vendredi 31 août 2012

A Surprisingly Bright Superbubble











NASA - Chandra X-ray Observatory patch.

August 31, 2012


This composite image shows a superbubble in the Large Magellanic Cloud (LMC), a small satellite galaxy of the Milky Way located about 160,000 light years from Earth. Many new stars, some of them very massive, are forming in the star cluster NGC 1929, which is embedded in the nebula N44, so named because it is the 44th nebula in a catalog of such objects in the Magellanic Clouds. The massive stars produce intense radiation, expel matter at high speeds, and race through their evolution to explode as supernovas. The winds and supernova shock waves carve out huge cavities called superbubbles in the surrounding gas. X-rays from NASA's Chandra X-ray Observatory (blue) show hot regions created by these winds and shocks, while infrared data from NASA's Spitzer Space Telescope (red) outline where the dust and cooler gas are found. The optical light from the 2.2-m Max-Planck-ESO telescope (yellow) in Chile shows where ultraviolet radiation from hot, young stars is causing gas in the nebula to glow.

A long-running problem in high-energy astrophysics has been that some superbubbles in the LMC, including N44, give off a lot more X-rays than expected from models of their structure. These models assume that hot, X-ray emitting gas has been produced by winds from massive stars and the remains of several supernovas. A Chandra study published in 2011 showed that there are two extra sources of N44’s X-ray emission not included in these models: supernova shock waves striking the walls of the cavities, and hot material evaporating from the cavity walls. The Chandra observations also show no evidence for an enhancement of elements heavier than hydrogen and helium in the cavities, thus ruling out this possibility as a third explanation for the bright X-ray emission. Only with long observations making full use of the capabilities of Chandra has it now become possible to distinguish between different sources of the X-rays produced by superbubbles.

Chandra X-ray Observatory

The Chandra study of N44 and another superbubble in the LMC was led by Anne Jaskot from the University of Michigan in Ann Arbor. The co-authors were Dave Strickland from Johns Hopkins University in Baltimore, MD, Sally Oey from University of Michigan, You-Hua Chu from University of Illinois and Guillermo Garcia-Segura from Instituto de Astronomia-UNAM in Ensenada, Mexico.

NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.

Read more/access all images: http://chandra.harvard.edu/photo/2012/n1929/

Chandra's Flickr photoset: http://www.flickr.com/photos/nasamarshall/sets/72157606205297786/

Images, Text, Credits: Credits: X-ray: NASA/CXC/U.Mich./S.Oey, IR: NASA/JPL, Optical: ESO/WFI/2.2-m.

Greetings, Orbiter.ch

jeudi 30 août 2012

The astronauts work outside the International Space Station












ISS - Expedition 32 Mission patch.

August 30, 2012

NASA Flight Engineer Sunita Williams and Japan Aerospace Exploration Agency Flight Engineer Akihiko Hoshide began the second spacewalk of the Expedition 32 mission at 8:16 a.m. EDT Thursday.

Expedition 32 Flight Engineers Sunita Williams and Akihiko Hoshide. Credit: NASA

Expedition 32 spacewalkers Sunita Williams and Akihiko Hoshide completed a 8 hour, 17 minute spacewalk on Thursday, the third longest spacewalk ever. After removing and stowing a failed power unit, the spacewalkers had difficulties driving the bolts to secure the replacement switching unit in the s-zero truss.

View graphics from the Aug. 14 spacewalk briefing: http://www.nasa.gov/mission_pages/station/expeditions/expedition32/eva_briefing_081412.html

Williams has conducted 4 previous spacewalks and is wearing a spacesuit bearing red stripes. Hoshide, wearing a spacesuit with no stripes, is conducting his first spacewalk. He is the third Japanese astronaut in history to conduct a spacewalk. The spacewalk is the 164th in support of station assembly and maintenance. This is the first U.S.-based spacewalk since July 2011.


Image above: Flight Engineer Akihiko Hoshide rides on the station's robotic arm. Credit: NASA TV.

Over the past couple of weeks, Williams and Hoshide completed a variety of tasks in anticipation of the spacewalk including resizing their U.S. extravehicular mobility unit spacesuits, conducting routine spacesuit maintenance, configuring spacewalk equipment and conducting a suited “dry run” check.

Expedition 32 spacewalkers Sunita Williams.  Credit: NASA TV

The first Expedition 32 spacewalk was performed by Commander Gennady Padalka and Flight Engineer Yuri Malenchenko on Aug. 20. The primary task during their 5-hour, 51-minute excursion was the move of the Strela-2 cargo boom from the Pirs docking compartment to the Zarya module. Other tasks included the installation of micrometeoroid debris shields on the exterior of the Zvezda service module and the deployment of a small science satellite.

video
‎"Astronauts in space: video" (EVA of 30.08.2012) In Russian

Read about more about the Aug. 20 spacewalk: http://www.nasa.gov/mission_pages/station/expeditions/expedition32/exp32_eva1.html

A camera on the International Space Station captured Hurricane Isaac on Aug. 29 as the orbital laboratory flew over the Texas and Gulf Coast area.

video
Hurricane Isaac

Read more about Expedition 32: http://www.nasa.gov/mission_pages/station/expeditions/expedition32/index.html

Expedition 32 Mission Summary (4.7 MB PDF): http://www.nasa.gov/pdf/668459main_exp32_summary.pdf

Images, Videos, Text, Credit: NASA / NASA TV / TV Roscosmos.

Greetings, Orbiter.ch

NASA's Dawn Prepares for Trek Toward Dwarf Planet












NASA - Dawn Mission patch.

