vendredi 1 avril 2011

Neighbouring volcanoes on Mars












ESA - Mars Express Mission patch.

1 April 2011

 Neighbouring volcanoes on Mars

ESA’s Mars Express has returned images of mist-capped volcanoes located in the northern hemisphere of the red planet. Long after volcanic activity ceased, the area was transformed by meteor impacts that deposited ejected material over the lower flanks of the volcanoes.

Permanent and transient features are on display in this newly released image of Mars. The image is derived from data acquired during three orbits of ESA’s Mars Express between 25 November 2004 and 22 June 2006. In that time, these dead volcanoes were not expected to change but, during the middle orbit, Mars Express captured icy clouds drifting past the summit of Ceraunius Tholus.

 Ceraunius Tholus and Uranius Tholus in context

By the time Mars Express crossed again and took the final strip of data needed for this image, the clouds had long since dispersed and so there is a sharp line across them in the finished mosaic.

The Latin word “tholus” means a conical dome and the base of Ceraunius Tholus is 130 km across, while the peak rises 5.5 km above the surrounding plains. At its summit is a large caldera 25 km across. With similar morphology to its neighbour and lying 60 km to the north, Uranius Tholus is a smaller volcano, with a base diameter of 62 km and a height of 4.5 km.

Features around Ceraunius Tholus and Uranius Tholus

The flanks of Ceraunius Tholus are relatively steep, at about 8° inclination, and are etched with valleys. They are deeply cut in many places, suggesting that soft and easily eroded material, such as layers of ash, were deposited during the volcano’s eruptions.

The largest and deepest of these valleys is about 3.5 km wide and 300 m deep. It terminates inside an otherwise unrelated elongated impact crater that happens to lie between the two volcanoes, and has created a fascinating fan shape of deposits.

Elevation of Ceraunius Tholus and Uranius Tholus

Although the source of the fan is still being debated in scientific circles, it may have been formed when material from a lava channel or tube was washed downwards by a melting ice cap on the volcano.

Certainly, the summit crater – the caldera – is flat and smooth, so it may have contained a lake early in Mars’ history when the atmosphere was denser. It is also possible that the water was produced when volcanic activity melted buried ice lenses. An ice lens forms when moisture seeps below the surface and forms a frozen layer between the top ‘soil’ and the rocky layer below.

Ceraunius Tholus and Uranius Tholus in high resolution

The elongated crater between the two volcanoes is called Rahe. It measures 35 km by 18 km and is the result of an oblique impact by a meteorite.

A smaller impact crater 13 km across can be seen to the west of Uranius Tholus. This one also formed after all the volcanic activity ended and served to cover the lower flanks of the volcanoes with ejected material, with the result that only the upper regions of the original structures are now visible.

Ceraunius Tholus in perspective
 
Ceraunius Tholus and Uranius Tholus in perspective

 Ceraunius Tholus and Uranius Tholus in perspective

 Ceraunius Tholus and Uranius Tholus in 3D

 Ceraunius Tholus and Uranius Tholus in 3D

Related links:

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

For specialists:

ESA Planetary Science archive (PSA): http://www.rssd.esa.int/PSA

NASA Planetary Data System: http://pds-geosciences.wustl.edu/missions/mars_express/hrsc.htm

HRSC data viewer: http://hrscview.fu-berlin.de/

Images, Text, Credits: ESA / DLR / FU Berlin (G. Neukum) / NASA MGS MOLA Science Team.

Best regards, Orbiter.ch

ESA - Soyuz launch site ready for first flight











ESA - Soyuz au CSG patch.

1 April 2011

The Soyuz site at Europe’s Spaceport in French Guiana is now ready for its first launch. ESA yesterday handed over the complex to Arianespace, marking a major step towards this year’s inaugural flight.

Construction of the Soyuz site began in February 2007, although initial excavation and ground infrastructure work began in 2005 and 2006, respectively.

Soyuz launch site

Russian staff arrived in French Guiana in mid-2008 to assemble the launch table, mobile gantry, fuelling systems and test benches.

The first two Soyuz launchers arrived from Russia by sea in November 2009 to be assembled in the new preparation and integration building.

