samedi 1 décembre 2012

Arianespace's Soyuz 2-1a medium-lift launcher orbits Pléiades 1B

Arianespace / ESA - Pleiades 1B / Soyuz Flight VS04 poster.

December  2, 2012

Soyuz rocket with Pleiades 1B "aboard" ready for launch

The maturity of Arianespace’s Soyuz launch system at French Guiana – and its confirmed role as a full-fledged member of the company’s launcher family – were demonstrated once again tonight’s successful orbiting of the Pléiades 1B satellite from the Spaceport.

 Launch of Pleiades 1B on Soyuz-STA from French Guiana

The fourth Soyuz rocket from Kourou in French Guiana launched today, December 2nd 2012 at 02:02 UTC carrying the EADS built Pleiades 1B satellite into orbit. Pleiades 1B for French CNES will provide very high resolution (50cm) imagery for French and Spanish defense ministries. The trip was onboard a Russian Soyuz-STA rocket with Fregat upperstage.

Separation of Pleiades 1B from Fregat upperstage

During a flight duration of 55 minutes, the Soyuz vehicle deployed its 970-kg. passenger into a targeted circular orbit of 695 km., inclined 98.2 deg., marking the medium-lift vehicle’s fourth mission from French Guiana since its introduction at this near-equatorial launch site in October 2011.

Pléiades 1B is a very-high-resolution dual-use satellite designed to provide optical imaging coverage for French and European defense ministries, institutions and civil users.  It joins the twin Pléiades 1A spacecraft that was launched in December 2011 on Arianespace’s second Soyuz mission from the Spaceport. 

Arianespace Chairman & CEO Jean-Yves Le Gall noted tonight’s launch was the ninth at French Guiana in 2012 for the company’s launcher family; following the lightweight Vega’s maiden flight in February; medium-lift  missions with Soyuz in October and today; along with heavy-lift Ariane 5 flights in March, May, July, August, September and November.

Le Gall thanked all involved in these successes, including the teams who work at the Spaceport for such an “impressive” year – during which a total of 23 primary and secondary payloads were placed into orbit from French Guiana.

Pleiades 1B satellite

The Pléiades 1A and 1B satellites launched by Arianespace create an optical observation system with great agility, a quick-response ground segment and daily revisit capability – offering a new generation of “real-world” satellite Earth imagery at a resolution of 70 cm.  Both Pléiades spacecraft are based on smaller, less expensive and more agile platforms than their predecessors – the highly-successful Spot satellite series that was lofted by Arianespace on its Ariane family launchers beginning in 1986.

France’s CNES space agency is prime contractor and architect for the Pléiades system, which is organized as part of a joint effort with Italy – whose Cosmo-Skymed satellite series delivers radar imaging coverage of the Earth.

Pléiades program participants are the space agencies of France, Austria, Belgium, Spain and Sweden; along with the defense ministries of France, Italy and Spain.

The Pléiades 1A and 1B spacecraft were built by EADS’ Astrium division.

Arianespace will wrap-up its 2012 launch activity at the Spaceport with a year-ending Ariane 5 mission on December 19 to orbit the Mexsat Bicentenario and Skynet 5D satellites.

For more information about Arianespace, visit:

Images, Video, Text, Credits: Arianespace / Arianespace TV / CNES / Aerospace.

Best regards,

vendredi 30 novembre 2012

Even Brown Dwarfs May Grow Rocky Planets

ESO - European Southern Observatory logo.

30 November 2012

ALMA sizes up grains of cosmic dust around failed star

Artist’s impression of the disc of dust and gas around a brown dwarf

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) have for the first time found that the outer region of a dusty disc encircling a brown dwarf contains millimetre-sized solid grains like those found in denser discs around newborn stars. The surprising finding challenges theories of how rocky, Earth-scale planets form, and suggests that rocky planets may be even more common in the Universe than expected.

Rocky planets are thought to form through the random collision and sticking together of what are initially microscopic particles in the disc of material around a star. These tiny grains, known as cosmic dust, are similar to very fine soot or sand. However, in the outer regions around a brown dwarf — a star-like object, but one too small to shine brightly like a star — astronomers expected that grains could not grow because the discs were too sparse, and particles would be moving too fast to stick together after colliding. Also, prevailing theories say that any grains that manage to form should move quickly towards the central brown dwarf, disappearing from the outer parts of the disc where they could be detected.

Artist’s impression of grains in the disc around a brown dwarf

“We were completely surprised to find millimetre-sized grains in this thin little disc,” said Luca Ricci of the California Institute of Technology, USA, who led a team of astronomers based in the United States, Europe and Chile. “Solid grains of that size shouldn’t be able to form in the cold outer regions of a disc around a brown dwarf, but it appears that they do. We can’t be sure if a whole rocky planet could develop there, or already has, but we’re seeing the first steps, so we’re going to have to change our assumptions about conditions required for solids to grow,” he said.

The brown dwarf ISO-Oph 102

ALMA’s increased resolution compared to previous telescopes also allowed the team to pinpoint carbon monoxide gas around the brown dwarf — the first time that cold molecular gas has been detected in such a disc. This discovery, and that of the millimetre-size grains, suggest that the disc is much more similar to the ones around young stars than previously expected.

