vendredi 23 août 2013

NASA's Spitzer Telescope Celebrates 10 Years in Space












NASA - SPITZER Space Telescope patch.

Aug. 23, 2013


Image above: A montage of images taken by NASA's Spitzer Space Telescope over the years. Image Credit: NASA/JPL-Caltech.

Ten years after a Delta II rocket launched NASA's Spitzer Space Telescope, lighting up the night sky over Cape Canaveral, Fla., the fourth of the agency's four Great Observatories continues to illuminate the dark side of the cosmos with its infrared eyes.

The telescope studied comets and asteroids, counted stars, scrutinized planets and galaxies, and discovered soccer-ball-shaped carbon spheres in space called buckyballs. Moving into its second decade of scientific scouting from an Earth-trailing orbit, Spitzer continues to explore the cosmos near and far. One additional task is helping NASA observe potential candidates for a developing mission to capture, redirect and explore a near-Earth asteroid.

"President Obama's goal of visiting an asteroid by 2025 combines NASA's diverse talents in a unified endeavor," said John Grunsfeld, NASA's associate administrator for science in Washington. "Using Spitzer to help us characterize asteroids and potential targets for an asteroid mission advances both science and exploration."


Image above: Massive stars can wreak havoc on their surroundings, as can be seen in this new view of the Carina nebula from NASA’s Spitzer Space Telescope. Image Credit: NASA/JPL-Caltech.

Spitzer's infrared vision lets it see the far, cold and dusty side of the universe. Close to home, the telescope has studied the comet dubbed Tempel 1, which was hit by NASA's Deep Impact mission in 2005. Spitzer showed the composition of Tempel 1 resembled that of solar systems beyond our own. Spitzer also surprised the world by discovering the largest of Saturn's many rings. The enormous ring, a wispy band of ice and dust particles, is very faint in visible light, but Spitzer's infrared detectors were able to pick up the glow from its heat.

Perhaps Spitzer's most astonishing finds came from beyond our solar system. The telescope was the first to detect light coming from a planet outside our solar system, a feat not in the mission's original design. With Spitzer's ongoing studies of these exotic worlds, astronomers have been able to probe their composition, dynamics and more, revolutionizing the study of exoplanet atmospheres.

Other discoveries and accomplishments of the mission include getting a complete census of forming stars in nearby clouds; making a  new and improved map of the Milky Way's spiral-arm structure; and, with NASA's Hubble Space Telescope, discovering that the most distant galaxies known are more massive and mature than expected.


Images above: The spectacular swirling arms and central bar of the Sculptor galaxy are revealed in this new view from NASA’s Spitzer Space Telescope. Image Credit: NASA/JPL-Caltech.

"I always knew Spitzer would work, but I had no idea that it would be as productive, exciting and long-lived as it has been," said Spitzer project scientist Michael Werner of NASA's Jet Propulsion Laboratory, Pasadena, Calif., who helped conceive the mission. "The spectacular images that it continues to return, and its cutting-edge science, go far beyond anything we could have imagined when we started on this journey more than 30 years ago."

In October, Spitzer will attempt infrared observations of a small near-Earth asteroid named 2009 DB to better determine its size, a study that will assist NASA in understanding potential candidates for the agency's asteroid capture and redirection mission. This asteroid is one of many candidates the agency is evaluating.

Spitzer, originally called the Space Infrared Telescope Facility, was renamed after its launch in honor of the late astronomer Lyman Spitzer. Considered the father of space telescopes, Lyman Spitzer began campaigning to put telescopes in space, away from the blurring effects of Earth's atmosphere, as early as the 1940s. His efforts also led to the development and deployment of NASA's Hubble Space Telescope, carried to orbit by the space shuttle in 1990.

In anticipation of the Hubble launch, NASA set up the Great Observatories program to fly a total of four space telescopes designed to cover a range of wavelengths: Hubble, Spitzer, the Chandra X-ray Observatory and the now-defunct Compton Gamma Ray Observatory.


Image above: This infrared image from NASA's Spitzer Space Telescope shows the Helix nebula, a cosmic starlet often photographed by amateur astronomers for its vivid colors and eerie resemblance to a giant eye. Image Credit: NASA/JPL-Caltech/Univ.of Ariz.

"The majority of our Great Observatory fleet is still up in space, each with its unique perspective on the cosmos," said Paul Hertz, Astrophysics Division director at NASA headquarters in Washington. "The wisdom of having space telescopes that cover all wavelengths of light has been borne out by the spectacular discoveries made by astronomers around the world using Spitzer and the other Great Observatories."

Spitzer ran out of the coolant needed to chill its longer-wavelength instruments in 2009, and entered the so-called warm mission phase. Now, after its tenth year of peeling back the hidden layers of the cosmos, its journey continues.

SPITZER Space Telescope. Image Credit: NASA/JPL-Caltech

"I get very excited about the serendipitous discoveries in areas we never anticipated," said Dave Gallagher, Spitzer's project manager at JPL from 1999 to 2004, reminding him of a favorite quote from Marcel Proust: "The real voyage of discovery consists not in seeking new landscapes, but in having new eyes."

JPL 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 / J.D. Harrington / JPL / Whitney Clavin.

Best regards, Orbiter.ch

SCISAT - From dawn to twilight














CSA-ASC - SCISAT-1 Mission patch / CSA-ASC - SCISAT-1 Atmospheric Chemistry Experiment (ACE) patch.

