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Sonntag, 26. August 2012 - 12:38 Uhr

Raumfahrt - Im Focus von Cassini

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Radiant Dione

This raw, unprocessed image was taken by NASA's Cassini spacecraft on May 2, 2012. The camera was pointing toward Dione at approximately 14,835 miles (23,875 kilometers) away.

Image credit: NASA/JPL/Space Science Institute

Line of Craters

 

The Cassini spacecraft takes a close look at a row of craters on Saturn's moon Tethys during the spacecraft's April 14, 2012, flyby of the moon.

Three large craters are visible along the terminator between day and night on Tethys (660 miles, or 1,062 kilometers across). The larger Odysseus crater also can be seen in profile on the right of the image. Odysseus Crater is 280 miles (450 kilometers) across. See PIA07693 for a closer view of Odysseus.

This view looks toward the area between the leading hemisphere and the anti-Saturn side of Tethys. North on Tethys is up and rotated 25 degrees to the right.

The image was taken in visible light with the Cassini spacecraft wide-angle camera on April 14, 2012. The view was acquired at a distance of approximately 12,000 miles (20,000 kilometers) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 66 degrees. Image scale is a half mile (1 kilometer) per pixel.

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

Peeping Mimas

Saturn's moon Mimas peeps out from behind the larger moon Dione in this view from the Cassini spacecraft.

Mimas (246 miles, or 396 kilometers across) is near the bottom center of the image. Saturn's rings are also visible in the top right.

This view looks toward the anti-Saturn side of Dione (698 miles, or 1,123 kilometers across). North on Dione is up and rotated 20 degrees to the right. This view looks toward the northern, sunlit side of the rings from just above the ringplane.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Dec. 12, 2011. The view was obtained at a distance of approximately 377,000 miles (606,000 kilometers) from Mimas. The view was obtained at a distance of approximately 56,000 miles (91,000 kilometers) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 42 degrees. Image scale is 1,773 feet (541 meters) per pixel on Dione.


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Sonntag, 26. August 2012 - 12:28 Uhr

Astronomie - Venus-Transit von 1639

 

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Sonntag, 26. August 2012 - 12:00 Uhr

Astronomie - Kepler-Teleskop findet 41 neue Planeten

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Samstag, 25. August 2012 - 22:26 Uhr

Raumfahrt - EILMELDUNG - Neil Armstrong verstorben

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Neil Armstrong, the first man to walk on the moon during the 1969 Apollo 11 mission, has died. He was 82.

"Neil Armstrong was also a reluctant American hero who always believed he was just doing his job," said a statement from his family.

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Apollo 11 Crew

The Apollo 11 lunar landing mission crew, pictured from left to right, Neil A. Armstrong, commander; Michael Collins, command module pilot; and Edwin E. Aldrin Jr., lunar module pilot.

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Boarding Gemini VIII

Commander Neil Armstrong (right) and pilot David R. Scott prepare to board the Gemini-Titan VIII. Gemini VIII successfully launched at 11:41 a.m. EST, March 16, 1966. The mission conducted the first docking of two spacecraft in orbit and landed safely back on Earth after an emergency abort.

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On the Lunar Surface

Apollo 11 astronauts trained on Earth to take individual photographs in succession in order to create a series of frames that could be assembled into panoramic images. This frame from Aldrin's panorama of the Apollo 11 landing site is the only good picture of mission commander Neil Armstrong on the lunar surface.

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Fly Me to the Moon

Grammy Award-winning producer Quincy Jones presented a platinum copy of 'Fly Me to the Moon' to Senator John Glenn and Apollo 11 Commander Neil Armstrong during NASA's 50th anniversary gala in 2008, a song he originally produced and performed with Frank Sinatra.

Senator Glenn became the first American to orbit the Earth as an astronaut in NASA's Mercury Program. Neil Armstrong is the first person to set foot on the moon.

During the gala, Jones performed 'Fly Me to the Moon' with Frank Sinatra Jr.

