samedi 12 mai 2012

CERN computing looks to the future












CERN - European Organization for Nuclear Research logo.

May 12, 2012

It's been an exciting week for computing at CERN


Image above: The Worldwide LHC Computing Grid (pictured: Tier-0 servers at CERN) will see increased capacity and development (Image: CERN).

On Tuesday CERN signed a contract with the Wigner Research Centre for Physics in Budapest, Hungary, for an extension to the CERN data centre. Under the new agreement, the Wigner Centre will host CERN equipment to extend the capabilities of the Worldwide LHC Computing Grid (WLCG) – a global computing system organized in tiers, with its central hub, Tier-0, at CERN. Tier-0 provides some 30 petabytes (PB) of data storage on disk, and includes the majority of the 65,000 processing cores in the CERN Computer Centre. The Wigner Centre will extend this capacity with 20,000 cores and 5.5 PB of disk data, which will double after 3 years.

And the 9 May CERN launched the fourth phase of CERN openlab – a unique public-private partnership between CERN and leading information-technology companies. The initiative brings together science and industry to develop advanced IT systems to cope with the computing challenges related to the Large Hadron Collider. This fourth phase of the intiative will address cloud computing, business analytics, next-generation hardware, and security for network devices.

CERN - The Grid, The World Wide Web server

Computing is a crucial part of CERN's activities. Initiatives like these will help physicists deal with the torrent of data expected as the LHC reaches higher intensities and energies in the coming years.

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

    Wigner Research Centre for Physics: http://www.rmki.kfki.hu/en

    CERN News: Openlab: https://cdsweb.cern.ch/record/1447092?ln=fr (in French)

    Cern Courier: The openlab adventure continues to thrive: http://cerncourier.com/cws/article/cern/49355

    Worldwide LHC Computing Grid (WLCG): http://lcg.web.cern.ch/lcg/public/default.htm

    Follow CERN on Twitter: http://twitter.com/cern/

Images, Text, Credit: CERN.

Best regards, Orbiter.ch

jeudi 10 mai 2012

NASA Dawn Mission Reveals Secrets of Large Asteroid












NASA - Dawn Mission patch.

May 10, 2012


This image, made from data obtained by NASA's Dawn spacecraft, shows the mineral distribution in the southern hemisphere of the giant asteroid Vesta. Image credit: NASA/JPL-Caltech/UCLA/INAF/MPS/DLR/IDA

NASA's Dawn spacecraft has provided researchers with the first orbital analysis of the giant asteroid Vesta, yielding new insights into its creation and kinship with terrestrial planets and Earth's moon.

Vesta now has been revealed as a special fossil of the early solar system with a more varied, diverse surface than originally thought. Scientists have confirmed a variety of ways in which Vesta more closely resembles a small planet or Earth's moon than another asteroid. Results appear in today's edition of the journal Science.

"Dawn's visit to Vesta has confirmed our broad theories of this giant asteroid's history, while helping to fill in details it would have been impossible to know from afar," said Carol Raymond, deputy principal investigator at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Dawn's residence at Vesta of nearly a year has made the asteroid's planet-like qualities obvious and shown us our connection to that bright orb in our night sky."

video
Dawn's Virtual Flight over Vesta

This movie uses data from NASA's Dawn spacecraft to simulate the view from the spacecraft flying over the surface of the giant asteroid Vesta. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

Scientists now see Vesta as a layered, planetary building block with an iron core – the only one known to survive the earliest days of the solar system. The asteroid's geologic complexity can be attributed to a process that separated the asteroid into a crust, mantle and iron core with a radius of approximately 68 miles (110 kilometers) about 4.56 billion years ago. The terrestrial planets and Earth's moon formed in a similar way.

Dawn observed a pattern of minerals exposed by deep gashes created by space rock impacts, which may support the idea the asteroid once had a subsurface magma ocean. A magma ocean occurs when a body undergoes almost complete melting, leading to layered building blocks that can form planets. Other bodies with magma oceans ended up becoming parts of Earth and other planets.

video
Touring Vesta's Craters. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/PSI.

Data also confirm a distinct group of meteorites found on Earth did, as theorized, originate from Vesta. The signatures of pyroxene, an iron- and magnesium-rich mineral, in those meteorites match those of rocks on Vesta's surface. These objects account for about 6 percent of all meteorites seen falling on Earth.

This makes the asteroid one of the largest single sources for Earth's meteorites. The finding also marks the first time a spacecraft has been able to visit the source of samples after they were identified on Earth.

Scientists now know Vesta's topography is quite steep and varied. Some craters on Vesta formed on very steep slopes and have nearly vertical sides, with landslides occurring more frequently than expected.


This image shows three slices of a class of meteorites that fell to Earth that NASA's Dawn mission has confirmed as originating from the giant asteroid Vesta. Image credit: University of Tennessee.

Another unexpected finding was that the asteroid's central peak in the Rheasilvia basin in the southern hemisphere is much higher and wider, relative to its crater size, than the central peaks of craters on bodies like our moon. Vesta also bears similarities to other low-gravity worlds like Saturn's small icy moons, and its surface has light and dark markings that don't match the predictable patterns on Earth's moon.