Aug. 23, 2013


SCISAT is completing 10 years in space. We are very proud of the unique measurement capabilities of this small Canadian satellite and of the large role that this space mission plays in monitoring stratospheric ozone and its associated chemistry.

Stratospheric ozone exists in a delicate balance of many chemical elements. SCISAT's solar-occultation instruments measure a wide range of gases, helping to monitor recovery of the ozone layer and address the Vienna Convention for the Protection of the Ozone Layer and the Montreal Protocol on Substances that Deplete the Ozone Layer.

The tenth anniversary of the first science data download from SCISAT will be marked by a scientific workshop at York University in October 2013!

Launched on August 12, 2003, SCISAT helps a team of Canadian and international scientists improve their understanding of the depletion of the ozone layer, with a special emphasis on the changes occurring over Canada and in the Arctic.

SCISAT/ACE: an important asset for international environmental policy

SCISAT focuses its attention in the stratosphere, where the ozone layer is located. SCISAT is providing the most accurate measurements to date of chemicals that affect ozone, which blocks the sun's biologically damaging ultraviolet radiation and prevents most of it from reaching the Earth's surface.

It measures more than 30 different molecules, which is "more thorough than anything that's up there," said Peter Bernath, a University of Waterloo chemistry professor who heads the SCISAT science team.

 CSA-ASC - SCISAT-1 in orbit

Ozone—comprised of three atoms of oxygen—is constantly being created and destroyed by natural chemical processes in the atmosphere. The amount of ozone present at any given time varies depending on the balance between the processes of creation and destruction.

Industrial activities on Earth produce chemicals— notably chlorofluorocarbons (CFCs)—that affect this balance by destroying stratospheric ozone. They not only reduce the ozone shield around the globe, they actually eat large holes in the ozone layer over the Antarctic each year, and also cause significant losses over the Arctic. In the past two decades, average ozone levels over Canada have dropped about 6%, while severe declines of 20—40% have occurred over the Arctic in the spring.

Lockheed TriStar launches Pegasus with SCISAT-1, August 12th, 2003

The Atmospheric Chemistry Experiment (ACE) on SCISAT was launched into a 650-kilometre-high, high-inclination orbit that takes it over the polar regions of the Earth, as well as tropical and mid-latitude locations. It measures chemical molecules that influence the distribution of stratospheric ozone, particularly in the Arctic. These data are making an important contribution to international environmental policy making aimed at protecting the ozone layer, such as the Montreal Protocol that bans certain CFCs.

SCISAT observations are also helping scientists better understand the effects of atmospheric chemistry, clouds and small particles (such as aerosols) on Earth's climate.

ACE measures the absorption of solar light by the atmosphere at sunrise and sunset. Different atmospheric constituents absorb different wavelengths of light in characteristic ways—a signature by which they can be identified. This technique is what allows ACE to make extremely accurate measurements.

Canada's SCISAT satellite

The trade-off for this precision is that SCISAT takes measurements in a limited number of locations. Other satellites do provide more global coverage, but their data are not as accurate. "That's why there's great value in combining the two," said Bernath.

With its instrument performing so well, SCISAT is now moving beyond its original mandate and providing excellent data related not only to ozone depletion, but also to climate change, and air quality and pollution. "There are many things we're doing now that we really didn't know we could do," Bernath said.

ACE has been used to measure the distribution of several molecules correlated with air pollution and biomass burning, providing data that complements the observations of the MOPITT satellite. "Together, they give you a picture of what's going on, and it's not a good picture. A lot of pollution that come from industrial activity travels all over the globe," Bernath noted.

ACE observations are also useful in climate studies. For example, they've shown that previously observed increases in the amount of water vapour being injected into the stratosphere have stopped. Water vapour is the most powerful natural greenhouse gas and plays a key role in the Earth's climate. "No one knew why it was increasing and we don't know why it stopped, so there are quite a few mysteries left," said Bernath.

Originally intended to last two years, ten years later the satellite is still operational and Bernath hopes it will continue to function beyond that. "It's been a real success."

SCISAT: Science team members and roles

The Canadian SCISAT mission is a partnership of universities, government, and industry. A scientific team of researchers from around the world, led by Professor Peter Bernath of the University of Waterloo is conducting in the Atmospheric Chemistry Experiment (ACE) which aims to measure and understand the chemical processes that control the distribution of ozone in the Earth's atmosphere, particularly in the northern latitudes.

Related links:

University of Waterloo: http://www.ace.uwaterloo.ca/

For more information about Canadian Space Agency (CSA-ASC), visit: http://www.asc-csa.gc.ca/index.html

Images, Text, Credits: CSA-ASC / NASA.

Greetings, Orbiter.ch

jeudi 22 août 2013

ROSCOSMOS - Russian Dnepr rocket launches with Arirang-5












ROSCOSMOS logo.

August 22, 2013

South Korea’s Arirang-5 satellite was launched on Thursday atop a Russian Dnepr rocket. The launch took place at 14:39 UTC (20:39 local time) from Site 370/13 at the Dombarovsky launch site near Russia’s border with Kazakhstan.

Russian Dnepr rocket launch

Arirang-5, or KOMPSat-5, is the fourth satellite in South Korea’s Arirang program. Arirang is also known as the Korea Multi-Purpose Satellite, or KOMPSAT, program.

