samedi 23 juin 2012

NASA Space Launch System Core Stage Moves From Concept to Design










NASA logo.

June 23, 2012

The nation's space exploration program is taking a critical step forward with a successful major technical review of the core stage of the Space Launch System (SLS), the rocket that will take astronauts farther into space than ever before.

The core stage is the heart of the heavy-lift launch vehicle. It will stand more than 200 feet (61 meters) tall with a diameter of 27.5 feet (8.4 meters).

NASA's Marshall Space Flight Center in Huntsville, Ala., hosted a comprehensive review. Engineers from NASA and The Boeing Co. of Huntsville presented a full set of system requirements, design concepts and production approaches to technical reviewers and the independent review board.

"This meeting validates our design requirements for the core stage of the nation's heavy-lift rocket and is the first major checkpoint for our team," said Tony Lavoie, manager of the SLS Stages Element at Marshall. "Getting to this point took a lot of hard work, and I'm proud of the collaboration between NASA and our partners at Boeing. Now that we have completed this review, we go from requirements to real blueprints. We are right on track to deliver the core stage for the SLS program."


Image above: An expanded view of an artist rendering of the 70 metric ton configuration of NASA's Space Launch System. (NASA).

The core stage will store liquid hydrogen and liquid oxygen to feed the rocket's four RS-25 engines, all of which will be former space shuttle main engines for the first few flights. The SLS Program has an inventory of 16 RS-25 flight engines that successfully operated for the life of the Space Shuttle Program. Like the space shuttle, SLS also will be powered initially by two solid rocket boosters on the sides of the launch vehicle.

The SLS will launch NASA's Orion spacecraft and other payloads, and provide an entirely new capability for human exploration beyond low Earth orbit. Designed to be safe, affordable and flexible for crew and cargo missions, the SLS will continue America's journey of discovery and exploration to destinations including nearby asteroids, Lagrange points, the moon and ultimately, Mars.

"This is a very exciting time for the country and NASA as important achievements are made on the most advanced hardware ever designed for human space flight," said William Gerstenmaier, associate administrator for the Human Exploration Operations Mission Directorate at NASA Headquarters in Washington. "The SLS will power a new generation of exploration missions beyond low Earth orbit and the moon, pushing the frontiers of discovery forward. The innovations being made now, and the hardware being delivered and tested, are all testaments to the ability of the U.S. aerospace workforce to make the dream of deeper solar system exploration by humans a reality in our lifetimes."

The first test flight of NASA's Space Launch System, which will feature a configuration for a 77-ton (70-metric-ton) lift capacity, is scheduled for 2017. As SLS evolves, a two-stage launch vehicle configuration will provide a lift capability of 143 tons (130 metric tons) to enable missions beyond low Earth orbit and support deep space exploration.

Boeing is the prime contractor for the SLS core stage, including its avionics. The core stage will be built at NASA's Michoud Assembly Facility in New Orleans using state-of-the-art manufacturing equipment. Marshall manages the SLS Program for the agency.

Across the SLS Program, swift progress is being made on several elements. The J-2X upper-stage rocket engine, developed by Pratt & Whitney Rocketdyne for the future two-stage SLS, is being tested at Stennis Space Center in Mississippi. The prime contractor for the five-segment solid rocket boosters, ATK of Brigham City, Utah, has begun processing its first SLS hardware components in preparation for an initial qualification test in 2013.

For more information about the Space Launch System, visit: http://www.nasa.gov/sls

Image, Text, Credit: NASA.

Greetings, Orbiter.ch

vendredi 22 juin 2012

Solar Impulse landed safely in Ouarzazate













SolarImpulse Destination Morocco patch.

June 22. 2012

Solar Impulse landed smoothly Friday at 1:25 (Swiss time) in Ouarzazate, a city in southern Morocco, after traveling 683 km.

Landing in Ouarzazate, the aircraft was piloted by André Borschberg

The solar unit has traveled 683 kilometers after leaving Rabat at 8:05. He had to turn around a week ago due to high winds.

The plane was piloted by Andre Borschberg who suffered the first hot then cold during this flight. For this second test, the aircraft followed a slightly different route, flying over the coast at low altitude - 600 meters - from 10:00 to off Casablanca.

video
SolarImpulse landing in Ouarzazate

The aircraft climbed to 9000 meters to cross the Atlas. His average speed was 64.8 km / h. The pilot, who has extracted 30 minutes later the cabin, was enthusiastically welcomed by the entire team of Solar Impulse, a Moroccan official delegation and folk groups.

