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Sonntag, 6. November 2016 - 17:30 Uhr

Astronomie - Neue Studie über gefundene Chemikalien auf Kometen

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New Study Reveals Relationships Between Chemicals Found on Comets

Hubble Space Telescope image of a comet disintegrating in 2006
 
This NASA/ESA Hubble Space Telescope image of comet 73P/Schwassmann-Wachmann 3 disintegrating in 2006 shows the tails and comas of the individual pieces of the comet; new research on comet composition included infrared spectrography of this comet during its breakup.
Image credit: NASA, ESA, H. Weaver (APL), M. Mutchler and Z. Levay (STScI)

A new study has revealed similarities and relationships between certain types of chemicals found on 30 different comets, which vary widely in their overall composition compared to one another. The research is part of ongoing investigations into these primordial bodies, which contain material largely unchanged from the birth of the solar system some 4.6 billion years ago.

By studying the composition of hazy comas and tails of these comets, researchers found that certain chemical ices on the comets would regularly appear in concert with other chemicals in a correlated way, while certain other chemicals appeared or were absent independently from others. “This relates to how the chemicals are stored together or sequestered in the nucleus, or body of the comet,” said the paper’s lead author, Neil Dello Russo, a space scientist at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

The amounts and relationships of the chemicals observed in comets can help researchers understand more about the formation of our solar system. “We want to study the abundances of these chemicals because comets are a window into the distant past, and they can tell us what the chemical characteristics and conditions were like in the early Solar System,” said Dello Russo. The team studied various types of simple but abundant chemicals, including volatiles such as water, methane, carbon monoxide and ammonia. Observations from Earth cannot directly detect these chemicals on the nucleus of comets, but gases, ices and grains released from the comet leave a chemical trail that can be observed in the hazy comas and tails of comets.

Researchers studied data gathered from 1997 to 2013, and included both short-period comets (those that are stored around the Kuiper Belt beyond the gas giant planets) and long-period comets (which formed among the gas giants before they were ejected to the far more distant Oort cloud). The study compared the chemical makeup of the comets measured after they were released from these reservoirs and found that while each comet has a unique chemical signature, short-period comets are on average more depleted in certain chemicals than long-period comets from the Oort cloud.

The findings were published in the November issue of Icarus.

The study utilized Earth-based high-resolution infrared spectrometers, which can observe minute differences in color that reveal diagnostic fingerprints of the chemicals present in comet tails. Data from the Near-Infrared Spectrometer (NIRSPEC) at the Keck 2 Telescope of the W. M. Keck Observatory on Mauna Kea, Hawaii; the Cryogenic Echelle Spectrometer (CSHELL) at the NASA Infrared Telescope Facility on Mauna Kea; the Infrared Camera and Spectrograph at the Subaru telescope, also on Mauna Kea; and the CRyogenic high-resolution InfraRed Echelle Spectrograph (CRIRES) spectrometer at the VLT Telescope at Cerro Paranal, Chile, were used. Dello Russo explained that this research was only made possible due to recent breakthroughs in infrared spectrometers: “In the past 20 years, technological advances have really made it possible to accurately detect volatile chemicals in comets, and to do so for comets that are fainter and farther away than previously possible. That allowed us to study a large enough group of comets to note and examine significant trends.”

Dello Russo said that studies such as these are needed to expand what scientists know about the nature and history of comets, how cometary ices are related, and how they are stored in and released from the nucleus. “Comets are very diverse,” he said. “When NASA or ESA sends a mission to a comet, we can learn a tremendous amount of detail on that specific comet. What our research does is put those findings into the larger chemical context of the overall comet population. We can help answer where an individual comet fits into the population of comets.”

The research was sponsored by NASA’s Planetary Astronomy and Planetary Atmospheres Programs and the Emerging Worlds Program, part of the Science Mission Directorate at NASA Headquarters in Washington, D.C

Quelle: The Johns Hopkins University


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Sonntag, 6. November 2016 - 14:00 Uhr

Luftfahrt - Morphing Flügel-Konzept

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Go, Go, Green Wing! Mighty Morphing Materials in Aircraft Design

 

Early studies of aerodynamics showed that the shape of a wing has enormous effects on flight – but there isn’t just one “best” wing shape. That definition will change for different aircraft, for different flights of the same aircraft, and even for different segments of a single flight. The best shape in any moment depends on many factors: how much the aircraft weighs, the speed it is flying, and whether the pilot wants to climb higher or descend, for instance. This means that a rigid wing with a limited number of moveable surfaces – also rigid – is only a compromise and can’t be the most efficient shape for the whole of any given flight. Increased efficiency means less fuel is needed, which means less weight on the aircraft, which also increases efficiency.

MADCAT morphing aircraft wing
This video shows the morphing wings twisting and moving independently of each other, eliminating the need for wing flaps and ailerons.
Credits: NASA/Kenneth Cheung
MADCAT morphing wing
The wing is constructed from building-block units made of advanced carbon fiber composite materials.
Credits: NASA/Kenneth Cheung

This “holy grail” of more efficient flight is always in the minds of the Mission Adaptive Digital Composite Aerostructure Technologies, or MADCAT, team at NASA’s Ames Research Center in California’s Silicon Valley. In collaboration with students from the Massachusetts Institute of Technology, Cornell University, UC Santa Cruz, UC Berkeley, and UC Davis, the team of NASA researchers and students is using emerging composite material manufacturing methods to build and demonstrate an ultra-light wing that actively changes shape. Kenneth Cheung, co-lead on the MADCAT project, believes that this could be an important part of the future of green aviation.