Image Credit: NASA/Bill Ingalls

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Apollo 11 astronauts, from left, Michael Collins, Neil Armstrong and Buzz Aldrin stand during a recognition ceremony at the U.S House of Representatives Committee on Science and Technology tribute to the Apollo 11 astronauts at the Cannon House Office Building on Capitol Hill, Tuesday, July 21, 2009, in Washington. The committee presented the three Apollo 11 astronauts with a framed copy of House Resolution 607 honoring their achievement, and announced passage of legislation awarding them and John Glenn the Congressional Gold Medal.

Image Credit: NASA/Bill Ingalls

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Samstag, 25. August 2012 - 18:15 Uhr

Raumfahrt - ISS-News in Bildern

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Fotos von ISS: NASA

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Cosmonaut Gennady Padalka

ISS032-E-020610 (20 Aug. 2012) --- Russian cosmonaut Gennady Padalka, Expedition 32 commander, participates in a session of extravehicular activity (EVA) to continue outfitting the International Space Station. During the five-hour, 51-minute spacewalk, Padalka and Russian cosmonaut Yuri Malenchenko (out of frame), flight engineer, moved the Strela-2 cargo boom from the Pirs docking compartment to the Zarya module to prepare Pirs for its eventual replacement with a new Russian multipurpose laboratory module. The two spacewalking cosmonauts also installed micrometeoroid debris shields on the exterior of the Zvezda service module and deployed a small science satellite.

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Astronaut Sunita Williams

ISS032-E-020798 (20 Aug. 2012) --- NASA astronaut Sunita Williams, Expedition 32 flight engineer, uses a High Definition Video (HDV) camera in the transfer compartment between the Zarya Functional Cargo Block (FGB) and the Zvezda Service Module of the International Space Station.

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Yuri Malenchenko

ISS032-E-021054 (20 Aug. 2012) --- Russian cosmonaut Yuri Malenchenko, Expedition 32 flight engineer, participates in a session of extravehicular activity (EVA) to continue outfitting the International Space Station. During the five-hour, 51-minute spacewalk, Malenchenko and Russian cosmonaut Gennady Padalka (out of frame), commander, moved the Strela-2 cargo boom from the Pirs docking compartment to the Zarya module to prepare Pirs for its eventual replacement with a new Russian multipurpose laboratory module. The two spacewalking cosmonauts also installed micrometeoroid debris shields on the exterior of the Zvezda service module and deployed a small science satellite.

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Aki Hoshide

ISS032-E-022180 (21 Aug. 2012) --- Japan Aerospace Exploration Agency astronaut Aki Hoshide, Expedition 32 flight engineer, assembles the JEM Robotic Maneuvering System Multi-Purpose Experiment Platform (JEMRMS MPEP) in the Kibo laboratory of the International Space Station.

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Aki Hoshide

ISS032-E-022200 (21 Aug. 2012) --- Japan Aerospace Exploration Agency astronaut Aki Hoshide, Expedition 32 flight engineer, talks on a microphone while working near the airlock in the Kibo laboratory of the International Space Station. The JEM Robotic Maneuvering System Multi-Purpose Experiment Platform (JEMRMS MPEP) is visible in the airlock.

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Joe Acaba

ISS032-E-022211 (21 Aug. 2012) --- NASA astronaut Joe Acaba, Expedition 32 flight engineer, is pictured near the newly assembled JEM Robotic Maneuvering System Multi-Purpose Experiment Platform (JEMRMS MPEP) in the Kibo laboratory of the International Space Station.

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Aki Hoshide

ISS032-E-020821 (20 Aug. 2012) --- Japan Aerospace Exploration Agency astronaut Aki Hoshide, Expedition 32 flight engineer, wearing a communication headset, works in the Zarya Functional Cargo Block (FGB) of the International Space Station.

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Gennady Padalka and Yuri Malenchenko

ISS032-E-021044 (20 Aug. 2012) --- Russian cosmonauts Gennady Padalka (top), Expedition 32 commander; and Yuri Malenchenko, flight engineer, participate in a session of extravehicular activity (EVA) to continue outfitting the International Space Station. During the five-hour, 51-minute spacewalk, Padalka and Malenchenko moved the Strela-2 cargo boom from the Pirs docking compartment to the Zarya module to prepare Pirs for its eventual replacement with a new Russian multipurpose laboratory module. The two spacewalking cosmonauts also installed micrometeoroid debris shields on the exterior of the Zvezda service module and deployed a small science satellite.