Arirang-5 is a radar imaging satellite, the first to be developed and operated by South Korea. Developed by KARI, with participation from the South Korean aerospace industry, Arirang-5 is based around the satellite bus developed for Arirang-2.

Russian Dnepr rocket description

It has a fuelled mass of approximately 1,400 kilograms (3,100 lb), and is expected to function for at least five years. The spacecraft will be powered by a pair of deployable solar arrays, generating upwards of 1,400 watts. These will charge lithium ion batteries, with a capacity of around 100 amp-hours.

KOMPSat-5 spacecraft

Data will be relayed to the ground via an x-band downlink, providing a data rate in the region of 310 megabits per second. A lower data-rate s-band transceiver will be used to relay telemetry and commands between the satellite and its ground stations.

Thursday’s launch was the first Dnepr launch in two years. The next launch is scheduled for November, carrying DubaiSat-2 and twenty six secondary payloads.

For more information about Korean Aerospace Research Institute (KARI), visit: http://www.kari.re.kr

Images, Text, Credits: ROSCOSMOS / KARI.

Cheers, Orbiter.ch

Spacewalkers Install Camera Platform, Inspect Station
















ISS - Expedition 36 Mission aptch / ISS - International Space Station patch.

Aug. 22, 2013

Two Russian cosmonauts wrapped up a 5-hour, 58-minute spacewalk at 1:32 p.m. EDT Thursday, completing the replacement of a laser communications experiment with a new platform for a small optical camera system, the installation of new spacewalk aids and an inspection of antenna covers.

Clad in Orlan spacesuits, Expedition 36 Flight Engineers Fyodor Yurchikhin and Alexander Misurkin began their second spacewalk within the span of a week when they opened the hatch to the International Space Station’s Pirs docking compartment at 7:34 a.m.


Image above: Flight Engineer Fyodor Yurchikhin works outside the Pirs docking compartment of the International Space Station during an Expedition 36 spacewalk. Image Credit: NASA TV.

As the two spacewalkers moved out to the first worksite on the Zvezda service module, they carried a combination EVA workstation and biaxial pointing platform upon which a small optical camera system will be installed during a future spacewalk.  After attaching the assembly  to a temporary stowage location, Yurchikhin and Misurkin removed the External Onboard Laser Communications System, which was installed on Zvezda in August 2011 during an Expedition 28 spacewalk.

video
Another Walk in Space for Russian Cosmonauts

With the laser communications experiment removed and temporarily stowed with its protective cover, the two spacewalkers began to install the camera platform before noticing that its base plate was not properly aligned.  Initially, Russian mission controllers told the spacewalkers to stand down on the installation, and Yurchikhin carried the platform back into the Pirs airlock. However, after determining that the alignment issue with base plate of the EVA workstation and biaxial pointing platform could be corrected after its installation, Russian flight controllers directed the spacewalkers to retrieve the platform from the airlock and install it at as planned on the starboard side of Zvezda. Two cameras, scheduled to be delivered to station aboard a Progress cargo craft in November, will be mounted on the platform during a spacewalk planned for December.


Image above: Flight Engineer Alexander Misurkin takes a look at a materials exposure experiment during an Expedition 36 spacewalk. Image Credit: NASA TV.

Misurkin and Yurchikhin then headed to various locations on Zvezda to inspect six antennas that are used to assist in providing navigation data during the rendezvous and docking of European Automated Transfer Vehicle cargo ships. The inspection involved work to check out the antenna covers and tighten screws on any loose covers. Flight Engineer Chris Cassidy observed one of the covers floating away from the station on Monday (video below), and Russian station officials wanted to determine its origin and insure that the remaining covers are secure.

video
Unidentified object floating outside station? Sort of...

While Yurchikhin completed the installation of some gap spanners – devices used to assist future spacewalkers in their movement from one module to another -- on the port side of Zvezda, Misurkin then headed over to the Poisk Mini-Research Module-2 where he used a test kit to collect a particulate sample from under a swath of thermal insulation near Poisk’s hatch. He also photographed a materials exposure experiment and associated cabling along Poisk.

Due to time constraints, the relocation of a foot restraint from the hull of Zvezda to the new spacewalk workstation was deferred to a later excursion.

This was the 173rd spacewalk in support of space station assembly and maintenance, the 8th in Yurchikhin’s career and the third for Misurkin.


Image above: Flight Engineers Fyodor Yurchikhin and Alexander Misurkin unfurl a Russian flag near the end of Thursday's spacewalk in commemoration of Russian Flag Day. Image Credit: NASA TV.

For the duration of Thursday’s spacewalk, Cassidy and station Commander Pavel Vinogradov were isolated to the Poisk module and their Soyuz TMA-08M spacecraft, while Flight Engineers Karen Nyberg of NASA and Luca Parmitano of the European Space Agency were free to move about the U.S. segment of the complex.

Nyberg spent much of her day working with the InSpace-3 experiment, which examines colloidal fluids classified as smart materials, transitioning to a solid-like state in the presence of a magnetic field.  The InSPACE-3 team believes the knowledge gleaned from this investigation may contribute to new technologies and new manufacturing processes based on the idea of having these nanoparticles act as self-assembling building blocks for larger structures.

Parmitano meanwhile rerouted an exhaust port on the Amine Swingbed. This technology demonstration is testing a smaller, more efficient carbon dioxide removal system. Size and efficiency are key factors as NASA begins building the Orion Multi-Purpose Crew Vehicle that will take astronauts deeper into space than ever before.