 

The wing is constructed from building-block units made of advanced carbon fiber composite materials. These building blocks are assembled into a lattice, or arrangement of repeating structures; the way that they are arranged determines how they flex. The wing also features actuators and computers that make it morph and twist to achieve the desired wing shape during flight. This type of wing could improve aerodynamic efficiency in future flight vehicles by reducing the amount of drag caused by rigid control surfaces like flaps, rudders, and ailerons.

 

The MADCAT project, which is funded by ARMD’s Transformative Aeronautics Concepts Program under the Convergent Aeronautics Solutions project, provides opportunities for the next generation of researchers to explore new methods to make groundbreaking aerodynamic improvements to technology. The team recently tested the new morphing wing concept at a remote test airfield near Modesto, California, and plans to further evolve the wing and assess the boundaries of its feasibility. 

 

NASA is committed to transforming aviation by dramatically reducing its environmental impact; improving efficiency, while maintaining safety in more crowded skies; and paving the way for revolutionary aircraft shapes and propulsion.

Quelle: NASA

 

 

 

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Sonntag, 6. November 2016 - 09:45 Uhr

Astronomi - Farbenfroher Carinanebel von nahen Sternen hell erleuchtet

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Säulen der Zerstörung

 

 

Riesige säulenartige Strukturen konnte ein internationales Astronomenteam, darunter auch Wissenschaftler aus Garching, München und Heidelberg, innerhalb des Carinanebels beobachten. Eine Analyse zeigte, dass es sich – im Gegensatz zu den bekannten und ähnlich geschaffenen Säulen der Schöpfung im Adlernebel – eher um Säulen der Zerstörung handelt. Die eindrucksvollen Bilder entstanden mit dem MUSE-Instrument am Very Large Telescope der ESO.

Die Türme und Säulen in dem neuen Bild des Carinanebels bestehen aus riesigen Staub- und Gaswolken inmitten einer Sternentstehungsregion in einer Entfernung von etwa 7500 Lichtjahren. Die Säulen im Nebel wurden von einem Team unter der Leitung von Anna McLeod, einer Doktorandin bei der ESO, mit dem MUSE-Instrument am Very Large Telescope der ESO beobachtet.

Die große Stärke von MUSE liegt darin, dass das Instrument tausende von Bildern des Nebels zur selben Zeit erstellen kann, jedes bei einer anderen Lichtwellenlänge. Das ermöglicht es Astronomen, die chemischen und physikalischen Eigenschaften der Materie an verschiedenen Orten im Nebel herauszuarbeiten.

Zusammen mit Aufnahmen ähnlicher Strukturen, wie den berühmten Säulen der Schöpfung [1] im Adlernebel und Sternentstehungsregionen wie NGC 3603, wurden insgesamt zehn Säulen beobachtet, wobei eine klare Verbindung zwischen der emittierten Strahlung von nahen massereichen Sternen und den Eigenschaften der Säulen selbst festgestellt werden konnte.

Die Ironie des Schicksals hierbei ist, dass die Wolken, in denen massereiche Sterne entstehen, durch eben jene zunehmend zerstört werden. Das Konzept, dass massereiche Sterne einen beträchtlichen Einfluss auf ihre Umgebung haben, ist nicht neu: Solche Sterne sind bekannt dafür, dass sie enorme Mengen ionisierender Strahlung aussenden – Strahlung mit genug Energie, um Elektronen aus Atomen zu lösen. Allerdings ist es sehr schwierig, nur durch Beobachtungen Hinweise auf die Wechselwirkung zwischen solchen Sternen und ihrer Umgebung zu finden.

Das Team analysierte die Auswirkung dieser energiereichen Strahlung auf die Säulen: ein Prozess, der als Photoevaporation bezeichnet wird, wenn Gas ionisiert und dann zerstreut wird. Indem sie die Folgen der Photoevaporation untersuchten – die den Massenverlust der Säulen mit einschließen – konnten die Forscher die Ursache ausmachen. Es gab einen deutlichen Zusammenhang zwischen der Menge ionisierter Strahlung, die von nahen Sternen emittiert wird, und der zunehmenden Auflösung der Säulen.

Es mag grausam erscheinen, dass sich die massereichen Sterne gegen ihre eigenen Schöpfer wenden, allerdings ist der komplexe Rückkopplungseffekt zwischen den Sternen und den Säulen bisher nur wenig verstanden. Zwar scheint es so, als seien die Säulen sehr dicht, jedoch trifft das für die Wolken aus Staub und Gas, aus denen Nebel bestehen, nicht zu. Möglicherweise bewirken die Strahlung und Sternwinde der massereichen Sterne tatsächlich, dass sich dichtere Orte innerhalb der Säule bilden, in denen dann Sterne entstehen können.

Fest steht, dass diese atemberaubenden himmlischen Strukturen uns noch mehr zu erzählen haben und das Instrument MUSE ist ideal dafür geeignet, all das herauszufinden.