 


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Samstag, 25. August 2012 - 17:51 Uhr

Raumfahrt - NASA ist für ist für Space-X-Programme startklar

 

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NASA Administrator Charles Bolden Thursday announced new milestones in the nation's commercial space initiatives from Cape Canaveral Air Force Station, near the agency's Kennedy Space Center in Florida.

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NASA Administrator Announces New Commercial Crew And Cargo Milestones

NASA Administrator Charles Bolden announced Thursday new milestones in the nation's commercial space initiatives from the agency's Kennedy Space Center in Florida. The latest advances made by NASA's commercial space partners pave the way for the first contracted flight of cargo to the International Space Station (ISS) this fall and mark progress toward a launch of astronauts from U.S. soil in the next 5 years.

Bolden announced Space Exploration Technologies (SpaceX) has completed its Space Act Agreement with NASA for Commercial Orbital Transportation Services (COTS). SpaceX is scheduled to launch the first of its 12 contracted cargo flights to the space station from Cape Canaveral in October, under NASA's Commercial Resupply Services Program.

"We're working to open a new frontier for commercial opportunities in space and create job opportunities right here in Florida and across the United States," Bolden said. "And we're working to in-source the work that is currently being done elsewhere and bring it right back here to the U.S. where it belongs."

Through the COTS program, NASA provides investments to stimulate the American commercial space industry. As part of its COTS partnership, SpaceX became the first commercial company to resupply the space station in May, successfully launching its Falcon 9 rocket and Dragon spacecraft to the orbiting complex. During the historic mission, the Dragon was captured by astronauts using the station's robot arm, unloaded and safely returned to Earth carrying experiments conducted aboard ISS. Later this winter, Orbital Sciences Corp. plans to carry out its first test flight under COTS.

Bolden also announced NASA partner Sierra Nevada Corp. has conducted its first milestone under the agency's recently announced Commercial Crew integrated Capability (CCiCap) initiative. The milestone, a program implementation plan review, marks an important first step in Sierra Nevada's efforts to develop a crew transportation system with its Dream Chaser spacecraft.

CCiCap is an initiative of NASA's Commercial Crew Program (CCP) and an Obama administration priority. The objective of the CCP is to facilitate the development of a U.S. commercial crew space transportation capability with the goal of achieving safe, reliable and cost-effective access to and from the space station and low Earth orbit. After the capability is matured, it is expected to be available to the government and other customers. NASA could contract to purchase commercial services to meet its station crew transportation needs later this decade.

While NASA works with U.S. industry partners to develop commercial spaceflight capabilities, the agency also is developing the Orion spacecraft and the Space Launch System (SLS), a crew capsule and heavy-lift rocket to provide an entirely new capability for human exploration. Designed to be flexible for launching spacecraft for crew and cargo missions, SLS and Orion will expand human presence beyond low Earth orbit and enable new missions of exploration across the solar system.

Quelle+Foto: NASA



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Freitag, 24. August 2012 - 20:11 Uhr

Astronomie - UNESCO Portal to the Heritage of Astronomy

 

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What is astronomical heritage?

Astronomical heritage is evidence relating to the practice of astronomy and to social uses and representations of astronomy. It exists in the form of the tangible remains of monuments, sites and landscapes with a link to the skies that constitute a well-defined physical property. It can also involve movable objects such as instruments and archives, intangible knowledge—including indigenous knowledge still preserved in the world today—and natural environments that support human interest in astronomy, for example through the cultural use of their horizons or dark night skies.

Astronomy in context

Practices related to astronomy are inextricably linked to broader assemblages of cultural activities. As a result, the material heritage of astronomy in the form of artefacts and constructions is often deeply integrated within material heritage of a broader nature and significance. This is equally true whether or not the astronomy in question constitutes modern ‘rational’ science. The pre-Columbian metallurgical centre at Viña del Cerro in Chile, for instance, provides an excellent example of astronomy in a broader, integrated context of resource exploitation, sacred places, calendar and landscape.

