Blogarchiv

Sonntag, 14. April 2013 - 23:15 Uhr

Astronomie - Sternenhimmel und ISS-Überflug am Sonntag-Abend

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Update 23.15 MESZ

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Fotos: ©hjkc


3815 Views

Sonntag, 14. April 2013 - 19:46 Uhr

Raumfahrt - Russland will 50 Milliarden Dollar bis zum Jahr 2020 in die Raumfahrt investieren

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Russia to work toward landing on moon, Mars by 2030, Deputy PM says
Blagoveshensk,-Russia will develop launch vehicles and other rocket technology for manned flights to the moon and Mars by 2030, Deputy Prime Minister Dmitry Rogozin says.
Rogozin, who oversees Russia's space and military industries, said work would begin to design a carrier rocket with a payload of 130 to 180 tons, as well as powerful interplanetary vehicles, RIA Novosti reported Friday.
The new technologies will lay the ground work for manned flights to the moon and later to Mars, Rogozin said.
He made the statements at a space industry conference in Russia's Far East Friday as Russia marked the anniversary of Yuri Gagarin's first manned space flight on April 12, 1961.
The Russian space industry is also embarking on a program to develop a robot system for moon exploration as well as construct a permanent research base there, he said.
Russia had previously worked on a large rocket in the 1960s, the N-1, for a lunar landing mission but abandoned the project after the United States won the race to land men on the moon in 1969.
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President Vladimir Putin on Friday unveiled a new $50 billion drive for Russia to preserve its status as a top space power, including the construction of a brand new cosmodrome from where humans will fly to space by the end of the decade.
Fifty-two years to the day since Yuri Gagarin became the Soviet Union's greatest hero by making the first human flight into space, Putin inspected the new Vostochny (Eastern) cosmodrome Russia is building in the Amur region of its Far East district.
Putin said in a live link-up with the multinational crew of the International Space Sation (ISS) that Russia hoped to have the first launches from Vostochny in 2015 and the first manned launches in 2018.
"It's going to be a great launch pad. It took a long time to choose but now work is fully underway," said Putin in comments broadcast on state television, adding that Vostochny would be fully operational by 2020.
Russia still carries out all manned launches from the Baikonur cosmodrome in Kazakhstan -- the same place where Gagarin made his historic flight. But this has been clouded in recent years by disputes with the Kazakh authorities over lease terms.
Putin announced that the town being built around the new cosmodrome to house its engineers and families would be called Tsiolkovsky, in honour of the Russian scientist Konstantin Tsiolkovsky who pioneered rocket design in the early Soviet era.
The Russian space programme has been hurt in recent years by a string of launch failures of unmanned probes and satellites, but Putin vowed Moscow would ramp up spending.
He said that from 2013-2020, Russia would be spending 1.6 trillion rubles ($51.8 billion, 38 million euros) on its space sector, a growth far greater than any other space power.
Putin complained that Russia was behind other states in space activities other than manned flights, which he said had long been the "priority" of the Russian space programme "to the detriment" of other projects.
With up to 58 percent of the Russian space budget going on manned space flight, Russia had lost ground to other powers, in particular in unmanned deep-space exploration, said Putin.
"We need to preserve what we have achieved in manned space flight but also to catch up in these other areas," said Putin, who said he also did not rule out the creation of a ministry of space.
One of Russia's most embarrassing failures was the loss of its Phobos-Grunt probe to Mars in 2012 which ended up crashing back into Earth rather than even coming close to completing its mission of visiting a Martian moon.
The disaster underlined Russia's weaknesses compared with US space agency NASA, which has basked in the huge public successes of its unmanned Mars missions in recent years.
But speaking to Canadian spaceman Chris Hadfield, currently commander of the ISS, Putin hailed cooperation in space which meant world powers could forget about the problems of international relations and think "about the future of mankind."
Russia's veteran Soyuz rocket and capsule system, based on the same principles as the system that launched Gagarin, is currently the sole means of transporting humans to the ISS since the retirement of the US shuttle.
Putin said that cosmonauts returning to Earth after lifting off from Vostochny would most likely splash down in the Pacific Ocean rather than land as they currently do in Kazakhstan.
"Most probably, according to specialists, they will come down on the ocean. So our cosmonauts will splash down rather than touch down," Putin said.
The head of Russia's space agency Roscosmos, Vladimir Popovkin, meanwhile said Moscow was targeting 2030 as the year in which it could begin creating a base on the moon for flights to Mars.
"The moon is a great launch pad, it's basically a big space object on which a whole load of things could be accommodated. Not using it would be sinful," he told state television.
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2936 Views

