samedi 8 décembre 2012

Space control












Space collision.

Dec. 8, 2012

Not long ago, the ISS has been attacked from space. Unknown object, most likely a small meteorite, damaged solar panel ISS. Threats to the station and the astronauts living there. But there is reason to think about the creation of a global system of control and protection from space aliens.

It was not even a meteorite, but just a little splinter. However, the damage inflicted serious - Solar panels will probably be repaired. Micrometeors was so small that on Earth, its rapprochement with the space station is simply not noticed. And they could not see.

Astronaut Scott Parazynski repairs a damaged ISS solar panel (STS-120)

Russian space control system, the heart of which the Mission Control Center outside Moscow, captures only an approximation much larger objects.

"The screen parameters are visible to the dangerous proximity of the ISS space object - says Deputy Chief of Mission Control, Nikolai Sokolov. Here the picture shows the contours of the ISS, the contours of the debris and that at the moment of closest approach of about 12 kilometers. "

Locators on Earth can detect a body larger than 20 centimeters. Spent satellites, rocket stages and much more - all that is left of humanity on the Earth's orbit. When the intruder suddenly approaching the ISS at least 15 kilometers, he is hired to control here in the Queen, and in the U.S. Mission Control Center in Houston. If the distance is less, to make joint decisions on evasion ISS from dangerous objects.

Micrometeor impact

"If the probability of a collision with the ISS space debris greater than 10 -4 degrees, there is once more attention to this situation and take measures preparatory, - the director of the Institute of Astronomy of the Russian Academy of Sciences Boris Shustov. If 10 to -3, the measures are not only, say, the deviation of the orbit of the station. Even taken measures such as congestion in the transport vehicle. "

Over the past 4 years debris threatened the ISS 22 times. Maneuvers do not have to every time. Objects in space do not move in a straight line, and sometimes change the path, for example, under the influence of the atmosphere and the sun.

"The average speed of the ISS more than 7 kilometers per second", - says Nikolay Sokolov. Velocity of the debris in the same orbit about the same. Debris to move in different directions. And if we take the worst case, if it is moving toward the International Space Station, and he and the other object is traveling at more than 7 kilometers per second, and they are facing, the relative velocity is obtained about 15 kilometers per second. "

Caution, Danger Room, a space at the speed of the ram 5400 miles per hour. Even modern technology in a collision at speeds not survive. It is currently tested American communications satellite Iridium, which in 2009 was faced with already defunct Russian spacecraft Cosmos.

2009 Iridium & Cosmos spacecrafts collision

"The bullet 9 grams, if it does not fly, it does not represent any danger - emphasizes the general designer of space control Victor Shilin. 400 meters per second out of the trunk is released, it is deadly to humans. The same 9 grams of any fragment of a spacecraft that fly at a speed of 8 kilometers per second, it is 20 times faster than a bullet. They can affect not only the astronaut, and the spacecraft. "

Today, on the initiative of Russian Space Agency in the country developing a new system of space monitoring. Network of robotic telescopes and radars will monitor closely all the firmament and risk taking under the supervision of the objects that present a threat.

Satellite hits by micrometeors

"If there is a chance to avoid the collision and new damage, you have to use it, - says Victor Shilin. Not waste fuel, should actually spend money that additional supplies of fuel were on board. Or rely on something that will have a shorter life activity of the spacecraft, but the collision will happen, will not happen littering not only for himself but for all of humanity of those orbits in which we operate. One must study the garbage and try to get away, to avoid these collisions. "

Space debris is planetary. Ideas are born, how to clean the orbit, for example, launched into space automatic cleaner. But even if the human race will cease to launch rockets and satellites, existing objects in orbit will decay and eventually litter the space. To break through the Earth's orbit will be impossible.

Original text in Russian: http://www.federalspace.ru/main.php?id=2&nid=19747

Images, Text, Credits: Roskosmos TV Studio / ROSCOSMOS / NASA / Kinyen Pong / Translation: Orbiter.ch.

Best regards, Orbiter.ch

Successful liftoff of the ILS Proton-M & Yamal-402

ILS / ROSCOSMOS - Yamal 402 Mission poster.

Dec. 8, 2012

 ILS Proton-M & Yamal-402, ready for launch

December 8 at 17.13.43 MSK from the launch complex of the platform 200 Baikonur, we had a successful liftoff of the ILS Proton-M Breeze-M rocket, which is carrying the Yamal 402 satellite onboard.

video
Launch of Yamal-402 Satellite on Russian Proton-M

According to the flight cyclogram 17:23 MSK head unit in the Republic of Belarus Breeze-M and the satellite Yamal-402 cleanly separated from the third stage of the launch vehicle.

Yamal-402

Telecommunications satellite Yamal-402 will have to top up the grouping of domestic communications satellites and provide broadcasting to Russia, Western and Central Europe, the Middle East and North Africa.

Satellite Use:

At an orbital location of 55° east longitude, the Yamal 402 communications satellite will provide services to Russia, CIS countries, Europe, the Middle East and Africa. The all Ku-band satellite will have 66 equivalent 36 MHz transponders, which will compose 4 fixed beams (Russian, Northern, European, Southern) and 1 steerable beam. JSC Gazprom Space Systems has ensured the development of the ground infrastructure based on ground stations and technical control means provided by Thales Alenia Space. With the addition of the Yamal 402 JSC Gazprom Space Systems will strengthen their position in the global satellite industry.

Press Service of the Russian Federal Space Agency (Roscosmos PAO) report: http://www.federalspace.ru/main.php?id=2&nid=19751

For more information about ILS, visit: http://www.ilslaunch.com/

Images, Video, Text, Credits: Press Service of the Russian Federal Space Agency (Roscosmos PAO) / ILS / ILS TV / Translation: Orbiter.ch.

Greetings, Orbiter.ch

jeudi 6 décembre 2012

ISS - Saying "Godspeed" to a Spidernaut












ISS - International Space Station patch.