For more information about International Space Station, visit: http://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Video, Text, Credits: NASA / NASA TV.

Greetings, Orbiter.ch

Astronomers Use Hubble Images for Movies Featuring Space Slinky











NASA - Hubble Space Telescope patch.

Aug. 22, 2013

Astronomers have assembled, from more than 13 years of observations from NASA's Hubble Space Telescope, a series of time-lapse movies showing a jet of superheated gas -- 5,000 light-years long -- as it is ejected from a supermassive black hole.

Galaxy M87 Jet – Annotated

The movies promise to give astronomers a better understanding of how black holes shape galaxy evolution.

video
 Hubble Follows Spiral Flow of Black-Hole-Powered Jet or Spac

"Central, supermassive black holes are a key component in all big galaxies," said Eileen T. Meyer of the Space Telescope Science Institute in Baltimore, Md. "Most of these black holes are believed to have gone through an active phase, and black-hole powered jets from this active phase play a key role in the evolution of galaxies. By studying the details of this process in the nearest galaxy with an optical jet, we can hope to learn more about galaxy formation and black hole physics in general."

The research team spent eight months analyzing 400 observations from Hubble's Wide Field Planetary Camera 2 and Advanced Camera for Surveys. The observations, taken from 1995 to 2008, are of a black hole sitting in the center of a giant galaxy dubbed M87.

Galaxy M87 Jet – Unannotated

"We analyzed several years' worth of Hubble data of a relatively nearby spiraling jet of plasma emitted from a black hole, which allowed us to see lots of details," Meyer said. "The only reason you see the distant jet in motion is because it is traveling very fast."

Meyer found evidence that suggests the jet's spiral motion is created by a helix-shaped magnetic field surrounding the black hole. In the outer part of the M87 jet, for example, one bright gas clump, called knot B, appears to zigzag, as if it were moving along a spiral path. Several other gas clumps along the jet also appear to loop around an invisible structure.

M87 resides at the center of the neighboring Virgo cluster of roughly 2,000 galaxies, located 50 million light years away. The galaxy's monster black hole is several billion times more massive than our sun.

Compass and Scale Image for M87 Jet

The Hubble data also provided information on why the M87 jet is composed of a long string of gas blobs, which appear to brighten and dim over time.

"The jet structure is very clumpy. Is this a ballistic effect, like cannonballs fired sequentially from a cannon?" Meyer asked, "or, are there some particularly interesting physics going on, such as a shock that is magnetically driven?"

Meyer's team found evidence for both scenarios. "We found things that move quickly," Meyer said. "We found things that move slowly. And, we found things that are stationary. This study shows us that the clumps are very dynamic sources."

Magnetic Funnel Around a Supermassive Black Hole

It is too soon to tell whether all black-hole-powered jets behave like the one in M87, which is why Meyer plans to use Hubble to study three more jets. "It's always dangerous to have exactly one example because it could be a strange outlier," Meyer said. "The M87 black hole is justification for looking at more jets."

The team's results appeared Aug. 22 in the online issue of The Astrophysical Journal Letters.

For images and more information about M87's jet, visit: http://www.nasa.gov/hubble and http://hubblesite.org/news/2013/32

Images, Video, Text, Credits: NASA, ESA, E. Meyer, W. Sparks, J. Biretta, J. Anderson, S.T. Sohn, and R. van der Marel (STScI), C. Norman (Johns Hopkins University), and M. Nakamura (Academia Sinica).

Best regards, Orbiter.ch

Italy in an espresso cup







ESA - PROBA-2 Mission logo.

22 August 2013

 Proba-2's X-Cam view of Europe

This cloudless view of central and northern Italy, the snow-capped Alps and the European heartland was snapped by an experimental camera, smaller than an espresso cup, aboard ESA’s minisatellite Proba-2.

This black and white image gives a wider perspective than a standard Earth observation instrument, more like an astronaut’s eye view, but was taken at around double the altitude that human crews currently fly, at more than 700 km up.

A sequence of crater lakes can be seen along central Italy – from south to north, Lake Bracciano, the smaller Lake Vico, Lake Bolsena and Lake Trasimeno. The Apennine chain of mountains is also visible, forming the spine of the Italian peninsula. Sardinia and Corsica are viewed towards bottom left.

Beneath the curved horizon the UK and Ireland to the left, the North Sea and Denmark to the right can also be glimpsed. The image also captures the whole of Switzerland – where this image’s instrument was designed and built.

Proba-2's small X-Cam

Less than a cubic metre in size, Proba-2 focuses on observing solar activity and space weather. But it also keeps a small eye on its home world.

One of the 17 experimental technologies hosted on Proba-2 is the compact Exploration Camera, X-Cam. Housed on the underside of the satellite, the monochrome X-Cam observes in the visible and infrared with a 100° field of view.

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

Similar compact imagers could in future keep watch on satellite surfaces to look out for damage or environmental effects.

Proba-2 in orbit

Swiss manufacturer Micro-Cameras & Space Exploration is due to fly cameras on ESA's Sentinel-1 Earth observation mission – launching this year – as well as the BepiColombo planetary science missions later this decade.

And in 2014 the company’s miniature imager on Rosetta’s lander should provide us with our closest view yet of a comet’s surface.

This image was acquired by Proba-2’s X-Cam on 7 June 2013.

