Blogarchiv

Samstag, 12. Juli 2014 - 09:40 Uhr

Astronomie - Indikator für erste Sterne des Universums

.

Out of An Hours-long Explosion, A Stand-In For The First Stars

In this artist's rendering of GRB 130925A, a sheath of hot, X-ray-emitting gas (red) surrounds a particle jet (white) blasting through the star's surface at nearly the speed of light. The source may have been a metal-poor blue supergiant, an important proxy for the universe's first stars.

.

Astronomers analyzing a long-lasting blast of high-energy light observed in 2013 report finding features strikingly similar to those expected from an explosion from the universe's earliest stars. If this interpretation is correct, the outburst validates ideas about a recently identified class of gamma-ray burst and serves as a stand-in for what future observatories may see as the last acts of the first stars.
"One of the great challenges of modern astrophysics has been the quest to identify the first generation of stars to form in the universe, which we refer to as Population III stars," explained lead scientist Luigi Piro, the director of research at the Institute for Space Astrophysics and Planetology in Rome, a division of Italy's National Institute for Astrophysics (INAF). "This important event takes us one step closer."
Gamma-ray bursts (GRBs) are the most luminous explosions in the universe. The blasts emit outbursts of gamma rays -- the most powerful form of light -- and X-rays, and produce rapidly fading afterglows that can be observed in visible light, infrared and radio wavelengths. On average, NASA's Swift satellite, Fermi Gamma-ray Space Telescope and other spacecraft detect about one GRB each day.
Shortly after 12:11 a.m. EDT on Sept. 25, 2013, Swift's Burst Alert Telescope triggered on a spike of gamma rays from a source in the constellation Fornax. The spacecraft automatically alerted observatories around the world that a new burst -- designated GRB 130925A, after the date -- was in progress and turned its X-ray Telescope (XRT) toward the source. Other satellites also detected the rising tide of high-energy radiation, including Fermi, the Russian Konus instrument onboard NASA's Wind spacecraft, and the European Space Agency's (ESA) INTEGRAL observatory.
The burst was eventually localized to a galaxy so far away that its light had been traveling for 3.9 billion years, longer than the oldest evidence for life on Earth.
,
A blue supergiant star, illustrated here, may be the most likely source of ultra-long gamma-ray bursts like GRB 130925A, which last hours rather than seconds. These stars contain about 20 times the sun's mass and may reach sizes large enough to span Jupiter's orbit.
.
Astronomers have observed thousands of GRBs over the past five decades. Until recently, they were classified into two groups, short and long, based on the duration of the gamma-ray signal. Short bursts, lasting only two seconds or less, are thought to represent a merger of compact objects in a binary system, with the most likely suspects being neutron stars and black holes. Long GRBs may last anywhere from several seconds to several minutes, with typical durations between 20 and 50 seconds. These events are thought to be associated with the collapse of a star many times the sun's mass and the resulting birth of a new black hole.
GRB 130925A, by contrast, produced gamma rays for 1.9 hours, more than a hundred times greater than a typical long GRB. Observations by Swift's XRT revealed an intense and highly variable X-ray afterglow that exhibited strong flares for six hours, after which it finally began the steady fadeout usually seen in long GRBs.
"GRB 130925A is a member of a rare and newly recognized class we call ultra-long bursts," said Eleonora Troja, a visiting research scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland, and a member of the study team. "But what really sets it apart is its unusual X-ray afterglow, which provides the strongest case yet that ultra-long GRBs come from stars called blue supergiants."
Astronomers think Wolf-Rayet stars best explain the origin of long GRBs. Born with more than 25 times the sun's mass, these stars burn so hot that they drive away their outer hydrogen envelopes through an outflow called a stellar wind. By the time it collapses, the star's outer atmosphere is essentially gone and its physical size is comparable to the sun's. A black hole forms in the star's core and matter falling toward it powers jets that burrow through the star. The jets continue operating for a few tens of seconds -- the time scale of long GRBs.
Because ultra-long GRBs last hundreds of times longer, the source star must have a correspondingly greater physical size. The most likely suspect, astronomers say, is a blue supergiant, a hot star with about 20 times the sun's mass that retains its deep hydrogen atmosphere, making it roughly 100 times the sun's diameter. Better yet, blue supergiants containing only a very small fraction of elements heavier than helium -- metals, in astronomical parlance -- could be substantially larger. A star's metal content controls the strength of its stellar wind, and this in turn determines how much of its hydrogen atmosphere it retains before collapse. For the largest blue supergiants, the hydrogen envelope would take hours to fall into the black hole, providing a sustained fuel source to power ultra-long GRBs.
Writing in the July 10 edition of The Astrophysical Journal Letters, the researchers note that radio observations of the GRB afterglow show that it displayed nearly constant brightness over a period of four months. This extremely slow decline suggests that the explosion's blast wave was moving essentially unimpeded through space, which means that the environment around the star is largely free of material cast off by a stellar wind.
The burst's long-lived X-ray flaring proved a more puzzling feature to explain, requiring observations from Swift, NASA's Chandra X-ray Observatory and ESA's XMM-Newton satellite to sort out. As the high-energy jet bores through the collapsing star, its leading edge rams into cooler stellar gas and heats it. This gas flows down the sides of the jet, surrounding it in a hot X-ray-emitting sheath. Because the jet travels a greater distance through a blue supergiant, this cocoon becomes much more massive than is possible in a Wolf-Rayet star. While the cocoon should expand rapidly as it exits the star, the X-ray evidence indicates that it remained intact. The science team suggests that magnetic fields may have suppressed the flow of hot gas across the cocoon, keeping it confined close to the jet.   
"This is the first time we have detected this thermal cocoon component, likely because all other known ultra-long bursts occurred at greater distances," said Piro.
The astronomers conclude that the best explanation for the unusual properties of GRB 130925A is that it heralded the death of a metal-poor blue supergiant, a model they suggest likely characterizes the entire ultra-long class.
Stars make heavy elements throughout their energy-producing lives and during their death throes in supernova explosions and GRBs. Each generation enriches interstellar gas with a greater proportion of metals, but the process is not uniform and metal-poor galaxies still exist nearby. Looking farther into the universe means looking deeper into the past, toward earlier stellar generations formed out of increasingly metal-poor gas. Astronomers think Population III stars ended their lives as blue supergiants, so GRB 130925A may prove to be a valuable nearby analog to phenomena we may one day detect from the universe's most distant stars.
Quelle: NASA