Dec. 6, 2012

"You have been my friend. That in itself is a tremendous thing. I wove my webs for you because I liked you. After all, what's a life, anyway? We're born, we live a little while, we die. A spider's life can't help being something of a mess, with all this trapping and eating flies. By helping you, perhaps I was trying to lift up my life a trifle. Heaven knows anyone's life can stand a little of that.”
-- E.B. White, Charlotte's Web.

Nefertiti didn't spin a web like Charlotte; her kind never could. But the red-back jumping spider earned a classy nickname, Spidernaut, as well as a bunk at the popular Insect Zoo of the National Museum of History of Washington for her out-of-this-world exploits.

(Credit: Julie Robinson)

Her move to the nation's capital in late November followed a 100-day mission aboard the International Space Station. There Nefertiti demonstrated that, like humans, her eight-legged species can adapt to the microgravity of space, then transition back to life on Earth.

On Dec. 3 the museum discovered that Nefertiti had died of natural causes. She lived for 10 months. Her species, Phidippus johnsoni, usually lives for one year.

Amr Mohammed of Alexandria, Egypt, proposed Neferiti's trip to the 250-mile-high station. The spider's trip is inspiring future generations of space explorers and scientists. Mohammed's proposal was one of two winning entries in the 2011 global YouTube SpaceLab contest. More than 2,000 students, ages 14 to 18, competed for the opportunity to fly an experiment to the space station based on two-minute YouTube videos explaining their research proposals.


Image above: Astronaut Suni Williams with the YouTube SpaceLab payload Spider Habitat where Nefertiti the spidernaut lived while she was on orbit. (Credit: NASA).

Mohammed, now 19, suggested that leaping insects like Salticus scenicus, the zebra jumping spider, and Phiddipus johnsoni, a red-back jumping variety, might have difficulty hunting in space before they adapted to microgravity. The red-backs are native to the grass, brush and woodlands of the western U.S. Spiders like Nefertiti hunt, not by spinning elaborate webs, but by vaulting towards their prey of smaller insects. They trail silk-like structures spun with their spinnerets and tacked to the leaves and logs from which they leap to serve as safety tethers.

Spidernaut Nefertiti. (Credit: NASA)

"The idea of sending an experiment to space is the most exciting thing I've ever heard of," Amr told Bill Nye, the Science Guy, in a YouTube Spacelab documentary on the student competition.

So Nefertiti traveled to the station on July 21 aboard an unpiloted HTV-3 cargo carrier launched from Tanegashima, Japan. She was housed in a multi-chambered enclosure that included a spider den, as well as an isolated compartment for her space prey, fruit flies.

NASA astronaut and Expedition 33 commander Sunita Williams kept tabs on Nefertiti while they were both in orbit. By activating small plungers, she could periodically release waves of fruit flies into the spider's den.

video
Nefertiti aboard the International Space Station in her experimental habitat

Nefertiti dined well, leaping towards the fruit flies, injecting them with a poison before feeding -- just as she would on Earth. Remnants of silken red-back safety tethers were evident everywhere.

"I saw her stalking a fruit fly," Williams explained in the documentary. "Unbeknownst to that poor little fruit fly, she was looking at it and getting real close. All of a sudden, she jumped right on him. It was amazing. So, I think the spiders absolutely adapted to space."

International Space Station (ISS). (Credit: NASA)

Nefertiti made history with her return to Earth, as well. She descended aboard the first SpaceX Commercial Resupply Services mission, splashing down on Oct. 28 in the Pacific Ocean. The spidernaut was removed from the Dragon capsule and returned to BioServe Space Technologies of Boulder, Colo., a collaborator on the spider investigation.

Kirk Johnson, the National Museum of Natural History's director, escorted Nefertiti to Washington. She was presented to the public on Nov. 29. She was put on display along with the home she lived in while in orbit.

Related links:

YouTube SpaceLab contest: http://www.nasa.gov/mission_pages/station/research/experiments/YouTube_Space_Lab.html

YouTube Spacelab documentary: http://www.youtube.com/watch?v=KCQVXEgSbrk

International Space Station: http://www.nasa.gov/mission_pages/station/main/index.html

Images (mentioned), Video, Text, Credit: NASA's Johnson Space Center.

Greetings, Orbiter.ch

Hubble sees a galaxy hit a bullseye












ESA - Hubble Space Telescope logo.

6 December 2012

 Hubble view of NGC 922

Bright pink nebulae almost completely encircle a spiral galaxy in this NASA/ESA Hubble Space Telescope image of NGC 922. The ring structure and the galaxy’s distorted spiral shape result from a smaller galaxy scoring a cosmic bullseye, hitting the centre of NGC 922 some 330 million years ago.

In Hubble’s image, NGC 922 clearly reveals itself not to be a normal spiral galaxy. The spiral arms are disrupted, a stream of stars extends out towards the top of the image, and a bright ring of nebulae encircles the core. Observing with NASA’s Chandra X-ray Observatory reveals more chaos in the form of ultraluminous X-ray sources dotted around the galaxy.

 Hubble and Chandra composite view of NGC 922 

NGC 922’s current unusual form is a result of a cosmic bullseye millions of years ago. A smaller galaxy, catalogued as 2MASXI J0224301-244443, plunged right through the heart of NGC 922 and shot out the other side. In wide-field views of the NGC 922, the small interloper can be still be seen shooting away from the scene of the crash.

As the small galaxy passed through the middle of NGC 922, it set up ripples that disrupted the clouds of gas, and triggered the formation of new stars whose radiation then lit up the remaining gas. The bright pink colour of the resulting nebulae is a characteristic sign of this process, and it is caused by excited hydrogen gas (the dominant element in interstellar gas clouds). This process of excitation and emission of light by gases is similar to that in neon signs.

 Wide-field view of the area around NGC 922 (ground-based image)

In theory, if two galaxies are aligned just right, with the small one passing through the centre of the larger one, the ring of nebulae should form a perfect circle, but more often the two galaxies are slightly off kilter, leading to a circle that, like this one, is noticeably brighter on one side than the other.