More information / Related links:

About Proba-2: http://www.esa.int/Our_Activities/Technology/Proba_Missions/About_Proba-2

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

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

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

Greetings, Orbiter.ch

mercredi 21 août 2013

NASA's Fermi Celebrates Five Years in Space, Enters Extended Mission











NASA - Fermi Gamma-ray Space Telescope logo.

Aug. 21, 2013

During its five-year primary mission, NASA's Fermi Gamma-ray Space Telescope has given astronomers an increasingly detailed portrait of the universe's most extraordinary phenomena, from giant black holes in the hearts of distant galaxies to thunderstorms on Earth.

But its job is not done yet. On Aug. 11, Fermi entered an extended phase of its mission -- a deeper study of the high-energy cosmos. This is a significant step toward the science team's planned goal of a decade of observations, ending in 2018.

video
NASA Fermi at Five Years

From blazars to thunderstorms, this video showcases highlights from the Fermi Gamma-ray Space Telescope's first five years in space.
Image Credit: NASA’s Goddard Space Flight Center.

"As Fermi opens its second act, both the spacecraft and its instruments remain in top-notch condition and the mission is delivering outstanding science," said Paul Hertz, director of NASA's astrophysics division in Washington.

Fermi has revolutionized our view of the universe in gamma rays, the most energetic form of light. The observatory's findings include new insights into many high-energy processes, from rapidly rotating neutron stars, also known as pulsars, within our own galaxy, to jets powered by supermassive black holes in far-away young galaxies.

The Large Area Telescope (LAT), the mission's main instrument, scans the entire sky every three hours. The state-of-the-art detector has sharper vision, a wider field of view, and covers a broader energy range than any similar instrument previously flown.

"As the LAT builds up an increasingly detailed picture of the gamma-ray sky, it simultaneously reveals how dynamic the universe is at these energies," said Peter Michelson, the instrument's principal investigator and a professor of physics at Stanford University in California.

Fermi's secondary instrument, the Gamma-ray Burst Monitor (GBM), sees all of the sky at any instant, except the portion blocked by Earth. This all-sky coverage lets Fermi detect more gamma-ray bursts, and over a broader energy range, than any other mission. These explosions, the most powerful in the universe, are thought to accompany the birth of new stellar-mass black holes.


Animation above: Fermi's portrait of the sky at energies beyond 1 GeV has steadily deepened with more data. This animation compares views of a 20-degree-wide region in the constellation Virgo after the LAT's first and fifth year of operations. Many additional strong sources (yellow, red) appear in the latest image. Image Credit: NASA/DOE/Fermi LAT Collaboration.

"More than 1,200 gamma-ray bursts, plus 500 flares from our sun and a few hundred flares from highly magnetized neutron stars in our galaxy have been seen by the GBM," said principal investigator Bill Paciesas, a senior scientist at the Universities Space Research Association's Science and Technology Institute in Huntsville, Ala.

The instrument also has detected nearly 800 gamma-ray flashes from thunderstorms. These fleeting outbursts last only a few thousandths of a second, but their emission ranks among the highest-energy light naturally occurring on Earth.

One of Fermi's most striking results so far was the discovery of giant bubbles extending more than 25,000 light-years above and below the plane of our galaxy. Scientists think these structures may have formed as a result of past outbursts from the black hole -- with a mass of 4 million suns -- residing in the heart of our galaxy.

To build on the mission's success, the team is considering a new observing strategy that would task the LAT to make deeper exposures of the central region of the Milky Way, a realm packed with pulsars and other high-energy sources. This area also is expected to be one of the best places to search for gamma-ray signals from dark matter, an elusive substance that neither emits nor absorbs visible light. According to some theories, dark matter consists of exotic particles that produce a flash of gamma rays when they interact.


This view shows the entire sky at energies greater than 1 GeV based on five years of data from the LAT instrument on NASA's Fermi Gamma-ray Space Telescope. Brighter colors indicate brighter gamma-ray sources. Image Credit: NASA/DOE/Fermi LAT Collaboration.

"Over the next few years, major new astronomical facilities exploring other wavelengths will complement Fermi and give us our best look yet into the most powerful events in the universe," said Julie McEnery, the mission's project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.

NASA's Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership. Goddard manages the mission. The telescope was developed in collaboration with the U.S. Department of Energy's Office of Science, with contributions from academic institutions and partners in the United States, France, Germany, Italy, Japan, and Sweden.

Related Links:

Download additional graphics from NASA Goddard's Scientific Visualization Studio: http://svs.gsfc.nasa.gov/goto?11342

Media gallery: Fermi's First Five Years: http://svs.gsfc.nasa.gov/Gallery/Fermi5.html

Fermi multiwavelength observing support programs: http://fermi.gsfc.nasa.gov/ssc/observations/multi/programs.html

"NASA Goddard Astrophysicist Wins Prize for Pulsar Work" (02.04.13): http://www.nasa.gov/centers/goddard/news/features/2013/harding-rossi-prize.html

"Fermi Improves its Vision for Thunderstorm Gamma-Ray Flashes" (12.06.12): http://www.nasa.gov/mission_pages/GLAST/news/vision-improve_prt.htm

"NASA's Fermi Spots 'Superflares' in the Crab Nebula" (05.11.11): http://www.nasa.gov/mission_pages/GLAST/news/crab-flare.html

"NASA's Fermi Catches Thunderstorms Hurling Antimatter into Space" (01.10.11): http://www.nasa.gov/mission_pages/GLAST/news/fermi-thunderstorms.html

"Fermi Sees Brightest-Ever Blazar Flare" (12.08.09): http://www.nasa.gov/mission_pages/GLAST/news/brightest-blazar.html

Images (mentioned), Video (mentioned), Text, Credits: NASA's Goddard Space Flight Center / Francis Reddy.