August 31, 2012

video

A simulated flyover of the most intriguing landmarks on giant asteroid Vesta, as seen by NASA's Dawn spacecraft. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

NASA's Dawn spacecraft is on track to become the first probe to orbit and study two distant solar system destinations, to help scientists answer questions about the formation of our solar system. The spacecraft is scheduled to leave the giant asteroid Vesta on Sept. 4 PDT (Sept. 5 EDT) to start its two-and-a-half-year journey to the dwarf planet Ceres.

Dawn began its 3-billion-mile (5-billion kilometer) odyssey to explore the two most massive objects in the main asteroid belt in 2007. Dawn arrived at Vesta in July 2011 and will reach Ceres in early 2015. Dawn's targets represent two icons of the asteroid belt that have been witness to much of our solar system's history.

To make its escape from Vesta, the spacecraft will spiral away as gently as it arrived, using a special, hyper-efficient system called ion propulsion. Dawn's ion propulsion system uses electricity to ionize xenon to generate thrust. The 12-inch-wide ion thrusters provide less power than conventional engines, but can maintain thrust for months at a time.

"Thrust is engaged, and we are now climbing away from Vesta atop a blue-green pillar of xenon ions," said Marc Rayman, Dawn's chief engineer and mission director, at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We are feeling somewhat wistful about concluding a fantastically productive and exciting exploration of Vesta, but now have our sights set on dwarf planet Ceres.

Dawn's orbit provided close-up views of Vesta, revealing unprecedented detail about the giant asteroid. The mission revealed that Vesta completely melted in the past, forming a layered body with an iron core. The spacecraft also revealed the scarring from titanic collisions Vesta suffered in its southern hemisphere, surviving not one but two colossal impacts in the last two billion years. Without Dawn, scientists would not have known about the dramatic troughs sculpted around Vesta, which are ripples from the two south polar impacts.


This image of NASA's Dawn spacecraft and the giant asteroid Vesta is an artist's concept. Dawn arrived at Vesta on July 15, 2011 PDT (July 16, 2011 EDT) and is set to depart on Sept. 4, 2012 PDT (Sept. 5, 2012 EDT). Image credit: NASA/JPL-Caltech.

"We went to Vesta to fill in the blanks of our knowledge about the early history of our solar system," said Christopher Russell, Dawn's principal investigator, based at the University of California Los Angeles (UCLA). "Dawn has filled in those pages, and more, revealing to us how special Vesta is as a survivor from the earliest days of the solar system. We can now say with certainty that Vesta resembles a small planet more closely than a typical asteroid."

The mission to Vesta and Ceres is managed by NASA's Jet Propulsion Laboratory in Pasadena, Calif., for the agency's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, which is managed by NASA's Marshall Space Flight Center in Huntsville, Ala.

UCLA is responsible for the overall Dawn mission science. Orbital Sciences Corp. of Dulles, Va., designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are part of the mission's team. The California Institute of Technology in Pasadena manages JPL for NASA.

For more information about Dawn, visit: http://www.nasa.gov/dawn and http://dawn.jpl.nasa.gov .

Image (mentioned), Video (mentioned), Text, Credits: NASA / Dwayne Brown / JPL / Jia-Rui Cook.

Best regards, Orbiter.ch

Colorful Colossi and Changing Hues












NASA / ESA - Cassini Mission to Saturn patch.

August 30, 2012


A giant of a moon appears before a giant of a planet undergoing seasonal changes in this natural color view of Titan and Saturn from NASA's Cassini spacecraft.

Titan, Saturn's largest moon, measures 3,200 miles, or 5,150 kilometers, across and is larger than the planet Mercury. Cassini scientists have been watching the moon's south pole since a vortex appeared in its atmosphere in 2012. See PIA14919 and PIA14920 to learn more about this mass of swirling gas around the pole in the atmosphere of the moon.

As the seasons have changed in the Saturnian system, and spring has come to the north and autumn to the south, the azure blue in the northern Saturnian hemisphere that greeted Cassini upon its arrival in 2004 is now fading. The southern hemisphere, in its approach to winter, is taking on a bluish hue. This change is likely due to the reduced intensity of ultraviolet light and the haze it produces in the hemisphere approaching winter, and the increasing intensity of ultraviolet light and haze production in the hemisphere approaching summer. (The presence of the ring shadow in the winter hemisphere enhances this effect.) The reduction of haze and the consequent clearing of the atmosphere makes for a bluish hue: the increased opportunity for direct scattering of sunlight by the molecules in the air makes the sky blue, as on Earth. The presence of methane, which generally absorbs in the red part of the spectrum, in a now clearer atmosphere also enhances the blue.

This view looks toward the northern, sunlit side of the rings from just above the ring plane.

This mosaic combines six images -- two each of red, green and blue spectral filters -- to create this natural color view. The images were obtained with the Cassini spacecraft wide-angle camera on May 6, 2012, at a distance of approximately 483,000 miles (778,000 kilometers) from Titan. Image scale is 29 miles (46 kilometers) per pixel on Titan.

Cassini spacecraft

The Cassini-Huygens mission is a cooperative project of NASA, 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, D.C. 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, Colo.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov. The Cassini imaging team homepage is at http://ciclops.org and http://www.esa.int/esaMI/Cassini-Huygens/

Images, Text, Credits:  Credit: NASA / ESA  / JPL-Caltech / SSI.

Greetings, Orbiter.ch

NASA Launches Radiation Belt Storm Probes Mission









NASA - Radiation Belt Storm Probes (RBSP) logo.

Aug. 30, 2012

NASA's Radiation Belt Storm Probes (RBSP), the first twin-spacecraft mission designed to explore our planet's radiation belts, launched into the predawn skies at 4:05a.m. EDT Thursday from Cape Canaveral Air Force Station, Fla.

video
Launch of RBSP

Video above: The RBSP mission begins with a thundering liftoff from SLC-41 at Cape Canaveral AFS on Aug. 30, 2012.