Location of the brown dwarf ISO-Oph 102 in the constellation of Ophiuchus

Ricci and his colleagues made their finding using the partially completed ALMA telescope in the high-altitude Chilean desert. ALMA is a growing collection of high precision, dish-shaped antennas that work together as one large telescope to observe the Universe with groundbreaking detail and sensitivity. ALMA “sees” the Universe in millimetre-wavelength light, which is invisible to human eyes. Construction of ALMA is scheduled to finish in 2013, but astronomers began observing with a partial array of ALMA dishes in 2011.

Wide-field view of the Rho Ophiuchi star-forming region in visible light

The astronomers pointed ALMA at the young brown dwarf ISO-Oph 102, also known as Rho-Oph 102, in the Rho Ophiuchi star-forming region in the constellation of Ophiuchus (The Serpent Bearer). With about 60 times the mass of Jupiter but only 0.06 times that of the Sun, the brown dwarf has too little mass to ignite the thermonuclear reactions by which ordinary stars shine. However, it emits heat released by its slow gravitational contraction and shines with a reddish colour, albeit much less brightly than a star.

The growth of cosmic dust grains in the disc around the brown dwarf ISO-Oph 102

ALMA collected light with wavelengths around a millimetre, emitted by disc material warmed by the brown dwarf. The grains in the disc do not emit much radiation at wavelengths longer than their own size, so a characteristic drop-off in the brightness can be measured at longer wavelengths. ALMA is an ideal instrument for measuring this drop-off and thus for sizing up the grains. The astronomers compared the brightness of the disc at wavelengths of 0.89 mm and 3.2 mm. The drop-off in brightness from 0.89 mm to 3.2 mm was not as steep as expected, showing that at least some of the grains are a millimetre or more in size.

Artist’s impression of grains in the disc around a brown dwarf

“ALMA is a powerful new tool for solving mysteries of planetary system formation,” commented Leonardo Testi from ESO, a member of the research team. “Trying this with previous generation telescopes would have needed almost a month of observing — impossibly long in practice. But, using just a quarter of ALMA's final complement of antennas, we were able to do it in less than one hour!” he said.

The Brown Dwarf ISO-Oph 102

In the near future, the completed ALMA telescope will be powerful enough to make detailed images of the discs around Rho-Oph 102 and other objects. Ricci explained, “We will soon be able to not only detect the presence of small particles in discs, but to map how they are spread across the circumstellar disc and how they interact with the gas that we’ve also detected in the disc. This will help us better understand how planets come to be.”

More information:

This research is presented in a paper in the Astrophysical Journal Letters.

Ricci and Testi worked with Antonella Natta of the INAF-Osservatorio Astrofisico de Arcetri, Aleks Scholz of the Dublin Institute for Advanced Studies, and Itziar de Gregorio-Monsalvo of the Joint ALMA Observatory.

ALMA, an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

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”.


    Research paper:

    More about ALMA at ESO:

    The Joint ALMA Observatory:

Images, Text, Credit: ALMA (ESO/NAOJ/NRAO)/M. Kornmesser (ESO)/L. Calçada (ESO)/Digitized Sky Survey 2. Acknowledgement: Davide De Martin/IAU and Sky & Telescope/Videos: ALMA (ESO/NAOJ/NRAO)/L. Calçada (ESO)/M. Kornmesser (ESO)/Nick Risinger ( Sky Survey 2 Music: movetwo.

Best regards,

jeudi 29 novembre 2012

MESSENGER Finds New Evidence for Water Ice at Mercury's Poles

NASA - MESSENGER Mission to Mercury patch.

Nov. 29, 2012

New observations by the MESSENGER spacecraft provide compelling support for the long-held hypothesis that Mercury harbors abundant water ice and other frozen volatile materials in its permanently shadowed polar craters.

Three independent lines of evidence support this conclusion: the first measurements of excess hydrogen at Mercury's north pole with MESSENGER's Neutron Spectrometer, the first measurements of the reflectance of Mercury's polar deposits at near-infrared wavelengths with the Mercury Laser Altimeter (MLA), and the first detailed models of the surface and near-surface temperatures of Mercury's north polar regions that utilize the actual topography of Mercury's surface measured by the MLA. These findings are presented in three papers published online today in Science Express.

Mercury's North Polar Region Acquired By The Arecibo Observatory

Given its proximity to the Sun, Mercury would seem to be an unlikely place to find ice. But the tilt of Mercury's rotational axis is almost zero — less than one degree — so there are pockets at the planet's poles that never see sunlight. Scientists suggested decades ago that there might be water ice and other frozen volatiles trapped at Mercury's poles.

The idea received a boost in 1991, when the Arecibo radio telescope in Puerto Rico detected unusually radar-bright patches at Mercury's poles, spots that reflected radio waves in the way one would expect if there were water ice. Many of these patches corresponded to the location of large impact craters mapped by the Mariner 10 spacecraft in the 1970s. But because Mariner saw less than 50 percent of the planet, planetary scientists lacked a complete diagram of the poles to compare with the images.