Best regards, Orbiter.ch

NASA Spacecraft Reactivated to Hunt for Asteroids










NASA - WISE Mission logo.

Aug. 21, 2013

Probe Will Assist Agency in Search for Candidates to Explore


Image above: This artist's concept shows the Wide-field Infrared Survey Explorer, or WISE spacecraft, in its orbit around Earth. In September of 2013, engineers will attempt to bring the mission out of hibernation to hunt for more asteroids and comets in a project called NEOWISE. Image Credit: NASA/JPL-Caltech.

A NASA spacecraft that discovered and characterized tens of thousands of asteroids throughout the solar system before being placed in hibernation will return to service for three more years starting in September, assisting the agency in its effort to identify the population of potentially hazardous near-Earth objects, as well as those suitable for asteroid exploration missions.

The Wide-field Infrared Survey Explorer (WISE) will be revived next month with the goal of discovering and characterizing near-Earth objects (NEOs), space rocks that can be found orbiting within 28 million miles (45 million kilometers) from Earth's path around the sun. NASA anticipates WISE will use its 16-inch (40-centimeter) telescope and infrared cameras to discover about 150 previously unknown NEOs and characterize the size, albedo and thermal properties of about 2,000 others -- including some which could be candidates for the agency's recently announced asteroid initiative.

"The WISE mission achieved its mission's goals and as NEOWISE extended the science even further in its survey of asteroids. NASA is now extending that record of success, which will enhance our ability to find potentially hazardous asteroids, and support the new asteroid initiative," said John Grunsfeld, NASA's associate administrator for science in Washington. "Reactivating WISE is an excellent example of how we are leveraging existing capabilities across the agency to achieve our goal."


This image shows the potentially hazardous near-Earth object 1998 KN3 as it zips past a cloud of dense gas and dust near the Orion nebula. Image Credit: NASA/JPL-Caltech.

NASA's asteroid initiative will be the first mission to identify, capture and relocate an asteroid. It represents an unprecedented technological feat that will lead to new scientific discoveries and technological capabilities that will help protect our home planet. The asteroid initiative brings together the best of NASA's science, technology and human exploration efforts to achieve President Obama's goal of sending humans to an asteroid by 2025.

Launched in December 2009 to look for the glow of celestial heat sources from asteroids, stars and galaxies, WISE made about 7,500 images every day during its primary mission, from January 2010 to February 2011. As part of a project called NEOWISE, the spacecraft made the most accurate survey to date of NEOs. NASA turned most of WISE's electronics off when it completed its primary mission.

"The data collected by NEOWISE two years ago have proven to be a gold mine for the discovery and characterization of the NEO population," said Lindley Johnson, NASA's NEOWISE program executive in Washington. "It is important that we accumulate as much of this type of data as possible while the WISE spacecraft remains a viable asset."

Because asteroids reflect but do not emit visible light, infrared sensors are a powerful tool for discovering, cataloging and understanding the asteroid population. Depending on an object's reflectivity, or albedo, a small, light-colored space rock can look the same as a big, dark one. As a result, data collected with optical telescopes using visible light can be deceiving.

During 2010, NEOWISE observed about 158,000 rocky bodies out of approximately 600,000 known objects. Discoveries included 21 comets, more than 34,000 asteroids in the main belt between Mars and Jupiter, and 135 near-Earth objects.

The WISE prime mission was to scan the entire celestial sky in infrared light. It captured more than 2.7 million images in multiple infrared wavelengths and cataloged more than 560 million objects in space, ranging from galaxies faraway to asteroids and comets much closer to Earth.

"The team is ready and after a quick checkout, we're going to hit the ground running," said Amy Mainzer, NEOWISE principal investigator at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "NEOWISE not only gives us a better understanding of the asteroids and comets we study directly, but it will help us refine our concepts and mission operation plans for future, space-based near-Earth object cataloging missions."

JPL manages WISE for NASA's Science Mission Directorate at the agency's headquarters in Washington. The mission is part of NASA's Explorers Program, which NASA's Goddard Space Flight Center in Greenbelt, Md., manages. The Space Dynamics Laboratory in Logan, Utah, built the science instrument. Ball Aerospace & Technologies Corp. of Boulder, Colo., built the spacecraft. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

More information about NEOWISE is available online at: http://www.nasa.gov/wise and http://www.jpl.nasa.gov/wise/ .

For more information on the asteroid initiative, visit: http://www.nasa.gov/asteroidinitiative .

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

Greetings, Orbiter.ch

Station Crew Completes Spacewalk Preps












ISS - Expedition 36 Mission patch.

Aug. 21, 2013

On the eve of the second excursion outside the International Space Station within the span of a week, the Expedition 36 crew completed final preparations Wednesday for that spacewalk while continuing to support a number of research and maintenance tasks.

Flight Engineers Fyodor Yurchikhin and Alexander Misurkin completed a final timeline review of the tasks they will perform during Thursday’s spacewalk.  During their excursion slated to last about six hours, the two cosmonauts will replace a laser communications experiment with a new platform for a small optical camera system, move a foot restraint and inspect several sites for the origin of a wayward antenna cover observed by Flight Engineer Chris Cassidy on Monday.