"We know a lot about the moon and we're only coming up to speed now on Vesta," said Vishnu Reddy, a framing camera team member at the Max Planck Institute for Solar System Research in Germany and the University of North Dakota in Grand Forks. "Comparing the two gives us two storylines for how these fraternal twins evolved in the early solar system."

Vesta's Internal Structure

Image above: This artist's concept shows the internal structure of the giant asteroid Vesta, based on data from NASA's Dawn mission. Dawn shows that Vesta has an iron core that is about 68 miles (110 kilometers) in radius, suggesting that Vesta completely melted in its early history, allowing iron to sink to form the core and producing a basaltic crust.

Dawn has revealed details of ongoing collisions that battered Vesta throughout its history. Dawn scientists now can date the two giant impacts that pounded Vesta's southern hemisphere and created the basin Veneneia approximately 2 billion years ago and the Rheasilvia basin about 1 billion years ago. Rheasilvia is the largest impact basin on Vesta.

"The large impact basins on the moon are all quite old," said David O'Brien, a Dawn participating scientist from the Planetary Science Institute in Tucson, Ariz. "The fact that the largest impact on Vesta is so young was surprising."


Image above: The giant asteroid Vesta is shown here as the smallest body among other similar bodies in the solar system: Mars, Mercury, Earth's moon and the dwarf planet Ceres. Image credit: NASA/JPL-Caltech/UCLA.

Launched in 2007, Dawn began exploring Vesta in mid-2011. The spacecraft will depart Vesta on August 26 for its next study target, the dwarf planet Ceres, in 2015.

Dawn's mission to Vesta and Ceres is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program managed by NASA's Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. in 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 international partners on the mission team. The California Institute of Technology in Pasadena manages JPL for NASA.

Image gallery: http://www.nasa.gov/mission_pages/dawn/multimedia/gallery-index.html

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

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

Greetings, Orbiter.ch

Cygnus-X: the cool swan glowing in flight












ESA - Herschel Mission patch.

10 May 2012

 Herschel’s swan (click on the image foe enlarge)

Chaotic networks of dust and gas signpost the next generations of massive stars in this stunning new image of the Cygnus-X star-nursery captured by ESA’s Herschel space observatory.

Cygnus-X is an extremely active region of massive-star birth some 4500 light-years from Earth in the constellation of Cygnus, the Swan.

Using Herschel’s far-infrared eyes, astronomers can seek out regions where dust has been gently heated by stars, pointing them to dense clumps of gas where new generations of stars are forming.

Bright white areas highlight zones where large stars have recently formed out of turbulent clouds, especially evident in the chaotic network of filaments seen in the right-hand portion of the image.

Here, dense knots of gas and dust mark intersections where filaments meet and collapse to form new stars, and where bubble-like structures are carved by their immense radiation.

In the centre of the image, fierce radiation and powerful stellar winds from stars undetected at Herschel’s wavelengths have partly cleared and heated interstellar material, which then glows blue in this representation.

Herschel’s swan, annotated

The left-hand part of the scene is dominated by a pillar of gas whose shape resembles that of the neck of a swan. 

Below and to the right, a shell of gas and dust has likely been ejected from a supergiant star at its centre, but which is not seen directly in this image.

Strings of compact red objects scattered throughout the scene map the cold seeds of future generations of stars.

The image combines data acquired with the PACS instrument at 70 microns (corresponding to the blue channel) and 160 microns (corresponding to the green channel) and with the SPIRE instrument at 250 microns (corresponding to the red channel). It highlights the unique capabilities of Herschel to probe the birth of large stars and their influence on the surrounding interstellar material with a level of detail at far-infrared wavelengths that has never before been available.

Related links:

Herschel: ESA's giant infrared observatory: http://www.esa.int/SPECIALS/Herschel/index.html

Herschel in depth: http://sci.esa.int/science-e/www/area/index.cfm?fareaid=16

Why infrared astronomy is a hot topic: http://www.esa.int/esaSC/SEMX9PZO4HD_index_0.html

L2, the second Lagrangian Point: http://www.esa.int/esaSC/SEMO4QS1VED_index_0.html

Herschel on YouTube:

Inside Herschel: http://www.youtube.com/watch?v=j9_VBKn8Jq4&feature=PlayList&p=CD471914889C152B&index=1

Herschel mission objectives: http://www.youtube.com/watch?v=YyEpV1_CH4w&feature=PlayList&p=CD471914889C152B&index=5

Images, Text, Credits: ESA/PACS/SPIRE/Martin Hennemann & Frédérique Motte, Laboratoire AIM Paris-Saclay, CEA/Irfu – CNRS/INSU – Univ. Paris Diderot, France.

Greetings, Orbiter.ch

NASA Mars Spacecraft Detects Large Changes in Martian Sand Dunes












NASA - Mars Reconnaissance Orbiter (MRO) patch.

May 10, 2012

NASA's Mars Reconnaissance Orbiter (MRO) has revealed that movement in sand dune fields on the Red Planet occurs on a surprisingly large scale, about the same as in dune fields on Earth.

