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Freitag, 3. April 2015 - 21:53 Uhr

Astronomie - Astronomen beobachten Dynamik einer jungen Riesensonne

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Data from 1996 - illustrated here as a 3D simulation - showed a compact, round blast of wind (in blue)

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Astronomers have witnessed a key stage in the birth of a very heavy star, using two radio telescope views of the process taken 18 years apart.
The young star is 4,200 light-years from Earth and appears to be surrounded by a doughnut-shaped cloud of dust.
That cloud slows down the hot, ionised wind that the star blasts into space, causing it to form an elongated column perpendicular to the dusty ring.
The new results represent "before and after" glimpses of that column forming.
They were captured by the Very Large Array, a battery of 27 antennae in the New Mexico desert, and are published in the journal Science.
"The comparison is remarkable," said first author Carlos Carrasco-Gonzalez, from the National Autonomous University of Mexico. The compact, rounded wind indicated by data from 1996 transforms - just 18 years later in 2014 - into a "distinctly elongated outflow".
One to watch
The infant star is about 300 times brighter than the Sun and goes by the catchy name of W75N(B)-VLA2.
Being able to observe its dramatic growing pains in real time is unique, according to Prof Huib van Langevelde from Leiden University in the Netherlands, another of the study's authors.
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The 2014 data revealed the wind to be much more elongated, emerging from the presumed ring of dust
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"This object is providing us an exciting opportunity to watch the developments over the next few years, as this very young star develops the characteristic bipolar outflow morphology," said Prof van Langevelde, who also works at the Joint Institute for VLBI in Europe (JIVE).
VLBI - very long baseline interferometry - is the method of comparing signals between widely-spaced antennae, effectively simulating one massive telescope.
One of the major findings that has already emerged from studying W75N(B)-VLA2 relates to earlier work led by JIVE scientists, who in 2009 traced the large-scale magnetic field in that region of space and reported that the field surrounding the young star was neatly aligned with it.
Now, it seems the elongated outflow that has burst forth in just 18 years is also aligned with that magnetic field - suggesting that magnetism is playing a crucial role in the star's formation.
The team hopes to watch and learn more as the "protostar" continues its turbulent development.
"Our understanding of how massive young stars develop is much less complete than our understanding of how Sun-like stars develop," said Dr Gabriele Surcis, another co-author from JIVE.
"It's going to be really great to be able to watch one as it changes."
Quelle: BBC

Tags: Astronomie 

2005 Views

Freitag, 3. April 2015 - 21:32 Uhr

Raumfahrt - Mission Namen für ESA Astronauten Thomas Pesquet gesucht

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ESA astronaut Thomas Pesquet will fly to the International Space Station next year on a six-month adventure of science in weightlessness. Now Thomas wants you to think of a name for his flight – and it will appear on the mission patch he will wear in space.
Thomas writes: “European astronauts fly to space to benefit people on Earth through scientific research and exploration. I want to share this once-in-a-lifetime experience with all European citizens, and I need your support along the way.”
“Finding an awesome name is the first step of our journey, so share your inspiration and come on board!”
Thomas will blast off in a Soyuz spacecraft in December 2016 as part of Expedition 50 with NASA astronaut Peggy Whitson and Russian commander Oleg Novitsky.
His flight follows a busy year for the 2009 class of ESA astronauts, with Samantha Cristoforetti now in space on her Futura mission, to be followed by Andreas Mogensen and Tim Peake later this year. On top of Thomas’ training for his mission, he will act as backup for Andreas’ 10-day mission in September. Tim’s Principia mission starts in December.
Born in Rouen, France, Thomas will be the 10th French person to go into space, following spationauts who inspired him with their missions when he was younger.
The last French astronaut to work on the Station was ESA’s Léopold Eyharts in 2008, who helped to install Europe’s Columbus laboratory. Thomas will work in Columbus on experiments for scientists all over the world to improve our lives and to explore our Solar System.
For Thomas, it will be a dream come true when he is launched into space. He is the first commercial airline pilot to be selected as an astronaut and has been passionate about aerospace from a very early age.
It’s all in the name
ESA and Thomas invite you to submit a name for his mission. As the name will be used on his mission patch and seen worldwide, it should be short and clear and easy to pronounce in French, English and many other languages. Read the full rules before submitting your proposal in a form on this page. The deadline for submission is 15 April.
In addition to seeing the name fly into space, the winner will receive a mission patch signed by Thomas himself.
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Thomas training in Soyuz spacecraft
Quelle: ESA