"Scientists will learn in unprecedented detail how the radiation belts are populated with charged particles, what causes them to change and how these processes affect the upper reaches of the atmosphere around Earth," said John Grunsfeld, associate administrator for NASA's Science Mission Directorate at Headquarters in Washington. "The information collected from these probes will benefit the public by allowing us to better protect our satellites and understand how space weather affects communications and technology on Earth."


Image above: A United Launch Alliance Atlas V rocket blasts off from Space Launch Complex-41 at 4:05 a.m. EDT with NASA's twin Radiation Belt Storm Probes mission. Credit: NASA TV.

The two satellites, each weighing just less than 1,500 pounds, comprise the first dual-spacecraft mission specifically created to investigate this hazardous regions of near-Earth space, known as the radiation belts. These two belts, named for their discoverer, James Van Allen, encircle the planet and are filled with highly charged particles. The belts are affected by solar storms and coronal mass ejections and sometimes swell dramatically. When this occurs, they can pose dangers to communications, GPS satellites and human spaceflight.

"We have never before sent such comprehensive and high-quality instruments to study high radiation regions of space," said Barry Mauk, RBSP project scientist at the Johns Hopkins University's Applied Physics Laboratory (APL) in Laurel, Md. "RBSP was crafted to help us learn more about, and ultimately predict, the response of the radiation belts to solar inputs."

The hardy RBSP satellites will spend the next 2 years looping through every part of both Van Allen belts. By having two spacecraft in different regions of the belts at the same time, scientists finally will be able to gather data from within the belts themselves, learning how they change over space and time. Designers fortified RBSP with special protective plating and rugged electronics to operate and survive within this punishing region of space that other spacecraft avoid. In addition, a space weather broadcast will transmit selected data from those instruments around the clock, giving researchers a check on current conditions near Earth.


An artist's rendition of what the two Radiation Belt Storm Probe spacecraft will look like in space. Credit: NASA/Goddard Space Flight Center.

"The excitement of seeing the spacecraft in orbit and beginning to perform science measurements is like no other thrill," said Richard Fitzgerald, RBSP project manager at APL. "The entire RBSP team, from across every organization, worked together to produce an amazing pair of spacecraft."

RBSP was lifted into orbit aboard an Atlas V 401 rocket from Space Launch Complex-41, as the rocket's plume lit the dark skies over the Florida coast. The first RBSP spacecraft is scheduled to separate from the Atlas rocket's Centaur booster 1 hour, 18 minutes, 52 seconds after launch. The second RBSP spacecraft is set to follow 12 minutes, 14 seconds later. Mission controllers using APL's 60-foot satellite dish will establish radio contact with each probe immediately after separation.

video
 RBSP Twin Probes Reach Space
 
Video above: The spacecraft have successfully separated from the Centaur upper stage.

During the next 60 days, operators will power up all flight systems and science instruments and deploy long antenna booms, two of which are more than 54 yards long. Data about the particles that swirl through the belts, and the fields and waves that transport them, will be gathered by five instrument suites designed and operated by teams at the New Jersey Institute of Technology in Newark; the University of Iowa in Iowa City; University of Minnesota in Minneapolis; and the University of New Hampshire in Durham; and the National Reconnaissance Office in Chantilly, Va. The data will be analyzed by scientists across the nation almost immediately.

The Electric Atmosphere: Plasma Is Next NASA Science Target


Two giant donuts of charged particles called the Van Allen Belts surround Earth. Credit: NASA/T. Benesch, J. Carns.

Image above: Two giant donuts of this plasma surround Earth, trapped within a region known as the Van Allen Radiation Belts. The belts lie close to Earth, sandwiched between satellites in geostationary orbit above and satellites in low Earth orbit (LEO) are generally below the belts. A new NASA mission called the Radiation Belt Storm Probes (RBSP), due to launch in August 2012, will improve our understanding of what makes plasma move in and out of these electrified belts wrapped around our planet.


Image above: Radiation Belt Storm Probes to study the Van Allen Belt. Credit: NASA/Goddard Space Flight Center.

RBSP is the second mission in NASA's Living With a Star (LWS) program to explore aspects of the connected sun-Earth system that directly affect life and society. LWS is managed by the agency's Goddard Space Flight Center in Greenbelt, Md. APL built the RBSP spacecraft and will manage the mission for NASA. NASA's Launch Services Program at Kennedy is responsible for launch management. United Launch Alliance provided the Atlas V launch service.

For more information about NASA's RBSP mission, visit: http://www.nasa.gov/rbsp

Images (mentioned), Videos, Text, Credit: NASA / NASA TV.

Cheers, Orbiter.ch

mercredi 29 août 2012

NASA Curiosity Rover Begins Eastbound Trek on Martian Surface












NASA - Mars Science Laboratory (MSL) patch.

Aug. 29, 2012

NASA's Mars rover Curiosity has set off from its landing vicinity on a trek to a science destination about a quarter-mile (400 meters) away, where it may begin using its drill.


Image above: Soil clinging to the right middle and rear wheels of NASA's Mars rover Curiosity can be seen in this image taken by the Curiosity's Navigation Camera after the rover's third drive on Mars. Image credit: NASA/JPL-Caltech.

The rover drove eastward about 52 feet (16 meters) on Tuesday, its 22nd Martian day after landing. This third drive was longer than Curiosity's first two drives combined. The previous drives tested the mobility system and positioned the rover to examine an area scoured by exhaust from one of the Mars Science Laboratory spacecraft engines that placed the rover on the ground.

"This drive really begins our journey toward the first major driving destination, Glenelg, and it's nice to see some Martian soil on our wheels," said mission manager Arthur Amador of NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif. "The drive went beautifully, just as our rover planners designed it."

Glenelg is a location where three types of terrain intersect. Curiosity's science team chose it as a likely place to find a first rock target for drilling and analysis.