Tags: Astronomie 

2216 Views

Samstag, 12. Juli 2014 - 09:30 Uhr

Raumfahrt - Landsat-8 scannt die ferne Mondoberfläche

.

Every full moon, Landsat 8 turns its back on Earth. As the satellite's orbit takes it to the nighttime side of the planet, Landsat 8 pivots to point at the moon. It scans the distant lunar surface multiple times, then flips back around to continue its task of collecting information on Earth.
Image Credit: NASA's Goddard Space Flight Center
.
Every full moon, Landsat 8 turns its back on Earth. As the satellite’s orbit takes it to the nighttime side of the planet, Landsat 8 pivots to point at the moon. It scans the distant lunar surface multiple times, then flips back around to continue its task of collecting land-cover information of the sunny side of Earth below.
These monthly lunar scans are key to ensuring the land-imaging instrument aboard Landsat 8 is detecting light consistently. For this, engineers need a consistent source of light to measure. And while there are some spots on Earth – like the Sahara Desert or other arid sites – that reflect a relatively stable amount of light, nothing on our planet beats the moon, which lacks an atmosphere and has an unchanging surface, barring the odd meteorite.
We really wanted something we could trust for Landsat 8,” said Brian Markham, leader of the calibration team for Landsat 8, which was built and launched by NASA and is now operated by the U.S. Geological Survey. “We do have Earth sites we look at for calibration. But the precision with which you can track things by using the Earth, because of the atmosphere, is not as good as the moon.”
Landsat 8’s Operational Land Imager, or OLI, collects information on the visible, near infrared and shortwave-infrared light reflecting off Earth’s surface. Each wavelength of light provides information about the ground surface below. OLI has 14 detector modules, each of which contains hundreds of individual detectors that record different spectral bands. The calibration team at Goddard and the U.S. Geological Survey’s EROS facility in South Dakota is tasked with making sure each of those detectors register light consistently over time.
Aboard the spacecraft, lamps provide light to calibrate OLl’s detectors, but the lamps aren’t perfect.  On the Landsat 7 satellite, the lamps started to fade before the detectors did.  Another option, solar diffusers, which use indirect sunlight, can darken as well.
“Everything else we’ve tried to use to monitor the stability of our instruments has often not been as good as the instruments themselves,” Markham said. But the moon is a steady, not-too-bright light in the sky. "As long as we know what its illumination conditions are, we can trend our instrument performance to it because we trust its stability.”
So Landsat 8 planners designed this latest satellite to image the moon as a baseline calibration. If, during these lunar tests, the OLI detectors indicate that the moon is getting slightly duller or brighter, then the Goddard scientists will know the instrument –not the moon – is off. With that data, they can adjust the algorithms that calculate land cover information during Landsat’s regular Earth-observation orbits.
It’s a fairly complicated operation to scan the moon each month, said Susan Good, a flight dynamics engineer at Goddard who works with Landsat 8.
“There are 14 detector modules,” Good said, “each of these has to scan the same path along the moon, so that you collect exactly the same data on each sensor.”
The flight dynamics software determines precisely where the spacecraft will need to point during a lunar calibration. The timing is set for just after the moon is completely full. Then, as Landsat 8 passes over Antarctica and heads north in Earth’s shadow, the spacecraft maneuvers to the precise location to start the first scan across the lunar surface.
It executes tiny and precise scans to take seven or eight passes across the moon – each one angled so that a different detector is centered on the moon. This takes about 18 minutes, by which time the spacecraft has almost reached the Arctic. So it maneuvers back to point at Earth, and complete its day-lit imaging. Then, Landsat 8 pivots to face the moon again, completing additional passes to test the remaining detectors. After two orbits, the lunar calibration is complete.
In Landsat 8’s first year, the lunar calibration tests show that the detectors are stable, Markham said, within a fraction of a percent. If the lunar calibrations and other tests show the detectors are off, the scientists can adjust the calculations that turn the raw Landsat data into information on land cover brightness, maintaining their accuracy.
Since the regular checks on Landsat 8’s performance, Good jokes that she will never look at the full moon the same. “I think oh, we’re having a lunar calibration,” she said. “I always know what Landsat' 8’s doing when the moon is full.”
.
.
.
.
.
.
Quelle: NASA

Tags: Raumfahrt 

2222 Views

Freitag, 11. Juli 2014 - 15:42 Uhr

Raumfahrt - Japan-U.S.. Weltraum Sicherheitsplan

.

