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Sonntag, 16. Februar 2014 - 18:18 Uhr

Astronomie - Das Chandra X-Ray beobachtet ein Herz in der Dunkelheit im jungen Sternhaufen NGC 346

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Chandra Observatory Sees a Heart in the Darkness

This Chandra X-Ray Observatory image of the young star cluster NGC 346 highlights a heart-shaped cloud of 8 million-degree Celsius gas in the central region. Evidence from radio, optical and ultraviolet telescopes suggests that the hot cloud, which is about 100 light years across, is the remnant of a supernova explosion that occurred thousands of years ago.

The progenitor could have been a companion of the massive young star that is responsible for the bright X-ray source at the top center of the image. This young star, HD 5980, one of the most massive known, has been observed to undergo dramatic eruptions during the last decade. An alternative model for the origin of the hot cloud is that eruptions of HD 5980 long ago produced the cloud of hot gas, in a manner similar to the gas cloud observed around the massive star Eta Carinae. Future observations will be needed to decide between the alternatives. Until then, the nature of the heart in the darkness will remain mysterious.

Quelle: NASA


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Sonntag, 16. Februar 2014 - 16:35 Uhr

Astronomie - SOFIA beobachtet Supernova SN2014J in M82

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In der letzten Januar und der ersten Februarwoche war SOFIA, die fliegende Sternwarte von NASA und DLR, wieder über dem kalifornischen Himmel unterwegs. Mit im Einsatz: Das deutsche Instrument GREAT. Im Rahmen des SOFIA-Bildungsprogramms hatte das im Auftrag des DLR Raumfahrtmanagements tätige Deutsche SOFIA Institut (DSI) an der Universität Stuttgart den Mitflug für vier deutsche Lehrer organisiert: Jörg Dewitz, Sven Hannsen, Olaf Hofschulz und Uwe Schierhorn. Sie begleiten SOFIA seit mehreren Jahren und behandeln astronomische Themen in Theorie und Praxis in ihrem Unterricht.

"Uns geht es darum, die an Bord gemachten einzigartigen Erfahrungen des Wissenschaftsbetriebs auf der fliegenden Sternwarte unseren Schülern möglichst realistisch zu vermitteln und unsere Begeisterung weiterzugeben", bestätigte die gesamte Gruppe. So konnten die Pädagogen im Flug 143 vom 4. auf den 5. Februar 2014 unter anderem miterleben, wie der Kern der Galaxie IC342 in der Linie des einfach ionisierten Kohlenstoffs [CII]  bei 1900,5369 THz erfolgreich kartiert wurde, und in Richtung des Kohlenstoffsterns IRC+10216 erstmals der Nachweis eines kosmischen HCN-Lasers im fernen Infrarot gelang. Die Blausäure (HCN) in der nahen Umgebung der Sternoberfläche - also der Photosphäre - wird bei diesem Objekt ähnlich wie ein Laser angeregt: Die Anzahl der pro Zeiteinheit durch induzierte Emission entstehenden Photonen ist größer als die Anzahl der in der gleichen Zeiteinheit absorbierten Photonen (Laserprinzip oder Besetzungsinversion).

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4. Februar 2014: Die deutschen Lehrer vor SOFIA im NASA-Betriebszentrum in Palmdale, Kalifornien, von links): Olaf Hofschulz, Uwe Schierhorn, Jörg Dewitz und Sven Hannsen.
Quelle: Antje Lischke-Weis, DSI.

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Bei Flug 141 vom 30. auf den 31. Januar 2014 gelang die Kartierung des OH-Moleküls bei etwa 2,514 THz in Richtung des Kleinmann-Low und Becklin-Neugebauer Objektes im Orion-Nebel. Bei Flug 142 vom 3. auf den 4. Februar 2014 erfolgte erstmals die Beobachtung der [CII]-Linie in der Zwerggalaxie IC10 und in den Flügen 142 und 143 konnte die Kartierung des im Sternbild Orion gelegenen Reflexionsnebels NGC2023 in den Übergängen des [CII] und CO(11-10) sowie die Messung derselben Linien in der benachbarten Sternbildungsgalaxie M101 vorgenommen werden.

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Antje Lischke-Weis vom DSI mit den Lehrern vor der speziellen Konsole für das SOFIA-Bildungsprogramm während des Flugs 143
Quelle: Antje Lischke-Weis, DSI.

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Auf Flug 141 waren wir besonders neugierig auf die Beobachtung der rund zwölf Millionen Lichtjahre entfernten Starburst-Galaxie M82, Zigarren-Galaxie genannt. In dieser Galaxie wurde am 21. Januar 2014 von drei Studenten des UCL (University of London Observatory) durch Zufall eine als kosmische Standardkerze für Entfernungsbestimmungen geeignete Supernova vom Typ Ia entdeckt (SN2014J). Zwar war die Supernova-Explosion kein für diese GREAT-Kampagne vorgesehenes Objekt, aber die lichtempfindlichen, schnellen Nachführkameras (Imager) des SOFIA-Observatoriums erlaubten es, nach der Supernova Ausschau zu halten.