Image above: NASA astronaut Chris Cassidy (left), Russian cosmonaut Alexander Misurkin, NASA astronaut Karen Nyberg and European Space Agency astronaut Luca Parmitano (right), all Expedition 36 flight engineers, pose for a portrait in the Zvezda Service Module of the International Space Station. Image Credit: NASA.

This will be the 173rd spacewalk in support of space station assembly and maintenance, the 8th in Yurchikhin’s career and the third for Misurkin. Both cosmonauts will wear blue-striped Orlan spacesuits outfitted with helmet cameras. Their previous excursion outside the station, a 7-hour, 29-minute marathon on Aug. 16 focusing on preparations for the future arrival of the “Nauka” Multipurpose Laboratory Module, was the longest spacewalk in history conducted by a pair of Russian cosmonauts.

NASA Television coverage of the spacewalk will begin at 7 a.m. Thursday, with hatch opening expected at 7:40 a.m.

Watch NASA TV: http://www.nasa.gov/ntv

View Russian EVA 35 Graphics: http://www.flickr.com/photos/nasa2explore/sets/72157635170597343/

View Russian EVA 35 timeline: http://www.nasa.gov/sites/default/files/files/Russian_EVA_35_Timeline.pdf


Image above: Flight Engineer Chris Cassidy performs routine maintenance on the International Space Station's Water Recovery System. Image Credit: NASA TV.

Meanwhile, Flight Engineer Chris Cassidy began his workday removing and replacing multifiltration units inside the Water Recovery System. Part of the station’s overall Environmental Control and Life Support System, the station’s Water Recovery System recycles condensation and urine into drinkable water, reducing the amount of fresh water that must be sent to the crew aboard resupply ships.

Afterward, Cassidy performed an ultrasound on Flight Engineer Luca Parmitano for the Spinal Ultrasound investigation. Medical researchers have observed that astronauts grow up to three percent taller during their long duration missions aboard the station and return to their normal height when back on Earth. The Spinal Ultrasound investigation seeks to understand the mechanism and impact of this change while advancing medical imaging technology by testing a smaller and more-portable ultrasound device aboard the station.

With an eye toward the return to Earth in three weeks, Cassidy joined Misurkin and Commander Pavel Vinogradov for a fit check of the “Kazbek” seat liners of their Soyuz TMA-08M spacecraft they will ride home in for a parachute-assisted landing on the steppe of Kazakhstan on the morning of Sept. 11, local time.

Flight Engineer Karen Nyberg spent part of her day in the Japanese Kibo module setting up a commercial payload. She also replaced a rope on the Advanced Resistive Exercise Device, or ARED, one of several exercise devices the station’s residents can use for their daily two-hour exercise regimen to combat the loss of muscle mass and bone density experienced by long-duration crews.


Image above: Central Idaho wildfires are featured in this image photographed by an Expedition 36 crew member on the International Space Station. Image Credit: NASA.

Parmitano exchanged a test sample cartridge in the Solidification and Quench Furnace for another round of data collection. This metallurgical research furnace provides three heater zones to ensure accurate temperature profiles and maintain a sample's required temperature variations throughout the solidification process.  It’s just one part of the Materials Science Research Rack, which allows for the on-orbit study of a variety of materials -- including metals, ceramics, semi-conductor crystals and glasses.

The station’s residents also had several opportunities throughout the day to photograph the Earth below as part of the ongoing Crew Earth Observations program. These photographs, such as the image of wildfires raging through central Idaho that was captured by the crew on Sunday, are made available to researchers studying dynamic events on Earth and published online at the Gateway to Astronaut Photography of Earth for public use.

Visit the Gateway to Astronaut Photography of Earth: http://eol.jsc.nasa.gov/

Images, Text, Credits: NASA.

Cheers, Orbiter.ch

mardi 20 août 2013

NASA / ESA Spacecraft Capture an Earth Directed Coronal Mass Ejection












NASA / ESA - SOHO Mission patch.

Aug. 20, 2013


Image above: The SOHO LASCO C2 instrument captured this image of the Earth-directed CME. SOHO's coronographs are able to take images of the solar corona by blocking the light coming directly from the Sun with an occulter disk. The location of the actual sun is shown with an image taken by SDO. Image Credit: ESA & NASA/SOHO, SDO.

On August 20, 2013 at 4:24 am EDT, the sun erupted with an Earth-directed coronal mass ejection or CME, a solar phenomenon which can send billions of tons of particles into space that can reach Earth one to three days later. These particles cannot travel through the atmosphere to harm humans on Earth, but they can affect electronic systems in satellites and on the ground.


Image above: The SOHO LASCO C3 instrument captured this coronographic image of the Earth-directed CME. The bright white object to the right is the planet Mercury. Image Credit: ESA & NASA/SOHO.

Experimental NASA research models, based on observations from NASA’s Solar Terrestrial Relations Observatory show that the CME left the sun at speeds of around 570 miles per second, which is a fairly typical speed for CMEs.

Earth-directed CMEs can cause a space weather phenomenon called a geomagnetic storm, which occurs when they funnel energy into Earth's magnetic envelope, the magnetosphere, for an extended period of time. The CME’s magnetic fields peel back the outermost layers of Earth's fields changing their very shape. In the past, geomagnetic storms caused by CMEs of this strength have usually been mild.