Tags: Raumfahrt 

1966 Views

Freitag, 3. April 2015 - 20:40 Uhr

Astronomie - Hubble findet Phantom Objekte in der Nähe von Toten Quasare

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NASA's Hubble Space Telescope has photographed a set of wispy, goblin-green objects that are the ephemeral ghosts of quasars that flickered to life and then faded.
The glowing structures have looping, helical, and braided shapes. "They don't fit a single pattern," said Bill Keel of the University of Alabama, Tuscaloosa, who initiated the Hubble survey. Keel believes the features offer insights into the puzzling behavior of galaxies with energetic cores.
The ethereal wisps outside the host galaxy are believed to have been illuminated by powerful ultraviolet radiation from a supermassive black hole at the core of the host galaxy. The most active of these galaxy cores are called quasars, where infalling material is heated to a point where a brilliant searchlight shines into deep space. The beam is produced by a disk of glowing, superheated gas encircling the black hole.
"However, the quasars are not bright enough now to account for what we're seeing; this is a record of something that happened in the past," Keel said. "The glowing filaments are telling us that the quasars were once emitting more energy, or they are changing very rapidly, which they were not supposed to do."
Keel said that one possible explanation is that pairs of co-orbiting black holes are powering the quasars, and this could change their brightness, like using the dimmer switch on a chandelier.
The quasar beam caused the once invisible filaments in deep space to glow through a process called photoionization. Oxygen atoms in the filaments absorb light from the quasar and slowly re-emit it over many thousands of years. Other elements detected in the filaments are hydrogen, helium, nitrogen, sulfur, and neon. "The heavy elements occur in modest amounts, adding to the case that the gas originated in the outskirts of the galaxies rather than being blasted out from the nucleus," Keel said.
The green filaments are believed to be long tails of gas pulled apart like taffy under gravitational forces resulting from a merger of two galaxies. Rather than being blasted out of the quasar's black hole, these immense structures, tens of thousands of light-years long, are slowly orbiting their host galaxy long after the merger was completed.
"We see these twisting dust lanes connecting to the gas, and there's a mathematical model for how that material wraps around in the galaxy," Keel said. Potentially, you can say we're seeing it 1.5 billion years after a smaller gas-rich galaxy fell into a bigger galaxy."
The ghostly green structures are so far outside the galaxy that they may not light up until tens of thousands of years after the quasar outburst, and would likewise fade only tens of thousands of years after the quasar itself does. That's the amount of time it would take for the quasar light to reach them.
Not coincidentally, galaxy mergers would also trigger the birth of a quasar by pouring material into the central supermassive black hole.
The first "green goblin" type of object was found in 2007 by Dutch schoolteacher Hanny van Arkel. She discovered the ghostly structure in the online Galaxy Zoo project. The project has enlisted the public to help classify more than a million galaxies catalogued in the Sloan Digital Sky Survey (SDSS), and moved on to add galaxies seen in Hubble images probing the distant universe. The bizarre feature was dubbed Hanny's Voorwerp, Dutch for Hanny's object.
Because his follow-up Hubble images of Hanny's Voorwerp were so intriguing, Keel started a deliberate hunt for more bizarre objects like it. They would share the rare and striking color signature of Hanny's Voorwerp on the SDSS images.
Keel had 200 people volunteer specifically to look at over 15,000 galaxies hosting quasars. Each candidate had to have at least 10 views that collectively reveal weirdly colored clouds.
Keel's team took the galaxies that looked the most promising and further studied them by dividing their light into its component colors through a process called spectroscopy. In follow-up observations from Kitt Peak National Observatory and the Lick Observatory, his team found 20 galaxies that had gas that was ionized by radiation from a quasar, rather than from the energy of star formation. And, the clouds extended more than 30,000 light-years outside the host galaxies.
Eight of the newly discovered clouds were more energetic than would be expected given the amount of radiation coming from the host quasar, even when observed in infrared light by NASA's Wide-field Infrared Survey Explorer (WISE) space telescope. The host quasars were as little as one-tenth the brightness needed to provide enough energy to photoionize the gas. Keel said that presumably the brightness changes are governed by the rate at which material is falling onto the central black hole.
Keel speculated that this quasar variability might be explained if there are two massive black holes circling each other in the host galaxy's center. This could conceivably happen after two galaxies merged. A pair of black holes whirling about each other could disrupt the steady flow of infalling gas. This would cause abrupt spikes in the accretion rate and trigger blasts of radiation.
When our Milky Way galaxy merges with the Andromeda galaxy (M31) in about 4 billion years, the black holes in each galaxy could wind up orbiting each other. So in the far future, our galactic system could have its own version of Hanny's Voorwerp encircling it.
Quelle: HUBBLESITE