This is unexpected because Mars has a much thinner atmosphere than Earth, is only about one percent as dense, and its high-speed winds are less frequent and weaker than Earth's.

For years, researchers debated whether or not sand dunes observed on Mars were mostly fossil features related to past climate, rather than currently active. In the past two years, researchers using images from MRO's High Resolution Imaging Science Experiment (HiRISE) camera have detected and reported sand movement.


Back-and-forth blinking of this two-image animation shows movement of a sand dune on Mars. Image credit: NASA/JPL-Caltech/Univ. of Arizona/JHU-APL.

Now, scientists using HiRISE images have determined that entire dunes as thick as 200 feet are moving as coherent units across the Martian landscape. The study was published online today by the journal Nature.

"This exciting discovery will inform scientists trying to better understand the changing surface conditions of Mars on a more global scale," said Doug McCuistion, director of NASA's Mars Exploration Program in Washington. "This improved understanding of surface dynamics will provide vital information in planning future robotic and human Mars exploration missions."

Researchers analyzed before-and-after images using a new software tool developed at the California Institute of Technology (Caltech) in Pasadena. The tool measured changes in the position of sand ripples, revealing the ripples move faster the higher up they are on a dune.

The study examined images taken in 2007 and 2010 of the Nili Patera sand dune field located near the Martian equator. By correlating ripples' movement to their position on the dune, the analysis determined the entire dunes are moving. This allows researchers to estimate the volume, or flux, of moving sand.

"We chose Nili Patera because we knew there was sand motion going on there, and we could quantify it," said Nathan Bridges, a planetary scientist at Johns Hopkins University Applied Physics Laboratory in Laurel, Md., and lead author of the Nature paper. "The Nili dunes also are similar to dunes in places like Antarctica and to other locations on Mars."


The before-and-after images were taken 15 weeks apart by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter. Image credit: NASA/JPL-Caltech/Univ. of Arizona/JHU-APL.

The study adds important information about the pace at which blowing sand could be actively eroding rocks on Mars. Using the new information about the volume of sand that is moving, scientists estimate rocks in Nili Patera would be worn away at about the same pace as rocks near sand dunes in Antarctica, where similar sand fluxes occur.

"Our new data shows wind activity is indeed a major agent of evolution of the landscape on Mars," said Jean-Philippe Avouac, Caltech team leader. "This is important because it tells us something about the current state of Mars and how the planet is working today, geologically."

Scientists calculate that if someone stood in the Nili Patera dunes and measured out a one-yard width, they would see more than two cubic yards of sand pass by in an Earth year, about as much as in a children's sand box.

"No one had estimates of this flux before," said Bridges. "We had seen with HiRISE that there was dune motion, but it was an open question how much sand could be moving. Now, we can answer that."

Mars Reconnaissance Orbiter (MRO). Credit: NASA/JPL.

Scientists will use the information to understand broader mysteries on Mars, like why so much of the surface appears heavily eroded, how that occurred, and whether it is a current process or it was done in the past. Scientists can now point to sand flux as a mechanism capable of creating significant erosion today on the Red Planet.

The HiRISE camera provides unprecedented resolution in studying the Martian landscape. NASA's Jet Propulsion Laboratory manages MRO for NASA's Science Mission Directorate in Washington. Lockheed Martin Space Systems, Denver, built the spacecraft. HiRISE is operated by the University of Arizona and was built by Ball Aerospace & Technologies Corp., Boulder, Colo.

For related images and more information about MRO, visit: http://www.nasa.gov/mro

Animations (mentioned), Image, Text, Credits: NASA / Dwayne Brown / JPL / Guy Webster / Johns Hopkins University Applied Physics Laboratory / Geoff Brown.

Cheers, Orbiter.ch

Saturn's Brightly Reflective Moon Enceladus








NASA / ESA - Cassini Insider's Mission logo.

May 10, 2012


A brightly reflective Enceladus appears before Saturn's rings, while the planet's larger moon Titan looms in the distance.

Jets of water ice and vapor emanating from the south pole of Enceladus, which hint at subsurface sea rich in organics, and liquid hydrocarbons ponding on the surface on the surface of Titan make these two of the most fascinating moons in the Saturnian system.

Enceladus (313 miles, or 504 kilometers across) is in the center of the image. Titan (3,200 miles, or 5,150 kilometers across) glows faintly in the background beyond the rings. This view looks toward the anti-Saturn side of Enceladus and the Saturn-facing side of Titan. The northern, sunlit side of the rings is seen from just above the ringplane.

The image was taken in visible green light with the Cassini spacecraft narrow-angle camera on March 12, 2012. The view was acquired at a distance of approximately 600,000 miles (1 million kilometers) from Enceladus and at a Sun-Enceladus-spacecraft, or phase, angle of 36 degrees. Image scale is 4 miles (6 kilometers) per pixel on Enceladus.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the mission for NASA's Science Mission Directorate in Washington. The imaging team is based at the Space Science Institute in Boulder, Colo.