Endnoten

[1] Die Säulen der Schöpfung sind auf einem berühmten Bild zu sehen, das mit dem Hubble-Weltraumteleskop der NASA/ESA aufgenommen wurde, und zählen zu den bekanntesten Strukturen dieser Art. Sie werden auch als Elefantenrüssel bezeichnet und können eine Länge von mehreren Lichtjahren erreichen.

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Diese  Zusammenstellung zeigt mehrere Säulen im Carinanebel, die mit dem MUSE-Instrument beobachtet und untersucht wurden, das am Very Large Telescope der ESO installiert ist. Die massereichen Sterne innerhalb der Sternentstehungsregion zerstören langsam die Säulen aus Staub und Gas, in denen sie geboren wurden.

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Dieses Bild wurde mit dem MUSE-Instrument aufgenommen, das am Very Large Telescope der ESO installiert ist, und zeigt die Region R18 im Carinanebel in einer Entfernung von 7500 Lichtjahren. Die massereichen Sterne innerhalb der Sternentstehungsregion zerstören langsam die Säulen aus Staub und Gas, in denen sie geboren wurden.

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Dieses Bild wurde mit dem MUSE-Instrument aufgenommen, das am Very Large Telescope der ESO installiert ist, und zeigt die Region R37 im Carinanebel in einer Entfernung von 7500 Lichtjahren. Die massereichen Sterne innerhalb der Sternentstehungsregion zerstören langsam die Säulen aus Staub und Gas, in denen sie geboren wurden.

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Dieses Bild wurde mit dem MUSE-Instrument aufgenommen, das am Very Large Telescope der ESO installiert ist, und zeigt die Region R45 im Carinanebel in einer Entfernung von 7500 Lichtjahren. Die massereichen Sterne innerhalb der Sternentstehungsregion zerstören langsam die Säulen aus Staub und Gas, in denen sie geboren wurden.

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Diese Säule ist Teil des massereichen Sternhaufens Trumpler 14 im Carinanebel in einer Entfernung von 7500 Lichtjahren. Das Bild wurde mit dem MUSE-Instrument am Very Large Telescope der ESO aufgenommen.

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Die markanten dunklen Flecken im mittleren Bereich und im rechten Teil des Bildes sind sogenannte Bok-Globule: isolierte und vergleichsweise kleine Dunkelwolken, die dichten Staub und Gas enthalten. Diese Objekte sind noch immer Gegenstand aktueller Forschung, da ihre Struktur und Dichte weiterhin ein Rätsel bleibt.

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Diese zerklüftete Fantasie-Bergspitze, die von dünnen Wolken eingehüllt ist, erscheint wie eine skurrile Landschaft. Allerdings handelt es sich um eine Säule aus Gas und Staub, drei Lichtjahre hoch, die vom hellen Licht naher Sterne weggefressen wird. Die Säule wird auch von innen angegriffen, da junge Sterne, die im Inneren verborgen sind, mit Jets aus Gas schießen, die aus hochragenden Spitzen strömen.

Quelle: ESO

 

 

 


882 Views

Samstag, 5. November 2016 - 19:00 Uhr

Mars-Chroniken - Ungewöhnliche Marsregion hinterlässt Hinweise auf die Vergangenheit des Planeten

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LSU Mars researchers study the Kilauea Iki lava lake on Hawaii, which offers a similar geological environment to Mars. Image courtesy Don Hood, LSU.

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Researcher Don Hood from LSU and colleagues from collaborating universities studied an unusual region on Mars - an area with high elevation called Thaumasia Planum. They analyzed the geography and mineralogy of this area they termed Greater Thaumasia, which is about the size of North America.

They also studied the chemistry of this area based on Gamma Ray Spectrometer data collected by the Mars Odyssey Orbiter, which was launched in 2001. What they found was the mountain ridge that outlines Greater Thaumasia was most likely created by a chain of volcanoes. The results were published recently in the Journal of Geophysical Research-Planets.

"The chemical changes we see moving northwestward through the region is consistent with the mantle evolving on Mars. Our research supports that this whole area was built as a volcanic construct," said Don Hood, LSU Department of Geology and Geophysics doctoral candidate and lead author of the paper.

The chemical composition changes throughout the region. Silica and H20 increase and potassium decreases from southeast to northwest.

"The chemical composition shifting is the key progression that tells us that this environment was most likely shaped by a series of volcanic events that continually erupted from a changing mantle composition," Hood said.

Hood and colleagues from Stony Brook University, University of Tokyo and Lehigh University ruled out another hypothesis that the abundance of H20 and potassium was caused by water interacting in rock.

"We looked for evidence of aqueous alteration through other geochemical means and didn't find it," he said.

The geography of the region has many shield volcanoes that are similar to the ones found in Hawaii. However from geochemical analyses, the researchers found that the sulfur that is present was most likely deposited as a volcanic ash. Volcanic ash from various areas could be evidence of explosive volcanism on Mars, which would be an important clue for piecing together the history of Mars. It is significant because explosive eruptions emit a lot of gas that can stay in the atmosphere and can cause global cooling and warming events.

"Whether there was explosive volcanism on Mars and how much of it there was is an important question in terms of finding out what the past climate was like," Hood said.