Tags: Astronomie 

1881 Views

Donnerstag, 2. April 2015 - 14:04 Uhr

Mars-Chroniken - Curiosity-Rover sieht herausragende Mineral Venen auf dem Mars

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This March 18, 2015, view from the Mast Camera on NASA's Curiosity Mars rover shows a network of two-tone mineral veins at an area called "Garden City" on lower Mount Sharp.
Image Credit: NASA/JPL-Caltech/MSSS
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Two-tone mineral veins at a site NASA's Curiosity rover has reached by climbing a layered Martian mountain offer clues about multiple episodes of fluid movement. These episodes occurred later than the wet environmental conditions that formed lake-bed deposits the rover examined at the mountain's base.
Curiosity has analyzed rock samples drilled from three targets lower on the mountain in the past seven months. It found a different mineral composition at each, including a silica mineral named cristobalite in the most recent sample. These differences, together with the prominent veins seen in images taken a little farther uphill, illustrate how the layers of Mount Sharp provide a record of different stages in the evolution of the area's ancient environment.
The two-tone veins are at the site called "Garden City." They appear as a network of ridges left standing above the now eroded-away bedrock in which they formed. Individual ridges range up to about 2.5 inches (6 centimeters) high and half that in width, and they bear both bright and dark material.
"Some of them look like ice-cream sandwiches: dark on both edges and white in the middle," said Linda Kah, a Curiosity science-team member at the University of Tennessee, Knoxville. "These materials tell us about secondary fluids that were transported through the region after the host rock formed."
Veins such as these form where fluids move through cracked rock and deposit minerals in the fractures, often affecting the chemistry of the rock surrounding the fractures. Curiosity has found bright veins composed of calcium sulfate at several previous locations. The dark material preserved here presents an opportunity to learn more. Kah said, "At least two secondary fluids have left evidence here. We want to understand the chemistry of the different fluids that were here and the sequence of events. How have later fluids affected the host rock?"
Some of the sequence is understood: Mud that formed lake-bed mudstones Curiosity examined near its 2012 landing site and after reaching Mount Sharp must have dried and hardened before the fractures formed. The dark material that lines the fracture walls reflects an earlier episode of fluid flow than the white, calcium-sulfate-rich veins do, although both flows occurred after the cracks formed.
Garden City is about 39 feet (12 meters) higher than the bottom edge of the "Pahrump Hills" outcrop of the bedrock forming the basal layer of Mount Sharp, at the center of Mars' Gale Crater. The Curiosity mission spent about six months examining the first 33 feet (10 meters) of elevation at Pahrump Hills, climbing from the lower edge to higher sections three times to vertically profile the rock structures and chemistry, and to select the best targets for drilling.
"We investigated Pahrump Hills the way a field geologist would, looking over the whole outcrop first to choose the best samples to collect, and it paid off," said David Blake of NASA's Ames Research Center, Moffett Field, California, principal investigator for the Chemistry and Mineralogy (CheMin) analytical laboratory instrument inside the rover.
Analysis is still preliminary, but the three drilled samples from Pahrump Hills have clear differences in mineral ingredients. The first, "Confidence Hills," had the most clay minerals and hematite, both of which commonly form under wet conditions. The second, "Mojave," had the most jarosite, an oxidized mineral containing iron and sulfur that forms in acidic conditions. The third is "Telegraph Peak." Examination of Garden City has not included drilling a sample.
Blake said, "Telegraph Peak has almost no evidence of clay minerals, the hematite is nearly gone and jarosite abundance is down. The big thing about this sample is the huge amount of cristobalite, at about 10 percent or more of the crystalline material." Cristobalite is a mineral form of silica. The sample also contains a small amount of quartz, another form of silica. Among the possibilities are that some process removed other ingredients, leaving an enrichment of silica behind; or that dissolved silica was delivered by fluid transport; or that the cristobalite formed elsewhere and was deposited with the original sediment.
NASA's Mars Science Laboratory Project is using Curiosity to examine environments that offered favorable conditions for microbial life on ancient Mars, if the planet ever has hosted microbes, and the changes from those environments to drier conditions that have prevailed on Mars for more than three billion years. 
After investigations in the Telegraph Peak area, the rover team plans to drive Curiosity through a valley called "Artist's Drive" to reach higher layers. Engineers are meanwhile developing guidelines for best use of the rover's drill, following detection of a transient short circuit last month while using the tool's percussion action to shake rock powder into a sample-processing device. Drilling can use both rotary and percussion actions.
"We expect to use percussion as part of drilling in the future while we monitor whether shorts become more frequent," said Steve Lee of NASA's Jet Propulsion Laboratory, Pasadena, California. Lee became deputy project manager for the Mars Science Laboratory Project this month. He previously led the project's Guidance, Navigation and Control Team from design through landing.
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This view from the Mars Hand Lens Imager on the arm of NASA's Curiosity Mars rover is a close-up of a two-tone mineral vein at a site called "Garden City" on lower Mount Sharp. It was taken during night, illuminated by LEDs, on March 25, 2015.
Image Credit: NASA/JPL-Caltech/MSSS
Quelle: NASA