The government has decided to create strategy guidelines for Japan on the use of space for security purposes, which would be comparable to the U.S. National Security Space Strategy (NSSS), The Yomiuri Shimbun has learned.
According to informed sources, Japan’s version of the NSSS will likely call for the strengthening of cooperation between Japan and the United States in the space field, including satellite-based maritime surveillance of China, which has been accelerating moves to utilize space for military purposes.
The government plans to compile the strategy document by the end of this year, so that it can be reflected in revisions to the Japan-U.S. defense cooperation guidelines that will be drawn up at year-end.
Japan’s NSSS is expected to include surveillance of space to detect suspicious satellites and floating space debris, as well as the development of a maritime surveillance system to monitor ocean and ships.
The strategy document will also likely stipulate that Japan and the United States will share data, collected by Japanese quasi-zenith satellites orbiting above areas from Japan to Australia and also by U.S. positioning satellites, as well as images taken by Japanese and U.S. information-gathering satellites, the sources said.
Late last month, the government set up a basic policy subpanel, under the Committee on the National Space Policy, staffed by experts who will decide the country’s space development policy. The subpanel plans to draw up Japan’s NSSS in cooperation with the National Security Secretariat, which is under the wing of the government’s National Security Council. An interim report on the strategy document is expected to be released in summer.
In May, the Japanese and U.S. governments affirmed the strengthening of cooperation in the space field during a meeting of the Japan-U.S. Comprehensive Dialogue on Space held in Washington.
The two countries are speeding up cooperation in the space field because the use of satellites and other space technology has become extremely important for military purposes. In modern combat operations satellites play indispensable roles, including detecting enemy forces with the help of ground radar and aircraft, and controlling precision-guided missiles.
China has been taking steady steps toward becoming a country with a strong space sector. In 2007, Beijing conducted an experiment to destroy a satellite with a missile. In December 2013, it successfully landed an unmanned probe on the moon.
According to observers, Japan wants to maintain the superiority of Japan and the United States in the space field with its planned NSSS. Some government officials expect an enhanced surveillance system using satellites will make it easier to identify Chinese military movements, which can be difficult to detect.
In May 2008, when the Basic Space Law was enacted, a ban on the use of space for defense purposes was lifted. The government then compiled a basic space policy in 2009. Japan’s NSSS will be the first strategy document drawn up by the government for the use of space for security purposes.
The United States has updated its NSSS every year since 2011 to promote the use of space for security purposes. With countries such as China in mind, the strategy says U.S. superiority in space is challenged more and more frequently and calls for the development of a comprehensive surveillance system in space
Quelle: The Japan News

2325 Views

Freitag, 11. Juli 2014 - 15:30 Uhr

Raumfahrt - Re-Entry über Australien durch Soyus 2-1B-Rakete Booster, die am 8.Juli den Wettersatelliten M2 gestartet hat.

.

10.07.2014

10.07.2014 - Frame grab from a Youtube video of the brilliant meteor that flared over Australia overnight.
“It first looked like a plane with fire coming out of the tail.” – Aaron O.
“I have never seen anything like it. Big, bright and moving gently across sky – slower than a plane, not falling at all but moving across.” – Shannon H.
.
“Viewed from cockpit of aircraft at 37,000′. Was visible for two or three minutes.” – Landy T.
Flaming plane? Incandescent visitor from the asteroid belt? As the these comments from the AMS Fireball Log attest, the brilliant and s-l-o-w fireball that seared the sky over  southeastern Australia tonight was probably one of the most spectacular displays of re-entering space junk witnessed in recent years.
Ted Molczan, citizen satellite tracker and frequent contributor to the amateur satellite watchers SeeSat-L site, notes that the timing and appearance almost certainly point to the decay or de-orbiting of the Russian Soyuz 2-1B rocket booster that launched the meteorological satellite Meteor M2 on July 8.
.
Frams von Video:
.
Meteor over New South Wales. Look closely near the end and you’ll see it disintegrate into small pieces.
The magnificent man-made meteor, weighing some 4,400 pounds (2,000 kg), was seen from Melbourne to Sydney across the states of Victoria and New South Wales around 10 p.m. Hundreds of people were stopped in their tracks.  Most noticed how slowly the fireball traveled and how long it continue to burn on the way down.
Spacecraft that reenter from either orbital decay or controlled entry usually break up at altitudes between 45-52 miles (84-72 km) traveling around 17,500 mph (28,000 km/hour) . Compression and friction from the ever-thickening air cause the craft, or in this case, the rocket booster, to slow down and heat up to flaming incandescence just like a hunk of space rock arriving from the asteroid belt. In both cases, we see a brilliant meteor, however manmade debris.
Reportedly, only one person has been struck by satellite debris. In 1997 Lottie Williams of Tulsa, Oklahoma was hit on the shoulder while walking by a small, twisted piece of metal weighing as much as a crushed soda can. It was traced back to the tank of a Delta II rocket that launched a satellite in 1996. I suppose it’s only a matter of time before someone else gets hit, but the odds aren’t great. More likely, you’ll see what alarmed and delighted so many southeastern Australians Thursday night: a grand show of disintegration.
Quelle: UT
.
Update: 11.07.2014
.

Fiery object that travelled in eastern Australian night skies believed to be space junk, not meteor