Quelle: SD

 

 


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Samstag, 5. November 2016 - 16:00 Uhr

Science-Fiction - TV-Bericht: National Geographic Mars, Von den Produzenten Brian Grazer und Ron Howard

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Mars
COURTESY OF NAT GEO

Part documentary, part space opera, ‘Mars’ attempts to chronicle humankind’s next giant leap

Science fiction is usually lumped in with fantasy and myth under the umbrella term “genre fiction,” encompassing those stories that feature devices and occurrences that do not happen in our world. An enchanted sword, a demigod, a craft capable of traveling faster than the speed of light — they mean different things, but they are all distant from our current reality.

But science fiction carries with it more plausibility than the other genres. At its core is the idea that its visions could be possible, with all of the wonder and terror that implies. With this in mind, “Mars,” a hybrid documentary/space opera from National Geographic executive produced by Brian Grazer and Ron Howard, explores what it positions as an essential task for humanity — the pilgrimage to the red planet, both as a scripted story of intrepid explorers in 2033 and a documentary investigating where we currently stand in the quest to jump planets. By pairing fact with fiction, the program cannily makes literal the essential tension of science fiction, using the documentary and scripted elements to play off of and enhance each other. And though the hybrid isn’t quite seamless, “Mars” is a thought-provoking and visually stunning production, albeit one that isn’t exactly riveting. It’s a slow, considered exploration — but when you think about it, that’s probably what our journey to Mars should be like.

What drives this production, aside from pure curiosity about our near neighbor (just 140 million miles away!), is that colonizing Mars might be necessary for human survival, given the pace at which we are either overpopulating or destroying Earth. “Mars” features interviews with such varied figures as SpaceX founder Elon Musk, “The Martian” author Andy Weir, and NASA planetary scientists and former astronauts, all of whom present a relatively unified and relatively radical front: Mars, as inhospitable and distant as it is, is what’s next. Current research and experimentation — including SpaceX’s failed launch last month and astronaut Scott Kelly’s year in space — are explained and contextualized as stepping stones on the path to Mars exploration.

This goes to explain why, in the scripted segments, Mars is not just a destination but a desperately desired goal, a moral and philosophical quest. The fictional elements of “Mars” are so sentimental, they can become melodramatic — driven especially by the portentous voiceover narration of Captain Ben Sawyer (Ben Cotton), which tends to meander into metaphysical ruminations about the nature of humanity and the romance of tackling the unknown. At the same time, despite “Mars” rather measured pace, it’s hard to not feel excited by the launch and arrival, which almost immediately begins to present challenges to the crew. The introduction of each crew member’s backstory is a bit inorganic, but in a clever use of the show’s own structural device, the embarking crew members introduce themselves to the viewer via documentary-style “interviews.” In a nod to Kelly’s mission — conducted in tandem with his twin brother, who stayed on Earth — pop singer JiHAE, in her television debut, plays twin sisters, one on Mars and one at home at mission control.

“Mars” is a smart idea, and an educational one, too. But the factually dense production is not always able to accelerate from information to narrative. Probably, for some viewers, that won’t be a problem — space is pretty interesting all on its own, and experiencing a mission to Mars is a reward in and of itself. But though the miniseries presents an immersive visual landscape, it doesn’t quite follow through with the emotional landscape of the mission; much like its vision of our world in 2033, it’s sterile and utopian in a way that doesn’t quite feel like the messy, selfish planet we call home.

Indeed, in some ways, the most difficult-to-imagine element of this program is not that astronauts would find a way to set up camp on a cracked, arid desert 140 million miles away, but that just 17 years in the future, an international federation would band together for the common good, to send its best and brightest on a daring mission. As NASA repeatedly demonstrates, and the show underscores, what is lacking is not technological prowess or vision, but willpower. “Mars” falls short because it’s too optimistic about what humanity is capable of.

Quelle: Variety


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Samstag, 5. November 2016 - 15:45 Uhr

Mars-Chroniken - Curiosity findet einen Meteoriten

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3.11.2016

But the likely nickel-iron meteorite isn't the first specimen the rover has discovered in the Martian dirt.

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NASA/JPL-Caltech/MSSS 

 

If you're familiar with the pockmarked landscape of Mars, you'll know that the Red Planet gets hit by meteorites a lot. So it stands to reason that you'll likely find the occasional ex-space rock just sitting out there on the surface, particularly if your primary task is to constantly look down. And it just so happens we have a robotic geologist that has been getting intimate with Mars rocks since 2012 and it has just found a new rock beyond Mars.

The meteorite was discovered in imagery taken by Curiosity's Mastcam on sol (day) 1503 of its mission (Oct. 28) and followup studies by the rover's ChemCam on Oct. 30 revealed the object's strange, melted structure (pictured below). Curiosity is currently climbing the slopes of Mount Sharp (Aeolis Mons) in the center of Gale Crater after leaving the geologically fascinating region of "Murray Buttes." 

University of Arizona planetary scientists believe that it is a metallic nickel-iron rich meteorite, which are commonly found on Earth. This Martian example has been nicknamed "Egg Rock" by the Curiosity mission team. 

The interesting thing about meteorites on the Martian surface is that they are not subject to some of the aggressive weathering terrestrial meteorites are. Mars' atmosphere is very dry, limiting the amount of moisture that can degrade the pristine material. These factors help to preserve the meteorite material for indefinite periods, particularly if they are metal-rich.

Also, as the Mars atmosphere is so thin, compared with Earth's hefty atmospheric gases, Mars meteors will more likely hit the ground as meteorites and not completely burn up. Therefore future human meteorite hunters would want to consider field trips to Mars to collect these treasures as they hold many clues to the composition of ancient asteroids that formed when the solar system was young. 