This implies that we should not focus exclusively upon ‘astronomical heritage sites’ per se but pay due attention to sites exhibiting an important set of valuable attributes, astronomy being just one component among others. An excellent example in this regard is the Einstein Tower in Potsdam, Germany, built in the 1920s, which combines outstanding scientific and architectural qualities.

Ulugh Beg’s observatory in Samarkand, Uzbekistan, is an example of the mutual reinforcement of value coming from different cultural fields—urban, social and political history, history of architecture and decoration, cultural practices in the arts, etc.—in Central Asia during the 15th century. The immediate urban surroundings of the 18th-century Jantar Mantar observatory in Jaipur, India, inscribed onto the World Heritage List in 2010, provide another example where overlapping aspects of value are gathered together in one property; similarly, Dengfeng Observatory in China, also inscribed in 2010, forms part of a large site including a range of 13 temples, towers, a monastery, and gardens.

Astronomy can take many forms but it is never alone: it is always a part of a larger ensemble of attributes that characterise a human society in its particular geographical and historical context.

The heritage of astronomy is often linked to complex systems of representation. For example, astronomical observations are frequently motivated by a need to predict the future (for various reasons including prognostication, predicting recurrent phenomena, or ‘testing’ hypotheses in modern ‘rational’ context), and this leads to the development and use of a variety of forms of symbolic notation. As a result, attempting to interpret the heritage involves examining the diverse relationships that exist between human beings and the sky as manifested through the use of artefacts and representations. These not only include notations and drawings but also architectural constructions and urban planning that ‘symbolise’ the skies in various ways: terrestrial material manifestations of the human cognisance of the universe that can be seen as a concretisation of the human relationship with the heavens. We must also be concerned with protocols and methods of observation, together with a full range of beliefs and modes of behaviour (i.e. magic as well as science, astrology as well as astronomy in the modern rational sense, and religious faiths as well as beliefs in physical laws).

This raises the issue of the meaning of the term ‘science’, both as simple terminology and as a more complex epistemological question. One can envisage, effectively, a straightforward dichotomy between modern ‘rational’ methods of enquiry (narrow definition of science) and any attempt to comprehend the nature of the perceived life-world by imposing some sort of cognitive structure upon it (wide definition). However, at a more subtle level the question of what constitutes ‘pure science’ in astronomy remains extremely open and dependent upon context. It is certainly allied to the question of predicting the future and it is also linked with cosmology (in the anthropological sense) and with religion and ideology. The general question of what constitutes ‘pure’ science or ‘pure’ astronomy is relevant in so far as it helps to define modes of connection between astronomical beliefs and practice and their social and cultural context and hence leads to more efficient ways of understanding the value of heritage sites with a relationship to astronomy.

An important category of astronomical heritage relates to the application of astronomical techniques and technology to other sciences. Thus the Struve geodetic arc represents astronomy as technology applied to earth science. Space science, in the sense of science carried out in space, may include astronomy but the fixed heritage associated with space science is purely technological.

 

Mehr darüber zu erfahren und eine Menge von Informationen gibt es hier: http://www2.astronomicalheritage.net/index.php/


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Freitag, 24. August 2012 - 18:00 Uhr

Raumfahrt - Start von NASA's Radiation Belt Storm Probes (RBSP)

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The Atlas V payload fairing containing the RBSP spacecraft is lifted at Space Launch Complex-41, where the booster awaits. Photo credit: NASA/Dimitri Gerondidakis

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Encircling the Earth's equator are two concentric, wide rings of high-intensity particles known as the Van Allen radiation belts. This dynamic region changes in response to the sun, with the potential to affect GPS satellites, satellite television and more.

NASA's Radiation Belt Storm Probes (RBSP) mission aims to study this ever-changing environment in greater detail than ever before.