A Mosaic of MESSENGER Images of Mercury's North Polar Region

MESSENGER's arrival at Mercury last year changed that. Images from the spacecraft's Mercury Dual Imaging System taken in 2011 and earlier this year confirmed that radar-bright features at Mercury's north and south poles are within shadowed regions on Mercury's surface, findings that are consistent with the water-ice hypothesis.

Now the newest data from MESSENGER strongly indicate that water ice is the major constituent of Mercury's north polar deposits, that ice is exposed at the surface in the coldest of those deposits, but that the ice is buried beneath an unusually dark material across most of the deposits, areas where temperatures are a bit too warm for ice to be stable at the surface itself.

Permanently Shadowed Polar Craters

MESSENGER uses neutron spectroscopy to measure average hydrogen concentrations within Mercury's radar-bright regions. Water-ice concentrations are derived from the hydrogen measurements. "The neutron data indicate that Mercury's radar-bright polar deposits contain, on average, a hydrogen-rich layer more than tens of centimeters thick beneath a surficial layer 10 to 20 centimeters thick that is less rich in hydrogen," writes David Lawrence, a MESSENGER Participating Scientist based at The Johns Hopkins University Applied Physics Laboratory and the lead author of one of the papers. "The buried layer has a hydrogen content consistent with nearly pure water ice."

MESSENGER Laser Altimeter

Data from MESSENGER's Mercury Laser Altimeter (MLA) — which has fired more than 10 million laser pulses at Mercury to make detailed maps of the planet's topography — corroborate the radar results and Neutron Spectrometer measurements of Mercury's polar region, writes Gregory Neumann of the NASA Goddard Space Flight Center. In a second paper, Neumann and his colleagues report that the first MLA measurements of the shadowed north polar regions reveal irregular dark and bright deposits at near-infrared wavelength near Mercury's north pole.

"These reflectance anomalies are concentrated on poleward-facing slopes and are spatially collocated with areas of high radar backscatter postulated to be the result of near-surface water ice," Neumann writes. "Correlation of observed reflectance with modeled temperatures indicates that the optically bright regions are consistent with surface water ice."

The MLA also recorded dark patches with diminished reflectance, consistent with the theory that the ice in those areas is covered by a thermally insulating layer. Neumann suggests that impacts of comets or volatile-rich asteroids could have provided both the dark and bright deposits, a finding corroborated in a third paper led by David Paige of the University of California, Los Angeles.

MESSENGER Spacecraft

Paige and his colleagues provided the first detailed models of the surface and near-surface temperatures of Mercury's north polar regions that utilize the actual topography of Mercury's surface measured by the MLA. The measurements "show that the spatial distribution of regions of high radar backscatter is well matched by the predicted distribution of thermally stable water ice," he writes.

According to Paige, the dark material is likely a mix of complex organic compounds delivered to Mercury by the impacts of comets and volatile-rich asteroids, the same objects that likely delivered water to the innermost planet.The organic material may have been darkened further by exposure to the harsh radiation at Mercury's surface, even in permanently shadowed areas.

Time-Lapsed Animation of a Mercury Day

This dark insulating material is a new wrinkle to the story, says Sean Solomon of the Columbia University's Lamont-Doherty Earth Observatory, principal investigator of the MESSENGER mission. "For more than 20 years the jury has been deliberating on whether the planet closest to the Sun hosts abundant water ice in its permanently shadowed polar regions. MESSENGER has now supplied a unanimous affirmative verdict."

"But the new observations have also raised new questions," adds Solomon. "Do the dark materials in the polar deposits consist mostly of organic compounds? What kind of chemical reactions has that material experienced? Are there any regions on or within Mercury that might have both liquid water and organic compounds? Only with the continued exploration of Mercury can we hope to make progress on these new questions."

For more information about the MESSENGER mission, visit: and

Related link:

Science Express:

Images, Videos, Text, Credits: NASA  / Goddard Space Flight Center / Johns Hopkins University Applied Physics Laboratory / Carnegie Institution of Washington / National Astronomy and Ionosphere Center, Arecibo Observatory.

Best regards,

Rocket Launch KSLV-1 postponed

KARI - Korea Space Launch Vehicle (KSLV-1) logo.


November 29 at the Naro Space Center (South Korea) during prelaunch identified remarks on the second stage of the launch vehicle (LV) KSLV-1 (the developer - Korea Aerospace Research Institute). At the request of the Korean administration,  preparations for launch was canceled.

According to preliminary data necessary to replace the device of the second stage, and therefore the KSLV-1 is removed from the launch-pad and is transported to the technical position to make a repair.

Korea Space Launch Vehicle (KSLV-1)

The first stage of the launch vehicle KSLV-1 is the prototype of the first stage of the launch vehicle "Angara" (designer and manufacturer - Khrunichev).

Time and date of the start of the launch vehicle KSLV-1 will be announced later.

Original text in Russian:

For more information about KARI, visit:

Images, Text, Credits: Press Service of the Russian Federal Space Agency (Roscosmos PAO) / KARI / Translation:


Space debris hazards spotlighted at conference

Space junk around the Earth.