"We are on our way, though Glenelg is still many weeks away," said Curiosity Project Scientist John Grotzinger of the California Institute of Technology (Caltech) in Pasadena. "We plan to stop for just a day at the location we just reached, but in the next week or so we will make a longer stop."


Image above: On Aug. 28, 2012, during the 22nd Martian day, or sol, after landing on Mars, NASA's Curiosity rover drove about 52 feet (16 meters) eastward, the longest drive of the mission so far. Image credit: NASA/JPL-Caltech.

During the longer stop at a site still to be determined, Curiosity will test its robotic arm and the contact instruments at the end of the arm. At the location reached Tuesday, Curiosity's Mast Camera (Mastcam) will collect a set of images toward the mission's ultimate driving destination, the lower slope of nearby Mount Sharp. A mosaic of images from the current location will be used along with the Mastcam images of the mountain taken at the spot where Curiosity touched down, Bradbury Landing. This stereo pair taken about 33 feet (10 meters) apart will provide three-dimensional information about distant features and possible driving routes.

Mars Science Laboratory (MSL). Image credit: NASA/JPL-Caltech

Curiosity is three weeks into a two-year prime mission on Mars. It will use 10 science instruments to assess whether the selected study area ever has offered environmental conditions favorable for microbial life. JPL, a division of Caltech, manages the mission for NASA's Science Mission Directorate in Washington.

More information about Curiosity is online at: http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl

You can follow the mission on Facebook and on Twitter at: http://www.facebook.com/marscuriosity and http://www.twitter.com/marscuriosity

Images (mentioned), Text, Credits: NASA / Dwayne Brown / JPL / Guy Webster / D.C. Agle.

Greetings, Orbiter.ch

NASA's WISE Survey Uncovers Millions of Black Holes









NASA - WISE Mission patch.

August 29. 2012


Image above: With its all-sky infrared survey, NASA's Wide-field Infrared Survey Explorer, or WISE, has identified millions of quasar candidates. Image credit: NASA/JPL-Caltech/UCLA.

NASA's Wide-field Infrared Survey Explorer (WISE) mission has led to a bonanza of newfound supermassive black holes and extreme galaxies called hot DOGs, or dust-obscured galaxies.

Images from the telescope have revealed millions of dusty black hole candidates across the universe and about 1,000 even dustier objects thought to be among the brightest galaxies ever found. These powerful galaxies, which burn brightly with infrared light, are nicknamed hot DOGs.


This zoomed-in view of a portion of the all-sky survey from WISE shows a collection of quasar candidates. Image credit: NASA/JPL-Caltech/UCLA/STScI.

"WISE has exposed a menagerie of hidden objects," said Hashima Hasan, WISE program scientist at NASA Headquarters in Washington. "We've found an asteroid dancing ahead of Earth in its orbit, the coldest star-like orbs known and now, supermassive black holes and galaxies hiding behind cloaks of dust."

WISE scanned the whole sky twice in infrared light, completing its survey in early 2011. Like night-vision goggles probing the dark, the telescope captured millions of images of the sky. All the data from the mission have been released publicly, allowing astronomers to dig in and make new discoveries.


Image above: WISE has identified about 1,000 extremely obscured objects over the sky, as marked by the magenta symbols. Image credit: NASA/JPL-Caltech/UCLA.

The latest findings are helping astronomers better understand how galaxies and the behemoth black holes at their centers grow and evolve together. For example, the giant black hole at the center of our Milky Way galaxy, called Sagittarius A*, has 4 million times the mass of our sun and has gone through periodic feeding frenzies where material falls towards the black hole, heats up and irradiates its surroundings. Bigger central black holes, up to a billion times the mass of our sun, may even shut down star formation in galaxies.


Artist's concept of a dusty torus, or donut, of accreting material fueling a quasar. A quasar is an active supermassive black hole. Image credit: NASA/ESA.

In one study, astronomers used WISE to identify about 2.5 million actively feeding supermassive black holes across the full sky, stretching back to distances more than 10 billion light-years away. About two-thirds of these objects never had been detected before because dust blocks their visible light. WISE easily sees these monsters because their powerful, accreting black holes warm the dust, causing it to glow in infrared light.


This image is a portion of the all-sky survey from WISE. It highlights the first of about 1,000 "hot DOGs" found by the mission (magenta circle). Image credit: NASA/JPL-Caltech/UCLA.

"We've got the black holes cornered," said Daniel Stern of NASA's Jet Propulsion Laboratory, Pasadena, Calif., lead author of the WISE black hole study and project scientist for another NASA black-hole mission, the Nuclear Spectroscopic Telescope Array (NuSTAR). "WISE is finding them across the full sky, while NuSTAR is giving us an entirely new look at their high-energy X-ray light and learning what makes them tick."

In two other WISE papers, researchers report finding what are among the brightest galaxies known, one of the main goals of the mission. So far, they have identified about 1,000 candidates.


This plot illustrates the new population of "hot DOGs," or hot dust-obscured objects, found by WISE. Image credit: NASA/JPL-Caltech/UCLA.

These extreme objects can pour out more than 100 trillion times as much light as our sun. They are so dusty, however, that they appear only in the longest wavelengths of infrared light captured by WISE. NASA's Spitzer Space Telescope followed up on the discoveries in more detail and helped show that, in addition to hosting supermassive black holes feverishly snacking on gas and dust, these DOGs are busy churning out new stars.

video
Starry Night Tango

This simulation, which represents a few billion years of evolution, shows two disk galaxies interacting in a graceful gravitational dance. Video courtesy Volker Springel, Heidelberg University, Germany.

"These dusty, cataclysmically forming galaxies are so rare WISE had to scan the entire sky to find them," said Peter Eisenhardt, lead author of the paper on the first of these bright, dusty galaxies, and project scientist for WISE at JPL. "We are also seeing evidence that these record setters may have formed their black holes before the bulk of their stars. The 'eggs' may have come before the 'chickens.'"