 

Curiosity's ChemCam's Remote Micro-Imager (RMI) took this image of 'Egg Rock" on Oct. 30

 

Due to their comparative abundance on the surface, future Mars colonists may also seek out meteorites such as these so precious metals can be extracted and used for industrial processes. Although the increased risk of more frequent meteorite strikes will be a problem, the reward could be a potential goldmine of rare metals that can be found on or near the surface. Why mine asteroids when you can extract asteroid chunks from the Martian dirt?

Though obviously a rare find for our robotic explorer, this certainly isn't the first meteorite that's been found on the Martian surface. For example, in 2014 the 6-wheeled rover spotted a huge 2 meter-wide meteorite sticking out of the Martian regolith. Mars Exploration Rovers Opportunity and Spirit have also been pretty successful meteorite hunters

As both Curiosity and Opportunity continue to explore the Martian surface, it will be interesting to see how many more space rocks they find, potentially providing an estimate of how many meteorites may be accessible to our future Martian explorers to find.

Quelle: Seeker

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Update: 5.11.2016

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Colorized view of a meteorite on Mars from the ChemCam instrument on NASA's Curiosity Mars rover
 
 
Mars image from the Mast Camera (Mastcam) on NASA's Curiosity Mars rover
 
 
 
 
The dark, golf-ball-size object in this composite, colorized view from the ChemCam instrument on NASA's Curiosity Mars rover is a nickel-iron meteorite, as confirmed by analysis using laser pulses from ChemCam on Oct. 30, 2016. The grid of bright spots on the rock resulted from the laser pulses. Credit: NASA/JPL-Caltech/LANL/CNES/IRAP/LPGNantes/CNRS/IAS/MSSS
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Laser-zapping of a globular, golf-ball-size object on Mars by NASA's Curiosity rover confirms that it is an iron-nickel meteorite fallen from the Red Planet's sky.

Iron-nickel meteorites are a common class of space rocks found on Earth, and previous examples have been seen on Mars, but this one, called "Egg Rock," is the first on Mars examined with a laser-firing spectrometer. To do so, the rover team used Curiosity's Chemistry and Camera (ChemCam) instrument.

Scientists of the Mars Science Laboratory (MSL) project, which operates the rover, first noticed the odd-looking rock in images taken by Curiosity's Mast Camera (Mastcam) at a site the rover reached by an Oct. 27 drive. 

"The dark, smooth and lustrous aspect of this target, and its sort of spherical shape attracted the attention of some MSL scientists when we received the Mastcam images at the new location," said ChemCam team member Pierre-Yves Meslin, at the Research Institute in Astrophysics and Planetology (IRAP), of France's National Center for Scientific Research (CNRS) and the University of Toulouse, France.

ChemCam found iron, nickel and phosphorus, plus lesser ingredients, in concentrations still being determined through analysis of the spectrum of light produced from dozens of laser pulses at nine spots on the object. The enrichment in both nickel and phosphorus at some of the same points suggests the presence of an iron-nickel-phosphide mineral that is rare except in iron-nickel meteorites, Meslin said.

Iron meteorites typically originate as core material of asteroids that melt, allowing the molten metal fraction of the asteroid's composition to sink to the center and form a core. 

"Iron meteorites provide records of many different asteroids that broke up, with fragments of their cores ending up on Earth and on Mars," said ChemCam team member Horton Newsom of the University of New Mexico, Albuquerque. "Mars may have sampled a different population of asteroids than Earth has."

In addition, the study of iron meteorites found on Mars -- including examples found previously by Mars rovers -- can provide information about how long exposure to the Martian environment has affected them, in comparison with how Earth's environment affects iron meteorites. Egg Rock may have fallen to the surface of Mars many millions of years ago. Researchers will be analyzing the ChemCam data from the first few laser shots at each target point and data from subsequent shots at the same point, to compare surface versus interior chemistry.

Egg Rock was found along the rover's path up a layer of lower Mount Sharp called the Murray formation, where sedimentary rocks hold records of ancient lakebed environments on Mars. The main science goal for Curiosity's second extended mission, which began last month, is to investigate how ancient environmental conditions changed over time. The mission has already determined that this region once offered conditons favorable for microbial life, if any life ever existed on Mars.

Curiosity was launched five years ago this month, on Nov. 26, 2011, from Cape Canaveral Air Force Station, Florida. It landed inside Gale Crater, near the foot of Mount Sharp, in August 2012. 

The rover remains in good condition for continuing its investigations, after working more than twice as long as its originally planned prime mission of about 23 months, though two of its 10 science instruments have recently shown signs of potentially reduced capability. The neutron-generating component of Curiosity's Dynamic Albedo of Neutrons (DAN) instrument, designed for working through the prime mission, is returning data showing reduced voltage. Even if DAN could no longer generate neutrons, the instrument could continue to check for water molecules in the ground by using its passive mode. The performance of the wind-sensing capability from Curiosity's Rover Environmental Monitoring Station (REMS) is also changing, though that instrument still returns other Mars-weather data daily, such as temperatures, humidity and pressure. Analysis is in progress for fuller diagnosis of unusual data from DAN, which was provided by Russia, and REMS, provided by Spain.