The French space agency, CNES, as prime contractor for the building work, along with its European and Russian partners, has spent recent months qualifying the site – known as Ensemble de Lancement Soyuz, or ELS for short.

The tests covered all the mechanical, fluid and electrical elements, such as the pad’s umbilical arms and fuelling vehicles, and all the buildings, including the launch control centre that will house the combined European and Russian teams.

The ‘acceptance review’ this week declared that the site is ready for its first rocket. At the same time CNES handed over the facilities to ESA.

Soyuz mobile gantry

The last step this week was ESA’s hand-over to Arianespace.

Main features of the Soyuz site

The launch site is almost identical to the other Soyuz sites in Kazakhstan and Russia, although adapted to conform to European safety regulations.

The most visible difference is the 45 m-tall mobile gantry, which provides a protected environment as payloads are installed on the vertical launcher. Its internal movable work platforms provide access to the Soyuz at various levels.

What’s next?

From now on Arianespace is responsible for the Soyuz launch site and will begin the campaign this month to qualify its launch operations.

A launch rehearsal will ensure that the Soyuz and the new facilities work together perfectly, while allowing the teams to train under realistic launch conditions.

This simulated launch campaign will include the vehicle’s transfer to the launch zone, its erection into the vertical position, its installation on the pad, and the testing of ground and launcher interfaces.

These final tests will give the green light for the first Soyuz flight from French Guiana in the third quarter of 2011.

Related links:

Arianespace: http://www.arianespace.com/index/index.asp

CNES: http://www.cnes.fr/web/CNES-en/7114-home-cnes.php

Roscosmos: http://www.roscosmos.ru/main.php?lang=en

Text, Credits: ESA / Images:  S. Corvaja, 2011.

Cheers, Orbiter.ch

Fukushima Daiichi Nuclear Plant Hi-Res Photos








AUVSI logo labeled.

31 March 2011

Photos shown are half-size of the originals. The 10 originals full-size: http://cryptome.org/eyeball/daiichi-npp/daiichi-photos.zip (11.5MB)

This is the AIR PHOTO SERVICE drone flying over the nuclear plant in Japan

Dates of photos taken from the EXIF data of the originals, supported by captions and credits later obtained from the Web.


In this March 24, 2011 aerial photo taken by a small unmanned drone and released by AIR PHOTO SERVICE, damaged Unit 3, left, and Unit 4 of the crippled Fukushima Dai-ichi nuclear power plant are seen in Okumamachi, Fukushima prefecture, northern Japan. (Air Photo Service Co. Ltd., Japan)


In this March 24, 2011 aerial photo taken by a small unmanned drone and released by AIR PHOTO SERVICE, Unit 4, left, and Unit 3 of the crippled Fukushima Dai-ichi nuclear power plant are seen in Okumamachi, Fukushima prefecture, northern Japan. (Air Photo Service Co. Ltd., Japan)


In this March 24, 2011 aerial photo taken by a small unmanned drone and released by AIR PHOTO SERVICE, damaged Unit 3 of the crippled Fukushima Dai-ichi nuclear power plant is seen in Okumamachi, Fukushima prefecture, northern Japan. (Air Photo Service Co. Ltd., Japan)


This March 24, 2011 aerial photo taken by a small unmanned drone and released by AIR PHOTO SERVICE shows damaged Unit 3 of the crippled Fukushima Dai-ichi nuclear power plant in Okumamachi, Fukushima Prefecture, northeastern Japan. (Air Photo Service Co. Ltd., Japan)


This March 24, 2011 aerial photo taken by a small unmanned drone and released by AIR PHOTO SERVICE shows damaged Unit 4 of the crippled Fukushima Dai-ichi nuclear power plant in Okumamachi, Fukushima prefecture, northern Japan. (Air Photo Service Co. Ltd., Japan)


In this March 20, 2011 aerial photo taken by a small unmanned drone and released by AIR PHOTO SERVICE, the crippled Fukushima Dai-ichi nuclear power plant is seen in Okumamachi, Fukushima prefecture, northern Japan. From top to bottom: Unit 1, Unit 2, Unit 3 and Unit 4. (Air Photo Service Co. Ltd., Japan)