For information about Cassini, visit: http://www.nasa.gov/cassini and http://www.esa.int/esaMI/Cassini-Huygens/

Image, Text, Credit: NASA / ESA / JPL-Caltech / Space Science Institute.

Best regards, Orbiter.ch

mercredi 9 mai 2012

Overfed Black Holes Shut Down Galactic Star-Making










ESA / NASA - Herschel Mission patch.

9 May 2012


This artistically modified image of the local galaxy Arp 220, captured by the Hubble Space Telescope, helps illustrate the Herschel results. Image credit: NASA/JPL-Caltech.

The Herschel Space Observatory has shown galaxies with the most powerful, active black holes at their cores produce fewer stars than galaxies with less active black holes. The results are the first to demonstrate black holes suppressed galactic star formation when the universe was less than half its current age. Herschel is a European Space Agency-led mission with important NASA contributions.

"We want to know how star formation and black hole activity are linked," said Mathew Page of University College London's Mullard Space Science Laboratory in the United Kingdom and lead author of a paper describing these findings in this week's journal Nature. "The two processes increase together up to a point, but the most energetic black holes appear to turn off star formation."

Supermassive black holes, weighing as much as millions of suns, are believed to reside in the hearts of all large galaxies. When gas falls upon these monsters, the material is accelerated and heated around the black hole, releasing great torrents of energy. Earlier in the history of the universe, these giant, luminous black holes, called active galactic nuclei, were often much brighter and more energetic. Star formation was also livelier back then.

Studies of nearby galaxies suggest active black holes can squash star formation. The revved-up, central black holes likely heat up and disperse the galactic reservoirs of cold gas needed to create new stars. These studies have only provided "snapshots" in time, however, leaving the overall relationship of active galactic nuclei and star formation unclear, especially over the cosmic history of galaxy formation.

"To understand how active galactic nuclei affect star formation over the history of the universe, we investigated a time when star formation was most vigorous, between eight and 12 billion years ago," said co-author James Bock, a senior research scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif., and co-coordinator of the Herschel Multi-tiered Extragalactic Survey. "At that epoch, galaxies were forming stars 10 times more rapidly than they are today on average. Many of these galaxies are incredibly luminous, more than 1,000 times brighter than our Milky Way."

For the new study, Page and colleagues used Herschel data that probed 65 galaxies at wavelengths equivalent to the thickness of several sheets of office paper, a region of the light spectrum known as far-infrared. These wavelengths reveal the rate of star formation, because most of the energy released by developing stars heats surrounding dust, which then re-radiates starlight out in far-infrared wavelengths.

Herschel

The researchers compared their infrared readings with X-rays streaming from the active central black holes in the survey's galaxies, measured by NASA's Chandra X-ray Observatory. At lower intensities, the black holes' brightness and star formation increased in sync. However, star formation dropped off in galaxies with the most energetic central black holes. Astronomers think inflows of gas fuel new stars and supermassive black holes. Feed a black hole too much, however, and it starts spewing radiation into the galaxy that prevents raw material from coalescing into new stars.

"Now that we see the relationship between active supermassive black holes and star formation, we want to know more about how this process works," said Bill Danchi, Herschel program scientist at NASA Headquarters in Washington. "Does star formation get disrupted from the beginning with the formation of the brightest galaxies of this type, or do all active black holes eventually shut off star formation, and energetic ones do this more quickly than less active ones?"

Herschel is a European Space Agency cornerstone mission, with science instruments provided by consortia of European institutes and important participation by NASA. NASA's Herschel Project Office is based at JPL. JPL contributed mission-enabling technology for two of Herschel's three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at Caltech, supports the United States astronomical community. Caltech manages JPL for NASA.

For NASA's Herschel website, visit http://www.nasa.gov/herschel . For ESA's Herschel website, visit http://www.esa.int/SPECIALS/Herschel .

Images, Text, Credits: ESA / NASA / J.D. Harrington / JPL / Whitney Clavin.

Cheers, Orbiter,ch

ESA declares end of mission for Envisat









ESA - ENVISAT Mission logo.

9 May 2012

Just weeks after celebrating its tenth year in orbit, communication with the Envisat satellite was suddenly lost on 8 April. Following rigorous attempts to re-establish contact and the investigation of failure scenarios, the end of the mission is being declared.

A team of engineers has spent the last month attempting to regain control of Envisat, investigating possible reasons for the problem.

Despite continuous commands sent from a widespread network of ground stations, there has been no reaction yet from the satellite.

As there were no signs of degradation before the loss of contact, the team has been collecting other information to help understand the satellite’s condition. These include images from ground radar and the French Pleiades satellite.

Envisat

With this information, the team has gradually elaborated possible failure scenarios. One is the loss of the power regulator, blocking telemetry and telecommands.

Another scenario is a short circuit, triggering a ‘safe mode’ – a special mode ensuring Envisat’s survival. A second anomaly may have occurred during the transition to safe mode, leaving the satellite in an intermediate and unknown condition.

Although chances of recovering Envisat are extremely low, the investigation team will continue attempts to re-establish contact while considering failure scenarios for the next two months.