Symbolic

"This is a fantastic event to be here in Ouarzazate, the result of many months of preparation," said Andre Borschberg on arrival. This flight lasting over 17 hours is symbolic in more ways than one, since it happened the first day of summer, coinciding with the Rio conference on sustainable development, he said.

"Unfortunately, the fact that many heads of state are not gone there shows that the environmental issue is still not taken seriously," he noted. Bertrand Piccard has meanwhile welcomed the implementation of technical concerns until now leave room for "the human adventure."

André Borschberg and Bertrand Piccard enthusiastically welcomed by the entire team of SolarImpulse

Last Wednesday, the prototype had to turn around mid-afternoon due to strong winds at high altitudes which were treading water. Solar Impulse is left at the end of May in Payerne (Switzerland) for its first intercontinental flight, before a world tour planned for 2014. The aircraft designed to fly day and night without fuel or polluting emissions stopped in Madrid, then won Rabat on June 6

Back in stages

Return to Switzerland will also be staged in Rabat and Madrid, as in the first leg. Bertrand Piccard, who was flying the route Madrid-Rabat, should again fly the aircraft for flight-Ouarzazate Rabat Rabat or step-Madrid.

The carbon fiber aircraft is powered by four electric motors, a power of ten horsepower each, powered by 12,000 photocells covering its huge wing. Energy is stored during the day in batteries, allowing the aircraft to fly at night. The wingspan of an Airbus A340, it weighs only 1.6 tons, or the weight of an average car.

Seven years of work were needed to build the device. The project was launched in 2003.

For more information on SolarImpulse: http://solarimpulse.com/en/home/

Images, Video, Text, Credits: SolarImpulse / AFP / ATS /  Newsnet.

Best regards, Orbiter.ch

Mars Rocks












NASA - Mars Reconnaissance Orbiter (MRO) patch.

June 22, 2012


This enhanced-color image from March 2012 of a region of Mars near Nili Fossae shows part of the ejecta from an impact crater and contains some of the best exposures of ancient bedrock on Mars.

The impact broke up already diverse rocks types and mixed them together to create this wild jumble of colors, each representing a different type of rock.

This image was taken by the Mars Reconnaissance Orbiter's HiRISE camera.

Mars Reconnaissance Orbiter

For more information about Mars Reconnaissance Orbiter, visit: http://marsprogram.jpl.nasa.gov/mro/

Images, Text, Credit: NASA / JPL-Caltech/University of Arizona.

Greetings, Orbiter.ch

jeudi 21 juin 2012

NuSTAR Observatory Unfurls its Unique Mast








NASA - NuSTAR Mission patch.

June 21, 2012

NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, has successfully deployed its lengthy mast, giving it the ability to see the highest energy X-rays in our universe. The mission is one step closer to beginning its hunt for black holes hiding in our Milky Way and other galaxies.

"It's a real pleasure to know that the mast, an accomplished feat of engineering, is now in its final position," said Yunjin Kim, the NuSTAR project manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif. Kim was also the project manager for the Shuttle Radar Topography Mission, which flew a similar mast on the Space Shuttle Endeavor in 2000 and made topographic maps of Earth.

NuSTAR's mast is one of several innovations allowing the telescope to take crisp images of high-energy X-rays for the first time. It separates the telescope mirrors from the detectors, providing the distance needed to focus the X-rays. Built by ATK Aerospace Systems in Goleta, Calif., this is the first deployable mast ever used on a space telescope.

On June 21 at 10:43 a.m. PDT (1:43 p.m. EDT), nine days after launch, engineers at NuSTAR's mission control at UC Berkeley in California sent a signal to the spacecraft to start extending the 33-foot (10-meter) mast, a stable, rigid structure consisting of 56 cube-shaped units. Driven by a motor, the mast steadily inched out of a canister as each cube was assembled one by one. The process took about 26 minutes. Engineers and astronomers cheered seconds after they received word from the spacecraft that the mast was fully deployed and secure.


Image above: Artist's concept of NuSTAR on orbit. NuSTAR has a 10-m (30') mast that deploys after launch to separate the optics modules (right) from the detectors in the focal plane (left). Image credit: NASA/JPL-Caltech.