Sonntag, 14. April 2013 - 18:30 Uhr

Mars-Curiosity-Chroniken - Curiosity-News Sol 232-234

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This image was taken by Mastcam: Right (MAST_RIGHT) onboard NASA's Mars rover Curiosity on Sol 232 (2013-04-01 11:17:10 UTC). 
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This image was taken by Mastcam: Right (MAST_RIGHT) onboard NASA's Mars rover Curiosity on Sol 232 (2013-04-01 11:27:36 UTC). 
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This image was taken by Mastcam: Right (MAST_RIGHT) onboard NASA's Mars rover Curiosity on Sol 232 (2013-04-01 11:31:35 UTC). 
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This image was taken by Mastcam: Right (MAST_RIGHT) onboard NASA's Mars rover Curiosity on Sol 232 (2013-04-01 11:30:22 UTC). 
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This image was taken by Mastcam: Right (MAST_RIGHT) onboard NASA's Mars rover Curiosity on Sol 232 (2013-04-01 11:40:58 UTC). 
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This image was taken by Mastcam: Right (MAST_RIGHT) onboard NASA's Mars rover Curiosity on Sol 232 (2013-04-01 11:45:01 UTC). 
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This image was taken by Mastcam: Right (MAST_RIGHT) onboard NASA's Mars rover Curiosity on Sol 232 (2013-04-01 11:47:42 UTC). 
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This image was taken by Mastcam: Right (MAST_RIGHT) onboard NASA's Mars rover Curiosity on Sol 232 (2013-04-01 11:51:43 UTC).
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This image was taken by Mastcam: Right (MAST_RIGHT) onboard NASA's Mars rover Curiosity on Sol 232 (2013-04-01 11:54:23 UTC). 
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This image was taken by Mastcam: Right (MAST_RIGHT) onboard NASA's Mars rover Curiosity on Sol 232 (2013-04-01 12:59:33 UTC). 
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This image was taken by ChemCam: Remote Micro-Imager (CHEMCAM_RMI) onboard NASA's Mars rover Curiosity on Sol 232 (2013-04-01 12:48:46 UTC).
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This image was taken by Navcam: Left B (NAV_LEFT_B) onboard NASA's Mars rover Curiosity on Sol 232 (2013-04-01 11:13:08 UTC). 
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This image was taken by Rear Hazcam: Left B (RHAZ_LEFT_B) onboard NASA's Mars rover Curiosity on Sol 232 (2013-04-01 08:56:07 UTC). 
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This image was taken by Front Hazcam: Left B (FHAZ_LEFT_B) onboard NASA's Mars rover Curiosity on Sol 232 (2013-04-01 08:55:41 UTC). 
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This image was taken by Mastcam: Right (MAST_RIGHT) onboard NASA's Mars rover Curiosity on Sol 233 (2013-04-02 11:44:58 UTC). 
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This image was taken by Mastcam: Right (MAST_RIGHT) onboard NASA's Mars rover Curiosity on Sol 233 (2013-04-02 11:55:06 UTC). 
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This image was taken by Mastcam: Right (MAST_RIGHT) onboard NASA's Mars rover Curiosity on Sol 233 (2013-04-02 11:59:26 UTC). 
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This image was taken by Mastcam: Right (MAST_RIGHT) onboard NASA's Mars rover Curiosity on Sol 233 (2013-04-02 12:09:19 UTC). 
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NASA's Mars rover Curiosity acquired this image using its Mars Hand Lens Imager (MAHLI), located on the turret at the end of the rover's robotic arm, on April 2, 2013, Sol 233 of the Mars Science Laboratory Mission, at 12:29:05 UTC.
When this image was obtained, the focus motor count position was 13256. This number indicates the internal position of the MAHLI lens at the time the image was acquired. This count also tells whether the dust cover was open or closed. Values between 0 and 6000 mean the dust cover was closed; values between 12500 and 16000 occur when the cover is open. For close-up images, the motor count can in some cases be used to estimate the distance between the MAHLI lens and target. For example, in-focus images obtained with the dust cover open for which the lens was 2.5 cm from the target have a motor count near 15270. If the lens is 5 cm from the target, the motor count is near 14360; if 7 cm, 13980; 10 cm, 13635; 15 cm, 13325; 20 cm, 13155; 25 cm, 13050; 30 cm, 12970. These correspond to image scales, in micrometers per pixel, of about 16, 25, 32, 42, 60, 77, 95, and 113.
Most images acquired by MAHLI in daylight use the sun as an illumination source. However, in some cases, MAHLI's two groups of white light LEDs and one group of longwave ultraviolet (UV) LEDs might be used to illuminate targets. When Curiosity acquired this image, the group 1 white light LEDs were off, the group 2 white light LEDs were off, and the ultraviolet (UV) LEDS were off. 
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This image was taken by Mastcam: Right (MAST_RIGHT) onboard NASA's Mars rover Curiosity on Sol 234 (2013-04-03 12:32:28 UTC). 
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This image was taken by Mastcam: Right (MAST_RIGHT) onboard NASA's Mars rover Curiosity on Sol 234 (2013-04-03 13:39:01 UTC). 
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This image was taken by ChemCam: Remote Micro-Imager (CHEMCAM_RMI) onboard NASA's Mars rover Curiosity on Sol 234 (2013-04-03 13:08:26 UTC).
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This image was taken by Front Hazcam: Right B (FHAZ_RIGHT_B) onboard NASA's Mars rover Curiosity on Sol 234 (2013-04-03 10:14:51 UTC). 
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Fotos: NASA