29 November 2012

In 2013, ESA will host a gathering of international specialists to study space debris hazards. The four-day event will spotlight the risks posed to space exploration by the growing number of debris objects in near-Earth space.

ESA will host the 6th European Conference on Space Debris at its European Space Operations Centre in Darmstadt, Germany, 22–25 April.

Space debris in orbit

The conference is expected to attract more than 300 leading experts from worldwide. It is co-sponsored by the British, French, German and Italian space agencies (UKSA, CNES, DLR and ASI), the UN Committee on Space Research (COSPAR) and the International Academy of Astronautics. 

How space debris affect everyone

Today, citizens worldwide rely on space assets to enable a wide and growing range of economically vital activities.

Just some of the space-based benefits on which all of us rely include TV, weather forecasting, Internet, daily banking, monitoring of crops and optimisation of farming, disaster relief and door-to-door navigation.

Space debris stem from man-made objects such as defunct satellites, upper stages, discarded rocket components and even dropped astronaut gloves.

Many of these objects that orbit our planet have the potential to break up or explode, proliferating the problem.

It is estimated that the levels of debris in orbit is of the order of 29 000 pieces larger than 10 cm (with 23 000 of them regularly tracked), 670 000 larger than 1 cm and more than 170 million larger than 1 mm. Some debris travels at up to 56 000 km/hr.

Dr Heiner Klinkrad, Head of ESA's Space Debris Office, ESOC

“Any of these objects can cause harm to an operational spacecraft,” says Heiner Klinkrad, Head of ESA’s Space Debris Office.

“A collision with a 10 cm object would cause a catastrophic fragmentation, a 1 cm object could disable a normal-size spacecraft or penetrate the shields of the specially protected ISS, and a 1 mm object could destroy sensitive satellite sensors.”

Debris in the spotlight

ESA’s 2013 conference will provide a forum for scientists, engineers and managers from all major spacefaring nations, including space operators, industry, academia and policy bodies, to present the latest findings, discuss policy and technical options and help define future directions for research on all aspects of space debris.

Topics will include measurement techniques, environment modelling theories, risk analysis, protection designs, mitigation and remediation concepts, and policy and legal issues.

Special sessions will be devoted to active debris removal, in support of space debris environment remediation, with the aim to ensure the long-term sustainability of activities in space.

The conference will also promote the regular discussions taking place in a number of organisations, including the Inter-Agency Space Debris Coordination Committee (IADC) and the working group on Long-term Sustainability of Space Activities (LTSSA) of the Scientific and Technical Subcommittee of the UN Committee on the Peaceful Uses of Outer Space (UNCOPUOS).

Details on the conference, the abstract submission process, and the registration procedure via Congrex:

Conference brochure (PDF):

About space debris:

Images, Text, Credits: ESA / J. Mai.

Best regards,

Quasar GB 1428

NASA - Chandra X-ray Observatory patch.

Nov. 29, 2012

This composite image shows the most distant X-ray jet ever observed. X-ray data from NASA's Chandra X-ray Observatory are shown in blue, radio data from the NSF's Very Large Array are shown in purple and optical data from NASA's Hubble Space Telescope are shown in yellow. The jet was produced by a quasar named GB 1428+4217, or GB 1428 for short, and is located 12.4 billion light years from Earth. Labels for the quasar and jet can be seen by mousing over the image. The shape of the jet is very similar in the X-ray and radio data.

Giant black holes at the centers of galaxies can pull in matter at a rapid rate producing the quasar phenomenon. The energy released as particles fall toward the black hole generates intense radiation and powerful beams of high-energy particles that blast away from the black hole at nearly the speed of light. These particle beams can interact with magnetic fields or ambient photons to produce jets of radiation.

As the electrons in the jet fly away from the quasar, they move through a sea of background photons left behind after the Big Bang. When a fast-moving electron collides with one of these so-called cosmic microwave background photons, it can boost the photon’s energy into the X-ray band. Because the quasar is seen when the universe is at an age of about 1.3 billion years, less than 10% of its current value, the cosmic background radiation is a thousand times more intense than it is now. This makes the jet much brighter, and compensates in part for the dimming due to distance.

While there is another possible source of X-rays for the jet - radiation from electrons spiraling around magnetic field lines in the jet - the authors favor the idea that the cosmic background radiation is being boosted because the jet is so bright.

Chandra X-ray Observatory

The researchers think the length of the jet in GB 1428 is at least 230,000 light years, or about twice the diameter of the entire Milky Way galaxy. This jet is only seen on one side of the quasar in the Chandra and VLA data. When combined with previously obtained evidence, this suggests the jet is pointed almost directly toward us. This configuration would boost the X-ray and radio signals for the observed jet and diminish those for a jet presumably pointed in the opposite direction.

This result appeared in the Sept. 1, 2012 issue of The Astrophysical Journal Letters.

Read more/access all images:

Chandra's Flickr photoset:

Images, Text, Credits: X-ray: NASA / CXC / NRC / C.Cheung et al; Optical: NASA / STScI; Radio: NSF / NRAO / VLA.

Best regards,

REXUS 11 takes to the skies

REXUS / BEXUS - Student Experiment Programme patch.