The NuSTAR team will now begin to verify the pointing and motion capabilities of the satellite, and fine-tune the alignment of the mast. In about five days, the team will instruct NuSTAR to take its "first light" pictures, which are used to calibrate the telescope.

Why did NuSTAR need such a long, arm-like structure? The answer has to do with the fact that X-rays behave differently than the visible light we see with our eyes. Sunlight easily reflects off surfaces, giving us the ability to see the world around us in color. X-rays, on the other hand, are not readily reflected: they either travel right through surfaces, as is the case with skin during medical X-rays, or they tend to be absorbed, by substances like your bone, for example. To focus X-rays onto the detectors at the back of a telescope, the light must hit mirrors at nearly parallel angles; if they were to hit head-on, they would be absorbed instead of reflected.

On NuSTAR, this is accomplished with two barrels of nested mirrors, each containing 133 shells, which reflect the X-rays to the back of the telescope. Because the reflecting angle is so shallow, the distance between the mirrors and the detectors is long. This is called the focal length, and it is maintained by NuSTAR's mast.

The fully extended mast is too large to launch in the lower-cost rockets required for relatively inexpensive Small Explorer class missions like NuSTAR. Instead NuSTAR launched on its Orbital Science Corporation's Pegasus rocket tucked inside a small canister. This rocket isn't as expensive as its bigger cousins because it launches from the air, with the help of a carrier plane, the L-1011 "Stargazer," also from Orbital.

NuSTAR is a Small Explorer mission led by the California Institute of Technology in Pasadena and managed by JPL for NASA's Science Mission Directorate in Washington. The spacecraft was built by Orbital Sciences Corporation, Dulles, Va. Its instrument was built by a consortium including Caltech; JPL; the University of California, Berkeley; Columbia University, New York; NASA's Goddard Space Flight Center, Greenbelt, Md.; the Danish Technical University in Denmark; Lawrence Livermore National Laboratory, Livermore, Calif.; and ATK Aerospace Systems, Goleta, Calif. NuSTAR will be operated by UC Berkeley, with the Italian Space Agency providing its equatorial ground station located at Malindi, Kenya. The mission's outreach program is based at Sonoma State University, Rohnert Park, Calif. NASA's Explorer Program is managed by Goddard. JPL is managed by Caltech for NASA.

For more information, visit http://www.nasa.gov/nustar and http://www.nustar.caltech.edu/

Image, Text, Credits: NASA / JPL-Caltech / Whitney Clavin.

Cheers, Orbiter.ch

mercredi 20 juin 2012

Researchers Estimate Ice Content of Crater at Moon's South Pole












NASA - Lunar Reconnaissance Orbiter (LRO) patch.

June 20, 2012

NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft has returned data that indicate ice may make up as much as 22 percent of the surface material in a crater located on the moon's south pole.

The team of NASA and university scientists using laser light from LRO's laser altimeter examined the floor of Shackleton crater. They found the crater's floor is brighter than those of other nearby craters, which is consistent with the presence of small amounts of ice. This information will help researchers understand crater formation and study other uncharted areas of the moon. The findings are published in Thursday's edition of the journal Nature.


Image above: Elevation (left) and shaded relief (right) image of Shackleton, a 21-km-diameter (12.5-mile-diameter) permanently shadowed crater adjacent to the lunar south pole. The structure of the crater's interior was revealed by a digital elevation model constructed from over 5 million elevation measurements from the Lunar Orbiter Laser Altimeter. Credit: NASA/Zuber, M.T. et al., Nature, 2012.

"The brightness measurements have been puzzling us since two summers ago," said Gregory Neumann of NASA's Goddard Space Flight Center in Greenbelt, Md., a co-author on the paper. "While the distribution of brightness was not exactly what we had expected, practically every measurement related to ice and other volatile compounds on the moon is surprising, given the cosmically cold temperatures inside its polar craters."

The spacecraft mapped Shackleton crater with unprecedented detail, using a laser to illuminate the crater's interior and measure its albedo or natural reflectance. The laser light measures to a depth comparable to its wavelength, or about a micron. That represents a millionth of a meter, or less than one ten-thousandth of an inch. The team also used the instrument to map the relief of the crater's terrain based on the time it took for laser light to bounce back from the moon's surface. The longer it took, the lower the terrain's elevation.

video

This visualization, created using Lunar Reconnaissance Orbiter laser altimeter data, offers a view of Shackleton Crater located in the south pole of the moon. Thanks to these measurements, we now have our best-yet maps of the crater's permanently-shadowed interior! Note: This video contains no audio. Credit: NASA/Goddard/Ernie Wright.