"We live in the atmosphere of the sun. So when the sun sneezes, the Earth catches a cold," explained Nicky Fox, deputy project scientist at Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md. "So whatever is happening on the sun, the Earth will feel an effect and will respond to that changing space weather."

The mission features nearly identical twin probes, each carrying a suite of advanced instruments to help scientists monitor and characterize changes within the radiation belts.

"The Radiation Belt Storm Probes will give us a better understanding of how the radiation belts actually work, and allow us to do a better job of predicting and protecting against the radiation that's up there in the future," said Mission Systems Engineer Jim Stratton, also of APL.

The RBSP mission is part of NASA's Living with a Star program, which is managed by the agency's Goddard Space Flight Center in Greenbelt, Md. The APL team built the RBSP spacecraft and will manage the two-year mission for NASA.

The discovery of the radiation belts dates back to the dawn of the space age. Their existence was detected in 1958 by a Geiger counter on NASA's first spacecraft, Explorer 1, built by James Van Allen and his team from the University of Iowa.

Now, more than half a century later, RBSP packs a comprehensive set of instruments designed to look at not only the particles within the radiation belts, but also the plasma waves, electric fields and magnetic fields that transport and guide those particles.

The mission needed two probes, Fox explained, because scientists want to be able to distinguish transient features from those that are there for a longer period, or may be changing.

"If you imagine having two buoys in the ocean, and one goes up, and comes down again, you don't know anything about what caused that to go up and down," Fox said. "If both of them go up, then you know you've got a very big feature that is affecting both of them at the same time. If you one goes up, then the other goes up, you can measure how fast that wave has traveled between them, and what direction it's going into. And if only one goes up and comes down again, then you've got a very, very localized feature that didn't travel anywhere.

"So in order to be able to really understand what is going on, these very fine-scale features in our radiation belts, we have two spacecraft to do that," she said.

The eight-sided probes weigh more than 1,400 pounds each and measure about six feet wide by three feet high. But the electric and magnetic fields sensors extend outward on booms that distance these instruments from the immediate vicinity of the spacecraft, which could generate its own electric and magnetic fields. Data filters and metal shielding on spacecraft electronics offer additional prevention against interference, as well as protection from the intense environment the probes will encounter daily.

"Definitely the biggest challenge that we face is the radiation environment that the probes are going to be flying through," Stratton said. "Most spacecraft try to avoid the radiation belts -- and we're going to be flying right through the heart of them."

RBSP is launching on the tried-and-true Atlas V built by United Launch Alliance.

"NASA has an excellent history with the Atlas V rocket. As a matter of fact, we are 100 percent, six for six, launching on Atlas V," said Tim Dunn, RBSP launch director for NASA's Launch Services Program (LSP). "We have launched missions to Jupiter, Pluto, the sun, the moon, and two missions to Mars."

Based at NASA's Kennedy Space Center in Florida, LSP has been involved in prelaunch planning for the RBSP mission for several years.

"The team has been preparing in total for about six years for the RBSP mission. The early planning began that long ago, back in about the 2006 timeframe. The core team came in at about contract award time in March of 2009," Dunn said. "So we've been very heavily involved with RBSP for the last three years."

Rex Engelhardt, LSP's mission manager for RBSP, has been working on the project since 2006. He pointed out that ensuring the separation of both spacecraft from the Centaur upper stage, after launch, required some extra attention. The probes will be deployed one at a time into separate orbits, so the Centaur will spin up, deploy the first probe, stop its spin, and then turn to aim the second probe toward its orbit.

"Then you've got to point it in the right direction, spin it back up again, separate the second (probe), then you've got to spin the Centaur back down again, and quietly back away," Engelhardt said.

Once the probes are placed in their proper orbits, they'll undergo a two-month "commissioning period." This offers the team plenty of time to extend the instrumentation booms, check out the probes' health and safety, and ensure the electronics are working.

"After you launch, after you get through the environments of launch and when you're up there in the space environment, you want to make sure everything's working perfectly," Stratton said. "So that takes about 60 days after launch, and then we'll start our prime mission as soon as that commissioning period is done."