29 November 2012

After a pause for 9 months, the delayed REXUS 11 sounding rocket took to the skies on 16 November 2012. It carried five student designed and built experiments, and successfully brought the programme to a close for 2012.

REXUS 11 Launch

The delayed REXUS launch resumed at 11:45 (CET) on 16 November 2012. The single-stage sounding rocket blasted off into the sky from the Esrange Space Center near Kiruna, in Northern Sweden. The payload was then recovered by helicopter and returned to the base at around 14:00 CET. It was the last launch in the REXUS (Rocket Experiments for University Students) programme in 2012.

Three experimental teams were sponsored by the Swedish National Space Board (SNSB) and ESA.

REXUS 11 payload

RAIN (Rocket deployed Atmospheric probes conducting Independent measurements in Northern Sweden) from KTH (Royal Institute of Technology), Sweden, set out to prove that high-resolution measurements of middle atmosphere’s aerosols could be made. To do this, the experiment ejected two Free Flying Units slightly before reaching 80km, the maximum altitude of its trajectory (or apogee). The units took measurements during their descent. Such data could improve our understanding of atmospheric composition, and its interaction with sunlight.

Telescobe 2 from DIT (Dublin Institute of Technology), Ireland, deployed a 1.6m boom during the flight to demonstrate that such a device could be used to mount scientific sensors. This experiment was equipped with a live-feed camera, which allowed the students and organisers in the Space Center to see the view from the rocket during part of the ascent.

GGES (Gravity Gradient Earth Sensor), from EPFL (École Polytechnique Fédérale de Lausanne), Switzerland, demonstrated a prototype sensor that used a Micro-Electro-Mechanical system to determine altitude in future CubeSats and nano-satellites.

REXUS 11 scientific payload

Two additional experiments were sponsored by the German Aerospace Center (DLR).

CaRu (Capillary under milligravity shown on Runge Pictures) from a student team of the Technical University of Dresden, Germany, examined the effect of low gravity conditions on the capillary effect and compared it with existing theoretical models. This experiment was also equipped with a live feed camera allowing a view of the inside of the module during some of the flight.

ADIOS (ADvanced Isolation On Sounding-rockets), provided by students of the FH (Fachhochschulen) Aachen in Germany, furthers a project to develop a cost-effective microgravity platform for use on sounding rockets that reduces the vibrations felt by the experiments.

ADIOS experiment

As well as the experimental results, working as part of the REXUS programme gave the students inspiration. “I have learned more from this experience than I have in any project I have ever undertaken before. The quality of engineering I have seen during the REXUS project was inspiring to say the very least. I have had the pleasure of meeting some of the finest engineers I have ever seen in action. I now have the pleasure of calling them friends,” says Jack Keegan from Telescobe 2.

The REXUS/BEXUS programme is realised under a bilateral Agency Agreement between the DLR and SNSB. The Swedish share of the payload has been made available to students from other European countries through a collaboration with the ESA.

EuroLaunch, a cooperation between the Esrange Space Center of SSC and the Mobile Rocket Base (MORABA) of DLR, is responsible for the campaign management and operations of the launch vehicles. Experts from ESA, SSC and DLR provide technical support to the student teams throughout the project.

The programme will continue next year with two more flights REXUS 13/14. The call for proposals for REXUS 15/16 closed on 22 October 2012.

Related links:

REXUS/BEXUS website:

Esrange Space Centre:

Swedish National Space Board, SNSB:

German Aerospace Center, REXUS BEXUS:

More information:

REXUS/BEXUS rocket & balloon experiments:

Sponsorship details:

Images, Text, Credits: Credits: ESA / ADIOS team.


mercredi 28 novembre 2012

Swirling Storms on Saturn

NASA / ESA - Cassini "Insider's" logo.

Nov.28, 2012

 Peering into the Storm

Image above: This image from NASA's Cassini mission was taken on Nov. 27, 2012, with Cassini's narrow-angle camera. Image credit: NASA/JPL-Caltech/Space Science Institute.

NASA's Cassini spacecraft has been traveling the Saturnian system in a set of inclined, or tilted, orbits that give mission scientists a vertigo-inducing view of Saturn's polar regions. This perspective has yielded images of roiling storm clouds and a swirling vortex at the center of Saturn's famed north polar hexagon.

Saturn's North Pole, Wide View

Image above: The camera was pointing toward Saturn from approximately 233,742 miles (376,171 kilometers) away. Image credit: NASA/JPL-Caltech/Space Science Institute.

These phenomena mimic what Cassini found at Saturn's south pole a number of years ago. Cassini has also seen storms circling Saturn's north pole in the past, but only in infrared wavelengths because the north pole was in darkness. (See .) But, with the change of the Saturnian seasons, the sun has begun to creep over the planet's north pole.

Vortex at Saturn's North Pole

Image above: The camera was pointing toward Saturn from approximately 248,578 miles (400,048 kilometers) away. Image credit: NASA/JPL-Caltech/Space Science Institute.

This particular set of raw, unprocessed images was taken on Nov. 27, 2012, from a distance of about 250,000 miles (400,000 kilometers) from Saturn.