More than 100 of these objects, located about 10 billion light-years away, have been confirmed using the W.M. Keck Observatory on Mauna Kea, Hawaii, as well as the Gemini Observatory in Chile, Palomar's 200-inch Hale telescope near San Diego, and the Multiple Mirror Telescope Observatory near Tucson, Ariz.

A WISE 'Eye' on the Whole Sky

Image above: The entire sky as mapped by WISE at infrared wavelengths is shown here, with an artist's concept of the WISE satellite superimposed. Image credit: NASA/JPL-Caltech/UCLA.

The WISE observations, combined with data at even longer infrared wavelengths from Caltech's Submillimeter Observatory atop Mauna Kea, revealed that these extreme galaxies are more than twice as hot as other infrared-bright galaxies. One theory is their dust is being heated by an extremely powerful burst of activity from the supermassive black hole.

"We may be seeing a new, rare phase in the evolution of galaxies," said Jingwen Wu of JPL, lead author of the study on the submillimeter observations. All three papers are being published in the Astrophysical Journal.


WISE images of our neighboring spiral galaxy, Andromeda (left) and the central region of a nearby cluster of elliptical galaxies, the Fornax cluster (right). NASA/JPL-Caltech/UCLA.

The three technical journal articles, including PDFs, can be found at http://arxiv.org/abs/1205.0811, http://arxiv.org/abs/1208.5517 and http://arxiv.org/abs/1208.5518 .

JPL manages and operates WISE for NASA's Science Mission Directorate, Washington. The principal investigator, Edward Wright, is at UCLA. The mission was competitively selected under NASA's Explorers Program managed by the Goddard Space Flight Center, Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory, Logan, Utah, and the spacecraft was built by Ball Aerospace & Technologies Corp., Boulder, Colo. Science operations and data processing and archiving take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

More information is online at http://www.nasa.gov/wise, http://wise.astro.ucla.edu and http://jpl.nasa.gov/wise .

Images (mentioned), Video (mentioned), Text, Credits: NASA / JPL / Whitney Clavin.

Best regards, Orbiter.ch

Testing begins for CERN's future linear accelerator












CERN - European Organization for Nuclear Research logo.

29 August 2012


Image above: The radiofrequency quadrupole module for linear accelerator 4 arrives at CERN for testing (Image: CERN).

During the LHC's long shutdown – scheduled to start on 10 February 2013 – a new linear accelerator, Linac4, will replace the existing Linac2 as the first link in CERN’s accelerator chain. It will deliver particles to the Proton-Synchrotron Booster at 160 MeV, more than triple the energy currently delivered by Linac2.

RFQ module is unloaded to its installation in the test line Linac4

First tests for the upcoming accelerator are underway, starting with the CERN-built radiofrequency quadrupole – a section of the accelerator that focuses, bunches and accelerates a continuous beam of charged particles within an electromagnetic field.

“It’s an extremely impressive module," says project coordinator Carlo Rossi. "Measuring just 3 metres in length, it can take the beam from 45keV up to 3MeV – just the right energy for injection into a typical accelerator.”

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:

CERN Bulletin: " Testing begins on Linac4": http://cdsweb.cern.ch/journal/CERNBulletin/2012/35/News%20Articles/1474081?ln=en

For more information about CERN, visit: http://public.web.cern.ch/public/Welcome.html

Images, Text, Credit: CERN.

Greetings, Orbiter.ch

Building blocks of life found around young star












ESO - European Southern Observatory logo.

29 August 2012

Sweet Result from ALMA

Sugar molecules in the gas surrounding a young Sun-like star

A team of astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) has spotted sugar molecules in the gas surrounding a young Sun-like star. This is the first time sugar been found in space around such a star, and the discovery shows that the building blocks of life are in the right place, at the right time, to be included in planets forming around the star.

The astronomers found molecules of glycolaldehyde — a simple form of sugar [1] — in the gas surrounding a young binary star, with similar mass to the Sun, called IRAS 16293-2422. Glycolaldehyde has been seen in interstellar space before [2], but this is the first time it has been found so near to a Sun-like star, at distances comparable to the distance of Uranus from the Sun in the Solar System. This discovery shows that some of the chemical compounds needed for life existed in this system at the time of planet formation [3].

“In the disc of gas and dust surrounding this newly formed star, we found glycolaldehyde, which is a simple form of sugar, not much different to the sugar we put in coffee,” explains Jes Jørgensen (Niels Bohr Institute, Denmark), the lead author of the paper. “This molecule is one of the ingredients in the formation of RNA, which — like DNA, to which it is related — is one of the building blocks of life.”

Artist’s impression of glycolaldehyde molecules

The high sensitivity of ALMA — even at the technically challenging shortest wavelengths at which it operates — was critical for these observations, which were made with a partial array of antennas during the observatory’s Science Verification phase [4].

“What it is really exciting about our findings is that the ALMA observations reveal that the sugar molecules are falling in towards one of the stars of the system,” says team member Cécile Favre (Aarhus University, Denmark). “The sugar molecules are not only in the right place to find their way onto a planet, but they are also going in the right direction.”

The gas and dust clouds that collapse to form new stars are extremely cold [5] and many gases solidify as ice on the particles of dust where they then bond together and form more complex molecules. But once a star has been formed in the middle of a rotating cloud of gas and dust, it heats the inner parts of the cloud to around room temperature, evaporating the chemically complex molecules, and forming gases that emit their characteristic radiation as radio waves that can be mapped using powerful radio telescopes such as ALMA.