Tags: Mars-Chroniken 

1888 Views

Donnerstag, 2. April 2015 - 14:00 Uhr

UFO-Forschung - Japans Verteidigungsminister: Aliens haben nie versucht, aus dem Weltraum einzudringen!

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2013: Raketenstart löste UFO-Alarm in Japan aus

Aliens have never tried to invade from space: Japan’s defense minister
Alien spaceships have never entered Japanese airspace, the country’s defense chief told the Diet on Thursday, amid questioning about the threat from space aliens.
Defense Minister Gen Nakatani said the nation’s warplanes can be scrambled whenever there is a report of an unidentified flying object. But, he said, jets have so far encountered no UFOs from space.
“When the Air Self Defense Force detects indications of an unidentified flying object that could violate our country’s airspace, it scrambles fighter jets if necessary and makes visual observation,” he said.
“They sometimes find birds or flying objects other than aircraft but I don’t know of a case of finding an unidentified flying object believed to have come over from anywhere other than Earth,” he said.
Nakatani, a sober politician with a reputation for thorough understanding of his brief, was responding to a question from flamboyant wrestler-turned-lawmaker Antonio Inoki.
At a meeting Wednesday of the Upper House Budget Committee, Inoki had asked if aircraft were dispatched to meet extraterrestrial visitors and “whether studies are going on.”
Inoki, known for his outsized chin and trademark red scarf, said he did not know whether or not aliens existed, but he had once seen a mysterious flying object rocket into the air on the horizon and disappear.
Wednesday’s exchange was not the first official Japanese pronouncement on space aliens and their aircraft.
A 2007 statement said the government “has not confirmed the existence of unidentified flying objects believed to have come from anywhere other than Earth.”
But the statement, formally endorsed at a Cabinet meeting, prompted a surprise rebuttal from the top government spokesman. “Personally, I absolutely believe they exist,” said Nobutaka Machimura, chief cabinet secretary at the time.
The defense minister of the day, Shigeru Ishiba, also said that in his personal opinion there were “no grounds” to deny the existence of UFOs controlled by alien life-forms.
Quelle: The Japan Times

Tags: UFO-Forschung aus dem Weltraum einzudringen! 

1919 Views

Donnerstag, 2. April 2015 - 12:35 Uhr

UFO-Forschung - 1968: Als April-Scherze noch Spaß machten: Die Anatomie biologischer Grenzschichtphänomene...

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Aus dem CENAP-Archiv:

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Quelle: aerokurier, CENAP-Archiv


Tags: UFO-Forschung 

1673 Views

Donnerstag, 2. April 2015 - 10:19 Uhr

Astronomie - Amateurastronomen beobachten grosse Protuberanzen auf der Sonne

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BIG SOLAR PROMINENCES: The face of the sun is quiet; no sunspots are flaring. The edge of the sun is a different matter. Amateur astronomers are monitoring a network of huge prominences rising above the sun's western limb. Bill Hrudey sends this picture from the Cayman Islands:

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"I used a Lunt solar telescope to photograph these interesting prominences," says Hrudey.
Prominences are massive plumes of hot plasma held above the surface of the sun by magnetic force fields. Frequently, these magnetic fields become unstable and erupt, hurling billions of tons of hot gas into space. Got a solar telescope? Monitoring is encouraged.
Quelle: Spaceweather

Tags: Astronomie 

1962 Views

Donnerstag, 2. April 2015 - 09:45 Uhr

UFO-Forschung - Ufo-Effekt durch Jupiter und Sirius über Leipzig

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Anmerkung: Wir freuen uns das unser Kollege Werner Walter nach langer Krankheit, bei Bedarf wieder aktiv bei der Erforschung außergewöhnlicher Himmelsphänomene unterstützt.