Die Nachführkameras des SOFIA-Teleskops dienen dazu, ausgewählten Leitsternen zu folgen, das heißt die Erddrehung zu kompensieren und Korrektursignale für das Gyrosystem des Teleskops zum Ausgleich der Gyrodrift zu liefern. Hierzu werden geeignete Sterne ausgesucht, die sich im Gesichtsfeld der mit den Infrarot-empfindlichen SOFIA-Instrumenten zu beobachtenden interstellaren Gaswolken befinden. Der Focal Plane Imager FPI  - eine Kamera in der Fokalebene des Teleskops - erhält sein Licht über den SOFIA-Primärspiegel von 2,5 m Durchmesser, den Sekundärspiegel und die beiden Tertiärspiegel. Der visuelle Anteil des Lichts durchdringt den ersten Tertiärspiegel und wird vom zweiten Tertiärspiegel auf den FPI umgelenkt. Die Belichtungszeiten können zwischen 1 und 10.000 Millisekunden gewählt werden, so dass sich noch Sterne unterhalb der 16. Größenklasse detektieren lassen. Zur Nachführung werden typische Belichtungszeiten von einer Sekunde verwendet. Das beigefügte Bild zeigt die Supernova in M82 (gelber Pfeil) bei einer Belichtungszeit von einer Sekunde, aufgenommen mit dem FPI über den SOFIA-Primärspiegel.

Zu beachten ist, dass im Gesichtsfeld des Imagers unterschiedliche "Geisterbilder" auftreten, hervorgerufen durch Reflexionen an den Spiegelflächen des Tertiärspiegels. Je nach Form der Geisterbilder können quasi echte Sterne optisch vorgetäuscht werden. Bei der Auswahl der Nachführsterne müssen die Teleskop-Operateure also darauf achten, dass nur tatsächliche Sterne als Leitobjekte ausgewählt werden. Auf der Abbildung markiert der rote Pfeil ein Geisterbild.

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Supernova SN2014J in M82, aufgenommen mit der Nachführkamera in der Fokalebene von SOFIA (Belichtungszeit eine Sekunde) während Flug 141 vom 30. auf den 31. Januar 2014.
Quelle: SOFIA-Observatorium NASA/DLR, D. Lilienthal.

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Quelle: DLR


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Sonntag, 16. Februar 2014 - 16:15 Uhr

Mars-Chroniken - Die aufgebrochene Marsoberfläche bei Claritas Fossae

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Teil der Abbruchkante Claritas Rupes auf dem Mars

Blick auf einen Teil der Abbruchkante von Claritas Rupes

Anaglyphenbild von Claritas Rupes

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Aktuelle Aufnahmen der vom Deutschen Zentrum für Luft- und Raumfahrt (DLR) betriebenen hochauflösenden Stereokamera HRSC auf der Mars Express-Sonde zeigen einen Teil der Abbruchkante Claritas Rupes auf dem Mars, die das Grabensystem Claritas Fossae umgibt. Es bildet die östliche Grenze der riesigen Vulkanregion Tharsis, in der sich die meisten großen Marsvulkane, darunter auch der Olympus Mons, befinden.

Die vielen Brüche, die das Gebiet durchziehen, sind durch Spannungen in der Marskruste bei der Bildung der bis zu zehn Kilometer hohen Tharsis-Aufwölbung entstanden. Dieses Aufbrechen der Oberfläche bewirkte, dass ganze Blöcke der Marskruste in die neu entstandenen Zwischenräume abglitten und so ein charakteristisches Landschaftsbild mit auffallenden Geländestufen erzeugten. Auf der Erde führten ähnliche Prozesse beispielsweise zu Grabenbrüchen wie dem Oberrheingraben zwischen Basel und Karlsruhe oder dem Eger-Graben in Tschechien.

Rechts im Bild erkennt man einen helleren Hügel, der aus relativ weichem und leicht erodierbarem Material zu bestehen scheint. Dieses befindet sich auch an der Abbruchkante in der rechten unteren Bildhälfte (Bilder 1 und 2). Dieses Material könnte sogenannte Phyllosilikate (Schichtsilikate) enthalten. Hierbei handelt es sich um Tonminerale, die reich an Eisen und Aluminium sind und die nur unter längerer Einwirkung von Wasser auf vulkanischem Gestein entstehen. Hinweise darauf lieferten auch Beobachtungen mit dem CRISM-Instrument an Bord des Mars Reconnaissance Orbiters der NASA, das in der Nähe ebenfalls solche hellen Materialien untersucht hatte.

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Übersichtskarte über das Gebiet von Claritas Rupes

Topographische Bildkarte von Claritas Rupes

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  • Bildverarbeitung

    Die Aufnahmen mit der HRSC (High Resolution Stereo Camera) entstanden am 30. November 2013 während Orbit 12.600 von Mars Express. Die Bildauflösung beträgt etwa 14 Meter pro Bildpunkt (Pixel). Die Abbildungen zeigen einen Ausschnitt bei etwa 27 Grad südlicher Breite und 254 Grad östlicher Länge. Die Farbdraufsicht (Bild 1) wurde aus dem senkrecht auf die Marsoberfläche gerichteten Nadirkanal und den Farbkanälen der HRSC erstellt; die perspektivische Schrägansicht (Bild 2) wurde aus den Stereokanälen der HRSC berechnet. Das Anaglyphenbild (Bild 3), das bei Betrachtung mit einer Rot-Blau- oder Rot-Grün-Brille einen dreidimensionalen Eindruck der Landschaft vermittelt, wurde aus dem Nadirkanal und einem Stereokanal abgeleitet. Die in Regenbogenfarben kodierte Draufsicht (Bild 5) beruht auf einem digitalen Geländemodell der Region, von dem sich die Topographie der Landschaft ableiten lässt.