Infrared view of the Rho Ophiuchi star-forming region

IRAS 16293-2422 is located around 400 light-years away, comparatively close to Earth, which makes it an excellent target for astronomers studying the molecules and chemistry around young stars. By harnessing the power of a new generation of telescopes such as ALMA, astronomers now have the opportunity to study fine details within the gas and dust clouds that are forming planetary systems.

"A big question is: how complex can these molecules become before they are incorporated into new planets? This could tell us something about how life might arise elsewhere, and ALMA observations are going to be vital to unravel this mystery,” concludes Jes Jørgensen.

IRAS 16293-2422 in the constellation of Ophiuchus

The work is described in a paper to appear in the journal Astrophysical Journal Letters.

video
Sugar molecules in the gas surrounding a young Sun-like star (zoom)

This video starts with a broad panorama of the spectacular central regions of the Milky Way seen in visible light. It then zooms in to the Rho Ophiuchi star-forming region in infrared light, highlighting IRAS 16293-2422. Finally, we see an artist's impression of glycolaldehyde molecules, showing glycolaldehyde's molecular structure (C2H4O2).

video
 Artist’s impression of glycolaldehyde molecules

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Southern Observatory (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

Notes:

[1] Sugar is the common name for a range of small carbohydrates (molecules containing carbon, hydrogen and oxygen, typically with a hydrogen:oxygen atomic ratio of 2:1, as in water). Glycolaldehyde has the chemical formula C2H4O2. The sugar commonly used in food and drink is sucrose, which is a larger molecule than glycolaldehyde, and another example of this set of compounds.

[2] Glycolaldehyde has been detected in two places in space so far — first towards the Galactic Centre cloud Sgr B2, using the National Science Foundation's (NSF) 12 Meter Telescope at Kitt Peak (USA) in 2000, and with the NSF's Robert C. Byrd Green Bank Telescope (also USA) in 2004, and in the high-mass hot molecular core G31.41+0.31 using the IRAM Plateau de Bure Interferometer (France) in 2008.

[3] Accurate laboratory measurements of the characteristic wavelengths of radio waves emitted by glycolaldehyde were critical for the team’s identification of the molecule in space. In addition to the glycolaldehyde, IRAS 16293-2422 is also known to harbour a number of other complex organic molecules, including ethylene glycol, methyl formate and ethanol.

[4] Early scientific observations with a partial array of antennas began in 2011 (see eso1137). Both before and after this, a range of Science Verification observations have been performed to demonstrate that ALMA is capable of producing data of the required quality, and the data produced have been made publicly available. The results described here use some of these Science Verification data. Construction of ALMA will be completed in 2013, when 66 high-precision antennas will be fully operational.

[5] They are usually around 10 degrees above absolute zero: about –263 degrees Celsius.

More information:

This research was presented in a paper “Detection of the simplest sugar, glycolaldehyde, in a solar-type protostar with ALMA”, by Jørgensen et al., to appear in Astrophysical Journal Letters.

The team is composed of Jes K. Jørgensen (University of Copenhagen, Denmark), Cécile Favre (Aarhus University, Denmark), Suzanne E. Bisschop (University of Copenhagen), Tyler L. Bourke (Harvard-Smithsonian Center for Astrophysics, Cambridge, USA), Ewine F. van Dishoeck (Leiden Observatory, The Netherlands; Max-Planck-Institut für extraterrestrische Physik, Garching, Germany) and Markus Schmalzl (Leiden Observatory).

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 ground-based astronomical observatory by far. 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:

    Research paper: http://www.eso.org/public/archives/releases/sciencepapers/eso1234/eso1234a.pdf

    More about ALMA at ESO: http://www.eso.org/public/teles-instr/alma.html

    The Joint ALMA Observatory: http://www.almaobservatory.org/

Credits:

Images: ESO / ALMA (ESO / NAOJ / NRAO) / L. Calçada (ESO) / IAU and Sky & Telescope / NASA / JPL-Caltech / WISE Team / Videos: ALMA (ESO/NAOJ/NRAO) / Nick Risinger (skysurvey.org) / S. Guisard (www.eso.org/~sguisard) / L. Calçada (ESO) & NASA / JPL-Caltech / WISE Team / Music: Disasterpeace.

Text: ESO / Douglas Pierce-Price / Leiden Observatory / Ewine van Dishoeck / Niels Bohr Institute, University of Copenhagen / Jes K. Jørgensen.

Greetings, Orbiter.ch

NASA's Kepler Discovers Multiple Planets Orbiting a Pair of Stars












NASA - Kepler Mission patch.

August 29, 2012

Coming less than a year after the announcement of the first circumbinary planet, Kepler-16b, NASA's Kepler mission has discovered multiple transiting planets orbiting two suns for the first time. This system, known as a circumbinary planetary system, is 4,900 light-years from Earth in the constellation Cygnus.

This discovery proves that more than one planet can form and persist in the stressful realm of a binary star and demonstrates the diversity of planetary systems in our galaxy.


Image above: Sharing the Light of Two Suns: This artist's concept illustrates Kepler-47, the first transiting circumbinary system. Credit: NASA/JPL-Caltech/T. Pyle.

Astronomers detected two planets in the Kepler-47 system, a pair of orbiting stars that eclipse each other every 7.5 days from our vantage point on Earth. One star is similar to the sun in size, but only 84 percent as bright. The second star is diminutive, measuring only one-third the size of the sun and less than 1 percent as bright.

"In contrast to a single planet orbiting a single star, the planet in a circumbinary system must transit a 'moving target.' As a consequence, time intervals between the transits and their durations can vary substantially, sometimes short, other times long," said Jerome Orosz, associate professor of astronomy at San Diego State University and lead author of the paper. "The intervals were the telltale sign these planets are in circumbinary orbits."


Graphic above: Orbiting in the Habitable Zone of Two Suns: This diagram compares our own solar system to Kepler-47, a double-star system containing two planets, one orbiting in the so-called "habitable zone." Credit: NASA/JPL-Caltech/T. Pyle.