These objects, called collisional ring galaxies, are relatively rare in our cosmic neighbourhood. Although galaxy collisions and mergers are commonplace, the precise alignment and ratio of sizes necessary to form a ring like this is not, and the ring-like phenomenon is also thought to be relatively short-lived.

video
Zoom into NGC 922 

The chances of seeing one of these galaxies nearby is therefore quite low. Despite the immense number of galaxies in the Universe, this is one of only a handful known in our cosmic neighbourhood (the Cartwheel Galaxy, see potw1036a, being the most famous example). Observations of the more distant Universe (where we see further into the past) show that these rings were more common in the past, however.

video
 Pan across NGC 922

Hubble’s image of NGC 922 consists of a series of exposures taken in visible light with Hubble’s Wide Field Camera 3, and in visible and near-infrared light with the Wide Field and Planetary Camera 2.

Notes:

The Hubble Space Telescope is a project of international cooperation between ESA and NASA.

A version of this image was entered into the Hubble’s Hidden Treasures image processing competition by contestant Nick Rose.

Links:

Hubblecast 60: Galaxy scores a bullseye: http://www.spacetelescope.org/videos/heic1218a/

Images of Hubble: http://www.spacetelescope.org/images/archive/category/spacecraft/

For more information about Hubble Space Telescope, visit: http://www.spacetelescope.org

Images, Text, credit: NASA / CXC / ESA/ Acknowledgement: Nick Rose / Digitized Sky Survey 2 (Acknowledgement: Davide De Martin).

Greetings, Orbiter.ch

Image of the Carina Nebula Marks Inauguration of VLT Survey Telescope












ESO - European Southern Observatory logo.

6 December 2012

 The Carina Nebula imaged by the VLT Survey Telescope

A spectacular new image of the star-forming Carina Nebula has been captured by the VLT Survey Telescope at ESO’s Paranal Observatory and released on the occasion of the inauguration of the telescope in Naples today. This picture was taken with the help of Sebastián Piñera, President of Chile, during his visit to the observatory on 5 June 2012.

The VST inauguration

The latest telescope at ESO's Paranal Observatory in Chile — the VLT Survey Telescope (VST) — was inaugurated today at the Italian National Institute for Astrophysics (INAF) Observatory of Capodimonte, in Naples, Italy. The ceremony was attended by the Mayor of Naples, Luigi De Magistris, the INAF President, Giovanni Bignami, the ESO representatives Bruno Leibundgut and Roberto Tamai, and the main promoter of the telescope, Massimo Capaccioli of the University of Naples Federico II and INAF.

President Sebastián Piñera of Chile in the Paranal Control Room

The VST is a state-of-the-art 2.6-metre telescope, with the huge 268-megapixel camera OmegaCAM at its heart. It is designed to map the sky both quickly and with very fine image quality. The VST is a joint venture between ESO and INAF and OmegaCam has been provided by the OmegaCam consortium [1]. This new telescope is the largest telescope in the world exclusively dedicated to surveying the sky at visible wavelengths (eso1119). The occasion of the inauguration has been marked by the release of a dramatic picture of the Carina Nebula taken with the new telescope.

This star formation region is one of the most prominent and frequently imaged objects of the southern sky. It has been the subject of many earlier images with ESO telescopes (eso1208, eso1145, eso1031, eso0905). However, the glowing gas cloud is huge and it is difficult for most large telescopes to study more than a tiny part of it at once. This makes it an ideal target for the VLT Survey Telescope and its big camera, OmegaCAM. The VST delivers very sharp images because of its high quality optics and the excellent site. But, as it was designed for surveys of the sky, it also has a very wide field of view that can take in almost all of the Carina Nebula in a single picture.

The Carina Nebula in the constellation of Carina

This object was a natural target when the President of Chile, Sebastián Piñera, accompanied by the First Lady, Cecilia Morel, were distinguished guests at the Paranal Observatory on 5 June 2012 (eso1223) and participated in observations with the VST. The picture that the President helped to take on this occasion has now been combined with other recent VST images of the Carina Nebula to produce one of the most richly detailed and colourful views of this object ever created.

Digitized Sky Survey Image of Eta Carinae Nebula

The Carina Nebula is a huge stellar nursery lying about 7500 light-years from Earth in the constellation of Carina (The Keel) [2]. This cloud of glowing gas and dust is one of the closest star formation regions to the Earth and includes several of the brightest and most massive stars known. The Carina Nebula is a perfect laboratory for astronomers studying the violent births and early lives of stars.

video
Zooming in on the Carina Nebula

The conspicuous red colour of the picture comes from hydrogen gas in the nebula that is glowing under the harsh ultraviolet light from many young and hot stars [3]. Other colours, originating from other elements in the gas, are also visible, as well as many dust clouds. Just above the centre of the picture lies the bright star Eta Carinae (eso0817). This huge and highly unstable star brightened dramatically in the nineteenth century and is a good candidate for a future supernova explosion.

video
Panning across a VST image of the Carina Nebula

Notes:

[1] The VST programme was a joint venture between the INAF–Osservatorio Astronomico di Capodimonte, Naples, Italy and ESO. INAF designed and built the telescope with the collaboration of leading Italian industries and ESO was responsible for the enclosure and the civil engineering works at the site. OmegaCAM, the VST’s camera, was designed and built by a consortium including institutes in the Netherlands, Germany and Italy with major contributions from ESO. The new facility is operated by ESO, which also archives and distributes data from the telescope. For further details please refer to eso1119.

[2] Carina is the keel of the mythological ship Argo, of Jason and the Argonauts fame.

[3] The special filter for observing hydrogen emission was kindly made available by the VPHAS+ Consortium.