According to Fox, the data from the RBSP mission will allow scientists dramatically improve current models of how the radiation belts form and change in response to the sun.

"That is important because it will allow us to design better spacecraft; we'll be able to protect them better and we also won't do costly overdesign," Fox explained. "It will help us protect astronauts that are out in Earth orbit, and it will benefit the science community by giving us a lot more information about fundamental particle physics.

Quelle+Fotos: NASA

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Technicians at the Astrotech payload processing facility prepare the RBSP spacecraft for encapsulation in the payload fairing. Photo credit: NASA/Kim Shiflett

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Spacecraft A, one of two Radiation Belt Storm Probes, is checked for proper balance during a spin test. Photo credit: NASA/Charisse Nahser

Quelle+Fotos:NASA

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Update: 24.08.2012

Frams: LIVE-Aufnahmen von NASA-TV

Start um 24 Stunden verschoben...

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Update: 24.08.2012 / 18.00 MESZ


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Donnerstag, 23. August 2012 - 23:17 Uhr

Astronomie - Ein ESO-Laserleitstern streift das Firmament

 

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Dieses atemberaubende Foto von Julien Girard zeigt einen hellen Laserstrahl, der zum Very Large Telescope (VLT) der ESO gehört, vor dem Nachthimmel über der chilenischen Atacama-Wüste. Weil der Laser während der 30-minütigen Belichtungszeit zum Ausgleich der Erddrehung bewegt wurde, erscheint der Strahl aufgefächert. Die Kamera, die das Bild aufgenommen hat, stand dagegen still, so dass die Sterne als Strichspuren abgebildet wurden, die besonders deutlich die unterschiedlichen Farben der Sterne zeigen.

Der Laser wird verwendet, um Natriumatome in 90 Kilometern Höhe zum Leuchten anzuregen und so in der Hochatmosphäre einen hellen Lichtpunkt – einen künstlichen Stern – zu erzeugen. Dieser sogenannte Laserleitstern wird dann als Referenz verwendet, um die Bildverschlechterungen durch die Einflüsse der Atmosphäre zu korrigieren. Dazu wird die Technik der sogenannten adaptiven Optik verwendet. Zwar können auch ausreichend helle echte Sterne als Referenz genommen werden, aber der Laserleitstern kann an jede gewünschte Stelle positioniert werden. Mit seiner Hilfe kann die adaptive Optik in viel mehr Himmelsbereichen eingesetzt werden.

Die vier großen Schutzbauten der 8,2-Meter-Hauptteleskope des VLT und dahinter das kleinere VLT Survey Telescope (VST) sind ebenfalls im Bild zu sehen. Julien arbeitet als Astronom für die ESO am VLT in Chile. In der Nacht, in der das hier gezeigte Foto aufgenommen wurde, unterstützte er Beobachtungen an dem VLT-Hauptteleskop auf der rechten Seite. Er nutzte die Gelegenheit, um seine Kamera aufzubauen, bevor er in den Kontrollraum zurückging und die VLT-Beobachtungen durchzuführen.

Die Bewegungen der Schutzbauten während der langen Belichtungszeit führen zu einem verwaschenen Eindruck. Ebenso sind schwache Lichtspuren zu erkennen, die von Personen stammen, die sich während der Belichtungszeit auf der Plattform zwischen den Teleskopen hin und her bewegt haben.

Julien hat dieses Foto in der „Your ESO Pictures“-Flickrgruppe veröffentlicht. Die besten Fotos aus dieser Gruppe werden regelmäßig für das Bild der Woche oder für unsere Bildergalerie ausgewählt. Als Teil des 50-jährigen Jubiläums der ESO freuen wir uns im Jahr 2012 besonders über historische Bilder mit Bezug zur ESO.