2907 Views

Sonntag, 14. April 2013 - 17:33 Uhr

Raumfahrt-History - Erster Space-Shuttle-Start mit Columbia am 12.April 1981

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First Shuttle Launch
A new era in space flight began on April 12, 1981, when Space Shuttle Columbia, or STS-1, soared into orbit from NASA's Kennedy Space Center in Florida. 
Astronaut John Young, a veteran of four previous spaceflights including a walk on the moon in 1972, commanded the mission. Navy test pilot Bob Crippen piloted the mission and would go on to command three future shuttle missions. The shuttle was humankind's first re-usable spacecraft. The orbiter would launch like a rocket and land like a plane. The two solid rocket boosters that helped push them into space would also be re-used, after being recovered in the ocean. Only the massive external fuel tank would burn up as it fell back to Earth. It was all known as the Space Transportation System.
Twenty years prior to the historic launch, on April 12, 1961, the era of human spaceflight began when Russian Cosmonaut Yuri Gagarin became the first human to orbit the Earth in his Vostock I spacecraft. The flight lasted 108 minutes. 
Pictured here: a timed exposure of STS-1, at Launch Pad A, Complex 39, turns the space vehicle and support facilities into a night- time fantasy of light. Structures to the left of the shuttle are the fixed and the rotating service structure. 
Quelle: NASA

2830 Views

Sonntag, 14. April 2013 - 11:23 Uhr

Mars-Chroniken - Curiosity-News

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Accurate pointing by Curiosity
NASA's Curiosity Mars rover targeted the laser of the Chemistry and Camera (ChemCam) instrument with remarkable accuracy for assessing the composition of the wall of a drilled hole and tailings that resulted from the drilling. This graphic diagrams the pointing and shows the resulting pits created by the laser shots. 
On the 180th Martian day, or sol, of Curiosity's work on Mars (Feb. 6, 2013), the rover performed a "mini drill test," followed on Sol 182 (Feb. 8, 2013) by the actual drilling to collect a sample from the interior of the rock. Both holes in the target rock "John Klein" are visible in the image at upper left, taken on Sol 182 by the rover's Navigation Camera (Navcam). Both the Navcam and the ChemCam are at the top of the Curiosity's remote-sensing mast. 
Each drilled hole is about 0.63 inch (1.6 centimeters) wide, and they are located about 8 feet (about 2.5 meters) away from the top of the mast. So small, so far away… 
On Sol 227 (March 26, 2013), ChemCam fired its laser 150 times (5 bursts of 30 shots, each burst at a different target point) on the drill tailings between the two holes and 300 times (10 bursts of 30 shots) in the drill hole itself. The same day, ChemCam's remote micro-imager (RMI) captured images of the laser pits: small craters in the loose tailing (center photo from RMI), and tiny scrapes on the hard surface of the hole walls (photo at right from RMI). Composition spectra from the ChemCam laser inspection are under investigation.
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Quelle: NASA