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 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:

    Photos of VST: http://www.eso.org/public/images/archive/search/?category=1111&adv=&description=VST

    Photos taken with the VST: http://www.eso.org/public/images/archive/search/?adv=&facility=62

    Photos of OmegaCAM: http://www.eso.org/public/images/archive/search/?category=1111&adv=&description=OmegaCAM

Images, Text, Credits: ESO / Enrico Cascone / Acknowledgement: VPHAS+ Consortium/Cambridge Astronomical Survey Unit/ IAU and Sky & Telescope / Digitized Sky Survey 2. Acknowledgment: Davide De Martin / Videos: ESO/Nick Risinger (skysurvey.org)/Digitized Sky Survey 2 . Music: John Dyson (from the album Moonwind). Acknowledgement: VPHAS+ Consortium/Cambridge Astronomical Survey Unit.

Best regards, Orbiter.ch

Fermi Improves its Vision for Thunderstorm Gamma-Ray Flashes











NASA - Fermi Gamma-ray Space Telescope logo.

Dec. 6, 2012

Thanks to improved data analysis techniques and a new operating mode, the Gamma-ray Burst Monitor (GBM) aboard NASA's Fermi Gamma-ray Space Telescope is now 10 times better at catching the brief outbursts of high-energy light mysteriously produced above thunderstorms.

The outbursts, known as terrestrial gamma-ray flashes (TGFs), last only a few thousandths of a second, but their gamma rays rank among the highest-energy light that naturally occurs on Earth. The enhanced GBM discovery rate helped scientists show most TGFs also generate a strong burst of radio waves, a finding that will change how scientists study this poorly understood phenomenon.

video
NASA Fermi's Finds Radio Bursts from Terrestrial Gamma-ray

Lightning in the clouds is directly linked to events that produce some of the highest-energy light naturally made on Earth: terrestrial gamma-ray flashes (TGFs). An instrument aboard NASA's Fermi Gamma-ray Space Telescope was recently fine-tuned to better catch TGFs, which allowed scientists to discover that TGFs emit radio waves, too.
Credit: NASA's Goddard Space Flight Center.

Before being upgraded, the GBM could capture only TGFs that were bright enough to trigger the instrument's on-board system, which meant many weaker events were missed.

"In mid-2010, we began testing a mode where the GBM directly downloads full-resolution gamma-ray data even when there is no on-board trigger, and this allowed us to locate many faint TGFs we had been missing," said lead researcher Valerie Connaughton, a member of the GBM team at the University of Alabama in Huntsville (UAH). She presented the findings Wednesday in an invited talk at the American Geophysical Union meeting in San Francisco. A paper detailing the results is accepted for publication in the Journal of Geophysical Research: Space Physics.

The results were so spectacular that on Nov. 26 the team uploaded new flight software to operate the GBM in this mode continuously, rather than in selected parts of Fermi's orbit.

Connaughton's team gathered GBM data for 601 TGFs from August 2008 to August 2011, with most of the events, 409 in all, discovered through the new techniques. The scientists then compared the gamma-ray data to radio emissions over the same period.

Lightning emits a broad range of very low frequency (VLF) radio waves, often heard as pop-and-crackle static when listening to AM radio. The World Wide Lightning Location Network (WWLLN), a research collaboration operated by the University of Washington in Seattle, routinely detects these radio signals and uses them to pinpoint the location of lightning discharges anywhere on the globe to within about 12 miles (20 km).

Scientists have known for a long time TGFs were linked to strong VLF bursts, but they interpreted these signals as originating from lightning strokes somehow associated with the gamma-ray emission.

"Instead, we've found when a strong radio burst occurs almost simultaneously with a TGF, the radio emission is coming from the TGF itself," said co-author Michael Briggs, a member of the GBM team.

Fermi Gamma-ray Space Telescope

The researchers identified much weaker radio bursts that occur up to several thousandths of a second before or after a TGF. They interpret these signals as intracloud lightning strokes related to, but not created by, the gamma-ray flash.

Scientists suspect TGFs arise from the strong electric fields near the tops of thunderstorms. Under certain conditions, the field becomes strong enough that it drives a high-speed upward avalanche of electrons, which give off gamma rays when they are deflected by air molecules.

"What's new here is that the same electron avalanche likely responsible for the gamma-ray emission also produces the VLF radio bursts, and this gives us a new window into understanding this phenomenon," said Joseph Dwyer, a physics professor at the Florida Institute of Technology in Melbourne, Fla., and a member of the study team.

Because the WWLLN radio positions are far more precise than those based on Fermi's orbit, scientists will develop a much clearer picture of where TGFs occur and perhaps which types of thunderstorms tend to produce them.

The GBM scientists predict the new operating mode and analysis techniques will allow them to catch about 850 TGFs each year. While this is a great improvement, it remains a small fraction of the roughly 1,100 TGFs that fire up each day somewhere on Earth, according to the team's latest estimates.

Likewise, TGFs detectable by the GBM represent just a small fraction of intracloud lightning, with about 2,000 cloud-to-cloud lightning strokes for every TGF.


This photograph, taken in May 2008 as the Fermi Gamma-ray Space Telescope was being readied for launch, highlights the detectors of the spacecraft's Gamma-ray Burst Monitor (GBM). The GBM is an array of 14 crystal detectors designed for transient lower-energy gamma-ray outbursts, such as TGFs. Credit: NASA/Jim Grossmann.

The Fermi Gamma-ray Space Telescope is an astrophysics and particle physics partnership and is managed by NASA's Goddard Space Flight Center in Greenbelt, Md. Fermi was developed in collaboration with the U.S. Department of Energy, with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden and the United States.

The GBM Instrument Operations Center is located at the National Space Science Technology Center in Huntsville, Ala. The GBM team includes a collaboration of scientists from UAH, NASA's Marshall Space Flight Center in Huntsville, the Max Planck Institute for Extraterrestrial Physics in Germany and other institutions.

Related Links:

Download video in HD formats from NASA Goddard's Scientific Visualization Studio: http://svs.gsfc.nasa.gov/vis/a010000/a011100/a011131/

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

Images, Video, Text, Credit: NASA's Goddard Space Flight Center / Francis Reddy.

Cheers, Orbiter.ch

Charitum Montes: a cratered winter wonderland












ESA - Mars Express Mission patch.