A leading Melbourne astronomer says an object that lit up eastern Australian skies last night was not a meteor but instead a piece of space junk.
Pilots, air traffic controllers and members of the public spotted the bright light streaking across the sky about 10:00pm.
But Melbourne Planetarium curator Dr Tanya Hill says it was space junk, not a meteor.
"What was really interesting about it was it was so bright and observers have reported being able to see it for more than 10 seconds or so," she said.
"That tells us that it was something probably more out of the ordinary than just a small meteor.
"This is ... what you would call an artificial meteor, caused by material we may well have sent up in space."
Dr Hill says NASA tracks more than 500,000 pieces of space junk that measure greater than the size of a marble.
"Narrowing down what it might be is actually going to be a really tough ask," she said.
"Probably about once a day a piece of space junk ... flies through our atmosphere. We were just lucky to be able to witness it last night."
Airservices Australia spokesman Paul Sadler says colleagues who saw the activity last night described it as a spectacular sight.
"Some controllers are looking at radar screens but those controllers looking out to the runways certainly could see it," he said.
"It was reported from northern NSW down to Hobart and it was in the north-western part of the sky.
"I'd be suggesting it was sort of somewhere over NSW."
Mr Sadler says some people who spotted the light confused the unusual sight for an aircraft in trouble.
"It's understood there were a number of triple-zero calls to emergency services possibly reporting a plane in trouble but that certainly wasn't the case," he said.
"A number of pilots flying in that airspace reported it to ... air traffic controllers [and said] it was just a spectacular sight."
.
.
Quelle: ABC-News
.
Fireball as Russian space junk 'belly flops' to Earth above Australia
Steven Wright saw the fireball Thursday, july 10: I was walking around Docklands taking photos on Thursday night, and while trying to frame a photo of the Melbourne Star, I saw this bright white dot flying across the sky with a massive tail. I had no idea what it was, and at first I thought it was a low flying jet with some wild vapor trails, because it was moving that fast. But because there was no sound, and it didn't make sense to see a vapor tail it behind the plane at night, I knew it had to be something else - I just didn't know what it was. It's actual speed was hard to articulate - it was slow looking, but had to be fast. It must have been pretty far away, as it moved across the sky, and all up, I think I saw it for about 30/45 seconds, and then it just faded away. Fair to say, I was concerned about what it was, and kept an eye on it until I couldn't see it, but all seemed to be okay."
Quelle: CNN
 
.

2187 Views

Freitag, 11. Juli 2014 - 09:46 Uhr

Astronomie - Astronomen entdecken sieben Zwerggalaxien bei M101

.

This image shows the field of view from the Dragonfly Telephoto Array, centered on M101. Inset images highlight the seven newly discovered galaxies.

.

Meet the seven new dwarf galaxies.
Yale University astronomers, using a new type of telescope made by stitching together telephoto lenses, recently discovered seven celestial surprises while probing a nearby spiral galaxy. The previously unseen galaxies may yield important insights into dark matter and galaxy evolution, while possibly signaling the discovery of a new class of objects in space.
For now, scientists know they have found a septuplet of new galaxies that were previously overlooked because of their diffuse nature: The ghostly galaxies emerged from the night sky as the team obtained the first observations from the “homemade” telescope.
The discovery came quickly, in a relatively small section of sky. “We got an exciting result in our first images,” said Allison Merritt, a Yale graduate student and lead author of a paper about the discovery in The Astrophysical Journal Letters. “It was very exciting. It speaks to the quality of the telescope.”
Pieter van Dokkum, chair of Yale’s astronomy department, designed the robotic telescope with University of Toronto astronomer Roberto Abraham. Their Dragonfly Telephoto Array uses eight telephoto lenses with special coatings that suppress internally scattered light. This makes the telescope uniquely adept at detecting the very diffuse, low surface brightness of the newly discovered galaxies.
.
Yale astronomers used a new telescope, the Dragonfly Telephoto Array, to detect the diffuse light of the new galaxies.
.
“These are the same kind of lenses that are used in sporting events like the World Cup. We decided to point them upward instead,” van Dokkum said. He and Abraham built the compact, oven-sized telescope in 2012 at New Mexico Skies, an observatory in Mayhill, N.M. The telescope was named Dragonfly because the lenses resemble the compound eye of an insect.
“We knew there was a whole set of science questions that could be answered if we could see diffuse objects in the sky,” van Dokkum said. In addition to discovering new galaxies, the team is looking for debris from long-ago galaxy collisions.
“It’s a new domain. We’re exploring a region of parameter space that had not been explored before,” van Dokkum said.
The Yale scientists will tackle a key question next: Are these seven newly found objects dwarf galaxies orbiting around the M101 spiral galaxy, or are they located much closer or farther away, and just by chance are visible in the same direction as M101?
If it’s the latter, Merritt said, these objects represent something entirely different. “There are predictions from galaxy formation theory about the need for a population of very diffuse, isolated galaxies in the universe,” Merritt said. “It may be that these seven galaxies are the tip of the iceberg, and there are thousands of them in the sky that we haven’t detected yet.”
Merritt stressed that until they collect more data and determine the distances to the objects, researchers won’t know their true nature. But the possibilities are intriguing enough that the team has been granted the opportunity to use the Hubble Space Telescope for further study.
“I’m confident that some of them will turn out to be a new class of objects,” van Dokkum said. “I’d be surprised if all seven of them are satellites of M101.”
Meanwhile, there is also more work to be done with the new telescope. “We are collecting new data with the Dragonfly telescope every clear night. We’re all curious to see what other surprises the night sky has in store for us,” Merritt said.
Quelle: Yale University

Tags: Astronomie 

2599 Views

Freitag, 11. Juli 2014 - 09:36 Uhr

Astronomie - Hubble zeigt Astronomen eine Reihe von kosmischen Perlen wie man sie noch nie gesehen hat

.

NASA's Hubble Space Telescope photographed a 100,000-light-year-long structure that looks like a string of pearls twisted into a corkscrew shape winds around the cores of the two massive galaxies. The “pearls” are superclusters of blazing, blue-white, newly born stars. (NASA/European Space Agency)

.

Astronomers are using words like "awesome" and "exciting" to describe the implications of a recent Hubble Space Telescope photograph. The photograph – wrap your head around this – shows a structure 100,000 light years long made of two colliding galaxies linked by a corkscrewing string of newly born stars.
You can't find a mundane explanation for this," German astronomer Grant Tremblay said in a NASA statement.
Scientists have seen the "beads on a string" phenomenon before on the arms of spiral galaxies and between galaxies. They've never seen one corkscrewing through two giant, merging galaxies.
Scientists have three possible explanations for the phenomenon and will try to figure which one is correct. Whatever the origin of the chain, Tremblay said "the result is awesome."
Quelle: The Huntsville Times.
.