The outstanding performance of Envisat over the last decade led many to believe that it would be active for years to come, at least until the launch of the follow-on Sentinel missions. 

However, Envisat had already operated for double its planned lifetime, making it well overdue for retirement.

With ten sophisticated sensors, Envisat has observed and monitored Earth’s land, atmosphere, oceans and ice caps during its ten-year lifetime, delivering over a thousand terabytes of data.

Last image before loss of contact

An estimated 2500 scientific publications so far have been based on this information, furthering our knowledge of the planet.

During those ten years, Envisat witnessed the gradual shrinking of Arctic sea ice and the regular opening of the polar shipping routes during summer months.

Together with other satellites, it monitored the global sea-level height and regional variations, as well as global sea-surface temperatures with a precision of a few tenths of a degree.

Years of Envisat data have led to a better understanding of ocean currents and chlorophyll concentrations.

In the atmosphere, the satellite observed air pollution increase in Asia and its stability in Europe and North America, and measured carbon dioxide and methane concentrations. Envisat also monitored the Antarctica ozone hole variations.

video

Over land, it mapped the speed of ice streams in Antarctica and Greenland. Its images were used regularly to update the global maps of land use, including the effects of deforestation.

Using its imaging radar, Envisat mapped ground displacements triggered by earthquakes and volcanic eruptions, improving understanding of tectonics and volcanic mechanisms.

Envisat provided crucial Earth observation data not only to scientists, but also to many operational services, such as monitoring floods and oil spills. Its data were used for supporting civil protection authorities in managing natural and man-made disasters.

Envisat has also contributed valuable information to the services within Europe’s Global Monitoring for Environmental Security (GMES) programme, paving the way for the next generation of satellites.

Now with the end of the mission, the launch of the upcoming GMES Sentinel satellites has become even more urgent to ensure the continuity of data to users, improve the management of the environment, understand and mitigate the effects of climate change and ensure civil security.

Related missions:
Envisat: http://www.esa.int/esaEO/SEMWYN2VQUD_index_0_m.html

Sentinels: http://www.esa.int/esaEO/SEMTOMASS2G_index_0_m.html

Global Monitoring for Environment and Security (GMES): http://www.esa.int/esaLP/LPgmes.html

Images, Video, Text, Credits: ESA / Edisoft /Arianespace.

Greetings, Orbiter.ch

VISTA Views a Vast Ball of Stars












ESO - European Southern Observatory logo.

9 May 2012

 VISTA infrared image of the globular star cluster Messier 55

A new image of Messier 55 from ESO's VISTA infrared survey telescope shows tens of thousands of stars crowded together like a swarm of bees. Besides being packed into a relatively small space, these stars are also among the oldest in the Universe. Astronomers study Messier 55 and other ancient objects like it, called globular clusters, to learn how galaxies evolve and stars age.

Globular clusters are held together in a tight spherical shape by gravity. In Messier 55, the stars certainly do keep close company: approximately one hundred thousand stars are packed within a sphere with a diameter of only about 25 times the distance between the Sun and the nearest star system, Alpha Centauri.

The globular star cluster Messier 55 in the constellation of Sagittarius

About 160 globular clusters have been spotted encircling our galaxy, the Milky Way, mostly toward its bulging centre. The two latest discoveries, made using VISTA, were recently announced (eso1141). The largest galaxies can have thousands of these rich collections of stars in orbit around them.

Observations of globular clusters' stars reveal that they originated around the same time — more than 10 billion years ago — and from the same cloud of gas. As this formative period was just a few billion years after the Big Bang, nearly all of the gas on hand was the simplest, lightest and most common in the cosmos: hydrogen, along with some helium and much smaller amounts of heavier chemical elements such as oxygen and nitrogen.

 Wide-field view of the sky around the globular star cluster Messier 55

Being made mostly from hydrogen distinguishes globular cluster residents from stars born in later eras, like our Sun, that are infused with heavier elements created in earlier generations of stars. The Sun lit up some 4.6 billion years ago, making it only about half as old as the elderly stars in most globular clusters. The chemical makeup of the cloud from which the Sun formed is reflected in the abundances of elements found throughout the Solar System — in asteroids, in the planets and in our own bodies.

Sky watchers can find Messier 55 in the constellation of Sagittarius (The Archer). The notably large cluster appears nearly two-thirds the width of the full Moon, and is not at all difficult to see in a small telescope, even though it is located at a distance of about 17 000 light-years from Earth.

video
Zooming in on the globular star cluster Messier 55

The French astronomer Nicolas Louis de Lacaille first documented the stellar grouping around 1752, and some 26 years later another French astronomer, Charles Messier, included the cluster as the 55th entry in his famous astronomical catalogue. The object is also cross-listed as NGC 6809 in the New General Catalogue, an often-cited and more extensive astronomical catalogue created in the late nineteenth century.

video
Panning across VISTA’s infrared image of the globular star cluster Messier 55

The new image was obtained in infrared light by the 4.1-metre Visible and Infrared Survey Telescope for Astronomy (VISTA, eso0949) at ESO's Paranal Observatory in northern Chile.