3265 Views

Freitag, 12. April 2013 - 22:13 Uhr

Raumfahrt - TEXUS 50: Jubiläum für Deutschlands Forschungsraketen-Programm

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50.Texus-Start

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Es ist das weltweit längste Raketenprogramm für Forschung in Schwerelosigkeit und feiert heute ein Jubiläum: 35 Jahre nach der ersten TEXUS-Mission im Dezember 1977 ist die 50. TEXUS-Rakete am 12. April 2013 um 6:25 Uhr Mitteleuropäischer Sommerzeit vom Raumfahrtzentrum Esrange bei Kiruna in Nordschweden erfolgreich in den Weltraum gestartet. 15 Minuten dauerte der Flug, davon herrschten 6 Minuten und 20 Sekunden Schwerelosigkeit. Ein Fallschirm brachte die wissenschaftlichen Nutzlasten nach dem Flug wieder zurück zum Boden.  
Die Forschungsrakete des Deutschen Zentrums für Luft- und Raumfahrt (DLR) trug vier deutsche Experimente aus Biologie und Materialforschung in eine Höhe von 261 Kilometern. Die Rakete des Typs "VSB-30" wurde dabei nur direkt nach dem Start beschleunigt und flog  dann antriebslos weiter.
"Hauptnutzlast der TEXUS-50-Mission ist die in Deutschland entwickelte Elektromagnetische Levitationsanlage EML", berichtet Otfried Joop, TEXUS-Projektleiter beim DLR-Raumfahrtmanagement, und ergänzt: "Mit ihr erforschen Wissenschaftler des DLR-Instituts für Materialphysik im Weltraum in zwei Experimenten thermophysikalische Eigenschaften und das Erstarrungsverhalten von Metall-Legierungen, die von industriellem Interesse sind. Die Forscher untersuchen dazu eine Aluminium-Nickel-Verbindung, die in der Luftfahrt und anderen Verkehrssystemen verwendet wird, sowie eine Nickel-Zirconium-Legierung."
Anhand von Sporenträgern eines Pilzes möchten Forscher der Universität Marburg die allerersten Reaktionen eines Organismus auf Schwerkraftänderungen untersuchen: Wie werden diese wahrgenommen und wie schnell reagiert der Pilz auf den Wechsel von Schwerkraft und Schwerelosigkeit?  "Die relativ lange Schwerelosigkeit der Rakete und eine eingebaute Präzisionszentrifuge sollen es den Wissenschaftlern erlauben, zum ersten Mal die Kinetik und den Grenzwert, also die Mindeststärke der Schwerkraft, die der Pilz braucht, um zu reagieren, zu messen", erklärt DLR-Projektleiter Otfried Joop.
Im zweiten biologischen Experiment auf TEXUS 50 wollen Wissenschaftler der Universität Freiburg Gene und Genprodukte ("Boten-RNA") identifizieren, die bei der Wahrnehmung und der Verarbeitung des Schwerkraftreizes in Pflanzen eine Rolle spielen. Dazu fliegen Keimlinge der "Acker-Schmalwand" mit, einer Pflanze, die aufgrund ihrer relativ einfachen genetischen Struktur seit den 1940er Jahren von Forschern als "Modellorganismus" benutzt wird. "Die TEXUS-Keimlinge werden im Anschluss an den Flug mit den am Boden gebliebenen Pflanzen verglichen", fasst Otfried Joop zusammen. Die Forscher suchen unter anderem Antworten auf die Frage, welche  Klassen von Genen bei der Schwerkraftänderung aktiviert  oder inaktiviert werden.
Doppelkampagne: Zwei Raketen in einer Woche
"Seit 1981 ist TEXUS 50/51 zudem die erste deutsche Doppelkampagne", schildert Otfried Joop. Eine Woche nach der Jubiläumsmission soll TEXUS 51 am 19. April 2013 mit vier weiteren Experimenten deutscher Wissenschaftler startbereit sein:
 