In addition to the possible evidence of ice, the group's map of Shackleton revealed a remarkably preserved crater that has remained relatively unscathed since its formation more than three billion years ago. The crater's floor is itself pocked with several small craters, which may have formed as part of the collision that created Shackleton.

The crater, named after the Antarctic explorer Ernest Shackleton, is two miles deep and more than 12 miles wide. Like several craters at the moon's south pole, the small tilt of the lunar spin axis means Shackleton crater's interior is permanently dark and therefore extremely cold.

"The crater's interior is extremely rugged," said Maria Zuber, the team's lead investigator from the Massachusetts Institute of Technology in Cambridge in Mass. "It would not be easy to crawl around in there."


Image above: This is an elevation map of Shackleton crater made using LRO Lunar Orbiter Laser Altimeter data. The false colors indicate height, with blue lowest and red/white highest. Credit: NASA/Zuber, M.T. et al., Nature, 2012.

While the crater's floor was relatively bright, Zuber and her colleagues observed that its walls were even brighter. The finding was at first puzzling. Scientists had thought that if ice were anywhere in a crater, it would be on the floor, where no direct sunlight penetrates. The upper walls of Shackleton crater are occasionally illuminated, which could evaporate any ice that accumulates. A theory offered by the team to explain the puzzle is that "moonquakes"-- seismic shaking brought on by meteorite impacts or gravitational tides from Earth -- may have caused Shackleton's walls to slough off older, darker soil, revealing newer, brighter soil underneath. Zuber's team's ultra-high-resolution map provides strong evidence for ice on both the crater's floor and walls.

"There may be multiple explanations for the observed brightness throughout the crater," said Zuber. "For example, newer material may be exposed along its walls, while ice may be mixed in with its floor."

The initial primary objective of LRO was to conduct investigations that prepare for future lunar exploration. Launched in June 2009, LRO completed its primary exploration mission and is now in its primary science mission. LRO was built and is managed by Goddard. This research was supported by NASA's Human Exploration and Operations Mission Directorate and Science Mission Directorate at the agency's headquarters in Washington.

video

Video made using LRO data showing the illumination of Shackleton crater, a 21-km-diameter (12.5 mile-diameter) structure situated adjacent to the Moon's south pole. The resolution is 30 meters (approximately 100 feet) per pixel. Frames are every hour from 01-Jun-2012 to 30-Jun-2012. Note: this video contains no audio. Credit: NASA/Zuber, M.T. et al., Nature, 2012.

For more information on LRO and the Lunar Orbiter Laser Altimeter, visit:
http://lunar.gsfc.nasa.gov

Images (mentioned), Videos (mentioned), Text, Credit: NASA's Goddard Space Flight Center / Bill Steigerwald.

Greetings, Orbiter.ch

'Like Salt Sprinkled on Black Velvet'











NASA - Hubble Space Telescope patch.

June 20, 2012


The NASA/ESA Hubble Space Telescope has captured this view of the dwarf galaxy UGC 5497, which looks a bit like salt sprinkled on black velvet in this image.

The object is a compact blue dwarf galaxy that is infused with newly formed clusters of stars. The bright, blue stars that arise in these clusters help to give the galaxy an overall bluish appearance that lasts for several million years until these fast-burning stars explode as supernovae.

UGC 5497 is considered part of the M 81 group of galaxies, which is located about 12 million light-years away in the constellation Ursa Major (The Great Bear). UGC 5497 turned up in a ground-based telescope survey back in 2008 looking for new dwarf galaxy candidates associated with Messier 81.

For images and more information about Hubble Space Telescope, visit: http://hubblesite.org/ and  http://www.nasa.gov/hubble

Image, Text, Credits:  Credit: ESA / NASA.

Cheers, Orbiter.ch

LHC delivers more collisions than in the whole of 2011












CERN - European Organization for Nuclear Research logo.

June 20, 2012

 The ATLAS detector (Image: CERN)

The Large Hadron Collider (LHC) has already delivered more collisions to the ATLAS and CMS experiments this year than it did in the whole of 2011.

Last year, ATLAS and CMS each recorded a total of around 5.6 inverse femtobarns of data. This measure of accelerator performance is equivalent to about 560 trillion proton-proton collisions. The accelerator today passed last year's totals and is well on its way its goal of delivering 1500 trillion proton-proton collisions in 2012.