In this March 20, 2011 aerial photo taken by a small unmanned drone and released by AIR PHOTO SERVICE, damaged Unit 4, left, and Unit 3 of the crippled Fukushima Dai-ichi nuclear power plant are seen in Okumamachi, Fukushima prefecture, northern Japan. (Air Photo Service Co. Ltd., Japan)


In this March 20, 2011 aerial photo taken by a small unmanned drone and released by AIR PHOTO SERVICE, the crippled Fukushima Dai-ichi nuclear power plant are seen in Okumamachi, Fukushima prefecture, northern Japan. From left: Unit 1, partially seen; Unit 2, Unit 3 and Unit 4. (Air Photo Service Co. Ltd., Japan)


In this March 20, 2011 aerial photo taken by a small unmanned drone and released by AIR PHOTO SERVICE, the crippled Fukushima Dai-ichi nuclear power plant is seen in Okumamachi, Fukushima prefecture, northern Japan. From right to left: Unit 1, Unit 2 and Unit 3. (Air Photo Service Co. Ltd., Japan)


In this March 20, 2011 aerial photo taken by a small unmanned drone and released by AIR PHOTO SERVICE, the crippled Fukushima Dai-ichi nuclear power plant is seen in Okumamachi, Fukushima prefecture, northern Japan. From right to left: Unit 1, Unit2, Unit 3 and Unit 4. (Air Photo Service Co. Ltd., Japan)

Fukushima Daiichi Nuclear Plant before the earthquake and tsunami
 
AUVSI members are part of the community of unmanned systems in Japan helping at the nuclear plant or in search and rescue operations. 
 
For more information about AUVSI, visit: http://www.auvsi.org
 

Incredible Unmanned Vehicles - UAVs

video

Images, Text, Video, Credits: Orbiter.ch / Cryptome / AP Photo / AIR PHOTO SERVICE / AUVSI.

Greetings, Orbiter.ch

jeudi 31 mars 2011

MESSENGER's First Orbital Images of Mercury












NASA - Messenger Mission to Mercury patch.

March 31, 2011

An artist's concept shows the MESSENGER spacecraft in orbit around Mercury

MESSENGER is sending back its first images from Mercury, including a first look at terrain near Mercury's north pole, after successfully going into orbit on March 17.

video
  MESSENGER Mercury Orbit Insertion with first orbit

Watch this animation to view the Mercury orbit insertion maneuver and the spacecraft’s first orbit around the planet.

An Annotated Guide to the First Orbital Image

This historic first orbital image of Mercury was acquired 37 years to the day after Mariner 10's historic first flyby of the innermost planet. Labels have been added to indicate several craters that were named based on Mariner 10 images, as well as Debussy, Matabei, and Berkel, which were named based on MESSENGER flyby images. The surface contained in the white lines is terrain previously unseen by spacecraft, and the star indicates the location of the south pole.

Date acquired: March 29, 2011

Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.

Exploring the Rays of Debussy

Bright rays, consisting of impact ejecta and secondary craters, spread across this NAC image and radiate from Debussy crater, located at the top. The image, acquired yesterday during the first orbit for which MDIS was imaging, shows just a small portion of Debussy's large system of rays in greater detail than ever previously seen. Images acquired during MESSENGER's second Mercury flyby showed that Debussy's rays extend for hundreds of kilometers across Mercury's surface. Debussy crater was named in March 2010, in honor of the French composer Claude Debussy (1862-1918).

Date acquired: March 29, 2011

Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.