The inner planet, Kepler-47b, orbits the pair of stars in less than 50 days. While it cannot be directly viewed, it is thought to be a sweltering world, where the destruction of methane in its super-heated atmosphere might lead to a thick haze that could blanket the planet. At three times the radius of Earth, Kepler-47b is the smallest known transiting circumbinary planet.

The outer planet, Kepler-47c, orbits its host pair every 303 days, placing it in the so-called "habitable zone," the region in a planetary system where liquid water might exist on the surface of a planet. While not a world hospitable for life, Kepler-47c is thought to be a gaseous giant slightly larger than Neptune, where an atmosphere of thick bright water-vapor clouds might exist.


Image above: The planets Kepler-47b and Kepler-47c: Kepler-47b has three times the radius of earth and orbits the pair of stars in less than 50 days while Kepler-47c is thought to be a gaseous giant, slightly larger than Neptune with an orbital period of 303 days. Credit: NASA/JPL-Caltech/T. Pyle.

"Unlike our sun, many stars are part of multiple-star systems where two or more stars orbit one another. The question always has been -- do they have planets and planetary systems? This Kepler discovery proves that they do," said William Borucki, Kepler mission principal investigator at NASA's Ames Research Center in Moffett Field, Calif. "In our search for habitable planets, we have found more opportunities for life to exist."

To search for transiting planets, the research team used data from the Kepler space telescope, which measures dips in the brightness of more than 150,000 stars. Additional ground-based spectroscopic observations using telescopes at the McDonald Observatory at the University of Texas at Austin helped characterize the stellar properties. The findings are published in the journal Science.

video

Video above: NASA's Kepler Mission Discovers Multiple Planets Orbiting Twin Suns. Credit: NASA/JPL-Caltech/T. Pyle.

"The presence of a full-fledged circumbinary planetary system orbiting Kepler-47 is an amazing discovery," said Greg Laughlin, professor of Astrophysics and Planetary Science at the University of California in Santa Cruz. "These planets are very difficult to form using the currently accepted paradigm, and I believe that theorists, myself included, will be going back to the drawing board to try to improve our understanding of how planets are assembled in dusty circumbinary disks."

Ames manages Kepler's ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, Calif., managed the Kepler mission development.

Ball Aerospace & Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder.

The Space Telescope Science Institute in Baltimore archives, hosts and distributes Kepler science data. Kepler is NASA's tenth Discovery Mission and funded by NASA's Science Mission Directorate at the agency's headquarters in Washington.

For more information about Kepler mission, visit: http://www.nasa.gov/mission_pages/kepler/main/index.html

Images (mentioned), Video (mentioned), Text, Credits: NASA / J.D. Harrington / Ames Research Center / Michele Johnson.

Best regards, Orbiter.ch

mardi 28 août 2012

Proba-2’s espresso-cup microcamera snaps Hurricane Isaac







ESA - Proba-2 Mission logo.

28 August 2012

 X-Cam image of Tropical Storm Isaac

An experimental camera smaller than an espresso cup on ESA’s Proba-2 microsatellite caught this view of soon-to-be Hurricane Isaac as it moved west of the Florida coast into the Gulf of Mexico on Monday.

The small satellite’s X-Cam – Exploration Camera – acquired this image at 11:38:33 GMT on 27 August.

At the time, Isaac was a tropical storm with maximum sustained winds of around 100 km/hr, with storm-force winds extending around 360 km from its centre.

Isaac is expected to become a fully fledged hurricane during Tuesday, fed by the warm waters of the Gulf of Mexico. 

Proba-2's small X-Cam

Less than a cubic metre in size, Proba-2’s main mission focuses on observing the Sun and space weather.

Observing in the visible and near-infrared with a 100º field of view, the monochrome X-Cam is housed on the underside of the microsatellite, one of 17 new technologies being demonstrated by Proba-2.

The instrument was designed by Swiss company Micro-Cameras & Space Exploration, the latest in a series of miniature cameras built by the company for ESA missions such as Proba-2 and SMART-1.

Proba-2

One on Rosetta – now cruising through deep space – should provide us with the first views from the surface of a comet in 2014.

X-Cam comes with embedded intelligence to let it judge the best automatic exposures for optimal image quality.

In future, similar compact imagers could keep watch on satellite surfaces to look out for damage or environmental effects.

The first mission in the ‘Project for Onboard Autonomy’ family, Proba-1, was launched in 2001 and still going strong. Proba-2 was launched in 2009. Proba-V, to monitor global vegetation, is due for launch next year.

Related links:

Micro-Cameras and Space Exploration: http://www.microcameras.ch/

X-Cam on Proba-2: http://www.microcameras.ch/files/proba2.htm

Proba: http://www.esa.int/SPECIALS/Proba/index.html

Images, Text, Credits: ESA, Pierre Carril / Micro-Cameras & Space Exploration.

Cheers, Orbiter.ch

lundi 27 août 2012

NASA Rover Returns Voice, Telephoto Views From Mars












NASA - Mars Science Laboratory (MSL) patch.

August 27, 2012


A chapter of the layered geological history of Mars is laid bare in this postcard from NASA's Curiosity rover. The image shows the base of Mount Sharp, the rover's eventual science destination. Image credit: NASA/JPL-Caltech/MSSS.

NASA's Mars Curiosity has debuted the first recorded human voice that traveled from Earth to another planet and back.

In spoken words radioed to the rover on Mars and back to NASA's Deep Space Network (DSN) on Earth, NASA Administrator Charles Bolden noted the difficulty of landing a rover on Mars, congratulated NASA employees and the agency's commercial and government partners on the successful landing of Curiosity earlier this month, and said curiosity is what drives humans to explore.