  • Die High Resolution Stereo Kamera wurde am Deutschen Zentrum für Luft- und Raumfahrt (DLR) entwickelt und in Kooperation mit industriellen Partnern gebaut (EADS Astrium, Lewicki Microelectronic GmbH und Jena-Optronik GmbH). Das Wissenschaftsteam unter Leitung des Principal Investigators (PI) Prof. Dr. Ralf Jaumann besteht aus 40 Co-Investigatoren, die aus 33 Institutionen und zehn Nationen stammen. Die Kamera wird vom DLR-Institut für Planetenforschung in Berlin-Adlershof betrieben. Die hier gezeigten Darstellungen wurden von der Planetary Sciences Group an der Freie Universität Berlin erstellt.
  • Quelle: DLR

Tags: Marsoberfläche bei Claritas Fossae 

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Sonntag, 16. Februar 2014 - 15:50 Uhr

Planet Erde - GOME -2 und IASI Instrumente auf Europas MetOp -A-und -B -Satelliten beobachten Kelut Eruption Aschewolke .

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Sulphur dioxide concentration over the Indonesian island of Java in the early morning of 14 February 2014 following the eruption of the Kelut volcano. This image is based on data from the GOME-2 instrument on the MetOp mission.

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The Kelut volcano on Indonesia’s Java island erupted late last night. While disaster-management authorities are busy on the ground, satellites are tracking the major cloud of ash and sulphur dioxide as it spreads in the atmosphere.

“The ash has reached high altitudes where commercial aircraft fly and is a significant hazard to aviation,” said Fred Prata from the Norwegian Institute for Air Research.

Airports across Java have closed, and multiple flights have been cancelled throughout the region.

“ESA and its partners are maintaining a constant vigil, and are providing satellite alerts to the relevant authorities through the Support to Aviation Control Service,” said Mr Prata.

The Support to Aviation Control Service – or SACS – uses satellite data to provide early warning information about ash, sulphur dioxide clouds and their dispersion following volcanic eruptions.

The presence of ash in the atmosphere can endanger jet engines.

When an eruption occurs, SACS sends a notification to users, most notably to the Volcanic Ash Advisory Centres (VAACs), and public maps are generated showing the extent and intensity of the volcanic plumes.

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Ash information over the Indonesian island of Java on 14 February 2014 following the eruption of the Kelut volcano. This image is based on data from the GOME-2 instrument on the MetOp mission.

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“The VACC in Darwin, Australia – which keeps track of volcanic eruptions mainly in southeast Asia – have been using satellite-derived sulphur dioxide and ash information as a verification tool for many years and are now tracking the plume from last night’s eruption,” said Andrew Tupper, head of Australia’s National Operations Centre at the Bureau of Meteorology.

“The sulphur dioxide imagery from this eruption is very useful indeed.”

Data from the GOME-2 and IASI instruments on Europe’s MetOp-A and -B satellites have been crucial to the monitoring of the Kelut eruption’s ash cloud.

IASI and GOME-2 – the Infrared Atmospheric Sounding Interferometer and Global Ozone Monitoring Experiment-2 – provide information about sulphur dioxide and aerosols.

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The Global Ozone Monitoring Experiment-2 (GOME-2) is one of the new-generation European instruments carried on MetOp and will continue the long-term monitoring of atmospheric ozone started by GOME on ERS-2 and SCIAMACHY on Envisat. The more advanced GOME-2 is set to make a significant contribution towards climate and atmospheric research, whilst providing near real-time data for use in air quality forecasting.

Different gases in the atmosphere absorb different wavelengths of light. The GOME-2 scanning spectrometer is designed to exploit this fact by capturing light reflected from the Earth's surface and atmosphere and splitting it into different wavelengths to reveal absorption lines, which correspond to certain gases present in the observed sample. GOME-2 will map concentrations of atmospheric ozone as well as nitrogen dioxide, sulphur dioxide, other trace gases and ultraviolet radiation. These profiles are representative of the lowermost 50 km of the Earth's atmosphere. These data are crucial for monitoring stratospheric ozone and atmospheric pollutants to keep a check on the health of the Earth's atmosphere.

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The Infrared Atmospheric Sounding Interferometer (IASI) is probably the most advanced instrument carried on the MetOp satellite. Marking a significant technological step forward, it will provide meteorologists with data of unprecedented accuracy and resolution on atmospheric temperature and humidity with which to improve weather prediction. This European instrument is also destined to provide a wealth of data on various components of the atmosphere to further our understanding of atmospheric processes and the interactions between atmospheric chemistry, climate and pollution. In addition, the IASI will deliver data on land-surface emissivity and sea-surface temperature (in cloud free conditions).

The sophisticated ISAI instrument is a Fourier Transform Spectrometer based on a Michelson Interferometer coupled to an integrated imaging system that observes and measures infrared radiation emitted from the Earth. The optical interferometry process offers fine spectral samplings of the atmosphere in the infrared band between wavelengths of 3.4 and 15.5 microns. This enables the instrument to establish temperature and water vapour profiles in the troposphere and the lower stratosphere, as well as measure quantities of ozone, carbon monoxide, methane and other compounds, all of which play major roles in atmospheric processes such as the greenhouse effect.

Quelle: ESA


Tags: Kelut Eruption Aschewolke 

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Sonntag, 16. Februar 2014 - 11:21 Uhr

Raumfahrt - Buzz Aldrin: Raumfahrtpolitik, mit gemeinsame Anstrengungen zum Mars und die Notwendigkeit, die zukünftige Generationen zu inspirieren

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A global space ambassador. Courtesy of the Buzz Aldrin Archive

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Buzz Aldrin is a retired US Air Force pilot, a former American astronaut and the second person to walk on the Moon, on July 21, 1969. He was the lunar module pilot on Apollo 11, the first manned lunar landing in history.