Mit dem Partikeleinbau bei der Züchtung von Siliziumkristallen für die Photovoltaik beschäftigen sich Forscher vom Fraunhofer IISB in Erlangen, der Universität Freiburg und der Universität Bayreuth bei ParSiWal. Das Experiment soll klären, durch welche Mechanismen für die Materialeigenschaften nachteilige Siliziumkarbid-Partikel bei der Kristallisation in den Siliziumkristall eingebaut werden. Denn bei der industriellen Produktion von Silizium-Solarzellen für die Photovoltaik behindern Siliziumcarbid (SiC)-Partikel  die mechanische Bearbeitung des Produktes und verschlechtern den Wirkungsgrad der Solarzellen. Der Einbau der SiC-Partikel in den Siliziumkristall muss deshalb vermieden werden. Die Partikel entstehen während der Kristallisation in einer mit Kohlenstoff verunreinigten Siliziumschmelze. Die Schwerkraft beeinflusst maßgeblich die Strömung in der Schmelze und  lässt die SiC-Partikel absinken, da sie eine höhere Dichte besitzen als Silizium. Im Weltall sind diese schwerkraftgetriebenen Effekte ausgeschaltet. Das verringert die Komplexität der Vorgänge erheblich und erleichtert damit auch deren physikalische Beschreibung. Die Erkenntnisse sollen schließlich zu einer Verbesserung von Qualität und Wirkungsgrad der Solarzellen beitragen.
Das Experiment FOKUS vom Max-Planck-Institut für Quantenoptik in München soll nachweisen, dass die Technologie eines so genannten "Frequenzkammes" für Anwendungen in der Raumfahrt ausgereift ist. Herzstück eines Frequenzkammes ist ein gepulster Laser, der  optische Frequenzen misst. Künftig soll diese Technologie in der Präzisions-Spektroskopie, etwa bei der Untersuchung von Spurengasen in der Atmosphäre, in der Astrophysik oder bei neuartigen, extrem genauen Atomuhren für Forschungsmissionen oder für die Navigation eingesetzt werden.  Der Frequenzkamm ist ein Laser, der 1999 am Max-Planck-Institut für Quantenoptik entwickelt wurde und für dessen Entwicklung Prof. Theodor W. Hänsch 2005 den Nobelpreis für Physik erhalten hat.
Das medizinisch-biologische Experiment SITI-2 einer Wissenschaftlergruppe der Universität Magdeburg möchte Mechanismen aufklären, die zu Störungen des menschlichen Immunsystems in der Schwerelosigkeit führen. So leiden einige Astronauten bei längeren Aufenthalten im All verstärkt unter Infektionen. Auf dem TEXUS-51-Flug werden dazu Zellkulturen eingesetzt, in denen die Aktivität von Genen des Immunsystems mithilfe moderner DNA-Chip-Technologie untersucht werden soll. Sollte sich die Vermutung der Wissenschaftler bestätigen, dass bestimmte Moleküle der Zellmembran für die durch Schwerelosigkeit hervorgerufenen Störungen verantwortlich sind, könnten diese Erkenntnisse langfristig zu neuen Ansätzen bei der Bekämpfung von Krankheiten führen.
Im materialwissenschaftlichen Experiment TRACE-3 vom Forschungszentrum ACCESS in Aachen werden schließlich Vorgänge und Strukturen analysiert, die bei der Erstarrung metallischer Legierungen eine Rolle spielen. Dies überprüfen die Wissenschaftler beispielhaft an einem Gemisch organischer Substanzen, das ähnlich wie flüssiges Metall erstarrt. Der Erstarrungsprozess kann dabei direkt beobachtet werden, da die  Legierung durchsichtig ist.  Die  Daten sollen industrielle Gießprozesse verbessern.
Im gesamten TEXUS-Programm wurden seit 1977 etwa 300 wissenschaftliche Experimente durchgeführt, 70 Prozent davon im Auftrag des DLR und etwa 30 Prozent im Rahmen einer Beteiligung durch die europäische Raumfahrtagentur ESA. "Zusammen mit anderen Fluggelegenheiten des DLR ist TEXUS damit ein essenzieller Baustein für die Grundlagenforschung in Schwerelosigkeit und damit auch für die Vorbereitung von längerfristigen Weltraumexperimenten, etwa auf der Internationalen Raumstation ISS", resümiert DLR-Projektleiter Joop.
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Texus-Booster
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Launchtower
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Quelle: DLR

3122 Views

Freitag, 12. April 2013 - 20:31 Uhr

Raumfahrt - Im Focus von Cassini - Eis Wolke läutet Herbst bei Titan´s Südpol ein

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The recently formed south polar vortex stands out in the color-swaddled atmosphere of Saturn's largest moon, Titan, in this natural color view from NASA's Cassini spacecraft. Image credit: NASA/JPL-Caltech/Space Science Institute