The LHC is now operating at 1380 proton bunches per beam, the maximum value set for this year, with around 1.5 × 1011 protons in each bunch. The accelerator has also far exceeded the best instantaneous collision rate achieved last year: the maximum peak luminosity in 2011 was 3.6 × 1033 collisions per square centimeter per second; the LHC has now reached 6.8 × 1033 cm-2 s-1.

The higher collision energy of 4 TeV per beam this year (compared to 3.5 TeV per beam in 2011) and the resulting higher number of collisions are expected to enhance the machine's discovery potential considerably, opening up new possibilities in the searches for new and heavier particles.

The Large Hadron Collider (LHC)

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 20 Member States.

Find out more:

    ATLAS: http://atlas.ch/

    CMS: http://cms.web.cern.ch/

    Large Hadron Collider (LHC): http://public.web.cern.ch/public/en/LHC/HowLHC-en.html

Images, Text, Credit: CERN.

Greetings, Orbiter.ch

VLT Takes a Close Look at NGC 6357












ESO - European Southern Observatory logo.

20 June 2012

 Close-up view of NGC 6357

ESO’s Very Large Telescope (VLT) has taken the most detailed image so far of a spectacular part of the stellar nursery called NGC 6357. The view shows many hot young stars, glowing clouds of gas and weird dust formations sculpted by ultraviolet radiation and stellar winds.

Deep in the Milky Way in the constellation of Scorpius (The Scorpion) lies NGC 6357 [1], a region of space where new stars are being born in of chaotic clouds of gas and dust [2]. The outer parts of this vast nebula have now been imaged by ESO’s Very Large Telescope, producing the best picture of this region taken so far [3].

The stellar nursery NGC 6357 in the constellation of Scorpius

The new picture shows a broad river of dust across the centre that absorbs the light from more distant objects. To the right there is a small cluster of brilliant blue-white young stars that have formed from the gas. These are probably only a few million years old, very young by stellar standards. The intense ultraviolet radiation streaming out from these stars is hollowing out a cavity in the surrounding gas and dust and sculpting it in strange ways.

Wide-field view of the area of NGC 6357

The whole image is covered with dark trails of cosmic dust, but some of the most fascinating dark features appear at the lower right and on the right hand edge of the picture. Here the radiation from the bright young stars has created curious elephant trunk columns, similar to the famous “pillars of creation” in the Eagle Nebula (opo9544a). Cosmic dust is much finer than the more familiar domestic variety. It more closely resembles smoke and consists mostly of tiny particles of silicates, graphite, and water ice that were produced and expelled into space by earlier generations of stars.

video
Zooming in on NGC 6357

The bright central part of NGC 6357 contains a cluster of high-mass stars whose inhabitants are among the brightest in our galaxy. This inner region, not seen in this new picture, has been much studied and imaged by the NASA/ESA Hubble Space Telescope (heic0619). But this new picture shows that even the less well known outer parts of this nursery contain fascinating structures that can be revealed by the power of the VLT.

video
Panning across the stellar nursery NGC 6357

This image was produced as part of the ESO Cosmic Gems programme [4].

Notes:

[1] This object also bears the curious name War and Peace Nebula, which has no link to Tolstoy’s great novel, but was given to this object by scientists working on the Midcourse Space Experiment. They noted that the bright, western part of the nebula resembled a dove, while the eastern part looked like a skull in their infrared images. Unfortunately this effect cannot be seen in the visible-light image presented here. The object is also occasionally nicknamed the Lobster Nebula.

[2] NGC 6357 was first recorded visually by John Herschel from South Africa in 1837. He only recorded the brightest central parts and the full scale of this huge nebula was only seen in photographs much later.

[3] The part of NGC 6357 shown in the new VLT image has not been targeted by the NASA/ESA Hubble Space Telescope.

[4] The ESO Cosmic Gems programme is an outreach initiative to produce images of interesting, intriguing or visually attractive objects using ESO telescopes, for the purposes of education and public outreach. The programme makes use of small amounts of observing time, combined with otherwise unused time on the telescopes’ schedules so as to minimise the impact on science observations. All data collected may also be suitable for scientific purposes, and are made available to astronomers through ESO’s science archive.