Upon returning from the moon, Dr Aldrin was decorated with the Presidential Medal of Freedom, the highest American peacetime award.

Since retiring from NASA and the Air Force, Col Aldrin has remained at the forefront of efforts to progress human space exploration. On November 16, 2011, Dr Aldrin was awarded the Congressional Gold Medal, the nation’s highest civilian honour, along with the other Apollo 11 crew members, Neil Armstrong and Michael Collins, and Mercury Seven astronaut, John Glenn, for their significant contribution to society and exploration.

Dr Aldrin has also written eight books including the New York Times best-selling autobiography, Magnificent Desolation, released in 2009 before the 40th Anniversary of the Apollo 11 moon landing. He has released best-selling illustrated children’s books, two space science-fiction novels and his most recent book Mission to Mars: My Vision for Space Exploration was published by the National Geographic Society in 2013.

“To realize the dream of humans on Mars we need a unified vision. We need to focus on a pathway to the prize.” These were the strident historic words articulated by Buzz Aldrin in July 2009 at the Smithsonian Air and Space Museum’s John Glenn Lecture Series for NASA’s 40th anniversary of the Apollo 11 Moon landing.  Five years on, and having very recently celebrated his 84th birthday, Dr Aldrin’s enthusiasm, ambassadorial work, resolute attitude and ideals are no less subdued.

Exciting developments in space science are coming thick and fast and showing notable progress. It is however, US President Barack Obama’s objective of a manned mission to Mars in his lifetime, preceded by a robotic landing on a real orbiting asteroid, that remains a most ambitious follow on to lunar robotic surface control by the US and the occupation of a jointly designed International Lunar Base.

 

Mars Settlement

Dr Aldrin would however like to see a more ambitious vision set out in Obama’s second term space policy. In his most recent book ‘Mission to Mars’, he calls for a future American President to make a commitment to establish permanent human presence on Mars. The timing would come 50 years after Dr Aldrin and Neil Armstrong became the first humans to step foot on the Moon on July 21, 1969.

“I see the larger advances in humanity here on planet earth will come when decisions are made to move earthlings from one planet where we’ve evolved for thousands and thousands of years, to the enormously historic beginning of a settlement and the colonisation of another planet,” he emphasizes. “It is a big objective, but I would like to see the US make a commitment within a definite time period of leading the other nations in international permanence on Mars.”

Budget Consistency

One notable issue Dr Aldrin highlights is that there is a clear lack of consistency in the government’s budgets for space technology development and the long term human space exploration objectives. The U.S 2013 budget proposal for NASA was $17.7bn, $59m less than what the space agency received in 2012. “The budget is driven absolutely by short term objectives and heritage components that don’t include investment in long term objectives,” Aldrin says frankly.

“It took the United States 3 ½ % to 4% of allotted or discretionary funding during the Apollo years to achieve the objective of sending humans to the Moon. In order to develop the long term capability of achieving the much more challenging goal of the first earthling settlements on Mars, we are certainly going to need to require much more than ½ %, which is what NASA has been receiving for tens of years now.

“We just cannot continue to lead the world and advance our space capabilities to that level and acquire the recognition of the inspiration benefits, and the increased progression of Science, Technology, Engineering and Math. STEM education requires the inspiration of individuals to choose subjects and to develop careers that contribute towards those objectives, and I don’t believe we’re doing that with an underfunded national priority of investment.”

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“The many ideas I reference in my life wouldn’t be possible without a strong and evolving background in the education of Science, Technology, Engineering and Math.” Courtesy of the Buzz Aldrin Archive.

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Cooperative Efforts

However Dr Aldrin remains optimistic nonetheless in all the high profile work he has done to this day, to encourage the global community towards new and permanent human exploration and settlement of space. He thinks with the right partnerships, constancy of purpose, policy consistency and the continuation of robotic missions to Mars throughout the 2020s, successful human mission to Mars can be achieved.

The objective, Dr Aldrin admits, will not be achieved by one nation alone and will need a cooperative and joint approach. This comes back to Dr Aldrin’s blueprint United Space Vision (USV).  In this, he encourages America to initiate a lunar consortium where international partners – China, Europe, South Korea, Russia, India and Japan – would do the lion’s share of the planning, technical development and funding for manned missions back to the moon.  Furthermore the United States would develop new strategies, launch vehicles and spacecraft to bring the country closer to Mars, by way of progressive missions to comets, asteroids and Mars’s moon Phobos.

“I think it’s imperative that we correct some mistakes that I feel have been made between nations by excluding China and its growing capability from cooperative activities at the international space station,” he says. “The United States should be helping to motivate the national efforts of other countries in space activity, bringing together our resources with other countries, specifically China, and using our knowledge to help further their goals and achievement. By carefully providing assistance, without consuming all our space activities, we can develop the stepping stones that will lead us to Mars.”

Inspiration through Education

Dr Aldrin talks fondly of his education and the role his father, Edwin Eugene Aldrin, a Colonel in the Air Force, played in inspiring his love for technology.  Growing up in New Jersey, he was an extremely smart student, graduating  early from Montclair High School before studying military engineering at the US Military Academy at West Point. “My education was largely inspired by the educational pursuits of my father that lead me to West Point and then to earn a Doctorate of Science in Astronautics at MIT, before eventually joining the astronaut programme.”