A Thirty Kiloparsec Chain of "Beads on a String" Star Formation Between Two Merging Early Type Galaxies in the Core of a Strong-Lensing Galaxy Cluster

New Hubble Space Telescope ultraviolet and optical imaging of the strong-lensing galaxy cluster SDSS J1531+3414 (z=0.335) reveals two centrally dominant elliptical galaxies participating in an ongoing major merger. The interaction is at least somewhat rich in cool gas, as the merger is associated with a complex network of nineteen massive superclusters of young stars (or small tidal dwarf galaxies) separated by ~1 kpc in projection from one another, combining to an estimated total star formation rate of ~5 solar masses per year. The resolved young stellar superclusters are threaded by narrow H-alpha, [O II], and blue excess filaments arranged in a network spanning ~27 kpc across the two merging galaxies. This morphology is strongly reminiscent of the well-known "beads on a string" mode of star formation observed on kpc-scales in the arms of spiral galaxies, resonance rings, and in tidal tails between interacting galaxies. Nevertheless, the arrangement of this star formation relative to the nuclei of the two galaxies is difficult to interpret in a dynamical sense, as no known "beads on a string" systems associated with kpc-scale tidal interactions exhibit such lopsided morphology relative to the merger participants. In this Letter we present the images and follow-up spectroscopy, and discuss possible physical interpretations for the unique arrangement of the young stellar clusters. While we suggest that this morphology is likely to be dynamically short-lived, a more quantitative understanding awaits necessary multiwavelength follow-up, including optical integral field spectroscopy, ALMA sub-mm interferometry, and Chandra X-ray imaging.
Quelle: Cornell University Library, Ithaca, NY 14853
 

Tags: Astronomie 

2231 Views

Freitag, 11. Juli 2014 - 09:28 Uhr

UFO-Forschung - IFO-Universität: Raketen-Start

.

Jellyfish in the sky was a high-flying rocket plume / Foto: Roscosmos

.

Deep in the sea or high in the sky? A Russian Soyuz rocket produced this eerie jellyfish-like plume as it climbed up through the thin air of near space.
Soon after launch on the morning of Tuesday 8 July, clear weather at the Russian space base in Baikonur, Kazakhstan, allowed photographer Anatoly Zak to capture the remarkable pattern on camera.
According to Jonathan McDowell at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, this is just one of many spectacular formations this kind of rocket can make as the core-stage rocket plume balloons out in the thin air high in the atmosphere. The cross at the top of the formation was made by the Soyuz's four boosters.
"It looks so interesting because we're not used to seeing gas dynamics in a near-vacuum. At that altitude there's not really any weather to interfere with the gases, so the gases form very regular formations and fill up a lot of space," says McDowell.
Strange formations like this have been catching the eyes of UFO-spotters since the cold war, when the Soviet Union started launching spy satellites on the same types of rockets from its once-secret launch pads.
The rocket's main payload was the 2.7-tonne Russian Meteor-M2 satellite, the second of its kind launched to watch global weather, the ozone layer, radiation in orbit, the ocean surface temperature and ice conditions on Earth.
Quelle: NewScientist

Tags: UFO-Forschung 

2394 Views

Freitag, 11. Juli 2014 - 09:17 Uhr

Mars-Chroniken - MRO erhält ein weiterer Beweis für Trockeneis-Schluchten auf dem Mars

.

This pair of images covers one of many sites on Mars where researchers use the HiRISE camera on NASA's Mars Reconnaissance Orbiter to study changes in gullies on slopes. Changes such as the ones visible in deposits near the lower end of this gully occur during winter and early spring on Mars.

.

Repeated high-resolution observations made by NASA’s Mars Reconnaissance Orbiter (MRO) indicate the gullies on Mars’ surface are primarily formed by the seasonal freezing of carbon dioxide, not liquid water.
The first reports of formative gullies on Mars in 2000 generated excitement and headlines because they suggested the presence of liquid water on the Red Planet, the eroding action of which forms gullies here on Earth. Mars has water vapor and plenty of frozen water, but the presence of liquid water on the neighboring planet, a necessity for all known life, has not been confirmed. This latest report about gullies has been posted online by the journal Icarus.
"As recently as five years ago, I thought the gullies on Mars indicated activity of liquid water," said lead author Colin Dundas of the U.S. Geological Survey's Astrogeology Science Center in Flagstaff, Arizona. "We were able to get many more observations, and as we started to see more activity and pin down the timing of gully formation and change, we saw that the activity occurs in winter."
Dundas and collaborators used the High Resolution Imaging Science Experiment (HiRISE) camera on MRO to examine gullies at 356 sites on Mars, beginning in 2006. Thirty-eight of the sites showed active gully formation, such as new channel segments and increased deposits at the downhill end of some gullies.
Using dated before-and-after images, researchers determined the timing of this activity coincided with seasonal carbon dioxide frost and temperatures that would not have allowed for liquid water.
Frozen carbon dioxide, commonly called dry ice, does not exist naturally on Earth, but is plentiful on Mars. It has been linked to active processes on Mars such as carbon dioxide gas geysers and lines on sand dunes plowed by blocks of dry ice. One mechanism by which carbon dioxide frost might drive gully flows is by gas that is sublimating from the frost providing lubrication for dry material to flow. Another may be slides due to the accumulating weight of seasonal frost buildup on steep slopes.
The findings in this latest report suggest all of the fresh-appearing gullies seen on Mars can be attributed to processes currently underway, whereas earlier hypotheses suggested they formed thousands to millions of years ago when climate conditions were possibly conducive to liquid water on Mars.
Dundas's co-authors on the new report are Serina Diniega of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, and Alfred McEwen of the University of Arizona, Tucson. 
"Much of the information we have about gully formation, and other active processes, comes from the longevity of MRO and other orbiters,” said Diniega. “This allows us to make repeated observation of sites to examine surface changes over time."
Although the findings about gullies point to processes that do not involve liquid water, possible action by liquid water on Mars has been reported in the past year in other findings from the HiRISE team. Those observations were of a smaller type of surface flow feature.
An upcoming special issue of Icarus will include multiple reports about active processes on Mars, including smaller flows that are strong indications of the presence of liquid water on Mars today.
"I like that Mars can still surprise us," Dundas said. "Martian gullies are fascinating features that allow us to investigate a process we just don't see on Earth."
.