More information:

The year 2012 marks the 50th anniversary of the founding of the European Southern Observatory (ESO). ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive astronomical observatory. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 40-metre-class European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Links:

Photos of the VLT: http://www.eso.org/public/images/archive/search/?adv=&subject_name=Very%20Large%20Telescope

Other images taken with the VLT: http://www.eso.org/public/images/archive/search/?adv=&facility=31

Midcourse Space Experiment: http://en.wikipedia.org/wiki/Midcourse_Space_Experiment

ESO Cosmic Gems programme: http://www.eso.org/public/outreach/gems.html

Images, Text, Credits: ESO, IAU and Sky & Telescope/Davide De Martin (ESA/Hubble), the ESA/ESO/NASA Photoshop FITS Liberator & Digitized Sky Survey 2/Videos: ESO/Digitized Sky Survey 2/Nick Risinger (skysurvey.org). Music: Disasterpeace (http://disasterpeace.com/).

Best regards, Orbiter.ch

mardi 19 juin 2012

Most Quasars Live on Snacks, Not Large Meals














NASA - Spitzer Space Telescope patch / NASA / ESA - Hubble Space Telescope patch.

June 19, 2012

Black holes in the early universe needed a few snacks rather than one giant meal to fuel their quasars and help them grow, according to observations from NASA's Spitzer and Hubble space telescopes.

Quasars are the brilliant beacons of light that are powered by black holes feasting on captured material, and in the process, heating some of the matter to millions of degrees. The brightest quasars reside in galaxies distorted by collisions with other galaxies. These encounters send lots of gas and dust into the gravitational whirlpool of hungry black holes.

Now, however, astronomers are uncovering an underlying population of fainter quasars that thrive in normal-looking spiral galaxies. They are triggered by black holes snacking on such tasty treats as a batch of gas or the occasional small satellite galaxy.


Images above: The galaxies pictured here have so much dust surrounding them that the brilliant light from their quasars cannot be seen in these images NASA's Hubble Space Telescope. Image credit: NASA/ESA/Yale.

A census of 30 quasar host galaxies conducted with two of NASA's premier observatories, Hubble and Spitzer, has found that 26 of the host galaxies bear no telltale signs of collisions with neighbors, such as distorted shapes. Only one galaxy in the sample shows evidence of an interaction with another galaxy. The galaxies existed roughly 8 billion to 12 billion years ago, during a peak epoch of black-hole growth.

The study, led by Kevin Schawinski of Yale University, New Haven, Conn., bolsters evidence that the growth of most massive black holes in the early universe was fueled by small, long-term events rather than dramatic short-term major mergers.

"Quasars that are products of galaxy collisions are very bright," Schawinski said. "The objects we looked at in this study are the more typical quasars. They're a lot less luminous. The brilliant quasars born of galaxy mergers get all the attention because they are so bright and their host galaxies are so messed up. But the typical bread-and-butter quasars are actually where most of the black-hole growth is happening. They are the norm, and they don't need the drama of a collision to shine."

Schawinski's science paper has been accepted for publication in a letter to the Monthly Notices of the Royal Astronomical Society.

For his analysis, Schawinski analyzed galaxies observed by the Spitzer and Hubble telescopes in the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey. He chose 30 dust-enshrouded galaxies that appeared extremely bright in infrared images taken by the Spitzer telescope, a sign that their resident black holes are feasting on surrounding material. The dust is blocking the quasar's light at visible wavelengths. But infrared light pierces the dust, allowing Schawinski to study the galaxies' detailed structure. The masses of those galaxies are comparable to that of our Milky Way.

Schawinski then studied the galaxies in near-infrared images taken by Hubble's Wide Field Camera 3. Hubble's sharp images allowed careful analysis of galaxy shapes, which would be significantly distorted if major galaxy mergers had taken place and were disrupting the structure. Instead, in all but one instance, the galaxies show no such disruption.

Hubble Space Telescope. Image credit: NASA

Whatever process is stoking the quasars, it's below the detection capability of even Hubble. "I think it's a combination of processes, such as random stirring of gas, supernovae blasts, swallowing of small bodies, and streams of gas and stars feeding material into the nucleus," Schawinski said.

A black hole doesn't need much gas to satisfy its hunger and turn on a quasar. "There's more than enough gas within a few light-years from the center of our Milky Way to turn it into a quasar," Schawinski explained. "It just doesn't happen. But it could happen if one of those small clouds of gas ran into the black hole. Random motions and stirrings inside the galaxy would channel gas into the black hole. Ten billion years ago, those random motions were more common and there was more gas to go around. Small galaxies also were more abundant and were swallowed up by larger galaxies."