Known as “Dr Rendezvous” because he was the first of his selected group of astronauts to have a doctorate, Dr Aldrin is keen to emphasize the benefits of aerospace education. “My continued efforts to improve the space leadership of the United States in the world by emphasising the objectives of Mars and the many innovative ideas I reference in my life wouldn’t be possible without a strong and evolving background in the education of Science, Technology, Engineering and Math; STEM.”

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“The aim is to give back and inspire, while advancing space science education.” Courtesy of the Buzz Aldrin Archive.

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The not-for-profit organisation Dr Aldrin has set up, The Share Space Foundation, is proof that he is determined in continuing to inspire future generations into space and through their educational paths. The Foundation shares educational resources for children of all ages to experience the wonders of space, as well as foster affordable space travel opportunities for all people. “As a young kid who grew up and pursued education, I had no idea of the career I would follow and the opportunities that would open up to me as a result of that. The aim is to give back and inspire, while advancing space science education.

“There are many other distractions for young people today and the need for inspiring them in traditional ways we once used to is very important. Increased inspiration comes from the knowledge we gain first by exploration and second by evolving science in development, commercialisation and of course security.”

Space Progress

In a year where a number of high profile space missions are taking place and which some are calling a critical year for commercial space travel, it is Dr Aldrin who remains the most pragmatic Lunar Ambassador and Global Space Statesman. Newspaper column inches will be no doubt be filled with the fascinating stories on the European Space Agency’s star-mapping Gaia craft and the ESA’s Rosetta craft rendezvous with Comet P67P/ Churyumov-Gerasimenko, NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission orbiting the red planet, and the Indian Space Research Organisation’s Mangalyaan probe arriving just days after.

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“The United States should be helping to motivate the national efforts of other countries in space activity.” Courtesy of Buzz Aldrin Archive.

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Broadening Space

As an unstinting advocate for private space travel, Dr Aldrin is keen to see future progress. He believes this type of travel will bring down the cost of single scientific missions through creating large sustainable markets and generate broad public interest and participation. The idea that tourists in space will nurture the next generation of astronauts, engineers and scientists, is one he believes strongly in. “Commercial passenger travel drives the requirements for reusable Earth to orbit transportation systems. Not only that but I believe public space travel by private citizens or non-professionals is critical as it makes space more familiar.”

Dr Aldrin’s ‘Mars Cycler’ was an idea from the 1980s that remains close to his heart. A spacecraft system with perpetual cycling orbits between Earth and Mars creating a space transportation network. “I came up with the idea in 1985 as a system that provided a transportation orbital strategy,” he excitedly exalts. “It would lead to a sustainable transportation system that could ferry people, supplies and equipment to Mars, utilizing a host spacecraft on a trajectory travelling between the two planets. I’m pretty confident we’re moving in the right direction, I just need to gather increased support for these lofty objectives.”

Until that day will happen, Dr Aldrin will continue to advocate for other private missions such as Space X, Mars One and the Inspiration Mars aspirations.  Mars One plans to send a group of people to colonize the planet on a one-way mission in 2024 and the latter aims to launch a couple on a flyby of Venus and Mars in 2021. “I am very encouraged and supportive of space activity from private firms who are looking towards Mars. Mars One originating from the Netherlands is doing some very interesting work. Human space travel is excitedly poised to go from the few to the many and hopefully my firm belief in the motto “Everybody needs space!” will go on.”

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“Dr Rendezvous”. Courtesy of the Buzz Aldrin Archive.

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Quelle: npg


Tags: Buzz Aldrin: Space policy 

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Sonntag, 16. Februar 2014 - 10:42 Uhr

Mars-Chroniken - Neuer Beweis für Alten Ozean auf dem Mars

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A new study suggests that large boulders on Mars' northern plains were delivered to their location via massive underwater landslides--bolstering evidence for an ancient Martian ocean. A vast ocean may have once covered a third of the Red Planet. Credit: ESA, C. Carreau

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Did a vast ocean once cover Mars' northern plains?

Boulder-size rocks in Arcadia Planitia, northern lowland of Mars (HiRISE ESP_019853_2410). Credit: NASA (Moscardelli 2014)

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The idea has been hotly debated among scientists for the past 20 years, ever since Viking Orbiter images revealed possible ancient shorelines near the pole. Later findings even suggested that the primordial ocean--dubbed Oceanus Borealis--could have covered a third of the planet.

But even if the evidence has mounted steadily, fostering our hopes of finding signs of past life on the Red Planet, the case for an ancient Martian ocean remains unsettled.

Now a new study by Lorena Moscardelli, a geologist at the University of Texas, Austin, puts forward yet another line of evidence.

Today, large fields of boulder-size rocks blanket parts of Mars' northern plains. By pointing to analogue geological features on our Earth, Moscardelli suggests that the boulders were delivered to their current locations by catastrophic underwater landslides--bolstering evidence for an ancient Martian ocean.

The boulders were spotted by the HiRISE camera on the Mars Reconnaissance Orbiter a while ago. So Moscardelli is not reporting their presence as something new, but rather a new interpretation of the processes behind their origin. The paper was published this month in a journal of the Geological Society of America.

Terrestrial Analogy

In the past, geoscientists thought of ocean sediments as mostly fine-grained, floating in the water column and settling like a slow "rain" on the sea floor, Moscardelli explained. But we now know it's not the only possible scenario.

"We know that 'submarine landslides' can transport big boulders--sometimes as big as a house--for hundreds of kilometers into the deep-water of the Earth oceans," she said. "Imagine a huge landslide affecting the entire state of Texas, but happening in the ocean." In her new study, Moscardelli documents several sites where these events have occurred on Earth, such as the Pennsylvanian Jackfork Group of south-central Arkansas; the outcrops of the Guandacol Formation in the Pangazo Basin, Argentina; or in the Santos Basin, offshore Brazil.