A New Gully Channel in Terra Sirenum, Mars
This pair of before (left) and after (right) images from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter documents the formation of a substantial new channel on a Martian slope between Nov. 5, 2010, and May 25, 2013.
The location is on the inner wall of a crater at 37.45 degrees south latitude, 222.95 degrees east longitude, in the Terra Sirenum region. Gully or ravine landforms are commonly found in the mid-latitudes on Mars, particularly in the southern highlands. These features typically have an alcove at the upper end, feeding into a channel and an apron of debris that has been carried from above. Researchers using HiRISE have discovered many examples of gully activity likely driven by seasonal carbon-dioxide frost (dry ice).
The changes visible by comparing the 2010 and 2013 observations at this site formed when material flowing down from the alcove broke out of an older route, eroded a new channel and formed a deposit on the apron. Although this pair of observations does not pin down the season of the event, locations HiRISE has imaged more often demonstrate that this sort of event generally occurs in winter, when liquid water is very unlikely. Despite their resemblance to water-formed ravines on Earth, carbon dioxide may play a key role in the formation of many Martian gullies.
.
Quelle: NASA

Tags: Mars-Chroniken 

2268 Views

Freitag, 11. Juli 2014 - 08:30 Uhr

Raumfahrt - Erfolgreicher Arianespace’s Start von Soyuz VS08 mit O3b Networks Satelliten am 10.Juli

.

Pre-launch processing begins for the O3b Networks satellites to be orbited on Arianespace’s upcoming Soyuz flight

One of the four O3b Networks satellites is removed from its shipping container inside the Spaceport’s S1B clean room facility, where each of these Ku-band spacecraft will be entering their pre-launch processing.

The next four satellites to serve O3b Networks in providing emerging market connectivity worldwide have entered their checkout phase at the Spaceport in French Guiana, readying them for launch on an Arianespace Soyuz mission planned for late June/early July.

These spacecraft are now inside the Spaceport’s S1B clean room facility, and are being removed from the individual shipping containers that protected them during a trans-Atlantic cargo jetliner flight from Europe to the equatorial launch site.

The O3b Networks satellites were produced by Thales Alenia Space, and have a trapezoidal-shaped main body to facilitate their integration on the Soyuz vehicle’s payload dispenser system. Outfitted with Ka-band transponders, the four spacecraft are to be positioned after launch at a medium-orbit altitude of 8,062 km.

This upcoming Soyuz mission is designated Flight VS08 in Arianespace’s launcher family numbering system, signifying the eighth liftoff of the medium-lift workhorse from the Spaceport since its 2011 introduction at French Guiana.

Arianespace orbited the initial four O3b Networks satellites on another Soyuz mission performed in June 2013. It marked the first step in O3b Networks’ creation of a space-based constellation to provide billions of consumers and businesses in nearly 180 countries with low-cost, high-speed, low latency Internet and mobile connectivity – delivering services over Asia, Africa, South America, Australia and the Middle East.

Soyuz is part of Arianespace’s three-member launcher family, which also includes the heavy-lift Ariane 5 and lightweight Vega – which also are operated at the Spaceport.

Quelle: arianespace

.

Update: 18.06.2014

.

Launch of Russia’s Soyuz rocket with European satellite due July 10



Russia’s Soyuz-ST-B rocket carrying the European communication satellite 03B from the Kourou space site in French Guiana has been scheduled for July 10, the press-service of Russia’s space agency Roskosmos told ITAR-TASS. The rocket is now being tested and the booster Fregat fuelled.
Soyuz-ST is a variety of the three-stage rocket Soyuz-2, adapted for launches from the Guiana space centre. The first four 03B satellites were put in orbit in June 2013. It was the first step to create a large orbital cluster for Internet access from remote regions. The group of satellites may be built up to 20. Over one billion dollars has been raised for the project. The satellite network will cover a vast expanse from Spain to South Africa, including a greater part of South America and Asia and all islands in the South Pacific.

Quelle: ITARTASS

.

Update: 20.06.2014

.

The O3b Networks payload “cluster” takes form for Arianespace’s upcoming Soyuz launch

The second of four O3b Networks satellites to be orbited on Arianespace’s upcoming Soyuz mission is integrated on the dispenser system during activity in the Spaceport’s S5 payload preparation building.  Soyuz Flight VS08 will be the second performed for O3b Networks.
.
Payload integration is underway for the four O3b Networks connectivity satellites to be orbited by Arianespace on its next Soyuz mission, scheduled for liftoff on July 10 from the Spaceport in French Guiana.
This integration involves a step-by-step installation of the spacecraft on a tube-shaped dispenser system, with the activity taking place inside the Spaceport’s S5 payload preparation facility. 
The dispenser will release O3b Networks’ four satellites into a medium-altitude Earth orbit during the mission, enabling these platforms to join the company’s initial batch of connectivity spacecraft lofted by Arianespace aboard another Soyuz in June 2013.
Thales Alenia Space produced the Ka-band relay platforms, which have a liftoff mass of approximately 700 kg. each and will create a constellation providing telecommunications and Internet services over Asia, Africa, South America, Australia and the Middle East – combining the global reach of satellite coverage with the speed of a fiber-optic network.
The July 10 flight will be Arianespace’s eighth mission from French Guiana with its workhorse medium-lift Soyuz, and carries the VS08 designation in the company’s launcher family numbering system.  Soyuz joins Arianespace’s other two launchers in service at the Spaceport: the heavy-lift Ariane 5, and lightweight Vega. 