6 December 2012

 Charitum Montes (Click on the images for enlarge)

The high-resolution stereo camera on ESA’s Mars Express imaged the Charitum Montes region of the Red Planet on 18 June, near to Gale crater and the Argyre basin featured in our October and November image releases.

The brighter features, giving the image an ethereal winter-like feel in the colour images, are surfaces covered with seasonal carbon dioxide frost.

Charitum Montes are a large group of rugged mountains extending over almost 1000 km and bounding the southernmost rim of the Argyre impact basin.

They can be seen from Earth through larger telescope and were named by Eugène Michel Antoniadi (1870–1944) in his 1929 work La Planète Mars. 

Annotated image

The images in this release all show the region’s old and highly-sculpted terrain, pockmarked with many large craters, all of which have been substantially filled in. The whole region is dusted with brighter carbon dioxide frost.

Perspective view

Numerous smaller ‘pedestal craters’ can also be seen in the 3D and 2D images. These are impact craters where the ejecta have formed a higher relief above the surroundings. One striking example is visible on the smooth plain to the lower right in the annotated image (Box A).

Topographic view

The ejecta surrounding pedestal craters form erosion-resistant layers, meaning that the immediate vicinity around the crater erodes more slowly than the surrounding terrain. The resistant ejecta layer is largely untouched, forming the pedestal.

Perspective view

Another well-preserved example of a pedestal feature surrounding an impact crater can be seen within the large, old and heavily-degraded crater on the lower-left side of the annotated image (Box B).

In the centre of the 2D images and dominating the perspective images is a crater some 50 km wide filled with thick sedimentary deposits.

These deposits appear to have been introduced through one of several breaches in the northern crater rim (Box C in the annotated image).

Dendritic channels appear to emanate from a completely filled-in crater in this region (Box D), at the periphery of the large crater’s northern edge.

Within the large crater, near to where the breach (C) in the crater wall occurred, though unconnected to this event, we can also see a small dune field (Box E).

A region of significant interest to scientists lies within the large crater towards the top left of the first image (Box F). This crater shows a diverse range of filling material, with layers of varying colour and texture.

Charitum Montes in context

The uppermost layer appears to be bright and smooth, taking on the appearance of a relatively thin blanket with some impact craters.

This layer interfaces with the underlying darker layer via some very sharply defined edges, possibly as a result of erosion.

The underlying darker material has a much rougher and mottled appearance, and planetary geologists are still studying possible causes.

To the left of the crater interior, another layer of sediments clearly sets itself apart from the underlying strata, partly forming flat-topped structures (Box G).

3D view

The complexity and diversity of some areas in this winter wonderland would doubtless give Father Christmas a hard time in finding somewhere safe to land, but images like these are giving planetary geologists yet another fascinating region of the Red Planet to study.

Related links:

Mars Express: http://www.esa.int/SPECIALS/Mars_Express/index.html

High Resolution Stereo Camera: http://berlinadmin.dlr.de/Missions/express/indexeng.shtml

Behind the lens: http://www.esa.int/SPECIALS/Mars_Express/SEMSXE1PGQD_0.html

Frequently asked questions: http://www.esa.int/SPECIALS/Mars_Express/SEM76D9OY2F_0.html

Mars Express blog: http://webservices.esa.int/blog/blog/7

Mars Webcam: http://blogs.esa.int/vmc

Images, Text, Credits: ESA / DLR / FU Berlin (G. Neukum).

Greetings, Orbiter.ch

mercredi 5 décembre 2012

NASA's GRAIL Creates Most Accurate Moon Gravity Map











NASA - GRAIL Mission patch.

Dec. 5, 2012

video
 GRAIL's Gravity Tour of the Moon

This movie shows the variations in the lunar gravity field as measured by NASA's Gravity Recovery and Interior Laboratory (GRAIL) during the primary mapping mission from March to May 2012. Very precise microwave measurements between two spacecraft, named Ebb and Flow, were used to map gravity with high precision and high spatial resolution. Video credit: NASA/JPL-Caltech/MIT/GSFC.

Twin NASA probes orbiting Earth's moon have generated the highest resolution gravity field map of any celestial body.

The new map, created by the Gravity Recovery and Interior Laboratory (GRAIL) mission, is allowing scientists to learn about the moon's internal structure and composition in unprecedented detail. Data from the two washing machine-sized spacecraft also will provide a better understanding of how Earth and other rocky planets in the solar system formed and evolved.


This image depicting the porosity of the lunar highland crust was derived using bulk density data from NASA's GRAIL mission and independent grain density measurements from NASA's Apollo moon mission samples as well as orbital remote-sensing data. Image credit: SA/JPL-Caltech/ IPGP.

The gravity field map reveals an abundance of features never before seen in detail, such as tectonic structures, volcanic landforms, basin rings, crater central peaks and numerous simple, bowl-shaped craters. Data also show the moon's gravity field is unlike that of any terrestrial planet in our solar system.

These are the first scientific results from the prime phase of the mission, and they are published in three papers in the journal Science.

"What this map tells us is that more than any other celestial body we know of, the moon wears its gravity field on its sleeve," said GRAIL Principal Investigator Maria Zuber of the Massachusetts Institute of Technology in Cambridge. "When we see a notable change in the gravity field, we can sync up this change with surface topography features such as craters, rilles or mountains."

According to Zuber, the moon's gravity field preserves the record of impact bombardment that characterized all terrestrial planetary bodies and reveals evidence for fracturing of the interior extending to the deep crust and possibly the mantle. This impact record is preserved, and now precisely measured, on the moon.

The probes revealed the bulk density of the moon's highland crust is substantially lower than generally assumed. This low-bulk crustal density agrees well with data obtained during the final Apollo lunar missions in the early 1970s, indicating that local samples returned by astronauts are indicative of global processes.


This map shows the gravity field of the moon as measured by NASA's GRAIL mission. Image credit: NASA/ARC/MIT.