She even shows that these underwater events can affect huge areas, as with a massive landslide that covered thousands of square kilometers in the Barents Sea, north of Russia, about a million years ago.

Some scientists have suggested that the boulders of Mars's northern plain could be the product of meteorite impacts. But to Moscardelli, that's not a fitting theory.

"That's possible for some of the boulders, especially those found close to craters," she says. "But how do you explain boulder fields that can cover thousands of square kilometers without any impact craters around? The submarine hypothesis provides a feasible alternative."

The Case for a Martian Ocean

In the 1980s, Viking spacecraft images revealed two possible ancient shorelines near the pole, much like those found in Earth's coastal regions. But further observations showed the coastlines varied in elevation, undulating like a wave, and thus casting much doubt on the Martian ocean hypothesis. However, later studies eventually showed that the deformation could be simply explained by the movement of Mars' spin axis.

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Lorena Moscardelli stands near megablocks embedded within mass-transport deposits of the Jackfork Group in Arkansas, USA. Image facilitated by Roger Slatt. (Moscardelli, 2014)

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What's more, the northern plains of Mars--also called the northern lowlands--lie at a lower elevation than the southern hemisphere, much like ocean basins found on Earth.

In addition to the boulders of the northern plains, Moscardelli had previously documented other geological features which can form underwater on Earth, including teardrop-shaped islands and polygon-shaped areas.

"There are many hypothesis out there and we still need to learn a whole lot before we can be confident about which one is right or wrong," she said. "I have an informed opinion based on my technical observations, but I am cautious and humble about it because I could be wrong! That said, I think my case is a strong one."

Some of the evidence for terrestrial analogues came from 3-D seismic surveys, a tool traditionally used by the oil and gas industry. So she hopes her approach will encourage more inter-disciplinary research.

"It is amazing to see how little the planetary science and the marine geoscience communities interacts," she said. "If anything, I hope my contributions can help improve that kind of cross-pollination and cooperation."

Quelle: ASTROBIOLOGY MAGAZINE



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Samstag, 15. Februar 2014 - 23:00 Uhr

Raumfahrt - Erfolgreicher Start von ILS Proton-M mit TURKSAT-4A

.9.02.2014

TURKSAT-4A is a commercial communication satellite built by Mitsubishi Electric. The satellite will provide telecommunication and direct TV broadcasting services over a wide geographic region between west of china and east of England spanning Turkey, as well as Europe, Central Asia, the Middle East and Africa. TURKSAT-4A consists of multiple transponders with an expected on-orbit Maneuver life of 30 years. TURKSAT-4A satellite will expand the space capacity of Turkey and provide enhanced performance to its coverage areas. The satellite will provide high flexibility of switchability and connectivity among different service areas to its customers.

Satellite Statistics:             
_Mitsubishi Electric’s DS2000 platform
_36 transponders
_2084 MHz communications capacity
_Extensive coverage & connectivity over Turkey, Europe, Middle East, Asia and Africa
_Satellite Maneuver Lifetime: 30 years

Mission Profile:                   
The Proton M launch vehicle, utilizing a 5-burn Breeze M mission design, will lift off from Pad 24 at Baikonur Cosmodrome, Kazakhstan, with the TURKSAT-4A satellite onboard. The first three stages of the Proton will use a standard ascent profile to place the orbital unit (Breeze M upper stage and the TURKSAT-4A satellite) into a sub-orbital trajectory. From this point in the mission, the Breeze M will perform planned mission maneuvers to advance the orbital unit first to a circular parking orbit, then to an intermediate orbit, followed by a transfer orbit, and finally to a geostationary transfer orbit. Separation of the TURKSAT-4A satellite is scheduled to occur approximately 9 hours, 13 minutes after liftoff.

Target Orbit at Separation:          
Perigee: 9,673 km
Apogee: 35,786 km
Inclination: 12.7 degrees

Spacecraft Separation:     
Approximately 9 hours, 13 minutes after liftoff

ILS Mission Statistics:      
_1st ILS Proton Launch in 2014
_85th ILS Proton Launch Overall
_1st TURKSAT Satellite Launched on ILS Proton
_1st Mitsubishi Electric Satellite Launched on ILS Proton

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Ankunft von TURKSAT-4A in Baikonur Cosmodrome, Kazakhstan

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Quelle: ILS      

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Update: 11.02.2014

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TURKSAT-4A

Launch Date: 
February 14, 2014 - 9:09pm GMT

Vehicle: Proton M/ Breeze M

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Quelle: ILS

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Update: 12.02.2014 

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Türksat 4A Ready for Rollout at Baikonur, Ahead of Friday Night Proton-M Launch

With three days to go, International Launch Services (ILS)—the joint U.S.-Russian company which operates all commercial Proton-M rockets out of Baikonur Cosmodrome, Kazakhstan—stands ready to deliver its first payload of 2014 into geostationary transfer orbit. With liftoff scheduled to occur at 3:09 a.m. local time Saturday (4:09 p.m. EST Friday), the 85th ILS Proton mission will deliver the Türksat 4A communications satellite into orbit on behalf of Türksat Satellite Communications and Cable TV Operations Company, headquartered in Gölbaşı, within Turkey’s Ankara Province. It will be the first time that Türksat has contracted with ILS for launch services.
Built by Mitsubishi Electric (MELCO) at its Kamakura plant in Tokyo, Türksat 4A and 4B will be placed into orbit at 42 degrees East and 50 degrees East longitude respectively. Contracts with ILS to launch the two 8,380-pound (3,800-kg) satellites were signed in April 2011. Speaking at the time, Hiroyuki Inahata, head of MELCO’s space systems division, remarked that the choice of ILS as launch services provider was made “based on their track record of reliability, precision, launch tempo and experience.” With Türksat 4B scheduled to ride another Proton-M later in 2014, efforts are now entering their final stages to prepare Turkey’s communications birds for their missions.