Artist view of the Spitzer Space Telescope. Image credit: NASA

The galaxies in Schawinski's study are prime targets for NASA's upcoming James Webb Space Telescope, a large infrared observatory scheduled to launch later this decade. "To get to the heart of what kinds of events are powering the quasars in these galaxies, we need the Webb telescope. Hubble and Spitzer have been the trailblazers for finding them."

The team of astronomers in this study consists of K. Schawinski, B.D. Simmons, C.M. Urry and E. Glikman (Yale University), and E. Treister (Universidad de Concepcion, Chile).

For images and more information about this study, visit http://hubblesite.org/news/2012/27 .

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA. For more information about Spitzer, visit http://spitzer.caltech.edu and http://www.nasa.gov/spitzer

Images (mentioned), Text, Credits: NASA / JPL / Whitney Clavin / STSI / Donna Weaver / Ray Villard.

Greetings, Orbiter.ch

Another Milestone for China's Space Program as Space Pod Docks With Orbital Lab










CNSA - China National Space Agency logo.

June 19, 2012

video

Video above: The Shenzhou-9 -- China's fourth manned space mission -- blasts off from the Jiuquan space base.

Chinese astronauts floated into an orbiting space lab Monday, another milestone for the country’s space program that puts it on par with Russia and the U.S. An automatically controlled docking maneuver connected the Tiangong-1 space lab with a manned Shenzhou space capsule early Monday morning U.S. time.


Image above: Taikonauts on the Tiangong A TV screen shot shows Chinese astronauts Jing Haipeng (right), Liu Wang (left) and Liu Yang entering the orbiting Tiangong-1 lab module on June 18.

Six days from now, the spacecraft will separate and the crew will re-dock, this time in manual mode instead of automatically. Two astronauts — known as taikonauts in China, and including China’s first female space voyager — will stay on the orbiting lab for the 13-day mission, while one will stay in the Shenzhou capsule for safety reasons.

Manned spacecraft docking with another object in space is something the U.S. first accomplished back in the Gemini program in the 1960s. But it’s worth noting that this is only China’s fourth manned spaceflight, and that its space program is not quite a decade old. China's space ambitions include building its own space station, which apparently has piqued the interest of U.S. defense officials.

video
Taikonauts reach Chinese space station

A manual docking will demonstrate China’s grasp of space rendezvous know-how, Chinese officials said. China launched the 8.5-ton space lab, named for “Heavenly Palace,” last September. An unmanned Shenzhou docked with it in November, testing procedures that led up to Monday’s manned docking. Eventually, it will serve as a component for a Chinese-built space station, which is planned to be complete by 2020.

 For more information about CNSA, visit: http://www.cnsa.gov.cn/n615709/cindex.html

Images, Videos, Text, Credits: AP / ImagineChina / CCTV / AlJazeera.

Cheers, Orbiter.ch

In the shadows of Saturn’s rings












ESA / NASA - Cassini Mission to Saturn & Titan patch.

19 June 2012

 In the shadows of Saturn’s rings

Titan appears to be strung like a bead on Saturn’s rings, which cast shadows onto the southern hemisphere of the gas giant in this beautiful image from Cassini.

Faint but exquisite detail in the gas giant’s upper atmosphere paints a tranquil scene. A thin band of bright white ammonia ice clouds is etched into the planet’s disc towards the top of the image while clouds dotted below are faded scars of a huge storm that raged across the planet through much of 2011.

Shadows cast by Saturn’s iconic rings appear painted onto the planet’s southern hemisphere in two thick bands broken by thin, lighter stripes, reflecting the intricacies of the individual rings.

As Saturn’s seasons progress towards northern hemisphere summer, the rings will appear to grow wider and wider.

Meanwhile Titan, Saturn’s largest moon, appears to hang on the planet’s rings like a bead on a necklace. The effect is a result of the line-of-sight viewing position; Titan orbits Saturn at an average distance of 1, 221, 870 km.

Cassini spacecraft

The moon is an enigma in itself – cloaked in a thick nitrogen-rich atmosphere, it is the only moon in the Solar System that has a dense atmosphere. Lakes of liquid hydrocarbons pool on its surface, and an active methane cycle plays a similar role to Earth’s water cycle, complete with clouds and methane rain.