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An ice cloud taking shape over Titan's south pole is the latest sign that the change of seasons is setting off a cascade of radical changes in the atmosphere of Saturn's largest moon. Made from an unknown ice, this type of cloud has long hung over Titan's north pole, where it is now fading, according to observations made by the composite infrared spectrometer (CIRS) on NASA's Cassini spacecraft. 
"We associate this particular kind of ice cloud with winter weather on Titan, and this is the first time we have detected it anywhere but the north pole," said the study's lead author, Donald E. Jennings, a CIRS Co-Investigator at NASA's Goddard Space Flight Center in Greenbelt, Md. 
The southern ice cloud, which shows up in the far infrared part of the light spectrum, is evidence that an important pattern of global air circulation on Titan has reversed direction. When Cassini first observed the circulation pattern, warm air from the southern hemisphere was rising high in the atmosphere and was transported to the cold north pole. There, the air cooled and sank down to lower layers of the atmosphere and formed ice clouds. A similar pattern, called a Hadley cell, carries warm, moist air from Earth's tropics to the cooler middle latitudes. 
Based on modeling, scientists had long predicted a reversal of this circulation once Titan's north pole began to warm and its south pole began to cool. The official transition from winter to spring at Titan's north pole occurred in August 2009. But because each of the moon's seasons lasts about seven-and-a-half Earth years, researchers still did not know exactly when this reversal would happen or how long it would take. 
The first signs of the reversal came in data acquired in early 2012, which came shortly after the start of southern fall on Titan, when Cassini images and visual and infrared mapping spectrometer data revealed the presence of a high-altitude "haze hood" and a swirling polar vortex at the south pole. Both features have long been associated with the cold north pole. Later, Cassini scientists reported that infrared observations of Titan's winds and temperatures made by CIRS had provided definitive evidence of air sinking, rather than upwelling, at the south pole. By looking back through the data, the team narrowed down the change in circulation to within six months of the 2009 equinox. 
Despite the new activity at the south pole, the southern ice cloud had not appeared yet. CIRS didn't detect it until about July 2012, a few months after the haze and vortex were spotted in the south, according to the study published in Astrophysical Journal Letters in December 2012. 
"This lag makes sense because first the new circulation pattern has to bring loads and loads of gases to the south pole. Then, the air has to sink. The ices have to condense. And the pole has to be under enough shadow to protect the vapors that condense to form those ices," said Carrie Anderson, a CIRS team member and Cassini participating scientist at Goddard. 
At first blush, the southern ice cloud seems to be building rapidly. The northern ice cloud, on the other hand, was present when Cassini first arrived and has been slowly fading the entire time the spacecraft has been observing it. 
So far, the identity of the ice in these clouds has eluded scientists, though they have ruled out simple chemicals, such as methane, ethane and hydrogen cyanide, which are typically associated with Titan. One possibility is that "species X," as some team members call the ice, could be a mixture of organic compounds.
"What's happening at Titan's poles has some analogy to Earth and to our ozone holes," said the CIRS Principal Investigator, Goddard's F. Michael Flasar. "And on Earth, the ices in the high polar clouds aren't just window dressing: They play a role in releasing the chlorine that destroys ozone. How this affects Titan chemistry is still unknown. So it's important to learn as much as we can about this phenomenon, wherever we find it." 
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency, and the Italian Space Agency. The mission is managed by the Jet Propulsion Laboratory for NASA's Science Mission Directorate, Washington. The CIRS team is based at NASA's Goddard Space Flight Center in Greenbelt, Md., where the instrument was built. JPL is a division of the California Institute of Technology.
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Quelle: NASA

2848 Views

Freitag, 12. April 2013 - 20:20 Uhr

Raumfahrt - Nachweis für Schwefelsäure-Sprüh-Regen auf Venus?

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A concept for the European Venus Explorer balloon seen floating in Venus’ atmosphere. The Soviet Vega missions would have looked similar to this proposed balloon probe. Image: T.Balint / EVE
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Soviet Balloon Probes May Have Seen Rain on Venus

 

A pair of balloon probes that floated in the atmosphere of Venus nearly 30 years ago may have run into a drizzle.
This being Earth’s hellish sister planet – where surface pressure is akin to being 900 m underwater and average temperatures are hot enough to melt lead – the shower wasn’t made of friendly water but rather corrosive sulfuric acid. The finding comes from a re-analysis of data taken by the Vega 1 and 2 missions and may represent the first onsite detection of rain ever made outside of Earth.
In 1984, the Soviet Union joined with several European countries to launch the Vega probes, a complex mission that dropped a pair of landers and balloons on Venus and then sent two spacecraft to make close encounters with Halley’s comet in 1986. No other mission has ever deployed balloons on another planet.
The two 3.5-m-diameter balloons floated for nearly two days in the Venusian atmosphere around 55 km above the surface. Unlike the hostile terrain below, the cloud layers at this height are a veritable wonderland. Temperature and pressure are comparable to Earth’s average and there is ample sunlight streaming in from above. If not for the sulfuric acid clouds and hurricane-force winds, the atmosphere of Venus would be a comfortable living space.
Most previous analyses of the mission noted that the balloons slowly leaked helium and descended as they traveled, and that has been considered the end of the story.
But the balloons were well built, made of a Teflon-impregnated material and “it would have been rare for them to start leaking,” said aeronautical engineer Graham Dorrington of the Royal Melbourne Institute of Technology in Australia, author of a paper on this work that appeared Apr. 6 in Advances in Space Research.
Looking again at the old data Dorrington noticed that one of the balloons, from Vega 2, seemed to have reduced its leakage rate at some point, as if it had somehow repaired itself. “I thought that was funny,” he said.
An alternative explanation for why the balloons descended would have been that they got heavier, most likely from a buildup of liquid on their outer surface. Sulfuric acid could have precipitated out of Venus’ clouds in a fine mist, coating the balloons and then slowly dripping off. In the case of the Vega 2 balloon, sensors indicated that at one point the probe’s buoyancy changed quickly, on the order of a minute, which could have happened when the balloon ran into a light drizzling shower.
“This work is credible and interesting, but speculative,” wrote planetary scientist Kevin McGouldrick of the University of Colorado, Boulder, who was not involved in the work, in an email to Wired.
Clouds are made of extremely tiny liquid drops that are suspended in the atmosphere. Rain happens when enough of these drops stick together to form a larger drop and fall from the sky.
While tiny particles of fine mist could conceivably form in the sulfuric acid clouds on Venus, it is an open question whether or not larger rain-like drops could exist, McGouldrick wrote. NASA’s Pioneer Venus spacecraft, which dropped a probe through the Venusian cloud layers and measured their properties in 1978, did not see large sulfuric acid drops during its fall.
But even on Earth, rainstorms are sporadic events, said Dorrington. The odds of a probe dropping through our atmosphere and hitting a downpour aren’t very big, so Pioneer Venus might have missed this evidence. And other spacecraft, like Mariner 10, have seen evidence of rainstorms, though nothing definitive. It will likely take a future mission to the cloud layers of Venus to conclusively confirm or deny the possibility of rain.
If the findings were proven, they would be the first onsite detection of rain on another planet. The European Space Agency’s Huygens probe, which landed on Saturn’s moon Titan in 2005, may have photographed a liquid drop from rain, though whether this came from the moon or the probe isn’t known.
Quelle: WIRED