Cassini spacraft. Image credit: NASA/JPL-Caltech

More raw images are available at . The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA's Science Mission Directorate, Washington. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute in Boulder, Colo.

ESA Cassini-Huygens website: At Saturn and Titan:

Images (mentioned), Text, Credits: NASA / ESA / JPL / Jia-Rui Cook / Space Science Institute / Steve Mullins.

Best regards,

International Space Station salutes the Sun

ISS - International Space Station patch.

28 November 2012

This weekend the International Space Station will turn itself to position ESA’s SOLAR instrument for a better view of the Sun. It will be the first time the Station has changed attitude for scientific reasons alone.

SOLAR has been monitoring our Sun’s output since it was installed on ESA’s Columbus laboratory module in February 2008. The package will celebrate its fifth anniversary next year.

International Space Station

“That is quite an achievement,” says Nadia This, operations engineer at the Belgian User Support and Operations Centre that controls SOLAR. “The instrument was designed to work for only 18 months.”

SOLAR needs to be in direct view of the Sun to take measurements but the Space Station’s normal orbit obscures the view for two weeks every month.


“We want to record a complete rotation of the Sun and that takes around 25 days,” explains Nadia.

The solution is to rotate the whole Station but moving a 450 tonne orbital outpost the size of a typical block of flats is not a simple undertaking.

Aside from calculating the correct orbit to keep SOLAR in view of the Sun, other factors need to be taken into account such as ensuring the solar panels that power the Station are not left in the dark.

Belgian support centre

Communication antennas need to be reoriented to stay in contact with Earth and other scientific experiments must be adjusted.

High-level discussions with all five Space Station partners were needed before the go-ahead was given.

SOLAR started recording a full rotation of the Sun on 19 November. On 1 December the Station will spend two hours turning about 7º so that observations can continue. It will hold this angle for ten days before returning to its original attitude. As usual, the Belgian centre will be following its progress 24 hours a day.

SOLAR on Station

SOLAR’s observations are improving our understanding of the Sun and allowing scientists to create accurate computer models and predict its behaviour. The more accurate data we acquire, the more we will understand our nearest star’s influence on Earth.

Recently, the 11-year solar cycle has shown irregularities and the next maximum is expected in 2013, so SOLAR’s spectral readings are of particular interest to scientists.

Related links: 


Research partners:


Fraunhofer Institute for Physical Measurement Techniques:

Centre national de la recherche scientifique:


Images, Text, Credits: ESA / NASA / BUSOC.


Titan’s seasons make sharp turn

NASA / ESA - Cassini-Huygens Mission to Saturn & Titan patch.

28 November 2012

Scientists using the international Cassini spacecraft have studied the rapid change in seasons on Saturn’s moon Titan, following equinox in August 2009, which saw the formation of a swirling vortex and a build up of exotic gases at unexpectedly high altitudes.

Titan is the only other body in the Solar System with a thick nitrogen-rich atmosphere like Earth’s. Titan’s atmosphere also contains methane and hydrogen, with trace amounts of other gases including hydrocarbons that form at high altitudes as a result of reactions with sunlight.

Vortex close up

These complex molecules filter down into the lower atmosphere and eventually combine to produce an orange smog.

A separate layer of haze is found at a much higher altitude of 400–500 km and can be seen at the limb of the moon, apparently detached from the rest of the atmosphere.

This haze was thought to represent the ceiling of Titan’s ‘middle atmosphere’ circulation which extends from pole to pole in one giant cell, but new results from Cassini suggest otherwise.

When Cassini arrived in the Saturn system in 2004, Titan sported a vortex with a ‘hood’ of enriched gas and dense haze high above its north, winter pole. After equinox in August 2009, spring arrived in the moon’s northern hemisphere while the southern hemisphere headed towards autumn.

The change in solar heating was reflected by a rapid reversal in circulation direction in Titan’s single pole-to-pole atmospheric cell, with an upwelling of gases in the summer hemisphere and downwelling in the winter hemisphere.

 Titan’s changing seasons (Click on the image for enlarge)

“Even though the amount of sunlight reaching the south pole was decreasing, the first thing we saw there during the six months after equinox was actually an increase in temperature at altitudes of 400–500 km, as atmospheric gases that had been lofted to these heights were compressed as they subsequently sank into a newly forming southern vortex,” says Dr Nick Teanby from the University of Bristol, UK, and lead author of the study reported in the journal Nature.

“This heating effect is the same one that causes compressed air in a bicycle pump to heat up, and provided the smoking gun that the change in seasons was underway.”

Image above: A vortex swirls at the south pole of Saturn’s moon Titan stands out brightly at lower right in this photo.  Credit: NASA / JPL-Caltech / Space Science Institute.

In the months that followed, up to a hundred-fold increase in atmospheric gas concentration was measured over the south pole at the same high altitudes.

Cassini’s instruments found that these gas molecules were sinking through the atmosphere at a rate of 1–2 millimetres per second.

Dr Teanby’s team conclude that for the enrichment and motion to be seen throughout these altitudes, the actual source of the complex gas molecules must be higher still, and that the detached haze layer cannot signal the top of the atmospheric circulation cell.