Quelle: NASA

 


1231 Views

Samstag, 5. November 2016 - 15:30 Uhr

Astronomie - Sommer Wolken auf Titan beobachtet

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Watching Summer Clouds on Titan
New video shows bright clouds of methane drifting across Saturn's largest moon, Titan. Image credit: NASA/JPL-Caltech/Space Science Institute
› Larger image

NASA's Cassini spacecraft watched clouds of methane moving across the far northern regions of Saturn's largest moon, Titan, on Oct. 29­­­­ and 30, 2016.

Several sets of clouds develop, move over the surface and fade during the course of this movie sequence, which spans 11 hours, with one frame taken every 20 minutes. Most prominent are long cloud streaks that lie between 49 and 55 degrees north latitude. While the general region of cloud activity is persistent over the course of the observation, individual streaks appear to develop then fade. These clouds are measured to move at a speed of about 14 to 22 miles per hour (7 to 10 meters) per second.

There are also some small clouds over the region of small lakes farther north, including a bright cloud between Neagh Lacus and Punga Mare, which fade over the course of the movie. This small grouping of clouds is moving at a speed of about 0.7 to 1.4 miles per hour (1 to 2 meters) per second.

Time-lapse movies like this allow scientists to observe the dynamics of clouds as they develop, move over the surface and fade. A time-lapse movie can also help to distinguish between noise in images (for example from cosmic rays hitting the detector) and faint clouds or fog.

In 2016, Cassini has intermittently observed clouds across the northern mid-latitudes of Titan, as well as within the north polar region -- an area known to contain numerous methane/ethane lakes and seas see PIA19657 and PIA17655. However, most of this year's observations designed for cloud monitoring have been short snapshots taken days, or weeks, apart. This observation provides Cassini's best opportunity in 2016 to study short-term cloud dynamics.

Models of Titan's climate have predicted more cloud activity during early northern summer than what Cassini has observed so far, suggesting that the current understanding of the giant moon's changing seasons is incomplete.

The mission will continue monitoring Titan's weather around the 2017 summer solstice in Titan's northern hemisphere.

The movie was acquired using the Cassini narrow-angle camera using infrared filters to make the surface and tropospheric methane clouds visible.

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

Quelle: NASA


1009 Views

Samstag, 5. November 2016 - 10:30 Uhr

Raumfahrt - Raumschiff ORION Update-14

4.11.2016

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Navy prepares for recovering NASA's Orion Capsule

SAN DIEGO (CBS8) - NASA and the U.S. Navy are conducting tests to prepare for the recovery of the Orion Spacecraft. 

The test capsule and the hardware that will be used to recover the spacecraft are being revealed at Naval Base San Diego Thursday. 

CBS News 8's Shannon Handy has the details in this video report. 

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Quelle: CBS8

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Update: 5.11.2016

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Orbital ATK reviews SRB plans and competitiveness for SLS EM-1 and beyond

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With booster casting operations for SLS’s EM-1 mission well underway at Orbital ATK’s manufacturing facility in Utah, the company is looking ahead in terms of how the boosters’ flight data will be transmitted to ground stations during flight.  Moreso, the company is looking beyond EM-1 to the build operations for the EM-2 flight boosters as well as how their SRBs remain competitive with Blue Origin’s New Glenn and SpaceX’s ITS super heavy lift rockets.

Orbital ATK’s SRBs – an evolving post-flight environment:

A hallmark of the Shuttle program was the return to port, disassembly, and full-bodied inspection of the twin, 4 segment Solid Rocket Boosters (SRBs) that powered the five iconic winged vehicles through the first two minutes of their flights.

Over the course of the 135 flight Shuttle program, 133 flight set SRBs were recovered for such inspection – with only the STS-4and STS-51L SRBs being lost to parachute failures and the in-flight break up of the vehicle, respectively.

This recovery and post-flight inspection aspect to Shuttle SRBs allowed Morton Thiokol, subsequently ATK – now Orbital ATK – to ensure not only the functionality of the boosters’ all important O-Ring joint seals, but also to have access to on-board recorded data of the flight performance of the boosters.

During the course of the Shuttle program, these post-flight inspections revealed issues with O-Ring seals on the STS-8/Challenger and STS-51C/Discovery missions, as well as a near burn-through event during the launch of Columbia on STS-78 due to a flight performance issue with a newly mandated EPA (Environmental Protection Agency) adhesive.

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But SLS will see a change to this 30 year practice, as the new 5 segment SRBs will not be recovered for post-flight disassembly and inspection.

To this end, the boosters will transmit their flight data to ground receiving stations at the Cape, notes Orbital ATK in an interview with NASASpaceflight.com.

“Flight data will be gathered real-time from onboard instrumentation and transmitted to ground telemetry stations,” states Jeff Foote, Orbital ATK Vice President, NASA Programs.

“Post-flight review timeline of telemetered data will be very similar to that of the Shuttle era, specifically the early Shuttle flights when the STS was most heavily instrumented.”

Additionally, Mr. Foote noted that the data will not only be transmitted in real-time, but controllers will monitor the SRB flight data as it comes in, with detailed evaluation of the collected data following over a period of “several weeks”.

Beyond EM-1 – second SLS booster set, advanced SRBs, & competitive markets

While Morton Thiokol and ATK had a rapid pace production schedule for SRB segments during the Shuttle era, the production schedule for SLS is considerably more relaxed given the anticipated four year gap between its first flight and its second.