CENAP-Mannheim


Tags: UFO-Forschung 

1943 Views

Mittwoch, 1. April 2015 - 21:30 Uhr

Luftfahrt - ESA unterstützt Entwicklung von Augmented-Reality-Objekte in Videostream für Drohnen

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Affordable eyes in the sky, drones have fast become a popular and versatile tool for land mapping. Now ESA-backed startup Sysveo has developed a way of integrating user-made augmented reality objects into a drone’s video stream.
This allows the drone operator to analyse data in real time and adapt the flight accordingly, making operations more time- and cost-efficient.
As a drone documents the site of new infrastructure, for instance, the operator could see how it would appear in the landscape.
Sysveo, specialising in customised drone integration for professional users, is a French company supported through ESA’s Business Incubation Centre Sud France. As well as augmented reality, Sysveo also provides anti-collision and indoor geolocalisation software for its drones.
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A free ESA app turns a popular iPhone-controlled ‘home drone’ into a spacecraft. The augmented reality game lets owners of Parrot AR.Drone quadcopters attempt dockings with a simulated International Space Station while flying their drones for real – in the process helping to improve robotic rendezvous methods. This new AstroDrone app is part of a scientific crowdsourcing project by ESA’s Advanced Concepts Team, gathering data to teach robots to navigate their environments.
Quelle: ESA

Tags: Luftfahrt 

1837 Views

Mittwoch, 1. April 2015 - 09:40 Uhr

Raumfahrt - ESA-Sonde Rosetta/Philae auf Komet 67P/Churyumov-Gerasimenko - Update-20