MESSENGER's Wide-Angle Camera

The wide-angle camera (WAC) is not a typical color camera. It can image in 11 colors, ranging from 430 to 1020 nm wavelength (visible through near-infrared). It does this with a filter wheel: the 11 narrow-band filters (plus one clear filter) are mounted onto a wheel that can be rotated to allow the camera to capture an image through each filter. In this image the 1000 nm, 750 nm, and 430 nm filters are displayed in red, green, and blue, respectively. Several craters appear to have excavated compositionally distinct low-reflectance (brown-blue in this color scheme) material, and the bright rays of Hokusai crater to the north cross the image. During MESSENGER’s orbital operations, we will typically use just eight of the WAC's filters. This decision was made to reduce the amount of data that must be stored on the spacecraft’s solid-state recorder before the information can be downlinked. It’s also quicker than cycling through all 11 filters – the spacecraft is moving rapidly over the surface, and there isn't much time to image the same spot on the surface 11 times over before moving to the next area of interest. The sets of color images will help us learn about the variation in composition from place to place on the planet. For example, some minerals such as olivine and pyroxene often absorb more light at longer wavelengths than at shorter ones, so we’ll be looking for their signatures in the reflectance spectra derived from each eight-color set. WAC images will be used in coordination with the Mercury Atmospheric and Surface Composition Spectrometer (MASCS), a hyperspectral instrument that provides reflectance information at many more wavelengths, but only for one spot on the surface at a time.

Date acquired: March 29, 2011

Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.

A First Look at Terrain Near Mercury's North Pole

This WAC image showing a never-before-imaged area of Mercury’s surface was taken from an altitude of 450 km (280 miles) above the planet during the spacecraft’s first orbit with the camera in operation. The area is covered in secondary craters made by an impact outside of the field of view. Some of the secondary craters are oriented in chain-like formations.

This image was taken during MESSENGER’s closest approach to the sunlit portion of the surface during this orbit, just before crossing over the terminator. The oblique illumination by the Sun causes the long shadows and accentuates topography. The highly elliptical orbit of MESSENGER brings the spacecraft down to a periapsis (MESSENGER’s closest approach to Mercury) altitude of 200 km (125 miles) and out to an apoapsis (MESSENGER’s farthest distance from Mercury) altitude of 15,000 km (9300 miles).

Date acquired: March 29, 2011

Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington.

Texts, Video, Credit: NASA / JPL-Caltech.

Best regards, Orbiter.ch

NASA Spacecraft Reveal Mysteries Of Jupiter And Saturn Rings












NASA - Cassini "Insinder's" logo / NASA - New Horizon Mission patch.

March 31, 2011

In a celestial forensic exercise, scientists analyzing data from NASA's Cassini, Galileo and New Horizons missions have traced telltale ripples in Saturn and Jupiter's rings to specific collisions with cometary fragments that occurred decades, not millions of years, ago.

Jupiter's ripple-producing culprit was comet Shoemaker-Levy 9. The comet's debris cloud hurtled through the thin Jupiter ring system on a collision course into the planet in July 1994. Scientists attribute Saturn's ripples to a similar object - likely another cloud of comet debris - plunging through the inner rings in 1983. The findings are detailed in two papers published Thursday in the journal Science.

"We're finding evidence that a planet's rings can be affected by specific, traceable events that happened in the last 30 years, rather than a hundred million years ago," said Matthew Hedman, a Cassini imaging team associate, lead author on one of the papers, and a research associate at Cornell University in Ithaca, N.Y. "The solar system is a much more dynamic place than we gave it credit for."


Image above: This artist's concept shows comet Shoemaker-Levy 9 heading into Jupiter in July 1994, while its dust cloud creates a rippling wake in Jupiter's ring. Image credit: copyright M. Showalter.

Scientists learned about the patchy patterns in Jupiter's rings in the late 1990s from Galileo's visit to Jupiter. Unfortunately, the images from that mission were fuzzy, and scientists didn't understand why such patterns would occur. Not until Cassini entered orbit around Saturn in 2004 and started sending back thousands of images did scientists have a better picture of the activity. A 2007 science paper by Hedman and colleagues first noted corrugations in Saturn's innermost ring, dubbed the D ring.

A group including Hedman and Mark Showalter, a Cassini co-investigator based at the SETI Institute in Mountain View, Calif., saw that the grooves in the D ring appeared to wind together more tightly over time. Playing the process backward, Hedman demonstrated the pattern originated when something tilted the D ring off its axis by about 300 feet (100 meters) in late 1983. The scientists found Saturn's gravity on the tilted area warped the ring into a tightening spiral.


Image above: Alternating light and dark bands, extending a great distance across Saturn's D and C rings, are shown here in these Cassini images taken one month before the planet's August 2009 equinox. Image credit: NASA / JPL / Space Science Institute.