Quelle:ESO


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Donnerstag, 23. August 2012 - 22:59 Uhr

Astronomie - Der Pfeifennebel wie er noch nie zuvor zu sehen war

 

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Eines der bekanntesten Werke des Malers René Magritte ist „Der Verrat der Bilder“. Es zeigt eine Pfeife zusammen mit dem Schriftzug „Dies ist keine Pfeife”, der besagen soll, dass ein Bild eines Objektes nicht gleichwertig mit dem Objekt selbst ist. Auch diese Aufnahme hier ist keine Pfeife, sondern ein Bild von Barnard 59, einem Teil einer auch als Pfeifennebel bekannten, ausgedehnten interstellaren Dunkelwolke. Das Bild wurde mit dem Wide Field Imager am MPG/ESO 2,2-Meter-Teleskop am La Silla-Observatorium der ESO aufgenommen und wird von der ESO heute, am 45. Todestag Magrittes, zu Ehren des Malers veröffentlicht.

Der Pfeifennebel ist typischer Vertreter der sogenannten Dunkelwolken. Ursprünglich gingen die Astronomen bei dieser Objektklasse davon aus, es mit Bereichen des Weltraums zu tun zu haben, die frei von Sternen sind. Erst später wurde klar, dass es sich in Wirklichkeit um dichte Wolken aus interstellarem Staub handelt, die das Licht der dahinterliegenden Sterne verdunkeln. Die Silhouette des Pfeifennebels ist vor dem Hintergrund der dichten Sternwolken nahe dem Zentrum der Milchstraße im Sternbild Ophiuchus (der Schlangenträger) besonders gut zu erkennen.

Barnard 59, das Mundstück der „Pfeife“ des Pfeifennebels, steht im Zentrum dieser neuen Aufnahme des Wide Field Imagers am MPG/ESO 2,2-Meter-Teleskop. Der auffällige Dunkelnebel, der eine komplexe Struktur aufweist, ist zwischen 600 und 700 Lichtjahre von der Erde entfernt.

Der Nebel trägt den Namen des amerikanischen Astronomen Edward Emerson Barnard, der Dunkelwolken mithilfe von Langzeitbeelichtungen als erster systematisch dokumentierte und dabei erkannte, dass es sich um Staubwolken handelt. Barnard katalogisierte insgesamt 370 Dunkelnebel, die über den ganzen Himmel verteilt sind. Als ein außergewöhnlicher Beobachter mit extrem guten Augen lieferte er Ende des 19. und Anfang des 20. Jahrhunderts gleich eine ganze Reihe wertvoller Beiträge zu diversen Bereichen der Astronomie. Vom Preisgeld für die Entdeckung mehrerer Kometen konnte er sich sogar ein Haus kaufen.

Beim Betrachten des Nebelbildes dürfte die Aufmerksamkeit zunächst auf dessen Zentrum gezogen werden, wo dunkle, verzwirbelte Wolken an die Beine einer riesigen Spinne erinnern, die in ihrem Netz aus Sternen sitzt. Schnell wird der Blick dann allerdings auf die vielen feinen Details gelenkt: rauchige Strukturen, die inmitten des Dunkels von Sternen aufgehellt werden, die gerade erst im Entstehen begriffen sind. Solche Sterngeburten sind typische Vorkommnisse im Inneren der dichten Molekülwolken, aus denen die Dunkelnebel bestehen. Gas und Staub bilden unter dem Einfluss der Schwerkraft Klumpen, die daraufhin mehr und mehr Materie anziehen – so lange, bis die Verklumpung genügend Masse besitzt, um ein Stern zu werden. Im Vergleich mit anderen Dunkelwolken entstehen in Barnard 59 allerdings vergleichsweise wenig Sterne, und der Nebel enthält noch viel ungebundenen Staub.

Bei genauerem Hinsehen bemerkt der Betrachter über das gesamte Bild verteilt etwa ein Dutzend kleiner blauer, grüner und roter Striche. Das sind die Spuren von Asteroiden Gesteinsbrocken mit einer Größe von maximal ein paar Kilometern, die die Sonne umlaufen und sich dabei im Vordergrund ins Bild geschoben haben. Die meisten von ihnen befinden sich im Asteroidengürtel, der zwischen den Umlaufbahnen der Planeten Mars und Jupiter liegt. Barnard 59 ist etwa zehn Millionen mal so weit von der Erde entfernt wie diese kleinen Himmelskörper.