"With our new crustal bulk density determination, we find that the average thickness of the moon's crust is between 21 and 27 miles (34 and 43 kilometers), which is about 6 to 12 miles (10 to 20 kilometers) thinner than previously thought," said Mark Wieczorek, GRAIL co-investigator at the Institut de Physique du Globe de Paris. "With this crustal thickness, the bulk composition of the moon is similar to that of Earth. This supports models where the moon is derived from Earth materials that were ejected during a giant impact event early in solar system history."

The map was created by the spacecraft transmitting radio signals to define precisely the distance between them as they orbit the moon in formation. As they fly over areas of greater and lesser gravity caused by visible features, such as mountains and craters, and masses hidden beneath the lunar surface, the distance between the two spacecraft will change slightly.

"We used gradients of the gravity field in order to highlight smaller and narrower structures than could be seen in previous datasets," said Jeff Andrews-Hanna, a GRAIL guest scientist with the Colorado School of Mines in Golden. "This data revealed a population of long, linear gravity anomalies, with lengths of hundreds of kilometers, crisscrossing the surface. These linear gravity anomalies indicate the presence of dikes, or long, thin, vertical bodies of solidified magma in the subsurface. The dikes are among the oldest features on the moon, and understanding them will tell us about its early history."

Gravity Recovery And Interior Laboratory (GRAIL) spacecrafts. Image credit: NASA/JPL-Caltech

While results from the primary science mission are just beginning to be released, the collection of gravity science by the lunar twins continues. GRAIL's extended mission science phase began Aug. 30 and will conclude Dec. 17. As the end of mission nears, the spacecraft will operate at lower orbital altitudes above the moon.

When launched in September 2011, the probes were named GRAIL A and B. They were renamed Ebb and Flow in January by elementary students in Bozeman, Mont., in a nationwide contest. Ebb and Flow were placed in a near-polar, near-circular orbit at an altitude of approximately 34 miles (55 kilometers) on Dec. 31, 2011, and Jan. 1, 2012, respectively.

NASA's Jet Propulsion Laboratory in Pasadena, Calif., manages the mission for NASA's Science Mission Directorate in Washington. GRAIL is part of the Discovery Program managed at NASA's Marshall Space Flight Center in Huntsville, Ala. Lockheed Martin Space Systems of Denver built the spacecraft.

To view the lunar gravity map, visit http://bit.ly/grailtour . For more information about the mission, visit: http://www.nasa.gov/grail .

JPL is a division of the California Institute of Technology in Pasadena.

Images (mentioned), Video (mentioned), Text, Credits: NASA / Dwayne Brown / JPL / DC Agle / Massachusetts Institute of Technology / Sarah McDonnell.

Greetings, Orbiter.ch

Galaxy-wide Echoes from the Past












ESO - European Southern Observatory logo.

5 December 2012

VLT observations identify very rare new kind of galaxy

The green bean galaxy J2240

A new galaxy class has been identified using observations from ESO’s Very Large Telescope (VLT), the Gemini South telescope, and the Canada-France-Hawaii Telescope (CFHT). Nicknamed “green bean galaxies” because of their unusual appearance, these galaxies glow in the intense light emitted from the surroundings of monster black holes and are amongst the rarest objects in the Universe.

Many galaxies have a giant black hole at their centre that causes the gas around it to glow. However, in the case of green bean galaxies, the entire galaxy is glowing, not just the centre. These new observations reveal the largest and brightest glowing regions ever found, thought to be powered by central black holes that were formerly very active but are now switching off.

Astronomer Mischa Schirmer of the Gemini Observatory had looked at many images of the distant Universe, searching for clusters of galaxies, but when he came across one object in an image from the Canada-France-Hawaii Telescope he was stunned — it looked like a galaxy, but it was bright green. It was unlike any galaxy he had ever seen before, something totally unexpected. He quickly applied to use ESO’s Very Large Telescope to find out what was creating the unusual green glow [1].

The green bean galaxy J2240 (annotated)

“ESO granted me special observing time at very short notice and just a few days after I submitted my proposal, this bizarre object was observed using the VLT,” says Schirmer. “Ten minutes after the data were taken in Chile, I had them on my computer in Germany. I soon refocused my research activities entirely as it became apparent that I had come across something really new.”

The new object has been labelled J224024.1−092748 or J2240. It lies in the constellation of Aquarius (The Water Bearer) and its light has taken about 3.7 billion years to reach Earth.

After the discovery, Schirmer’s team searched through a list of nearly a billion other galaxies [2] and found 16 more with similar properties, which were confirmed by observations made at the Gemini South telescope. These galaxies are so rare that there is on average only one in a cube about 1.3 billion light-years across. This new class of galaxies has been nicknamed green bean galaxies because of their colour and because they are superficially similar to, but larger than, green pea galaxies [3].

video
The green bean galaxy J2240

In many galaxies the material around the supermassive black hole at the centre gives off intense radiation and ionises the surrounding gas so that it glows strongly. These glowing regions in typical active galaxies are usually small, up to 10% of the diameter of the galaxy. However, the team’s observations showed that in the case of J2240, and other green beans spotted since, it is truly huge, spanning the entire object. J2240 displays one of the biggest and brightest such regions ever found. Ionised oxygen glows bright green, which explains the strange colour that originally caught Schirmer’s attention.

“These glowing regions are fantastic probes to try to understand the physics of galaxies — it’s like sticking a medical thermometer into a galaxy far, far away,” says Schirmer. “Usually, these regions are neither very large nor very bright, and can only be seen well in nearby galaxies. However, in these newly discovered galaxies they are so huge and bright that they can be observed in great detail, despite their large distances.”

The team’s further analysis of the data soon revealed another puzzle. J2240 appeared to have a much less active black hole at its centre than expected from the size and brightness of the glowing region. The team thinks that the glowing regions must be an echo from when the central black hole was much more active in the past, and that they will gradually dim as the remnants of radiation pass through them and out into space [4].