Cassini imaging scientists received another clue around August 2009 when the sun shone directly along Saturn's equator and lit the rings edge-on. The unique lighting conditions highlighted ripples not previously seen in another part of the ring system. Whatever happened in 1983 was big - not a small, localized event.

The collision tilted a region more than 12,000 miles (19,000 kilometers) wide, covering part of the D ring and the next outermost ring, called the C ring. Unfortunately, spacecraft were not visiting Saturn at that time, and the planet was on the far side of the sun out of sight from ground or space-based telescopes.

Hedman and Showalter, the lead author on the second paper, wondered whether the long-forgotten pattern in Jupiter's ring system might illuminate the mystery. Using Galileo images from 1996 and 2000, Showalter confirmed a similar winding spiral pattern by applying the same math they had applied to Saturn and factoring in Jupiter's gravitational influence. Galileo was launched on a space shuttle in 1989 and studied Jupiter until 2003.


Image above: This graphic shows in a series of three images how Saturn's rings, after they became tilted relative to Saturn's equatorial plane, would have transformed into a corrugated ring. Image credit: NASA / JPL / Cornell.

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Unwinding the spiral pinpointed the date when Jupiter's ring was tilted off its axis between June and September 1994. Shoemaker-Levy plunged into the Jovian atmosphere in late July. The Galileo images also revealed a second spiral, which was calculated to have originated in 1990. Images taken by New Horizons in 2007, when the spacecraft flew by Jupiter on its way to Pluto, showed two newer ripple patterns, in addition to the fading echo of the Shoemaker-Levy impact.

"We now know that collisions into the rings are very common – a few times per decade for Jupiter and a few times per century for Saturn," Showalter said. "Now scientists know that the rings record these impacts like grooves in a vinyl record, and we can play back their history later."

video
New Horizons Halfway to Pluto

Launched in Oct. 15, 1997, Cassini began orbiting Saturn in 2004 and sends back data daily.


These images above, derived from data obtained by NASA's Galileo spacecraft, show the subtle ripples in the ring of Jupiter that scientists have been able to trace back to the impact of comet Shoemaker-Levy 9 in July 1994. Image credit: NASA / JPL-Caltech / SETI.

"Finding these fingerprints still in the rings is amazing and helps us better understand impact processes in our solar system," said Linda Spilker, Cassini project scientist, based at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Cassini's long sojourn around Saturn has helped us tease out subtle clues that tell us about the history of our origins."

Jupiter and Io view by New Horizon spacecraft

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The mission is managed by JPL for NASA's Science Mission Directorate in Washington. The imaging team is based at the Space Science Institute in Boulder, Colo. For more information about Cassini, visit: http://www.nasa.gov/cassini

Pluto New Horizons launched in 2006 on the first mission to study Pluto and the Kuiper Belt. The mission is managed by the Johns Hopkins Applied Physics Laboratory in Laurel, Md., for NASA. The mission is part of the New Frontiers program managed at the agency's Marshall Space Flight Center in Huntsville, Ala. For more information about Pluto New Horizons, visit: http://www.nasa.gov/newhorizons

Images (mentioned), Videos, Text, Credits: NASA / JPL.

Cheers, Orbiter.ch

Earth's gravity revealed in unprecedented detail









ESA - GOCE Mission logo.

31 March 2011

video
 Best view yet of global gravity

After just two years in orbit, ESA's GOCE satellite has gathered enough data to map Earth's gravity with unrivalled precision. Scientists now have access to the most accurate model of the 'geoid' ever produced to further our understanding of how Earth works.

The new geoid was unveiled today at the Fourth International GOCE User Workshop hosted at the Technische Universität München in Munich, Germany. Media representatives and scientists from around the world have been treated to the best view yet of global gravity.

The geoid is the surface of an ideal global ocean in the absence of tides and currents, shaped only by gravity. It is a crucial reference for measuring ocean circulation, sea-level change and ice dynamics – all affected by climate change.