As well as the stars of Messier 55, this VISTA image also records many galaxies lying far beyond the cluster. A particularly prominent edge-on spiral galaxy appears to the upper right of the centre of the picture.

More information:

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

Links:

    Photos of VISTA: http://www.eso.org/public/images/archive/search/?adv=&subject_name=Visible%20and%20Infrared%20Survey%20Telescope%20for%20Astronomy

    Image of other objects from VISTA: http://www.eso.org/public/images/archive/search/?adv=&facility=30

Images, Text, Credits: ESO/J. Emerson/Richard Hook/VISTA. Acknowledgment: Cambridge Astronomical Survey Unit/IAU and Sky & Telescope/Digitized Sky Survey 2/Videos: ESO and Digitized Sky Survey 2/J. Emerson/VISTA/Nick Risinger (skysurvey.org) Acknowledgment: Cambridge Astronomical Survey Unit Music: Compass by Disasterpeace (www.disasterpeace.com).

Greetings, Orbiter.ch

mardi 8 mai 2012

TDRS-4 Mission Complete; Spacecraft Retired From Active Service













NASA - TDRS 4 Mission patch.

May 8, 2012

The Tracking and Data Relay Satellite 4 (TDRS-4) recently completed almost 23 years of operations support and successfully completed end-of-mission de-orbit and decommissioning activities. TDRS-4's operational life span was well beyond its original 10-year design.

Launched on March 13, 1989, from onboard Space Shuttle Discovery, TDRS-4 operated in geosynchronous (GEO) altitude at more than 22,000 miles above the Atlantic Ocean region. As part of the spacecraft's end-of-mission activities, its orbit was raised above the congested geosynchronous orbit.

An Artist Rendering of TDRS-4. Credit: NASA

TDRS-4 was forced to retire after the loss of one of three Nickel-Cadmium (24 cell) batteries and the reduction in storage capacity for the two remaining batteries that power the satellite. Retirement for the satellite consisted of excess fuel depletion, disconnecting batteries, and powering down the Radio Frequency Transmitters and receivers so that the satellite is completely and permanently passive. This ensures the satellite will never interfere with other satellites from the radio frequency perspective.

This is the second retirement from within the fleet of TDRS. The fleet of seven remaining satellites operates through a supporting ground system and together they make up the Space Network (SN). The SN provides highly automated, user-driven services supporting customer spacecraft with tracking and data acquisition. The network supports a varied number of missions, including the International Space Station, Hubble Space Telescope, launch vehicles, and a variety of other science missions. The SN also provided primary communication support to the Space Shuttle Project.

"The Space Network spacecraft engineering and operations teams worked together very effectively to execute a practically flawless decommissioning of an incredible satellite," says Mike Rackley, SN deputy project manager at NASA's Goddard Space Flight Center, Greenbelt, Md. "TDRS-4 made great and important contributions to NASA's human spaceflight and science missions. We will certainly miss her."

This is the second end-of-mission execution for the fleet of aging first generation TDRS spacecraft. TDRS-4's retirement was preceded by TDRS-1, which was decommissioned and raised to its permanent orbit in June 2010.

A total of six first generation spacecraft were successfully placed into orbit from April 1983 through July 1995, of which four are still active. The spacecraft are approaching the end of their operational life span but they are supplemented by three, second-generation spacecraft.

Together they provide customers with global space to ground communication services.

TDRS-4 onboard space shuttle Discovery about to deploy during STS-29. Credit: NASA

To continue this critical lifeline, NASA has contracted Boeing to build three additional follow-on TDRS spacecraft, replenishing TDRS-1 and TDRS-4, and expanding NASA's communication services. TDRS-K is scheduled for launch in December of this year followed by TDRS-L in 2013 and TDRS-M in 2015.

The SN is managed by GSFC and its primary ground communications facility is located at the White Sands Complex in Las Cruses, NM. The Human Exploration and Operations Mission Directorate and the Space Communications and Navigation Program at NASA Headquarters fund NASA's Space Network.

Images (mentioned), Text, Credit: NASA's Goddard Space Flight Center / Nicole Hagey and Dewayne Washington.

Best regards, Orbiter.ch

NASA's Spitzer Sees the Light of Alien "Super Earth"












NASA - SPITZER Space Telescope patch.

May 8, 2012

NASA's Spitzer Space Telescope has detected light emanating from a "super-Earth" planet beyond our solar system for the first time. While the planet is not habitable, the detection is a historic step toward the eventual search for signs of life on other planets.

video
Super Earth Reveals Itself to Spitzer. Credit: NASA/JPL-Caltech

This artist's animation depicts 55 Cancri e as it orbits its star. The planet whips around the star closely and quickly: It is 25 times closer to the star than Mercury is to our sun and completes one orbit -- its year -- in a mere 18 hours.

"Spitzer has amazed us yet again," said Bill Danchi, Spitzer program scientist at NASA Headquarters in Washington. "The spacecraft is pioneering the study of atmospheres of distant planets and paving the way for NASA's upcoming James Webb Space Telescope to apply a similar technique on potentially habitable planets."