These galaxies signal the presence of a fading galactic centre, marking a very fleeting phase in a galaxy’s life. In the early Universe galaxies were much more active, growing massive black holes at their centres that swallowed up surrounding stars and gas and shining brilliantly, easily producing up to 100 times more light than all the stars in the galaxy together. Light echoes like that seen in J2240 allow astronomers to study the shutdown processes of these active objects to understand more about how, when, and why they halt — and why we now see so few of them in younger galaxies. This is what the team aims to do next, by following up on this research with further X-ray and spectroscopic observations.

“Discovering something genuinely new is an astronomer's dream come true, a once-in-a-lifetime event,” concludes Schirmer. “It's very inspiring!”

Notes:

[1] The astronomers studied the object using the powerful X-shooter spectrograph on the VLT. By splitting the light up into its component colours they could find out the composition of the glowing material and why it was shining so brightly.

[2] The search was made using the huge online database of the Sloan Digital Sky Survey (SDSS).

[3] Green Pea galaxies are small, luminous galaxies undergoing vigorous star formation. They were first spotted in 2007 by participants in the astronomical crowd-sourcing project Galaxy Zoo. Unlike green beans, these galaxies are very small — our Milky Way galaxy contains a mass equivalent to that of around 200 average green pea galaxies. The similarity between green pea and green bean galaxies is limited to their appearance, as most of them are not closely related.

[4] In many active galaxies the view of the central black hole is blocked by large amounts of dust, making it difficult to measure the activity of the black hole. To check whether green bean galaxies are indeed different from other galaxies with hidden centres, the astronomers looked at data from these galaxies at much longer infrared wavelengths that easily penetrate even very thick dust clouds. The central regions of J2240, and the other green bean galaxies, turned out to be much fainter than expected. This means that the active nucleus is now really much weaker than suggested by the brightness of the glowing regions.

More information:

This research was presented in a paper, “A sample of Seyfert-2 galaxies with ultra-luminous galaxy-wide NLRs – Quasar light echos?”, to appear in The Astrophysical Journal.

The team is composed of M. Schirmer (Gemini Observatory, Chile; Argelander-Institut für Astronomie, Universität Bonn, Germany), R. Diaz (Gemini Observatory, Chile), K. Holhjem (SOAR Telescope, Chile), N. A. Levenson (Gemini Observatory, Chile) and C. Winge (Gemini Observatory, Chile).

The year 2012 marks the 50th anniversary of the founding of the European Southern Observatory (ESO). ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning the 39-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

The Gemini Observatory is an international collaboration with two identical 8-meter telescopes. The Frederick C. Gillett Gemini Telescope is located on Mauna Kea, Hawai'i (Gemini North) and the other telescope on Cerro Pachón in central Chile (Gemini South); together the twin telescopes provide full coverage over both hemispheres of the sky. The telescopes incorporate technologies that allow large, relatively thin mirrors, under active control, to collect and focus both visible and infrared radiation from space.

The Gemini Observatory provides the astronomical communities in seven partner countries with state-of-the-art astronomical facilities that allocate observing time in proportion to each country's contribution. In addition to financial support, each country also contributes significant scientific and technical resources. The national research agencies that form the Gemini partnership include: the US National Science Foundation (NSF); the UK Science and Technology Facilities Council (STFC); the Canadian National Research Council (NRC); the Chilean Comisión Nacional de Investigación Cientifica y Tecnológica (CONICYT); the Australian Research Council (ARC); the Argentinean Ministerio de Ciencia, Tecnología e Innovación Productiva; and the Brazilian Ministério da Ciência, Tecnologia e Inovação. The observatory is managed by the Association of Universities for Research in Astronomy, Inc. (AURA) under a cooperative agreement with the NSF. The NSF also serves as the executive agency for the international partnership.

The Canada-France-Hawaii Telescope (CFHT) is operated by the National Research Council of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of Hawaii.

Links:

    Research paper: http://www.eso.org/public/archives/releases/sciencepapers/eso1249/eso1249a.pdf

    Photos of the VLT: http://www.eso.org/public/images/archive/category/paranal/

    Web feature at Gemini Observatory: http://www.gemini.edu/node/11904/

Images, Text, Credits: ESO / M. Schirmer / CFHT / Video: CFHT / ESO / M. Schirmer. Music: movetwo.

Best regards, Orbiter.ch

mardi 4 décembre 2012

NASA Opportunity Rover Does Walkabout of Crater Rim











NASA - Mars Exploration Rover B (MER-B) patch.

Dec. 4, 2012

The latest work assignment for NASA's long-lived Mars rover Opportunity is a further examination of an area where the robot just completed a walkabout.

"If you are a geologist studying a site like this, one of the first things you do is walk the outcrop, and that's what we've done with Opportunity," said Steve Squyres, the mission's principal investigator at Cornell University in Ithaca, N.Y.

Coming up on its ninth anniversary, Opportunity still is a capable robotic explorer. It has been investigating a crater-rim site where observations from orbiting Mars spacecraft detected traces of clay minerals, which form under wet, non-acidic conditions that can be favorable for life. The rover's current activities were presented at the Fall Meeting of the American Geophysical Union in San Francisco.

The rover team chose this site as a driving destination years earlier. The site is named Matijevic Hill in honor of the late Jacob Matijevic, who led the engineering team for the twin Mars exploration rovers Spirit and Opportunity for several years.


This map shows the route driven by NASA's Mars Exploration Rover Opportunity during a reconnaissance circuit around an area of interest called "Matijevic Hill" on the rim of a large crater. Image credit: NASA/JPL-Caltech/Arizona State Univ.

Opportunity drove about 1,160 feet (354 meters) in a counterclockwise circuit around Matijevic Hill in October and November, bringing the total miles driven on the mission to 22 miles (35.4 kilometers). Researchers used the rover to survey the extent of Matijevic Hill outcrops and identify the best places to investigate further.

"We've got a list of questions posed by the observations so far," Squyres said. "We did this walkabout to determine the most efficient use of time to answer the questions. Now we have a good idea what we're dealing with, and we're ready to start the detailed work."