3339 Views

Freitag, 12. April 2013 - 20:00 Uhr

Raumfahrt - NASA Mars Orbiter entdeckt sowjetische Mars-Sonde von 1971

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This set of images shows what might be hardware from the Soviet Union's 1971 Mars 3 lander, seen in a pair of images from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. Image credit: NASA/JPL-Caltech/Univ. of Arizona

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Hardware from a spacecraft that the Soviet Union landed on Mars in 1971 might appear in images from NASA's Mars Reconnaissance Orbiter. 
While following news about Mars and NASA's Curiosity rover, Russian citizen enthusiasts found four features in a five-year-old image from Mars Reconnaissance Orbiter that resemble four pieces of hardware from the Soviet Mars 3 mission: the parachute, heat shield, terminal retrorocket and lander. A follow-up image by the orbiter from last month shows the same features. 
The Mars 3 lander transmitted for several seconds after landing on Dec. 2, 1971, the first spacecraft to survive a Mars landing long enough to transmit anything. 
"Together, this set of features and their layout on the ground provide a remarkable match to what is expected from the Mars 3 landing, but alternative explanations for the features cannot be ruled out," said HiRISE Principal Investigator Alfred McEwen of the University of Arizona, Tucson. "Further analysis of the data and future images to better understand the three-dimensional shapes may help to confirm this interpretation." 
In 1971, the former Soviet Union launched the Mars 2 and Mars 3 missions to Mars. Each consisted of an orbiter plus a lander. Both orbiter missions succeeded, although the surface of Mars was obscured by a planet-encircling dust storm. The Mars 2 lander crashed. Mars 3 became the first successful soft landing on the Red Planet, but stopped transmitting after just 14.5 seconds for unknown reasons. 
The predicted landing site was at latitude 45 degrees south, longitude 202 degrees east, in Ptolemaeus Crater. HiRISE acquired a large image at this location in November 2007. This image contains 1.8 billion pixels of data, so about 2,500 typical computer screens would be needed to view the entire image at full resolution. Promising candidates for the hardware from Mars 3 were found on Dec. 31, 2012. 
Vitali Egorov from St. Petersburg, Russia, heads the largest Russian Internet community about Curiosity. His subscribers did the preliminary search for Mars 3 via crowdsourcing. Egorov modeled what Mars 3 hardware pieces should look like in a HiRISE image, and the group carefully searched the many small features in this large image, finding what appear to be viable candidates in the southern part of the scene. Each candidate has a size and shape consistent with the expected hardware, and they are arranged on the surface as expected from the entry, descent and landing sequence. 
"I wanted to attract people's attention to the fact that Mars exploration today is available to practically anyone," Egorov said. "At the same time we were able to connect with the history of our country, which we were reminded of after many years through the images from the Mars Reconnaissance Orbiter." 
An advisor to the group, Alexander Basilevsky, of Vernadsky Institute of Geochemistry and Analytical Chemistry, Moscow, contacted McEwen suggesting a follow-up image. HiRISE acquired the follow-up on March 10, 2013. This image was targeted to cover some of the hardware candidates in color and to get a second look with different illumination angles. Meanwhile, Basilevsky and Erogov contacted Russian engineers and scientists who worked on Mars 3 for more information. 
The candidate parachute is the most distinctive feature in the images. It is an especially bright spot for this region, about 8.2 yards (7.5 meters) in diameter. The parachute would have a diameter of 12 yards (11 meters) if fully spread out over the surface, so this is consistent. In the second HiRISE image, the parachute appears to have brightened over much of its surface, probably due to its better illumination over the sloping surface, but it is also possible that the parachute brightened in the intervening years because dust was removed. 
The descent module, or retrorocket, was attached to the lander container by a chain, and the candidate feature has the right size and even shows a linear extension that could be a chain. Near the candidate descent module is a feature with the right size and shape to be the actual lander, with four open petals. The image of the candidate heat shield matches a shield-shaped object with the right size if partly buried. 
Philip J. Stooke from the University of West Ontario, Canada, suggested the direction of search and offered helpful advice. Arnold Selivanov (one of the creators of Mars 3) and Vladimir Molodtsov (an engineer at NPO Lavochkin, Moscow) helped with access to data archives. 
HiRISE is operated by the University of Arizona, Tucson. The instrument was built by Ball Aerospace & Technologies Corp., Boulder, Colo. The Mars Reconnaissance Orbiter Project and Curiosity are managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science Mission Directorate, Washington. JPL is a division of the California Institute of Technology in Pasadena. 
Quelle: NASA
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The Mars-3 probe successfully landed on the Red Planet on December 2, 1971, but only functioned for 14.5 seconds, after which all communication with the vehicle was lost. It is believed that the electronics aboard the probe were fried by an electrical discharge created by the extremely dry environment on Mars.
Another Soviet probe, the Mars-2, crashed while landing on the Red Planet on November 27, 1971, becoming the first man-made object on Mars. The mysterious crash and failure of two successive Soviet Mars probes sparked speculation about the ‘curse of Mars,’ and that the vehicles had been destroyed by Martians.
Quelle: RT