The planet, called 55 Cancri e, falls into a class of planets termed super Earths, which are more massive than our home world but lighter than giant planets like Neptune. Fifty-five Cancri e is about twice as big and eight times as massive as Earth. The planet orbits a bright star, called 55 Cancri, in a mere 18 hours.

Previously, Spitzer and other telescopes were able to study the planet by analyzing how the light from 55 Cancri changed as the planet passed in front of the star. In the new study, Spitzer measured how much infrared light comes from the planet itself. The results reveal the planet is likely dark and its sun-facing side is more than 2,000 Kelvin (3,140 degrees Fahrenheit), hot enough to melt metal.


Image above: Seen here in this artist's concept, the planet is called 55 Cancri e. It's a toasty world that rushes around its star every 18 hours. Image credit: NASA/JPL-Caltech.

The new information is consistent with a prior theory that 55 Cancri e is a water world: a rocky core surrounded by a layer of water in a "supercritical" state where it is both liquid and gas, and topped by a blanket of steam.

"It could be very similar to Neptune, if you pulled Neptune in toward our sun and watched its atmosphere boil away," said Michaël Gillon of Université de Liège in Belgium, principal investigator of the research, which appears in the Astrophysical Journal. The lead author is Brice-Olivier Demory of the Massachusetts Institute of Technology in Cambridge.

The 55 Cancri system is relatively close to Earth at 41 light-years away. It has five planets, with 55 Cancri e being the closest to the star and tidally locked, so one side always faces the star. Spitzer discovered the sun-facing side is extremely hot, indicating the planet probably does not have a substantial atmosphere to carry the sun's heat to the unlit side.

NASA's James Webb Space Telescope, scheduled to launch in 2018, likely will be able to learn even more about the planet's composition. The telescope might be able to use a similar infrared method as Spitzer to search other potentially habitable planets for signs of molecules possibly related to life.

"When we conceived of Spitzer more than 40 years ago, exoplanets hadn't even been discovered," said Michael Werner, Spitzer project scientist at NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif. "Because Spitzer was built very well, it's been able to adapt to this new field and make historic advances such as this."


This plot of data from NASA's Spitzer Space Telescope reveals the light from a "super Earth" called 55 Cancri e. Image credit: NASA/JPL-Caltech/MIT.

In 2005, Spitzer became the first telescope to detect light from a planet beyond our solar system. To the surprise of many, the observatory saw the infrared light of a "hot Jupiter," a gaseous planet much larger than the solid 55 Cancri e. Since then, other telescopes, including NASA's Hubble and Kepler space telescopes, have performed similar feats with gas giants using the same method.

In this method, a telescope gazes at a star as a planet circles behind it. When the planet disappears from view, the light from the star system dips ever so slightly, but enough that astronomers can determine how much light came from the planet itself. This information reveals the temperature of a planet, and, in some cases, its atmospheric components. Most other current planet-hunting methods obtain indirect measurements of a planet by observing its effects on the star.

During Spitzer's ongoing extended mission, steps were taken to enhance its unique ability to see exoplanets, including 55 Cancri e. Those steps, which included changing the cycling of a heater and using an instrument in a new way, led to improvements in how precisely the telescope points at targets.

JPL manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate in Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology (Caltech) 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://www.nasa.gov/spitzer and http://spitzer.caltech.edu/ . More information about exoplanets and NASA's planet-finding program is at http://planetquest.jpl.nasa.gov .

Images (mentioned), Video (mentioned), Credits: NASA / J.D. Harrington / JPL / Whitney Clavin.

Cheers, Orbiter.ch

Keeping immune cells alive and kicking












ESA - PromJSSe Mission patch.

8 May 2012

New results from research on the International Space Station are offering clues on why astronauts’ immune systems don’t work as well in space. The findings may benefit the elderly on Earth.

Astronauts suffer many types of stress adapting to weightlessness. For years, scientists have known that our immune system works less well in space, and trying to find the reason is a driving force for space research.

André freezing blood samples

Researchers at the University of Teramo, the European Centre for Brain Research and the Santa Lucia Foundation have discovered that a particular enzyme, called 5-LOX, becomes more active in weightlessness. 

The 5-LOX enzyme in part regulates the life expectancy of human cells. Most human cells divide and regenerate but the number of times they replicate is limited.

Could a change in 5-LOX enzyme activity affect astronauts’ health in space?

To find out, the researchers needed to test their theory in the only laboratory that can ‘switch off’ gravity: the International Space Station.

Target locked on 5-LOX

Blood samples from two healthy donors were sent to the orbital outpost. One set was exposed to weightlessness for two days, while the other was held in a small centrifuge to simulate Earth-like gravity. The samples were then frozen and sent back to Earth for analysis.

Blood samples

As predicted, the weightless samples showed more 5-LOX activity than the centrifuged samples and a set that had remained on the ground. In fact, the centrifuged samples remained identical to the ground samples.

Professor Mauro Maccarrone from the University of Teramo explains, “We now have a target enzyme that could play a real role in causing weakened immune systems.

