M. Dickinson (National Optical Astronomy Observatory, Tucson, USA), E. Giallongo (INAF-OAR), M. Giavalisco (University of Massachusetts, Amherst, USA), R. Maiolino (INAF-OAR), A. Moorwood (ESO, Garching), P. Santini (INAF-OAR).
ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive astronomical observatory. 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 a 40-metre-class European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.
Research paper: http://www.eso.org/public/archives/releases/sciencepapers/eso1138/eso1138.pdf
Photos of the VLT: http://www.eso.org/public/images/archive/category/paranal/
Images, Video, Text, Credit: ESO / M. Kornmesser / L. Pentericci.
Best regards, Orbiter.ch
Publié par Orbiter.ch à 03:58
mardi 11 octobre 2011
NASA - SPITZER Space Telescope logo.
Oct. 11, 2011
(Click on the image for enlarge)
Looking like a pair of eyeglasses only a rock star would wear, this nebula brings into focus a murky region of star formation. NASA's Spitzer Space Telescope exposes the depths of this dusty nebula with its infrared vision, showing stellar infants that are lost behind dark clouds when viewed in visible light.
Best known as Messier 78, the two round greenish nebulae are actually cavities carved out of the surrounding dark dust clouds. The extended dust is mostly dark, even to Spitzer's view, but the edges show up in mid-wavelength infrared light as glowing, red frames surrounding the bright interiors. Messier 78 is easily seen in small telescopes in the constellation of Orion, just to the northeast of Orion's belt, but looks strikingly different, with dominant, dark swaths of dust. Spitzer's infrared eyes penetrate this dust, revealing the glowing interior of the nebulae.
A string of baby stars that have yet to burn their way through their natal shells can be seen as red pinpoints on the outside of the nebula. Eventually these will blossom into their own glowing balls, turning this two-eyed eyeglass into a many-eyed monster of a nebula.
This is a three-color composite that shows infrared observations from two Spitzer instruments. Blue represents 3.6- and 4.5-micron light, and green shows light of 5.8 and 8 microns, both captured by Spitzer's infrared array camera. Red is 24-micron light detected by Spitzer's multiband imaging photometer.
For more information about SPITZER Space Telescope, visit: http://www.spitzer.caltech.edu/
Image, Text, Credit: NASA / JPL-Caltech.
Publié par Orbiter.ch à 13:16
NASA - Hubble Space Telescope patch.
Oct. 11, 2011
(Click on the image for enlarge)
This NASA / ESA Hubble Space Telescope infrared mosaic image represents the sharpest survey of the Galactic Center to date. It reveals a new population of massive stars and new details in complex structures in the hot ionized gas swirling around the central 300 x 115 light-years. This sweeping infrared panorama offers a nearby laboratory for how massive stars form and influence their environment in the often violent nuclear regions of other galaxies. The infrared mosaic was taken with Hubble's Near Infrared Camera and Multi-Object Spectrometer (NICMOS). The Galactic core is obscured in visible light by dust clouds, which infrared light can penetrate.
The new NICMOS data show the glow from ionized hydrogen gas as well as a multitude of stars. NICMOS shows a large number of these massive stars distributed throughout the region. A new finding is that astronomers now see that the massive stars are not confined to one of the three known clusters of massive stars in the Galactic Center, known as the Central cluster, the Arches cluster, and the Quintuplet cluster. These three clusters are easily seen as tight concentrations of bright, massive stars in the NICMOS image. The distributed stars may have formed in isolation, or they may have originated in clusters that have been disrupted by strong gravitational tidal forces.
The winds and radiation from these stars form the complex structures seen in the core and in some cases they may be triggering new generations of stars. At upper left, large arcs of ionized gas are resolved into arrays of intriguingly organized linear filaments indicating a critical role of the influence of locally strong magnetic fields.
The lower left region shows pillars of gas sculpted by winds from hot massive stars in the Quintuplet cluster. At the center of the image, ionized gas surrounding the supermassive black hole at the center of the galaxy is confined to a bright spiral embedded within a circum-nuclear dusty inner-tube-shaped torus.
The false-color image was taken through a filter that reveals the glow of hot hydrogen in space.
NASA Hubble website: http://hubblesite.org/
ESA Hubble website: http://www.spacetelescope.org/
Image, Text, Credit: NASA / ESA and Q.D. Wang (University of Massachusetts, Amherst).
Publié par Orbiter.ch à 03:15
lundi 10 octobre 2011
NASA - Mars Exploration Rover "Opportunity" (MER-B) patch.
Oct. 10, 2011
While NASA's Mars Exploration Rover Opportunity was traveling from Victoria crater to Endeavour crater, between September 2008 and August 2011, the rover team took an end-of-drive image on each Martian day that included a drive. A new video compiles these 309 images, providing an historic record of the three-year trek that totaled about 13 miles (21 kilometers) across a Martian plain pocked with smaller craters.
This image from the navigation camera on NASA's Mars Exploration Rover Opportunity shows the view ahead on the day before the rover reached the rim of Endeavour crater. Image credit: NASA / JPL-Caltech.
The video featuring the end-of-drive images is now available online, at http://www.nasa.gov/multimedia/videogallery/index.html?media_id=114782241 . It shows the rim of Endeavour becoming visible on the horizon partway through the journey and growing larger as Opportunity neared that goal. The drive included detours, as Opportunity went around large expanses of treacherous terrain along the way.
The rover team also produced a sound track for the video, using each drive day's data from Opportunity's accelerometers. The low-frequency data has been sped up 1,000 times to yield audible frequencies.
Rover's Eye View of Three-Year Trek on Mars
"The sound represents the vibrations of the rover while moving on the surface of Mars," said Paolo Bellutta, a rover planner at NASA's Jet Propulsion Laboratory, Pasadena, Calif., who has plotted many of Opportunity's drives and coordinated production of the video. "When the sound is louder, the rover was moving on bedrock. When the sound is softer, the rover was moving on sand."
Opportunity and its rover twin, Spirit, completed their three-month prime missions on Mars in April 2004. Both rovers continued for years of bonus, extended missions. Both have made important discoveries about wet environments on ancient Mars that may have been favorable for supporting microbial life. Spirit stopped communicating in 2010. Opportunity continues its work at Endeavour. NASA will launch the next-generation Mars rover, car-size Curiosity, this autumn, for arrival at Mars' Gale crater in August 2012.
JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover Project for the NASA Science Mission Directorate, Washington. More information about the rovers is online at: http://www.nasa.gov/rovers and http://marsrovers.jpl.nasa.gov . You can also follow the mission on Facebook at http://www.facebook.com/marsrovers and on Twitter at http://www.twitter.com/marsrovers .
Image (mentioned), Video, Text, Credits: NASA / JPL / Guy Webster.
Publié par Orbiter.ch à 16:51