The hill is on the western rim of Endeavour Crater, a bowl 14 miles (22 kilometers) in diameter. An impact from a celestial object dug this crater more than 3 billion years ago, pushing rocks onto the rim from a greater depth than Opportunity reached during its first several years on Mars. Since the impact, those rocks may have been altered by environmental conditions. Sorting out the relative ages of local outcrops is a key to understanding the area's environmental history.

"Almost nine years into a mission planned to last for three months, Opportunity is fit and ready for driving, robotic-arm operations and communication with Earth," said the mission's deputy project scientist, Diana Blaney, of NASA's Jet Propulsion Laboratory in Pasadena, Calif.

Mars Exploration Rover "Opportunity". Image credit: NASA/JPL-Caltech

Two outcrops of high interest on Matijevic Hill are "Whitewater Lake" and "Kirkwood." Whitewater Lake is light-toned material that science team members believe may contain clay. Kirkwood contains small spheres with composition, structure and distribution that differ from other iron-rich spherules, nicknamed blueberries, that Opportunity found at its landing site and throughout the Meridiani Planum area it has explored. Squyres calls the Kirkwood spheres "newberries."

"We don't know yet whether Whitewood Lake and Kirkwood are from before or after the crater formed," he said. "One of the most important things to work out is the order and position of the rock layers to tell us the relative ages. We also need more work on the composition of Whitewater and debris shed by Whitewater to understand the clay signature seen from orbit, and on the composition of the newberries to understand how they formed."

NASA launched Spirit and Opportunity in 2003. Both completed their three-month prime missions in April 2004 with Spirit ceasing operations in 2010. The mission's goal is to learn about the history of wet environments on ancient Mars. JPL manages the Mars Exploration Rover Project for NASA's Science Mission Directorate at NASA Headquarters in Washington.

For more information about Opportunity, visit: http://www.nasa.gov/rovers .

You can follow the project on Twitter and on Facebook at: http://twitter.com/MarsRovers and http://www.facebook.com/mars.rovers .

JPL is a division of the California Institute of Technology in Pasadena.

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

Best regards, Orbiter.ch

Herschel and Keck take census of the invisible Universe












NASA - HERSCHEL Mission patch.

4 December 2012

By combining the observing powers of ESA’s Herschel space observatory and the ground-based Keck telescopes, astronomers have characterised hundreds of previously unseen starburst galaxies, revealing extraordinary high star-formation rates across the history of the Universe.

Starburst galaxies across the Universe

Starburst galaxies give birth to hundreds of solar masses’ worth of stars each year in short-lived but intense events.

By comparison, our own Milky Way Galaxy on average produces the equivalent of only one Sun-like star per year.

Starburst galaxies generate so much starlight that they should outshine our Galaxy hundreds to thousands of times over, but the enormous quantities of gas fuelling them also contain vast amounts of dust as a result of the frantic star formation.

The dust absorbs much of the visible light, meaning that many of them look quite insignificant in that part of the spectrum.

However, the dust is warmed by the surrounding hot stars and re-emits the energy at far-infrared wavelengths.

Using ESA’s infrared Herschel space observatory, astronomers measured the temperature and brightness of thousands of dusty galaxies. From these, their star-formation rate could be then calculated.

“Starburst galaxies are the brightest galaxies in the Universe and contribute significantly to cosmic star formation, so it’s important to study them in detail and understand their properties,” says Dr Caitlin Casey of the University of Hawai‘i, lead author of the papers discussing the results in the Astrophysical Journal.

“Some of the galaxies found in this new survey have star-formation rates equivalent to the birth of several thousand solar-mass stars per year, constituting some of the brightest infrared galaxies yet discovered.”

To provide context to the observations and understand how star formation has changed over the Universe’s 13.7 billion year history, the distances to the galaxies were also needed.

With Herschel signposting the way, Dr Casey’s team used spectrometers on the twin 10-metre W.M. Keck telescopes on Mauna Kea, Hawai‘i, and obtained the redshifts of 767 of the starburst galaxies.

Redshifts provide astronomers with a measure of how long the light from each galaxy has travelled across the Universe, which, in turn, indicates when in cosmic history the light from each galaxy was emitted.

ESA’s Herschel space observatory

For most of the galaxies it was found that the light has been travelling towards us for 10 billion years or less.

About 5% of the galaxies are at even greater redshifts: their light was emitted when the Universe was only 1–3 billion years old.

“The Herschel data tell us how fiercely and prolifically these galaxies are producing stars,” says Seb Oliver from University of Sussex, UK, and Principal Investigator for the HerMES Key Programme, within which the data have been collected.

“Combining this information with the distances provided by the Keck data, we can uncover the contribution of the starburst galaxies to the total amount of stars produced across the history of the Universe.” 

How such large numbers of starburst galaxies formed during the first few billions of years of the Universe’s existence poses a vital problem for galaxy formation and evolution studies.

One leading theory proposes that a collision between two young galaxies could have sparked an intense short-lived phase of star formation.

Another theory speculates that, when the Universe was young, individual galaxies had much more gas available to them to feed from, enabling higher rates of star formation without the need of collisions.

“It’s a hotly debated topic that requires details on the shape and rotation of the galaxies before it can be resolved,” adds Dr Casey.

“Before Herschel, the largest similar survey of distant starbursts involved only 73 galaxies – we’ve improved on that by over a factor of ten in this combined survey with Keck to determine the characteristics of this important galaxy population,” adds Göran Pilbratt, ESA’s Herschel project scientist.

Related links:

W.M. Keck Observatory: http://keckobservatory.org/

HerMES project: http://hermes.sussex.ac.uk/

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

Herschel overview: http://www.esa.int/SPECIALS/Herschel/index.html

Online Showcase of Herschel Images OSHI: http://oshi.esa.int/

Images, Text, Credits: ESA/C. Carreau/C. Casey (University of Hawai'i); COSMOS field: ESA/Herschel/SPIRE/HerMES Key Programme; Hubble images: NASA, ESA.

Greetings, Orbiter.ch