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Update: 13.02.2014

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FINAL DAYS!

February 13, 2014 8:00 pm (GMT)
ILS Launch Team

Today, the ILS Proton stands vertical at Launch Pad 24.  With the assistance of the enormous mobile service tower final checks are being made to the Proton rocket.  TURKSAT-4A is safely enclosed and its environment is constantly monitored.   Tests will continue followed by the launch countdown rehearsal and the State Commission to approve the go for launch.  With just over a day to go, the anticipation is building!

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Quelle: ILS

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Update: 14.02.2014

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Update: 15.02.2014

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Erfolgreicher Start von Proton-M mit TURKSAT-4A

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ILS Proton Successfully Launches TURKSAT-4A for TURKSAT

First Proton Launch of the Year; 85th ILS Proton Launch Overall


BAIKONUR COSMODROME, Kazakhstan, February 15, 2014 – International Launch Services (ILS), a leader in providing mission integration and launch services to the global commercial satellite industry, successfully launched the TURKSAT-4A satellite into orbit today on an ILS Proton vehicle. The satellite was built by Mitsubishi Electric Corporation for TURKSAT Satellite Communication, Cable TV and Operation Inc. Co. (TURKSAT A.S.), one of the world’s leading operators in the satellite communication business. This was the first ILS Proton launch for both the satellite operator and the manufacturer; it was also the first Proton launch of the year.

The ILS Proton Breeze M vehicle launched from Pad 24 at the Baikonur Cosmodrome at 03:09 today local time (14 February: 21:09 GMT and 16:09 EST).  The first three stages of the Proton used a standard ascent profile to place the orbital unit (Breeze M upper stage and the TURKSAT-4A satellite) into a sub-orbital trajectory. From this point in the mission, the Breeze M performed planned mission maneuvers to advance the orbital unit first to a circular parking orbit, then to an intermediate orbit, followed by a transfer orbit, and finally to a geostationary transfer orbit. Separation of the TURKSAT-4A satellite occurred approximately 9 hours and 13 minutes after liftoff.

TURKSAT-4A will provide telecommunication and direct TV broadcasting services over a wide geographic region between west of China and east of England, spanning Turkey, as well as Europe, Central Asia, the Middle East and Africa. TURKSAT-4A is a multi-band satellite with an expected on-orbit maneuver lifespan of 30 years. The satellite will provide high flexibility of switchability and connectivity among different service areas to its customers.

The satellite weighed 4.8 metric tons at liftoff and is the ninth satellite built on Mitsubishi Electric’s DS2000 platform, a fully proven modular platform with the flexibility to handle a broad range of payload applications.

ILS President Phil Slack stated, “This is the first ILS Proton launch for our partners, Mitsubishi Electric and TURKSAT, and we are happy to have such a strong foundation for our new relationship. We are honored to be entrusted to deliver our customers’ satellites to orbit. Thank you to all of the teams at Mitsubishi Electric, TURKSAT, Khrunichev, and ILS, who have made this launch a success.”

Ozkan Dalbay, TURKSAT A.S. CEO and Chairman of the Board, said, “The TURKSAT-4A satellite will increase coverage and enhance customer services across Turkey as well as through areas of Europe, Central Asia, the Middle East and Africa. Today's launch is a significant milestone that strengthens our ties with both ILS and Khrunichev. Thank you to everyone involved in the success of this launch.”

Mitsubishi Electric General Manager of Space Systems Division, Yasunori Kamochi added, “We appreciate that through ILS’ conscientious efforts, they conducted a flawless mission leading to the successful launch of TURKSAT 4A, our first Proton launch.  We are certain that ILS’ assurance in quality and scheduling will allow our customer to engage its satellite mission in a timely manner. We would like to thank everyone involved with the TURKSAT-4A launch for their diligence and outstanding capabilities.”

This was the 85th ILS Proton Launch and the 394th launch for Proton overall since its maiden flight in 1965. The Proton Breeze M vehicle is developed and built by Khrunichev Research and Production Space Center of Moscow, Russia’s premier space industry manufacturer and majority shareholder in ILS.

Quelle: ILS


3012 Views

Samstag, 15. Februar 2014 - 18:56 Uhr

Astronomie - Die Wächter der Himmelskörper

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Vor einem Jahr explodierte ein Meteorit über der russischen Stadt Tscheljabinsk. Er hat daran erinnert, welche Gefahren im All lauern. In Freiburg wird daran geforscht, noch viel größere Gesteinsbrocken am Aufprall auf der Erde zu hindern.

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Wissenschaftler Frank Schäfer vom Fraunhofer Institut für Kurzzeitdynamik in Freiburg mit einer Hülle eines Satelliten.

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Freiburg . Am 15. Februar 2013 explodiert über der russischen Millionenstadt Tscheljabinsk ein Meteorit. Die Druckwelle lässt Tausende Scheiben zerbersten und deckt Dächer ab, rund 1500 Menschen werden von Glassplittern verletzt. Voraussehen konnte den zerstörerischen Himmelskörper niemand. Zu klein war der etwa 10 000 Tonnen schwere und 20 Meter im Durchmesser große Brocken, um mit Teleskopen aufgespürt zu werden.