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Nonetheless, Orbital ATK will not wait four years to begin the casting process for the EM-2 flight set boosters.

According to Mr. Foote, “Fabrication is scheduled to start shortly after the EM-1 build, with the first EM-2 segment propellant cast in late Spring 2017 and the last segment cast about a year later.”

In all, Orbital ATK noted that enough SRB casings exist for 18 total motors, with a tentative plan to use two motors for additional ground tests and 16 motors for the first eight flights of SLS.

Given an uncertain but anticipated one-flight-per-year mission rate for SLS beginning in 2022 or 2023, that would take the current casing inventory out to 2028 or 2029 – likely longer given programmatic delays and a growing need to more definitively define SLS’s flight parameters, mission destinations, and mission objectives.

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Regardless, the Block 1 and Block 1B variants of SLS will be the vehicle configurations used by NASA for those first 8 flights of SLS. 

In terms of the SRBs and the understood nature and directive from NASA to create Advanced or next-generation flight set boosters, Orbital ATK stated that “The initial Block 1 and Block 1B vehicle configurations [utilize] existing SLS SRBs [that] provide an unrivaled launch capability that will enable beyond earth orbit human exploration and deep space science missions for at least the next decade. 

“The need for future vehicle upgrades will be mission based. 

“Previous NASA communications regarding the need for and timing of an advanced/upgraded booster center around SLS missions to Mars, which according to NASA documents will happen in the 2030s timeframe.”

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To this end, Orbital ATK added that the company remains “dedicated to serving NASA with advanced and upgraded booster options and continues to invest in preliminary development of various booster technologies.”

Regardless of when NASA would ask for formal development of advanced Solid Rocket Booster technology for the eventual SLS Mars campaigns, the benefits of those advanced boosters are already well understood.

According to Mr. Foote, “More advanced SRBs are anticipated to provide more lift capability for the launch vehicle to reach space destinations. While performance (increased thrust, lower weight) is always a key metric in evaluating advanced SRBs, affordability, reliability, and common use are other key metrics that may prove to be just as important. 

“Orbital ATK is currently developing commercially available solid propulsion system solutions at extremely competitive price points which contain a high degree of manufacturing and design commonality with human-rated deep space exploration requirements.”

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The extremely competitive price points and extreme reliability for the amount of lift capability they generate are two very important aspects to Orbital ATK’s Solid Rocket Booster technology – especially given this year’s formal announcements of Blue Origin’s New Glenn and SpaceX’s Interplanetary Transport System (ITS) super heavy-lift rockets.

While much speculation and discussion has been given to SLS’s place in the changing launch market, as well as the specific role of government super heavy lift rockets versus their commercial counterparts, Orbital ATK pointed out that SLS itself will hold a unique place in the launch market.

“NASA’s SLS will … serve a different piece of the global launch market than SpaceX and Blue Origin and even Orbital ATK’s own Antares launch vehicle,” noted Mr Foote.

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“The SLS is well positioned to serve the launch market where mission success, flexibility, adaptability, and on time launch is paramount.”

However, just because SLS will serve a unique niche in the super heavy lift launch market, that does not mean that NASA and Orbital ATK are complacent about the need to continuously evolve the SRB designed to suit SLS’s mission specific needs

In fact, the two organizations are taking a strong approach toward evolving SRB design.

“NASA’s SRBs have been the benchmark of reusability since the inception of the Space Shuttle. With NASA’s current predicted launch cadence, the SLS vehicle experts at NASA are evaluating the place for reusable components including upgraded/advanced SRBs based on the economic use of reusable launch technology.”

Quelle: NS

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Update:

Orion's service module 

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Quelle: Airbus

 

Orion Test Article on the Move



Time-lapse video shows the move of Orion's service module from the vibration table to the assembly high bay area in Plum Brook's Space Power Facility. Image courtesy NASA.

Engineers recently lifted and moved a full-scale test version of the 13-ton Orion service module in preparation for upcoming pyroshock tests at NASA Glenn's Plum Brook Station in Sandusky, Ohio.

During the tests, engineers will fire pyrotechnics to simulate the shocks the service module will experience as Orion separates from the Space Launch System (SLS) rocket.

The service module is an essential part of the spacecraft. It will propel, power and cool Orion in addition to providing air and water for the crew.

In this time-lapse video, the Plum Brook team removes the test article from the world's most powerful spacecraft vibration table and transports it into the assembly high bay area in Plum Brook's Space Power Facility.

Prior to the move, the test article passed a series of vibration tests to verify that it can withstand the vibrations as it launches and travels into space.

A thousand sensors collected data on Orion's service module as it was shaken on a vibration table. This testing simulated how Orion's structure flexed and will stand up to 35 tons of spacecraft weight during a launch.

Orion's first flight atop SLS, known as Exploration Mission-1 or EM-1, is targeted to launch in late 2018. It will venture tens of thousands of miles beyond the moon.

The test article was provided by ESA (European Space Agency) and built by Airbus Defence and Space.