Launch window for VS08

UTC

Kourou, French Guiana

Paris, France

Washington, D.C.

Moscow, Russia

At 18:55:56
on July 10, 2014

At 03:55:56 p.m.
on July 10, 2014

At 08:55:56 p.m.
on July 10, 2014

At 02:55:56 p.m.
on July 10, 2014

At 10:55:56 p.m. 
on July 10, 2014

.
Quelle: arianespace

.

Update: 6.07.2014 

.

O3b’s satellite cluster receives its orbital “kick” for the upcoming Arianespace Soyuz launch

The mating of O3b Networks’ four satellites to the Fregat upper stage is shown in this series of photos, beginning with its hoisting inside the Spaceport’s S3B payload preparation facility, and their positioning atop Fregat – which is covered by gold-colored thermal insulation.
.
The next satellite cluster for O3b Networks’ affordable, high-speed connectivity system has been mated to its Fregat upper stage in French Guiana, marking one of the final steps in Arianespace’s Soyuz launch campaign for a liftoff next week from the Spaceport.
During operations in the Spaceport’s S3B payload preparation facility, the four satellites – which previously were integrated on their tube-shaped dispenser system – have been mated atop Soyuz’ Fregat upper stage. The highly flexible Fregat stage will perform multiple burns during Arianespace’s July 10 flight, deploying the spacecraft into orbit.
This week’s mating operation with Fregat will be followed by Soyuz’ subsequent rollout to the ELS launch complex near the French Guiana town of Sinnamary, allowing the satellite payload to be installed on the medium-lift workhorse launcher.
The July 10 mission, designated Flight VS08 in Arianespace’s launcher family numbering system, will be the eighth with Soyuz since the vehicle’s 2011 introduction at the Spaceport – joining the company’s heavy-lift Ariane 5 and lightweight Vega.
Flight VS08 will be the second Arianespace mission at the service of O3b Networks, following the orbiting of its initial four satellites with Soyuz in June 2013.
O3b Networks’ Ka-band relay platforms will create a satellite constellation for telecommunications and Internet services that combine high speed and affordable costs for billions of people across the world who do not yet have adequate internet access.  Thales Alenia Space produced the spacecraft, which have a liftoff mass of approximately 700 kg. each. 
Quelle: arianespace

.

 

Update: 9.07.2014

.

O3b Networks’ four satellites are integrated on Soyuz for Arianespace’s July 10 mission

Integration of Flight VS08’s “upper composite” is shown in these photos from the Spaceport’s ZLS launch complex at French Guiana, beginning with its delivery by a special transporter to the mobile gantry that protects Arianespace’s Soyuz. This composite – composed of O3b Networks’ four spacecraft, the Fregat upper stage, plus the protective payload fairing – was then hoisted inside the gantry, and installed atop the workhorse medium-lift vehicle in the gantry’s upper level to complete its build-up.
.
Soyuz Flight VS08
Arianespace’s next medium-lift Soyuz to be launched from French Guiana is now complete following the integration of its “upper composite,” made up of four O3b Networks connectivity satellites, their protective payload fairing and the Fregat upper stage.
This activity was performed at the Spaceport’s ZLS launch complex near the town of Sinnamary. It began with the upper composite’s transfer from the S3B payload preparation facility on a special transporter, and was followed by hoisting to the upper level of a purpose-built mobile gantry – which provides a protected environment for the vertical installation.
Final checkout of the Soyuz launcher is now underway, leading up to the Arianespace liftoff planned on Thursday, July 10 at precisely 03:55:56 p.m. local time in French Guiana. This mission is designated Flight VS08 in the company’s numbering system, representing the workhorse Soyuz’ eighth flight from French Guiana. 
The upcoming launch’s payload – four Thales Alenia Space-produced satellites that will join O3b Networks’ pioneering high-speed connectivity system – are to be deployed during a flight lasting 2 hrs., 22 min. Equipped with Ka-band transponders, the satellites will be positioned at a medium-orbit altitude of 8,062 km.
Total payload lift performance is estimated at 3,204 kg., including a combined mass of approximately 2,800 kg. for the four spacecraft – which will create a constellation providing telecommunications and Internet services over Asia, Africa, South America, Australia and the Middle East, combining the global reach of satellite coverage with the speed of a fiber-optic network.
Flight VS08 will be the second Arianespace mission at the service of O3b Networks, following the orbiting of its initial four satellites with Soyuz in June 2013. 
Quelle: arianespace

.

 

Update: 10.07.2014 / 0.15 MESZ

.

.

.

.

Quelle: ESA

.

Update: 10.07.2014 / 12.55 MESZ 


.

Update: 20.25 MESZ - LIVE Frams von Start Soyus VS08 

...

...

...

 

...

...

...


Quelle: arianespace 

.

Update: 11.07.2014

.