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IMHOTEP UP – COMETWATCH 20 MARCH
This single frame NAVCAM image was taken on 20 March 2015 at a distance of 81.7 km from the centre of Comet 67P/Churyumov-Gerasimenko. The image scale of the original 1024 x 1024 pixel image is 7 m/pixel and the image measures 7.1 km across; a cropped, processed version is shown below.
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Cropped and processed single frame NAVCAM image of Comet 67P/C-G taken on 20 March 2015 from a distance of 81.7 km to the comet centre. This cropped version measures about 5.8 x 6.1 km. The image is lightly processed to bring out the details of the outflowing material. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
From this orientation we have a great view across the Imhotep region on the ‘underside’ of the comet’s large lobe, providing additional context for the close flyby images of 14 February. The annotated diagram below points to the approximate regions covered by the NAVCAM and OSIRIS flyby images, including the image featuring Rosetta’s shadow (bottom left image).
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CometWatch 20 March with the 14 February flyby images added as insets. The image outlines vary in shape due to the change in relative position of the comet and spacecraft on the times/dates the images were taken.
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Annotated map of the 'underside' of the comet's large lobe, showing the Imhotep region. Credit: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
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In this orientation, the boundary between Imhotep and Ash can be seen towards the right of the comet’s large lobe. Apis is towards the bottom right, and includes the region with the sharp shadow.
Part of the comet’s small lobe can be seen to the far right of the image, the cliffs of Hathor largely in the shadow cast by the large lobe.
Meanwhile jets of cometary material can be seen rising from the nucleus; in this orientation to the top and right of the image.
The original 1024 x 1024 pixel image for 20 March is provided below:
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Quelle: ESA
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Update: 29.03.2015
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COMETWATCH: AROUND ANUBIS AND ATUM
Today’s CometWatch entry presents a recent image of Comet 67P/Churyumov-Gerasimenko – taken on 21 March 2015 – along with three previously unpublished close-up images taken during last October’s 10 km bound orbit.
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Cropped and processed single frame NAVCAM image of Comet 67P/C-G taken on 21 March 2015 from a distance of 82.6 km to the comet centre. This cropped version measures about 6.2 x 6.2 km. The image is lightly processed to bring out the details of the outflowing material. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
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The full-comet image from 21 March (above) has been lightly processed to enhance the details of the outflowing material. It was taken from a distance of 82.6 km, the image scale is 7 m/pixel, and the 1024 x 1024 pixel image measures 7.2 km across.
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Processed version of the 21 October single frame NAVCAM image. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
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The close-ups highlight the range of contrasting surface features seen on the comet, in particular in the Anubis and Atum regions on the comet’s large lobe. The graphic above locates the approximate regions of each inset on the comet – note that due to the change in distance and orientation, the insets are not exactly oriented with how they appear on the main image and the illumination conditions are also different. The close-ups have been processed to bring out the details of the surface and the local nebulosity; the original frames are provided at the end of the post.
The bottom image in the context graphic captures part of the smooth Anubis region on the large lobe (left half of the image), a small portion of the rugged Seth terrain (centre), and the smooth Hapi region that defines the comet neck (right).
Relatively speaking, Anubis and Seth lie in the foreground, while Hapi is in the background: this can be seen clearly in the main image, where parts of the surface clearly visible in the close-up are shadowed by the large lobe.
As described in the recent OSIRIS papers published in Science, the smooth portions of Anubis appear faulted or folded in some places, and scattered boulders may be the products of mass wasting.
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Processed version of the 19 October single frame NAVCAM image. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
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The inset at the top right of the context graphic also shows part of Anubis, close to the border of Seth (towards the right in the close-up). Scattered boulders are also visible here, along with more plentiful debris seen typically at the base of cliffs.
This close-up image has been processed to emphasise the faint nebulosity above the horizon on the right, to show the 'peaks' on the horizon silhouetted against this nebulosity, and to see the deeper, darker shadows they're casting onto the nucleus.
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Processed version of the 24 October single frame NAVCAM image. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
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Last but certainly not least is the close-up at the left of the context graphic, which highlights part of the highly complex Atum region and its aligned linear features.
This close-up image has been processed to reveal more of the dimly lit portions of the nucleus surrounding the prominent layered structure. A large boulder – approximately 30 m across – appears to be perched at the edge of the curious three-slabbed 'outcrop', casting its shadow onto the layer below.
Quelle: ESA
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Update: 30.03.2015
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COMETWATCH 22 MARCH
This single frame Rosetta Navigation Camera image was taken on 22 March 2015 at a distance of 77.8 km from the centre of Comet 67P/C-G. The image scale is 6.6 m/pixel and the 1024 x 1024 pixel image measures 6.8 km across.
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Cropped and processed single frame NAVCAM image of Comet 67P/C-G taken on 22 March 2015 from a distance of 77.8 km to the comet centre. The processed image is cropped and measures 6 x 6 km. Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
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The image above has been processed to bring out the details of the comet’s activity, while also emphasising details on the nucleus.
The image presents another interesting view of regions previously cast in shadow, particularly on the small lobe around Hatmehit, and of the topography on the large lobe close to Aker and Khepry. (The 9 March image also offered a new view of these regions, from a slightly different angle).
At the bottom right, the large lobe is casting a shadow over the broader ‘atmosphere’ around the comet.
The original 1024 x 1024 image is provided below.
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Quelle: ESA
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Update: 1.04.2015
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IMAGE BROWSER UPDATE: APPROACH TO COMET, PLUS CRUISE PHASE IMAGES!
The Rosetta downlink and archive teams at ESAC are pleased to announce that the next set of NAVCAM image data are now available in ESA’s Planetary Science Archive (PSA) and via the new NAVCAM Image Browser tool.
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This sequence of 76 images was prepared using images acquired on 30 July and 1 August. The apparent darkening of the nucleus during the
sequence is caused by the dependence of the reflectance factor on phase angle, which evolves from 3.4 to 8.5 degrees, when the distance from Rosetta to the comet reduced from 1332 km to 853 km.
Credits: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0
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The Image Browser was launched earlier this month with NAVCAM image data from the first half of 2014. The latest set of 214 images, taken between 2 July and 1 August, cover the period when Rosetta moved from 42 980 km to 848 km from the comet, and the shape of 67P/C-G was finally revealed. During this phase, 4-5 images were taken per day for navigation, with one image taken every 30 minutes from 30 July to 1 August.
As an added bonus, the Image Browser has now also been updated with images from the cruise phase of the mission (the underpinning data was already accessible via the PSA). That is, the NAVCAM images taken during the swing-bys of Earth and Mars, and asteroids Steins and Lutetia are now also available via the Image Browser (although note that the cruise phase datasets for Steins and Lutetia only contain navigation images from a far distance, so the asteroids are not resolved).
The next NAVCAM data release is expected on 30 April.
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Rosetta MARS-SWING-BY:
 
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PRELANDING MTP005:
Quelle: ESA

Tags: Raumfahrt 

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