Als letztes sollte sich der Betrachter bewusst werden, dass dies eine astronomische Miniatur ist: In Originalgröße am Nachthimmel kann man die auf der Aufnahme sichtbare Sternenlandschaft aufgrund der großen Entfernung zu Barnard 59 mit dem Daumen an der ausgestreckten Hand abdecken, und das, obwohl die Wolke eine Ausdehnung von über sechs Lichtjahren besitzt.

Endnoten

[1] Zum Pfeifennebel gehören außer Barnard 59 noch Barnard 65, 66, 67 und 78. Bei dunklem, klarem Himmel ist der Nebel leicht mit bloßem Auge auszumachen. Die besten Beobachtungsbedingungen herrschen allerdings in südlicheren Gegenden, da er dort höher über dem Horizont steht.

[2] Asteroiden bewegen sich während der Belichtungszeit der einzelnen Aufnahmen und erzeugen daher sogenannte Strichspuren. Da das hier gezeigte Farbbild aus mehreren Schwarzweißaufnahmen entstanden ist, die mit verschiedenen Farbfiltern aufgenommen wurden, sind die farbigen Strichspuren gegeneinander versetzt.

Weitere Informationen

Das MPG/ESO 2,2-Meter-Teleskop wurde 1984 in Betrieb genommen und ist eine Leihgabe der Max-Planck-Gesellschaft an die ESO. Sein Wide Field Imager, eine astronomische Kamera mit besonders großem Blickfeld und einem Detektor mit 67 Millionen Pixeln, liefert Bilder, die nicht nur von wissenschaftlichem, sondern auch von ästhetischem Wert sind.

Im Jahr 2012 feiert die Europäische Südsternwarte ESO (European Southern Observatory) das 50-jährige Jubiläum ihrer Gründung. Die ESO ist die führende europäische Organisation für astronomische Forschung und das wissenschaftlich produktivste Observatorium der Welt. Getragen wird die Organisation durch ihre 15 Mitgliedsländer: Belgien, Brasilien, Dänemark, Deutschland, Finnland, Frankreich, Italien, die Niederlande, Österreich, Portugal, Spanien, Schweden, die Schweiz, die Tschechische Republik und das Vereinigte Königreich. Die ESO ermöglicht astronomische Spitzenforschung, indem sie leistungsfähige bodengebundene Teleskope entwirft, konstruiert und betreibt. Auch bei der Förderung internationaler Zusammenarbeit auf dem Gebiet der Astronomie spielt die Organisation eine maßgebliche Rolle. Die ESO betreibt drei weltweit einzigartige Beobachtungsstandorte in Nordchile: La Silla, Paranal und Chajnantor. Auf dem Paranal betreibt die ESO mit dem Very Large Telescope (VLT) das weltweit leistungsfähigste Observatorium für Beobachtungen im Bereich des sichtbaren Lichts und zwei Teleskope für Himmelsdurchmusterungen: VISTA, das größte Durchmusterungsteleskop der Welt, arbeitet im Infraroten, während das VLT Survey Telescope (VST) für Himmelsdurchmusterungen ausschließlich im sichtbaren Licht konzipiert ist. Die ESO ist der europäische Partner für den Aufbau des Antennenfelds ALMA, das größte astronomische Projekt überhaupt. Derzeit entwickelt die ESO ein Großteleskop der 40-Meter-Klasse für Beobachtungen im Bereich des sichtbaren und Infrarotlichts, das einmal das größte optische Teleskop der Welt werden wird, das European Extremely Large Telescope (E-ELT).

Die Übersetzungen von englischsprachigen ESO-Pressemitteilungen sind ein Service des ESO Science Outreach Network (ESON), eines internationalen Netzwerks für astronomische Öffentlichkeitsarbeit, in dem Wissenschaftler und Wissenschaftskommunikatoren aus allen ESO-Mitgliedsstaaten (und einigen weiteren Ländern) vertreten sind. Deutscher Knoten des Netzwerks ist das Haus der Astronomie in Heidelberg.

Quelle:ESO


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