Arianespace launches O3b satellites on Soyuz mission
Arianespace and O3b team up to offer an innovative spaceborne solution that benefits people on Earth
On Thursday, July 10, 2014 at 3:55 pm local time in French Guiana, Arianespace successfully performed its second launch for O3b Networks, following the successful launch of the operator's first four satellites last year. With this eighth Soyuz launch from the Guiana Space Center, all successful, Arianespace proves its long-term support for new operators and helps reduce the world's digital divide.
O3b, a mission to provide low-cost, high-speed Internet access to the “other 3 billion” people on Earth
Arianespace lofted four more satellites in the O3b constellation (the "Other 3 billion") into an equatorial orbit. Built by Thales Alenia Space as prime contractor, these four satellites will enable O3b Networks to supply broadband Internet access at moderate prices to emerging markets in Asia, Africa, Latin America, Australia and the Middle East, totaling nearly 150 countries surrounding the equator where broadband access is rarely available. Following this launch, the O3b constellation will be deployed in its initial configuration and will be fully operational.
Arianespace's partnership with O3b clearly reflects one of the company's basic values, namely making the benefits of space available to people on Earth.
Arianespace, trusted partner for new operators
Arianespace has long supported new operators as they enter the market, by providing services tailored to their specific requirements, backed by launch systems renowned for their reliability and availability. For O3b Networks, Arianespace and partners developed a special technique to deploy these satellites into equatorial orbit, combining a dedicated multiple launch configuration and an optimized launch campaign. Furthermore, access to an export credit arrangement facilitated project financing. Arianespace is already gearing up for a third O3b launch, scheduled for the first quarter of 2015.
Arianespace, the global benchmark in launch services
With the Ariane 5, Soyuz and Vega launchers fully operational at the Guiana Space Center in French Guiana, Arianespace is the only launch services company in the world capable of launching all payloads into all orbits, from the smallest spacecraft to the largest geostationary satellites, as well as satellite clusters for constellations and cargo missions to the International Space Station. Arianespace continues to set the standard in launch services for all operators, and guarantee independent access to space.
Shortly after the official announcement of the orbital injection of the four O3b satellites, Stéphane Israël, Chairman and CEO of Arianespace, said: "We are very proud of our role in this outstanding project, which will reduce the digital divide by supplying broadband Internet access to populations in equatorial regions. I would like to thank O3b, a key customer for Arianespace, for continuing to place their trust in us for the second phase of 
constellation deployment, which transforms their innovative vision into a reality. I would also like to congratulate Thales Alenia Space for the timely availability of the satellites, and our Russian partners for the unmatched reliability of the Soyuz launcher.
I would like to thank the ground industrialists, CNES/CSG teams, and the space center staff for their efforts on this fifth successful launch of the year. Thank you to the Arianespace teams for this latest success. More than ever, this reinforces Arianespace’s position as the world leader in space transportation in the framework of an exceptional year."

Quelle: arianespace


2560 Views

Donnerstag, 10. Juli 2014 - 19:31 Uhr

UFO-Forschung - Hat Buzz Aldrin wirklich ein UFO gesehen? Technisch gesehen, ja!

.

Col. Buzz Aldrin, former Apollo 11 lunar module pilot, waves from inside a NASA Mobile Quarantine Facility, identical to the one he spent time in immediately upon his return from his voyage to the moon.

Did Buzz Aldrin really see a UFO? Technically, yes.
On NASA's famed Apollo 11 mission to the moon, astronaut Buzz Aldrin said he spotted a light traveling alongside his spacecraft. In a very narrow sense of the term, the light qualified as a UFO.
.
During the Apollo 11 mission to the moon in 1969, Buzz Aldrin made history by being the second man to set foot on the surface of the moon.
He also became famous, in certain circles, for seeing a UFO.
During an "Ask Me Anything" session on the popular social networking service Reddit, the former astronaut opened up about the sighting, emphasizing that the unidentified object in question was definitely not an alien spaceship.
Recommended: Are you scientifically literate? Take our quiz
On one of his Reddit posts, Col. Aldrin explained, “On Apollo 11 in route to the Moon, I observed a light out the window that appeared to be moving alongside us. There were many explanations of what that could be, other than another spacecraft from another country or another world – it was either the rocket we had separated from, or the 4 panels that moved away when we extracted the lander from the rocket and we were nose to nose with the two spacecraft. So in the close vicinity, moving away, were 4 panels. And I feel absolutely convinced that we were looking at the sun reflected off of one of these panels. Which one? I don't know. So technically, the definition could be ‘unidentified.’”
“It was not an alien,” he added.
While Aldrin's explanation will no doubt be disappointing to some and likely ignored by the more hardcore conspiracy theorists, there are a few other UFO sightings by astronauts that some feel haven’t been satisfactorily explained.
In 2005, for instance, astronaut Leroy Chiao reportedly saw four mysterious lights pass by between him and the Earth. However, the explanation may be disappointingly mundane—brightly lit fishing boats at night on the Earth below may have been responsible, according to the Huffington Post. Chaio himself doubts that what he saw was the result of an alien spacecraft.
Apollo 14 astronaut Edgar Mitchell, by contrast, is convinced that aliens have been seen on Earth and that humans have made contact with them. He has publicly claimed that he has sources who have told him that UFOs have been covered up by the government, though he admits “I have not seen one personally,” according to Bloomberg.
Mitchell’s claims of UFO conspiracies place him in the minority of astronauts. Nevertheless, Buzz Aldrin clarified on Reddit that while he had never seen a UFO and doubted that humans have ever made contact with aliens, he does believe there is life elsewhere in the universe.
“There may be aliens in our Milky Way galaxy, and there are billions of other galaxies. The probability is almost CERTAIN that there is life somewhere in space. It was not that remarkable, that special, that unusual, that life here on earth evolved gradually, slowly, to where we are today.”
Aldrin’s Reddit session comes with the 45th anniversary of Apollo 11 just around the corner. The mission that departed Earth on July 16, 1969 to land on the moon on July 20th marked the first time in history that humans stood on the lunar surface.
Aldrin discussed a wide variety of topics for Reddit questioners, including the possibility of humans landing on Mars, his personal musings on what it was like to walk on the moon, and most importantly, what is favorite ice cream flavor is.
Aldrin’s answer to that question was enthusiastic and succinct.
Quelle: CS-Monitor
 

Tags: UFO-Forschung ja! 

2268 Views


Weitere 7 Nachrichten nachladen...