Prof. Reiner Rummel, former Head of the Institute for Astronomical and Physical Geodesy at the Technische Universität München, said, "We see a continuous stream of excellent GOCE gradiometry data coming in. With each new two-month cycle, our GOCE gravity field model is getting better and better.

To understand ocean circulation

"Now the time has come to use GOCE data for science and applications. I am particularly excited about the first oceanographic results.

"They show that GOCE will give us dynamic topography and circulation patterns of the oceans with unprecedented quality and resolution. I am confident that these results will help improve our understanding of the dynamics of world oceans."

The two-day workshop provides the science community with the latest information on the performance of the satellite and details about data products and user services.

New GOCE geoid

Participants are also discussing how the GOCE geoid will make advances in ocean and climate studies, and improve our understanding of Earth’s internal structure.

For example, the gravity data from GOCE are helping to develop a deeper knowledge of the processes that cause earthquakes, such as the event that recently devastated Japan.

Since this earthquake was caused by tectonic plate movement under the ocean, the motion cannot be observed directly from space. However, earthquakes create signatures in gravity data, which could be used to understand the processes leading to these natural disasters and ultimately help to predict them.

The GOCE satellite was launched in March 2009 and has now collected more than 12-months of gravity data.

GOCE in orbit

Volker Liebig, Director of ESA's Earth Observation Programmes said, "Benefiting from a period of exceptional low solar activity, GOCE has been able to stay in low orbit and achieve coverage six weeks ahead of schedule.

"This also means that we still have fuel to continue measuring gravity until the end of 2012, thereby doubling the life of the mission and adding even more precision to the GOCE geoid."

GOCE has achieved many firsts in Earth observation. Its gradiometer – six highly sensitive accelerometers measuring gravity in 3D – is the first in space.

It orbits at the lowest altitude of any observation satellite to gather the best data on Earth's gravity. The design of this sleek one-tonne satellite is unique.

In addition, GOCE uses an innovative ion engine that generates tiny forces to compensate for any drag the satellite experiences as it orbits through the remnants of Earth's atmosphere.

video
Counteracting drag

Prof. Liebig added, "You could say that, at its early conception, GOCE was more like science fiction. GOCE has now clearly demonstrated that it is a state-of-the-art mission."

Rune Floberghagen, ESA's GOCE Mission Manager, noted "This is a highly significant step for the mission. We now look forward to the coming months, when additional data will add to the accuracy of the GOCE geoid, further benefiting our data users."

Related links:

GOCE press briefing, Watch replay: http://www.esa.int/SPECIALS/GOCE/SEM43Y3UFLG_0.html

Fourth International GOCE User Workshop: http://www.goce2011.org/

Access GOCE data: http://earth.esa.int/GOCE/

Images, Videos, Text, Credits: ESA / HPF / DLR / AOES Medialab.

Greetings, Orbiter.ch

mercredi 30 mars 2011

NASA's servers would be too vulnerable












NASA patch.

30 March 2011

Paul Martin, Inspector General of NASA, said the infrastructure of the U.S. space agency would be too few secure face new cyber intrusions.

Cyber-Intrusion (Hacker)

In the aftermath of the confession of the hacker Texan Jeremy Parker, an internal investigation was conducted within NASA to determine ways to secure its servers. It must be said that Mr. Parker had accessed confidential information transmitted from the satellites to the U.S. services on behalf of scientists specialized in the study of ocean data.

"We found that the servers of all departments of the agency's missions had big security holes through the Internet, " says Martin. It specifies that six computer servers used to control the space shuttle and containing sensitive data could be infiltrated and disabled. Note also that these machines contain the information necessary to obtain more sensitive data from the highest level.


NASA has suffered numerous problems in recent years. Further intrusion revealed by Jeremy Parker last month, in May 2009, the agency networks were attacked by a group of cyber hackers who seized 22 GB of data. In December last, 10 computers belonging to the Kennedy Space Center had been sold to individuals while they still contained information deemed confidential. It also remembers the British hacker Gary McKinnon, who had penetrated from 97 machines in the Pentagon and NASA in search of information on the existence of an alien form. More recently, in January, the agency's website fell victim to SQL injection.