Charles Bolden, 12th Administrator of NASA. Credit: NASA/Bill Ingalls

"The knowledge we hope to gain from our observation and analysis of Gale Crater will tell us much about the possibility of life on Mars as well as the past and future possibilities for our own planet. Curiosity will bring benefits to Earth and inspire a new generation of scientists and explorers, as it prepares the way for a human mission in the not too distant future," Bolden said in the recorded message.

The voice playback was released along with new telephoto camera views of the varied Martian landscape during a news conference today at NASA's Jet Propulsion Laboratory, Pasadena, Calif.

Watch video: http://www.nasa.gov/multimedia/videogallery/index.html?media_id=151243351

"With this voice, another small step is taken in extending human presence beyond Earth, and the experience of exploring remote worlds is brought a little closer to us all," said Dave Lavery, NASA Curiosity program executive. "As Curiosity continues its mission, we hope these words will be an inspiration to someone alive today who will become the first to stand upon the surface of Mars. And like the great Neil Armstrong, they will speak aloud of that next giant leap in human exploration."

The telephoto images beamed back to Earth show a scene of eroded knobs and gulches on a mountainside, with geological layering clearly exposed. The new views were taken by the 100-millimeter telephoto lens and the 34-milllimeter wide angle lens of the Mast Camera (Mastcam) instrument. Mastcam has photographed the lower slope of the nearby mountain called Mount Sharp.

"This is an area on Mount Sharp where Curiosity will go," said Mastcam principal investigator Michael Malin, of Malin Space Science Systems in San Diego. "Those layers are our ultimate objective. The dark dune field is between us and those layers. In front of the dark sand you see redder sand, with a different composition suggested by its different color. The rocks in the foreground show diversity -- some rounded, some angular, with different histories. This is a very rich geological site to look at and eventually to drive through."

A drive early Monday placed Curiosity directly over a patch where one of the spacecraft's landing engines scoured away a few inches of gravelly soil and exposed underlying rock. Researchers plan to use a neutron-shooting instrument on the rover to check for water molecules bound into minerals at this partially excavated target.

Curiosity's Sample Analysis at Mars.  Image credit: NASA/JPL-Caltech

During the news conference, the rover team reported the results of a test on Curiosity's Sample Analysis at Mars (SAM) instrument, which can measure the composition of samples of atmosphere, powdered rock or soil. The amount of air from Earth's atmosphere remaining in the instrument after Curiosity's launch was more than expected, so a difference in pressure on either side of tiny pumps led SAM operators to stop pumping out the remaining Earth air as a precaution. The pumps subsequently worked, and a chemical analysis was completed on a sample of Earth air.

"As a test of the instrument, the results are beautiful confirmation of the sensitivities for identifying the gases present," said SAM principal investigator Paul Mahaffy of NASA's Goddard Space Flight Center in Greenbelt, Md. "We're happy with this test and we're looking forward to the next run in a few days when we can get Mars data."

Curiosity already is returning more data from the Martian surface than have all of NASA's earlier rovers combined.

"We have an international network of telecommunications relay orbiters bringing data back from Curiosity," said JPL's Chad Edwards, chief telecommunications engineer for NASA's Mars Exploration Program. "Curiosity is boosting its data return by using a new capability for adjusting its transmission rate."

Curiosity is 3 weeks into a two-year prime mission on Mars. It will use 10 science instruments to assess whether the selected study area ever has offered environmental conditions favorable for microbial life.

Coronation's Chemicals


This is the first laser spectrum from the Chemistry and Camera (ChemCam) instrument on NASA's Curiosity rover, sent back from Mars on August 19, 2012. The plot shows emission lines from different elements present in the target, a rock near the rover's landing site dubbed "Coronation" (see inset).

ChemCam's detectors observe light in the ultraviolet (UV), violet, visible and near-infrared ranges using three spectrometers, covering wavelengths from 240 to 850 nanometers. The light is produced when ChemCam’s laser pulse strikes a target, generating ionized gases in the form of plasma, which is then analyzed by the spectrometers and their detectors for the presence of specific elements. The detectors can collect up to 16,000 counts produced by the light in any of its 6,144 channels for each laser shot.

The plot is a composite of spectra taken over 30 laser shots at a single 0.016-inch (0.4-millimeter) diameter spot on the target. An inset on the left shows detail for the minor elements titanium and manganese in the 398-to-404-nanometer range. An inset at the right shows the hydrogen and carbon peaks. The carbon peak was from the carbon dioxide in Mars' air. The hydrogen peak was only present on the first laser shot, indicating that the element was only on the very surface of the rock. Magnesium was also slightly enriched on the surface. The heights of the peaks do not directly indicate the relative abundances of the elements in the rock, as some emission lines are more easily excited than others.

A preliminarily analysis indicates the spectrum is consistent with basalt, a type of volcanic rock, which is known from previous missions to be abundant on Mars. Coronation is about three inches (7.6 centimeters) across, and located about 5 feet (1.5 meters) from the rover and about nine feet (2.7 meters) from ChemCam on the mast. Image credit: NASA/JPL-Caltech/LANL/CNES/IRAP.

JPL manages the mission for NASA's Science Mission Directorate in Washington. The rover was designed, developed and assembled at JPL. NASA's DSN is an international network of antennas that supports interplanetary spacecraft missions and radio and radar astronomy observations for the exploration of the solar system and the universe. The network also supports selected Earth-orbiting missions.

The full text of the administrator's message, as well as a video clip and audio clip with his recorded voice, are available at: http://www.nasa.gov/mission_pages/msl/news/bolden20120827.html .

To view the new images, and for more information about the Curiosity rover, visit: http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl

Images (mentioned), Text, Credits: NASA / Dwayne Brown / JPL / Guy Webster / D.C. Agle.

Best regards, Orbiter.ch