Quelle: SD

 

 


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Samstag, 5. November 2016 - 10:00 Uhr

Astronomie - Mickey Mouse Ohren können die größten Explosionen des Universums erklären

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Mickey Mouse ears may explain universe’s biggest explosions

 

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Glittering remains from a supernova

NASA/CXC/IAFE/G. Dubner et al. & ESA/XMM-Newton

The ears have it. Many of the glittering shrapnel clouds left behind by the universe’s most violent supernovae seem to have bulging protuberances called “ears” – cute features that have now been enlisted in a debate about how these explosions go off in the first place.

When a massive star runs out of fuel, it blows up, spewing its atmosphere across space. One such event, in the constellation Taurus, was observed by multiple cultures on Earth in 1054, and we still study the debris cloud – the Crab nebula – today.  But the details of how exactly a star tears through its own immense gravity to explode are hotly contested.

These so-called core-collapse supernovae are hard to detonate, because the heavy weight of the star’s atmosphere presses down and threatens to hold the impending explosion in. The dominant model of these cataclysms, which has held since 1985, suggests that a shock wave rips through the star’s atmosphere, boosted by a deluge of neutrinos from the core.

Alternatively, Noam Soker at the Technion-Israel Institute of Technology in Haifa has spent the last few years arguing that jets of charged particles emitted from the massive star’s spinning core punch a path out.

 

Ears, which stick out on either side from supernova remnants, might help settle the debate. Aldana Grichener, Soker’s student at the Technion, set out to find and measure them more systematically in published images of the remains of massive stars.

Jet-propelled bulges

Grichener and Soker have concluded that about a third of core-collapse supernova remnants have a pair of ears, and that these side bulges were probably inflated by jets.

Given their sizes and shapes, they estimate that roughly 10 per cent of all the energy from these supernova explosions goes into blowing up the ears.  “It tells you – if the assumption is correct – that jets are quite energetic and play a significant role in the explosion or shortly after,” Soker says.

Other theorists who study this type of supernova explosion are sceptical, though. Adam Burrows at Princeton University in New Jersey thinks that jets may play a part in some explosions, even to the point of inflating the ears – but that the neutrino-boosted shock wave is more important in most of these detonations.

Still, Grichener’s paper is an interesting look at an understudied quirk of supernova remnants, he says: “I agree with the idea of trying to explain these so-called ears. I think it’s interesting and people haven’t emphasised it enough.”

Soker plans to submit the paper to journals, but anticipates the kind of opposition his jet idea often engenders. “We are in the minority among people who work in the explosion mechanisms,” he says. “So we don’t always have an easy time, to put it mildly.”

Quelle: NewScientist


1023 Views

Freitag, 4. November 2016 - 19:45 Uhr

Astronomie - ESA und die Apostolische Bibliothek des Vatikans

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ESA AND THE VATICAN JOIN FORCES TO SAVE DATA IN THE DIGITAL AGE

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At a ceremony held in Vatican City today, ESA and the Vatican Apostolic Library have agreed to continue their years-long cooperation on the preservation, management and exploitation of archived information.

The declaration follows a five-year activity by the Vatican Library to digitise its ancient collection using the ‘FITS’ flexible image transport system format, to ensure that future generations will have access to the books. ESA and NASA developed FITS in the 1970s, stemming from radio astronomy.

“Our collaboration is based on the common intention by our two institutions to promote the long-term preservation of images in electronic format,” said Monsignor Cesare Pasini, Prefect of the Vatican Apostolic Library.

He noted how the recent seismic events in Italy has further highlighted the importance of the preservation of information, drawing attention the need to affront changes in the technology of information storage.

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Signing ceremony

“Thanks to our cooperation with ESA, the Vatican Library has found the courage to make an innovative choice to use the FITS format for long-term storage.”

Josef Aschbacher, Director of Earth Observation Programmes at ESA, highlighted that the two institutions are facing very similar issues in relation to data assets preservation and exploitation and can achieve mutual benefit in cooperating and complementing each other lessons learned and experiences.

“The Vatican Apostolic Library and ESA are two examples that attest to the approach of collaboration for global benefit,” Mr Aschbacher said.

“While ESA provides global information about the state of our planet through satellite observations, the Vatican Apostolic Library offers a unique source of wisdom that has contributed to the development of our society and culture.”

Founded in 1475 and one of the world’s oldest libraries, the Vatican Library houses tens of thousands of manuscripts and codices from before the invention of the printing press – some are 1800 years old. In addition to preserving and restoring its collection, the Library has a mandate to ensure free consultation for scholars around the world.

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Exchange of gifts

In addition to making the contents more accessible, the FITS digitising has helped to preserve the original documents. Pressed against a plate of glass, the old pages can be distorted, but scanner software developed for the Vatican’s project automatically calculates the different angles, resulting in an accurate, flat image.

The format’s instructions for reading and processing the data are in a text header tacked on top of the data. In a century, when computers will presumably be very different, all the information needed to decode the data will be found within the same files.

FITS can always be read without the need for conversion to another format, which could lose information or be incompatible with future systems.

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Since 2008, ESA has been addressing the preservation, accessibility and future exploitation of its heritage Earth observation data assets through the Long Term Data Preservation Programme. ESA plans to use FITS to ensure that both old and new satellite data and associated information are available for scientists, policy makers and value-adding companies.

Future collaboration between ESA and the Vatican Library will allow both organisations to better evaluate digital formats and emerging technologies. The collaboration also aims to facilitate multidisciplinary applications through the use of archived information from ESA and the Vatican Library.

Quelle: ESA


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