Artist's illustration of the SOHO spacecraft. Image credit: NASA / ESA

Magnetic storms can degrade communication signals and cause unexpected electrical surges in power grids. They also can cause aurora.

NOAA's Space Weather Prediction Center (http://swpc.noaa.gov) is the U.S. government's official source for space weather forecasts, alerts, watches and warnings. Updates will be provided if needed.

For more information about Solar and Heliospheric Observatory (SOHO), visit:  http://sohowww.nascom.nasa.gov/ and http://soho.esac.esa.int/

Images (mentioned), Text, Credits: NASA's Goddard Space Flight Center / Susan Hendrix.

Greetings, Orbiter.ch

ALMA Takes Close Look at Drama of Starbirth












ESO - European Southern Observatory logo.

20 August 2013

 Stunning ALMA and NTT image of Newborn Star

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have obtained a vivid close-up view of material streaming away from a newborn star. By looking at the glow coming from carbon monoxide molecules in an object called Herbig-Haro 46/47 they have discovered that its jets are even more energetic than previously thought. The very detailed new images have also revealed a previously unknown jet pointing in a totally different direction.

ALMA’s view of the outflow associated with the Herbig-Haro object HH 46/47

Young stars are violent objects that eject material at speeds as high as one million kilometres per hour. When this material crashes into the surrounding gas it glows, creating a Herbig-Haro object [1]. A spectacular example is named Herbig-Haro 46/47 and is situated about 1400 light-years from Earth in the southern constellation of Vela (The Sails). This object was the target of a study using ALMA during the Early Science phase, whilst the telescope was still under construction and well before the array was completed.

The Herbig-Haro object HH 46/47 seen with ESO’s New Technology Telescope

The new images reveal fine detail in two jets, one coming towards Earth and one moving away. The receding jet was almost invisible in earlier pictures made in visible light, due to obscuration by the dust clouds surrounding the new-born star. ALMA has not only provided much sharper images than earlier facilities but also allowed astronomers to measure how fast the glowing material is moving through space.

These new observations of Herbig-Haro 46/47 revealed that some of the ejected material had velocities much higher than had been measured before. This means the outflowing gas carries much more energy and momentum than previously thought.

Wide-field view of the star-forming region around the Herbig-Haro object HH 46/47

The team leader and first author of the new study, Héctor Arce (Yale University, USA) explains that "ALMA's exquisite sensitivity allows the detection of previously unseen features in this source, like this very fast outflow. It also seems to be a textbook example of a simple model where the molecular outflow is generated by a wide-angle wind from the young star."

The observations were obtained in just five hours of ALMA observation time – even though ALMA was still under construction at the time – similar quality observations with other telescopes would have taken ten times longer.

"The detail in the Herbig-Haro 46/47 images is stunning. Perhaps more stunning is the fact that, for these types of observations, we really are still in the early days. In the future ALMA will provide even better images than this in a fraction of the time," adds Stuartt Corder (Joint ALMA Observatory, Chile), a co-author on the new paper.

The Herbig-Haro object HH 46/47 in the constellation of Vela

Diego Mardones (Universidad de Chile), another co-author, emphasises that "this system is similar to most isolated low mass stars during their formation and birth. But it is also unusual because the outflow impacts the cloud directly on one side of the young star and escapes out of the cloud on the other. This makes it an excellent system for studying the impact of the stellar winds on the parent cloud from which the young star is formed."

The sharpness and sensitivity achieved by these ALMA observations also allowed the team to discover an unsuspected outflow component that seems to be coming from a lower mass companion to the young star. This secondary outflow is seen almost at right angles to the principal object and is apparently carving its own hole out of the surrounding cloud.

video
Zooming in on the Herbig-Haro object HH 46/47

Arce concludes that "ALMA has made it possible to detect features in the observed outflow much more clearly than previous studies. This shows that there will certainly be many surprises and fascinating discoveries to be made with the full array. ALMA will certainly revolutionise the field of star formation!"

Notes:

[1] The astronomers George Herbig and Guillermo Haro were not the first to see one of the objects that now bear their names, but they were the first to study the spectra of these strange objects in detail. They realised that they were not just clumps of gas and dust that reflected light, or glowed under the influence of the ultraviolet light from young stars, but were a new class of objects associated with shocks created by material ejected at high speeds in star formation regions.

More information:

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.

This research was presented in a paper entitled "ALMA Observations of the HH 46/47 Molecular Outflow" by Héctor Arce et al, to appear in the Astrophysical Journal.

The team is composed of Héctor G. Arce (Yale University, New Haven, USA), Diego Mardones (Universidad de Chile, Santiago, Chile), Stuartt A. Corder (Joint ALMA Observatory, Santiago, Chile), Guido Garay (Universidad de Chile), Alberto Noriega-Crespo (Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, USA) and Alejandro C. Raga (Instituto de Ciencias Nucleares, Mexico).

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 the 39-metre 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/eso1336/eso1336a.pdf

More about ALMA: http://www.eso.org/alma

Photos of ALMA: http://www.eso.org/public/images/archive/category/alma/

Images, Text, Credits: ESO/ALMA (ESO/NAOJ/NRAO)/H. Arce. Acknowledgements: Bo Reipurth/Digitized Sky Survey 2. Acknowledgement: Davide De Martin/IAU and Sky & Telescope/Video: Digitized Sky Survey 2/Nick Risinger (skysurvey.org).

Best regards, Orbiter.ch