Cassini spacecraft and Titan

The new observations instead suggest that these complex haze molecules are produced higher up, but that when they drop down to the 400–500 km level, a change in the character of the haze takes place, perhaps as individual particles clump together.

“It’s impressive to see such dramatic solar-driven seasonal changes on a world where the sunlight is nearly a hundred times weaker than it is on Earth,” adds Dr Teanby.

“Since a year on Titan is nearly 30 Earth years long, for the atmosphere to change over a period of just six months is extremely rapid.”

“Models have predicted this change in Titan’s atmospheric circulation for nearly 20 years, but Cassini has provided the first direct observations of it actually happening,” says Nicolas Altobelli, ESA’s Cassini project scientist.

Related links:

At Saturn and Titan:

Cassini-Huygens in depth:

NASA JPL Cassini-Huygens site:

Italian Space Agency (ASI):

Images, Text, Credits: ESA / AOES / NASA / JPL–Caltech / Space Science Institute.

Best regards,

Biggest Black Hole Blast Discovered

ESO - European Southern Observatory logo.

28 November 2012

New ESO observations reveal most powerful quasar outflow ever found

Artist’s impression of the huge outflow ejected from the quasar SDSS J1106+1939

Astronomers using ESO’s Very Large Telescope (VLT) have discovered a quasar with the most energetic outflow ever seen, at least five times more powerful than any that have been observed to date. Quasars are extremely bright galactic centres powered by supermassive black holes. Many blast huge amounts of material out into their host galaxies, and these outflows play a key role in the evolution of galaxies. But, until now, observed quasar outflows weren’t as powerful as predicted by theorists.

Quasars are the intensely luminous centres of distant galaxies that are powered by huge black holes. This new study has looked at one of these energetic objects — known as SDSS J1106+1939 — in great detail, using the X-shooter instrument on ESO’s VLT at the Paranal Observatory in Chile [1]. Although black holes are noted for pulling material in, most quasars also accelerate some of the material around them and eject it at high speed.

“We have discovered the most energetic quasar outflow known to date. The rate that energy is carried away by this huge mass of material ejected at high speed from SDSS J1106+1939 is at least equivalent to two million million times the power output of the Sun. This is about 100 times higher than the total power output of the Milky Way galaxy — it’s a real monster of an outflow,” says team leader Nahum Arav (Virginia Tech, USA). “This is the first time that a quasar outflow has been measured to have the sort of very high energies that are predicted by theory.”

Many theoretical simulations suggest that the impact of these outflows on the galaxies around them may resolve several enigmas in modern cosmology, including how the mass of a galaxy is linked to its central black hole mass, and why there are so few large galaxies in the Universe. However, whether or not quasars were capable of producing outflows powerful enough to produce these phenomena has remained unclear until now [2].

The newly discovered outflow lies about a thousand light-years away from the supermassive black hole at the heart of the quasar SDSS J1106+1939. This outflow is at least five times more powerful than the previous record holder [3]. The team’s analysis shows that a mass of approximately 400 times that of the Sun is streaming away from this quasar per year, moving at a speed of 8000 kilometres per second.

“We couldn’t have got the high-quality data to make this discovery without the VLT’s X-shooter spectrograph,” says Benoit Borguet (Virginia Tech, USA), lead author of the new paper. “We were able to explore the region around the quasar in great detail for the first time.”

As well as SDSS J1106+1939, the team also observed one other quasar and found that both of these objects have powerful outflows. As these are typical examples of a common, but previously little studied, type of quasars [4], these results should be widely applicable to luminous quasars across the Universe. Borguet and colleagues are currently exploring a dozen more similar quasars to see if this is the case.

“I’ve been looking for something like this for a decade,” says Nahum Arav, “so it’s thrilling to finally find one of the monster outflows that have been predicted!”

ESO’s Very Large Telescope (VLT)


[1] The team observed SDSS J1106+1939 and J1512+1119 in April 2011 and March 2012 using the X-shooter spectrograph instrument attached to ESO’s VLT. By splitting the light up into its component colours and studying in detail the resultant spectrum the astronomers could deduce the velocity and other properties of the material close to the quasar.

[2] The powerful outflow observed in SDSS J1106+1939 carries enough kinetic energy to play a major role in active galaxy feedback processes, which typically require a mechanical power input of roughly 5% of the luminosity of the quasar. The rate at which kinetic energy is being transferred by the outflow is described as its kinetic luminosity.

[3] SDSS J1106+1939 has an outflow with a kinetic luminosity of at least 1046 ergs s−1. The distances of the outflows from the central quasar (300–8000 light-years) was greater than expected suggesting that we observe the outflows far from the region in which we assume them to initially accelerated (0.03–0.4 light-years).

[4] A class known as Broad Absorption Line (BAL) quasars.

More information:

This research was presented in a paper, “Major contributor to AGN feedback: VLT X-shooter observations of SIV BAL QSO outflows”, to appear in The Astrophysical Journal.

The team is composed of B. C. J. Borguet (Virginia Tech, USA), N. Arav (Virginia Tech, USA), D. Edmonds (Virginia Tech, USA), C. Chamberlain (Virginia Tech, USA), C. Benn (Isaac Newton Group of Telescopes, Spain).