“The 5-LOX enzyme can be blocked with existing drugs, so using these findings to improve human health could be a close reality.”

Space centrifuge

Research will continue on the 5-LOX enzyme and related compounds. A follow-up experiment returned to Earth in a Soyuz capsule with the Expedition 30 crew last week. Scientists will look for other changes in the cells to understand the underlying mechanisms fully.

Limiting biological activity of cell signals such as those controlled by 5-LOX might even slow parts of the ageing process.

These findings are being shared with the scientific community, especially researchers studying people with reduced immune response. The chances are that elderly people could benefit from this field of investigation.

Partner universities:

University of Teramo: http://www.unite.it/english_version/home01.htm

European Centre for Brain Research: http://www.ebri.it/

Search experiments:

Experiment archive: http://eea.spaceflight.esa.int/

Human Spaceflight Research / Erasmus Centre: http://www.esa.int/SPECIALS/HSF_Research/index.html

Human Spaceflight: http://www.esa.int/esaHS/index.html

International Space Station: http://www.esa.int/esaHS/iss.html

International Space Station Benefits for Humanity: http://www.esa.int/SPECIALS/ISSBenefits/index.html

Follow André!:

Follow André's mission: http://www.esa.int/SPECIALS/PromISSe/SEM2N1WWVUG_0.html

André's blog: http://blogs.esa.int/andre-kuipers/?lang=en

PromISSe blog: http://blogs.esa.int/promisse

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

Images, Text, Credits: ESA / J. Hatton / NASA.

Greetings, Orbiter.ch

dimanche 6 mai 2012

Hubble to Use Moon as Mirror to See Venus Transit











NASA - Hubble Space Telescope patch.

May 6, 2012


This mottled landscape showing the impact crater Tycho is among the most violent-looking places on our Moon. Credit: NASA / ESA/ D. Ehrenreich.

This mottled landscape showing the impact crater Tycho is among the most violent-looking places on our moon. Astronomers didn't aim NASA's Hubble Space Telescope to study Tycho, however. The image was taken in preparation to observe the transit of Venus across the sun's face on June 5-6.

Hubble cannot look at the sun directly, so astronomers are planning to point the telescope at the Earth's moon, using it as a mirror to capture reflected sunlight and isolate the small fraction of the light that passes through Venus's atmosphere. Imprinted on that small amount of light are the fingerprints of the planet’s atmospheric makeup.

These observations will mimic a technique that is already being used to sample the atmospheres of giant planets outside our solar system passing in front of their stars. In the case of the Venus transit observations, astronomers already know the chemical makeup of Venus's atmosphere, and that it does not show signs of life on the planet. But the Venus transit will be used to test whether this technique will have a chance of detecting the very faint fingerprints of an Earth-like planet, even one that might be habitable for life, outside our solar system that similarly transits its own star. , Venus is an excellent proxy because it is similar in size and mass to our planet.

The astronomers will use an arsenal of Hubble instruments, the Advanced Camera for Surveys, Wide Field Camera 3, and Space Telescope Imaging Spectrograph, to view the transit in a range of wavelengths, from ultraviolet to near-infrared light. During the transit, Hubble will snap images and perform spectroscopy, dividing the sunlight into its constituent colors, which could yield information about the makeup of Venus's atmosphere.

Hubble will observe the moon for seven hours, before, during, and after the transit so the astronomers can compare the data. Astronomers need the long observation because they are looking for extremely faint spectral signatures. Only 1/100,000th of the sunlight will filter through Venus's atmosphere and be reflected off the moon.

This image, taken with Hubble's Advanced Camera for Surveys, reveals lunar features as small as roughly 560 feet (170 meters) across. The large "bulls-eye" near the top of the picture is the impact crater, caused by an asteroid strike about 100 million years ago. The bright trails radiating from the crater were formed by material ejected from the impact area during the asteroid collision. Tycho is about 50 miles (80 kilometers) wide and is circled by a rim of material rising almost 3 miles (5 kilometers) above the crater floor. The image measures 430 miles (700 kilometers) across, which is slightly larger than New Mexico.

Because the astronomers only have one shot at observing the transit, they had to carefully plan how the study would be carried out. Part of their planning included the test observations of the moon, made on Jan. 11, 2012, as shown in the release image.

Hubble Space Telescope (HST). Credit: NASA.

Hubble will need to be locked onto the same location on the moon for more than seven hours, the transit's duration. For roughly 40 minutes of each 96-minute orbit of Hubble around the Earth, the Earth occults Hubble's view of the moon. So, during the test observations, the astronomers wanted to make sure they could point Hubble to precisely the same target area.

This is the last time this century sky watchers can view Venus passing in front of the sun. The next transit won't happen until 2117. Venus transits occur in pairs, separated by eight years. The last event was witnessed in 2004.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Md., conducts Hubble science operations. STScI is operated by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.

For images and more information about Hubble’s view of the Moon and the Venus transit, visit:
http://hubblesite.org/news/2012/22

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

Images (mentioned), Text, Credit: NASA / Cheryl Gundy, STScI.

Best regards, Orbiter.ch