Deutlich größere Himmelskörper haben Forscher des internationalen Forschungsprojekts „NEOshield“ im Blick. Solche, die der Erde nahe kommen könnten und deutlich gefährlicher sind als der Meteorit von Tscheljabinsk. Wie diese sich im Notfall von ihrer Bahn abbringen ließen, untersuchen Wissenschaftler des Fraunhofer-Instituts für Kurzzeitdynamik in Freiburg. Dort werden Asteroiden im Miniaturformat von winzigen Satelliten beschossen.

Nichts deutet im Untergeschoss des Instituts darauf hin, dass dort daran geforscht wird, die Erde vor tödlichen Brocken aus dem All zu retten. „Städte- und Regional-Killer“ nennt Wissenschaftler Frank Schäfer die Asteroiden, die ihn beschäftigen. Sie haben einen Durchmesser zwischen 100 Metern und 300 Metern und könnten ganze Städte und Regionen auslöschen. Rund 10 000 solcher „Near-Earth-Objects“ - Asteroiden, die der Erde nahe kommen können - haben Astronomen bisher registriert.

Teleskope oder Messinstrumente zur Beobachtung von Asteroiden sucht man am Arbeitsplatz von Schäfer vergeblich. Ein etwa sieben Meter langer Apparat steht im Labor des Physikers. Es ist eine Art Kanone, mit der winzige Kügelchen aus Aluminium auf Gesteinsbrocken geschossen werden. Schäfer nennt sie ganz futuristisch „Spacegun“, oder, wissenschaftlich ausgedrückt, Beschleunigungsanlage. Mit ihr wird die Abwehr gefährlicher Asteroiden mit Satelliten simuliert.

Ziel der „NEOshield“-Forscher ist es, künftig eine Raumsonde auf einem Asteroiden einschlagen lassen zu können und diesen so von seiner Umlaufbahn abzulenken. „Das ist ähnlich wie beim Billard», erklärt Schäfer. „Wenn eine Kugel auf die andere trifft, ändert diese ihre Bahn.“ Wie genau diese Veränderungen aussehen könnten, erforscht Schäfer mit sogenannten Pendeltests.

An einem Ende wird die „Spacegun“ mit einer Aluminiumkugel von der Größe eines Stecknadelkopfes geladen. Auf der anderen Seite hängt ein Betonklotz, etwa 20 Zentimeter breit, tief und hoch. Er hat eine ähnliche Dichte wie ein Asteroid. Porös, aber stabil. Porenbeton sagen Fachleute dazu. Dann wird geschossen, das Kügelchen knallt mit rund 30 000 Stundenkilometern auf den Klotz. Zeitlupenkameras zeichnen den Aufprall auf, Sensoren messen, wie sich der Klotz bewegt. Die Wissenschaftler rechnen dann in reale Größenordnungen um und stellen die Frage: Reicht die Kraft, um einen bedrohlichen Asteroiden aus seiner Bahn zu werfen?

Alan Harris, der das Projekt „NEOshield“ am Deutschen Zentrum für Luft- und Raumfahrt leitet, hält es für realistisch, dass eine Sonde von der Größe eines Kleinlasters auf einen 100 Meter bis 300 Meter großen Test-Asteroiden geschossen wird, um diesen aus der Bahn zu kegeln. „Wir haben schon den ein oder anderen Asteroiden im Blick, den wir beschießen könnten“, sagt Harris. Welche das sind, bleibt geheim. „Es sind natürlich Kaliber, die nicht auf die Erde zurasen, sondern in sicherer Entfernung an ihr vorbeifliegen.“

Was passiert, wenn ein Asteroid nicht an der Erde vorbeifliegt, zeigt ein Blick in die Vergangenheit - etwa der Einschlag eines Asteroiden im Nördlinger Ries in Bayern vor etwa 14,6 Millionen Jahren. Der Krater hat einen Durchmesser von bis zu 24 Kilometern. Auch der Barringer-Krater in Arizona (USA) mit einem Durchmesser von 1200 Metern wurde von einem Asteroiden verursacht. Er dürfte gerade mal 50 Meter groß gewesen sein. Und 1908 hat in Sibirien die Explosion eines Asteroiden Millionen Bäume entwurzelt.

Quelle: Schaumburger Nachrichten


2636 Views

Samstag, 15. Februar 2014 - 12:00 Uhr

Raumfahrt - Outer Space ISS-Photographs

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Quelle: NASA


2440 Views

Samstag, 15. Februar 2014 - 11:35 Uhr

Raumfahrt - Chang'e-2-Mondsonde erreicht 70 Mio. km Marke

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China's second lunar probe, Chang'e-2, has traveled more than 70 million km into deep space in good condition, so far the longest voyage of a Chinese spacecraft, a senior engineer said Friday.

Chang'e-2 was launched on Oct. 1, 2010 to verify crucial technologies for Chang'e-3. It set off from its moon orbit for outer space in June 2011 after finishing all of its tasks.

Chang'e-2 is expected to travel as far as 300 million km from the earth, after which it will return to perigee of about 7 million km from the earth around 2029, said Zhou Jianliang, chief engineer of the Beijing Aerospace Control Center.

The probe will reach 100 million km from Earth in July of this year.

The control center has made many breakthroughs in fuel use and orbital decay technologies, which will boost China's future deep space exploration, Zhou said.

Quelle: Xinhua


2617 Views


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