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”.


Research paper:

Photos of the VLT:

Images, Text, Credits: ESO / L. Calçada / Richard Hook/ Virginia Tech / Nahum Arav / Benoît Borguet.


mardi 27 novembre 2012

Why Study Plants in Space?

ISS - International Space Station patch.

Nov. 27, 2012

Why is NASA conducting plant research aboard the International Space Station? Because during future long-duration missions, life in space may depend on it.

The ability of plants to provide a source of food and recycle carbon dioxide into breathable oxygen may prove critical for astronauts who will live in space for months at a time. In addition, plants provide a sense of well-being. At the McMurdo Station for research in Antarctica -- a site that in the dead of winter resembles the space station in its isolation, cramped quarters, and hostile environment -- the most sought after section of the habitat is the greenhouse.

NASA and the European Space Agency, or ESA, are studying how plants adapt to micro- and low-gravity environments in a series of experiments designed to determine the ability of vegetation to provide a complete, sustainable, dependable and economical means for human life support in space. As researchers continue to gain new knowledge of how plants grow and develop at a molecular level, this insight also may lead to significant advances in agriculture production on Earth.

Image above: Samples from the Seedling Growth investigation aboard the International Space Station help researchers study the impact of the microgravity environment on plant growth. (NASA).

Plant biology experiments on the space station using the European Modular Cultivation System, or EMCS, allow scientists to investigate plant growth and the processes within their cells to understand how plant life responds to conditions in space. Researchers currently are planning three new plant growth investigations specifically designed to examine the growth of seedlings in microgravity using this facility.

Combining the proposals of NASA Principal Investigator John Z. Kiss, and ESA Principal Investigator Javier Medina, the Seedling Growth investigation will continue at the space station for a series of experiments: Seedling Growth 1, 2 and 3 in 2013, 2014 and 2015 respectively. The results of these experiments will help researchers understand how plants sense and respond to the space environment.

Once aboard the space station, astronauts will conduct experiments to examine the seedlings' cultivation and stimulation under controlled temperature, atmosphere composition, limited water supply, illumination and acceleration conditions using centrifuges. Because the station crew is key to the success of the experiments, crew members will receive significant training, including on-board computer video instruction.

Thus far, NASA's Ames Research Center, Moffett Field, Calif., has completed three experiments using the EMCS. The 2006 study called Root Phototropism, or Tropi, used Thale cress (Arabidopsis thaliana) seeds from the mustard family to investigate how plant roots respond to varying levels of light and gravity. Using a rotating centrifuge, Kiss designed the experiment to expose the plants to different gravity conditions.

In 2010, the Tropi-2 experiment expanded on the knowledge gained from the first Tropi investigation. Collectively, the two studies demonstrated how red and blue light affects plant growth differently at varied levels of gravity. With this information, researchers now know that they can optimize plant root and shoot growth in space by fine-tuning the plants' exposure to light.

Image above: View of the TROPI seedling cassette for the European Modular Cultivation System, or EMCS, aboard the International Space Station Destiny laboratory module during Expedition 14. (NASA).

Most recently, the Plant Signaling space experiment, led by Principal Investigator Imara Perera, research associate professor at North Carolina State University, Raleigh, N. C., studied the roots and shoots of wild type and genetically modified Thale cress plant seedlings in microgravity and 1g -- a simulation of Earth's gravity. Images of the seedlings were sent to Earth before astronauts harvested and preserved the seedlings for post-flight analysis. The frozen plants are scheduled to return to Earth in 2013 aboard a SpaceX Dragon capsule.

The analysis of these data will lead to an understanding of the molecular mechanisms plants use to sense and respond to changes in their environment. Insights gained from this study will help scientists identify plants that are better able to withstand long duration spaceflight and microgravity conditions.

Description of the International Space Station's, U.S. Destiny laboratory location on ISS

Unique Environments Demand Specialized Equipment

Provided by ESA, the EMCS consists of a holding structure filling four station lockers and includes an incubator with two centrifuges. Two to four Ames-developed Experiment Containers, or ECs, can mount to each of the two centrifuge rotors to allow scientists to perform experiments at various g-levels up to twice Earth's gravity, or 2g.

The EMCS design enables control of temperature, humidity, oxygen and carbon dioxide. Equipped with white and infrared lights, EMCS also can control g-level simulation and water to perform experiments with biological samples. Video observation, imaging, data handling and command systems allow for control of the experiments inside the ECs. The ECs have specialized systems to study cell biology, small aquatic animals, roundworms, fruit flies and plants.

NASA's Ames Research Center worked closely with ESA to develop specific experimental units designed to grow plant seedlings, particularly Thale Cress, as well as other plant species. The hardware has performed flawlessly in supporting the Tropi-1, Tropi-2 and Plant Signaling experiments and will be used in the upcoming Seedling Growth study.

European Modular Cultivation System (EMCS):

For more information about the International Space Station (ISS), visit:

Images, Text, Credits: NASA / Ames Research Center / Barbara Patterson /  ESA.

Best regards,