Cassini has been in orbit around Saturn since 2004 and is now in its second extended mission phase, the Cassini Solstice Mission, which will continue until 2017. 

Links:

At Saturn and Titan: http://www.esa.int/SPECIALS/Cassini-Huygens/index.html

Cassini in depth: http://sci.esa.int/science-e/www/area/index.cfm?fareaid=12

Images, Text, Credits: ESA / NASA / JPL-Caltech / Space Science Institute / J. Major.

Greetings, Orbiter.ch

lundi 18 juin 2012

Data From NASA's Voyager 1 Point to Interstellar Future











NASA - Voyager 1 Mission patch.

June 18, 2012

Data from NASA's Voyager 1 spacecraft indicate that the venerable deep-space explorer has encountered a region in space where the intensity of charged particles from beyond our solar system has markedly increased. Voyager scientists looking at this rapid rise draw closer to an inevitable but historic conclusion – that humanity's first emissary to interstellar space is on the edge of our solar system.

"The laws of physics say that someday Voyager will become the first human-made object to enter interstellar space, but we still do not know exactly when that someday will be," said Ed Stone, Voyager project scientist at the California Institute of Technology in Pasadena. "The latest data indicate that we are clearly in a new region where things are changing more quickly. It is very exciting. We are approaching the solar system's frontier."


This artist's concept shows NASA's two Voyager spacecraft exploring a turbulent region of space known as the heliosheath, the outer shell of the bubble of charged particles around our sun. Image credit: NASA/JPL-Caltech.

The data making the 16-hour-38 minute, 11.1-billion-mile (17.8-billion-kilometer), journey from Voyager 1 to antennas of NASA's Deep Space Network on Earth detail the number of charged particles measured by the two High Energy telescopes aboard the 34-year-old spacecraft. These energetic particles were generated when stars in our cosmic neighborhood went supernova.

"From January 2009 to January 2012, there had been a gradual increase of about 25 percent in the amount of galactic cosmic rays Voyager was encountering," said Stone. "More recently, we have seen very rapid escalation in that part of the energy spectrum. Beginning on May 7, the cosmic ray hits have increased five percent in a week and nine percent in a month."

video
Voyager 1 at the Final Frontier

This marked increase is one of a triad of data sets which need to make significant swings of the needle to indicate a new era in space exploration. The second important measure from the spacecraft's two telescopes is the intensity of energetic particles generated inside the heliosphere, the bubble of charged particles the sun blows around itself. While there has been a slow decline in the measurements of these energetic particles, they have not dropped off precipitously, which could be expected when Voyager breaks through the solar boundary.

The final data set that Voyager scientists believe will reveal a major change is the measurement in the direction of the magnetic field lines surrounding the spacecraft. While Voyager is still within the heliosphere, these field lines run east-west. When it passes into interstellar space, the team expects Voyager will find that the magnetic field lines orient in a more north-south direction. Such analysis will take weeks, and the Voyager team is currently crunching the numbers of its latest data set.

Artist concept of NASA's Voyager spacecraft. Image credit: NASA/JPL-Caltech

"When the Voyagers launched in 1977, the space age was all of 20 years old," said Stone. "Many of us on the team dreamed of reaching interstellar space, but we really had no way of knowing how long a journey it would be -- or if these two vehicles that we invested so much time and energy in would operate long enough to reach it.”

Launched in 1977, Voyager 1 and 2 are in good health. Voyager 2 is more than 9.1 billion miles (14.7 billion kilometers) away from the sun. Both are operating as part of the Voyager Interstellar Mission, an extended mission to explore the solar system outside the neighborhood of the outer planets and beyond. NASA's Voyagers are the two most distant active representatives of humanity and its desire to explore.

The Voyager spacecraft were built by NASA's Jet Propulsion Laboratory in Pasadena, Calif., which continues to operate both. JPL is a division of the California Institute of Technology. The Voyager missions are a part of the NASA Heliophysics System Observatory, sponsored by the Heliophysics Division of the Science Mission Directorate in Washington.

More information about Voyager is available at: http://www.nasa.gov/voyager and http://voyager.jpl.nasa.gov

Images (mentioned), Video, Text, Credits: NASA / Dwayne Brown / JPL / DC Agle / NASA ScienceCasts.

Best regards, Orbiter.ch