Images, Text, Credit: NASA (patch) / Orbiter.ch (text) / Armaggedon (images).

Greetings, Orbiter.ch

First Image Ever Obtained from Mercury Orbit












NASA - MESSENGER Mission to Mercury patch.

30 March 2011


At 5:20 am EDT on Mar. 29, 2011, MESSENGER captured this historic image of Mercury. This image is the first ever obtained from a spacecraft in orbit about the Solar System's innermost planet. Over the subsequent six hours, MESSENGER acquired an additional 363 images before downlinking some of the data to Earth. The MESSENGER team is currently looking over the newly returned data, which are still continuing to come down.

Image, Text, Credit: NASA / Johns Hopkins University Applied Physics Laboratory / Carnegie Institution of Washington.

Best regards, Orbiter.ch

The Rose-red Glow of Star Formation












ESO - European Southern Observatory logo.

30 March 2011

The star cluster and nebula NGC 371

The vivid red cloud in this new image from ESO’s Very Large Telescope is a region of glowing hydrogen surrounding the star cluster NGC 371. This stellar nursery lies in our neighbouring galaxy, the Small Magellanic Cloud.

The object dominating this image may resemble a pool of spilled blood, but rather than being associated with death, such regions of ionised hydrogen — known as HII regions — are sites of creation with high rates of recent star birth. NGC 371 is an example of this; it is an open cluster surrounded by a nebula. The stars in open clusters all originate from the same diffuse HII region, and over time the majority of the hydrogen is used up by star formation, leaving behind a shell of hydrogen such as the one in this image, along with a cluster of hot young stars.

The star cluster and nebula NGC 371 in the constellation of Tucana

The host galaxy to NGC 371, the Small Magellanic Cloud, is a dwarf galaxy a mere 200 000 light-years away, which makes it one of the closest galaxies to the Milky Way. In addition, the Small Magellanic Cloud contains stars at all stages of their evolution; from the highly luminous young stars found in NGC 371 to supernova remnants of dead stars. These energetic youngsters emit copious amounts of ultraviolet radiation causing surrounding gas, such as leftover hydrogen from their parent nebula, to light up with a colourful glow that extends for hundreds of light-years in every direction. The phenomenon is depicted beautifully in this image, taken using the FORS1 instrument on ESO’s Very Large Telescope (VLT).

Open clusters are by no means rare; there are numerous fine examples in our own Milky Way. However, NGC 371 is of particular interest due to the unexpectedly large number of variable stars it contains. These are stars that change in brightness over time. A particularly interesting type of variable star, known as slowly pulsating B stars, can also be used to study the interior of stars through asteroseismology [1], and several of these have been confirmed in this cluster. Variable stars play a pivotal role in astronomy: some types are invaluable for determining distances to far-off galaxies and the age of the Universe.

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Zooming in on the cluster and nebula NGC 371

The data for this image were selected from the ESO archive by Manu Mejias as part of the Hidden Treasures competition [2]. Three of Manu’s images made the top twenty; his picture of NGC 371 was ranked sixth in the competition.

Notes:

[1] Asteroseismology is the study of the internal structure of pulsating stars by looking at the different frequencies at which they oscillate. This is a similar approach to the study of the structure of the Earth by looking at earthquakes and how their oscillations travel through the interior of the planet.

[2] ESO’s Hidden Treasures 2010 competition gave amateur astronomers the opportunity to search through ESO’s vast archives of astronomical data, hoping to find a well-hidden gem that needed polishing by the entrants. Participants submitted nearly 100 entries and ten skilled people were awarded some extremely attractive prizes, including an all expenses paid trip for the overall winner to ESO’s Very Large Telescope (VLT) on Cerro Paranal, in Chile, the world’s most advanced optical telescope. The ten winners submitted a total of 20 images that were ranked as the highest entries in the competition out of the near 100 images.
More information

ESO, the European Southern Observatory, 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 VISTA, the world’s largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Credit: ESO / Manu Mejias / IAU and Sky & Telescope / Video: ESO/Manu Mejias / S. Brunier/NOAO / Digitized Sky Survey 2. Music: John Dyson (from the album Moonwind).

 Cheers, Orbiter.ch