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Donnerstag, 11. April 2013 - 20:45 Uhr

Astronomie - SOHO sieht M6.5 Flare am Morgen des 11. April 2013

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The joint ESA/NASA Solar Heliospheric Observatory (SOHO) captured this series of images of a coronal mass ejection (CME) on the morning of April 11, 2013 over the course of 3:48 EDT to 4:36 EDT. Mars can be seen on the left. Credit: ESA&NASA/SOHO/GSFC

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The M6.5 flare on the morning of April 11, 2013, was also associated with an Earth-directed coronal mass ejection (CME), another solar phenomenon that can send billions of tons of solar particles into space and can reach Earth one to three days later. CMEs can affect electronic systems in satellites and on the ground. Experimental NASA research models show that the CME began at 3:36 a.m. EDT on April 11, leaving the sun at over 600 miles per second.

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Earth-directed CMEs can cause a space weather phenomenon called a geomagnetic storm, which occurs when they connect with the outside of the Earth's magnetic envelope, the magnetosphere, for an extended period of time.
The recent space weather also resulted in a weak solar energetic particle (SEP) event near Earth. These events occur when very fast protons and charged particles from the sun travel toward Earth, sometimes in the wake of a solar flare. These events are also referred to as solar radiation storms. Any harmful radiation from the event is blocked by the magnetosphere and atmosphere, so cannot reach humans on Earth. Solar radiation storms can, however, disturb the regions through which high frequency radio communications travel.
NOAA's Space Weather Prediction Center (http://swpc.noaa.gov) is the United States Government official source for space weather forecasts, alerts, watches and warnings. NASA and NOAA – as well as the US Air Force Weather Agency (AFWA) and others -- keep a constant watch on the sun to monitor for space weather effects such as geomagnetic storms. With advance notification many satellites, spacecraft and technologies can be protected from the worst effects.
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NASA's Solar Dynamics Observatory captured this image of an M6.5 class flare at 3:16 EDT on April 11, 2013. This image shows a combination of light in wavelengths of 131 and 171 Angstroms. Credit: NASA/SDO
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The sun emitted a mid-level flare, peaking at 3:16 a.m. EDT on April 11, 2013.
Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground, however -- when intense enough -- they can disturb the atmosphere in the layer where GPS and communications signals travel. This disrupts the radio signals for as long as the flare is ongoing, anywhere from minutes to hours.
This flare is classified as an M6.5 flare, some ten times less powerful than the strongest flares, which are labeled X-class flares. M-class flares are the weakest flares that can still cause some space weather effects near Earth. This flare produced a radio blackout that has since subsided. The blackout was categorized as an R2 on a scale between R1 and R5 on NOAA’s space weather scales.
This is the strongest flare seen so far in 2013. Increased numbers of flares are quite common at the moment, since the sun's normal 11-year activity cycle is ramping up toward solar maximum, which is expected in late 2013. Humans have tracked this solar cycle continuously since it was discovered, and it is normal for there to be many flares a day during the sun's peak activity.
Updates will be provided as need on the flare and its associated coronal mass ejection (CME), another solar phenomenon that can send solar particles into space and affect electronic systems in satellites and on Earth.
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Quelle: NASA

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