samedi 8 juin 2013

Small Asteroid pass Between Earth and Moon











Asteroid Watch.

June 8, 2013


Image above: This illustration shows the path of the small asteroid 2013 LR6, safely pass within 65,000 miles (105,000 kilometers) of Earth on June 7 at 9:42 p.m. PDT (June 8 at 12:42 a.m. EDT). Image credit: NASA/JPL-Caltech.

Small asteroid 2013 LR6 safely fly past this evening at 9:42 p.m. PDT (which is June 8 at 12:42 a.m. EDT/June 8 at 04:42 UTC) at a distance of about 65,000 miles (105,000 kilometers) above Earth's surface. The space rock, which is about 30 feet (10 meters) in diameter, will be above the Southern Ocean, south of Tasmania, at the time of closest approach. Asteroid 2013 LR6 was discovered by the NASA-sponsored Catalina Sky Survey on June 6.

Small Asteroid pass Between Earth and Moon (Artist's view)

NASA's Near-Earth Object Program at NASA Headquarters, Washington, manages and funds the search, study and monitoring of asteroids and comets whose orbits periodically bring them close to Earth. JPL manages the Near-Earth Object Program Office for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena. 



More information about asteroids and near-Earth objects is available at: http://neo.jpl.nasa.gov/, http://www.jpl.nasa.gov/asteroidwatch and via Twitter at http://www.twitter.com/asteroidwatch

Images, Text, Credits: NASA / Dwayne Brown / JPL / DC Agle / JPL-Caltech.

Greetings, Orbiter.ch

vendredi 7 juin 2013

Timelapse: Giant magnet flies through ALICE cavern












CERN - European Organization for Nuclear Research logo.

June 7, 2013

video
 Lowering magnet Q5L8 ALICE cavern

The CERN accelerator complex is in its first long shutdown and undergoing a process called "consolidation," which means that engineers and maintenance crews are repairing and strengthening accelerator components in preparation for running at higher energy in 2015.


Image above: Engineers in the ALICE cavern supervise lowering the magnet onto the wheeled transporter. The large red doors of the ALICE detector are open, revealing the complex detector systems inside (Image: CERN).

As part of the shutdown, up to 18 superconducting magnets on the Large Hadron Collider (LHC) will be replaced, including 15 dipole magnets 3 and quadrupole magnet assemblies. Quadrupole magnets help to focus the particles into a tight beam so they are more likely to collide in greater numbers as they reach the LHC detectors. Each quadrupole has four magnetic poles arranged symmetrically around the beam pipe to squeeze the beam either vertically or horizontally.

This week technicians lowered a replacement quadrupole magnet assembly down the access shaft to the ALICE cavern. The cavern provides a handy access point to get equipment in and out of the LHC tunnel.


Image above: The quadrupole magnet arrives, carried by a wheeled transporter to its final position on the LHC (Image: CERN).

In the timelapse video above, magnet is lowered, raised then lowered once again onto a wheeled transporter that will carry it to position on the LHC.

Note:

CERN, the European Organization for Nuclear Research, is the world's leading laboratory for particle physics. It has its headquarters in Geneva. At present, its Member States are Austria, Belgium, Bulgaria, the Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Italy, the Netherlands, Norway, Poland, Portugal, Slovakia, Spain, Sweden, Switzerland and the United Kingdom. Romania is a candidate for accession. Israel is an Associate Member in the pre-stage to Membership. India, Japan, the Russian Federation, the United States of America, Turkey, the European Commission and UNESCO have Observer status.

Download a diagram of the main consolidations on the LHC: http://cds.cern.ch/record/1516031?ln=en

First long shutdown: http://home.web.cern.ch/about/updates/2013/02/long-shutdown-1-exciting-times-ahead

Large Hadron Collider (LHC): http://home.web.cern.ch/about/accelerators/large-hadron-collider

ALICE: http://home.web.cern.ch/about/experiments/alice

Images (mentioned), Text, Credits: CERN / Cian O'Luanaigh.

Cheers, Orbiter.ch

SMOS maps record soil water before flood









ESA - SMOS Mission logo.

7 June 2013

As parts of central Europe are battling with the most extensive floods in centuries, forecasters are hoping that ESA’s SMOS satellite will help to improve the accuracy of flood prediction in the future.

As its name suggests, the Soil Moisture and Ocean Salinity (SMOS) mission monitors the amount of water held in the surface layers of the soil and the concentration of salt in the top layer of seawater.

Soil moisture from SMOS

This information is helping scientists understand more about how water is cycled between the oceans, atmosphere and land – Earth’s water cycle. It is also helping to improve weather forecasts.

The massive flooding that central Europe is currently suffering was brought about by a wet spring and sudden heavy rains.

SMOS carries a novel microwave sensor to capture images of ‘brightness temperature’ to derive information on soil moisture.

SMOS in orbit

Prior to the torrential rains, SMOS showed that soils in Germany were showing record levels of moisture – in fact, the highest ever observed.

The animation above shows the wet soils in blues and the dryer soils in yellows.

ESA’s SMOS mission scientist, Matthias Drusch, explains, “Data from SMOS can be used to monitor the saturation of the soil.

“At the end of May we see that the soil was almost fully saturated, with record values for moisture. More rain meant that it immediately ran off as the surplus water could not soak into the soil, and this resulted in these terrible floods.

Flood mapping through the International Charter

“Numerical Weather Predication centres are currently assessing the possibility of using SMOS data to improve weather and flood forecasts, so hopefully we will be better placed to predict these events more accurately in the future. ”

Satellite missions such as Germany’s TerraSAR-X and RapidEye are providing imagery to aid the relief effort through the International Charter Space and Major Disasters.

Related links:

ESA SMOS: http://www.esa.int/Our_Activities/Observing_the_Earth/SMOS

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

CESBIO–SMOS blog: http://www.cesbio.ups-tlse.fr/SMOS_blog/

European Centre for Medium-Range Weather Forecasts: http://www.ecmwf.int/

International Charter Space and Major Disasters: http://www.disasterscharter.org/

More information:

German weather service: http://www.dwd.de/bvbw/generator/DWDWWW/Content/Presse/Pressemitteilungen/2013/20130606__HochwasserJuni,templateId=raw,property=publicationFile.pdf/20130606_HochwasserJuni.pdf

Images, Text, Credits: ESA / CESBIO / AOES Medialab / DLR / Astrium Services/Infoterra GmbH / map ZKI.

Best regards, Orbiter.ch

jeudi 6 juin 2013

Stars Don't Obliterate Their Planets (Very Often)












NASA - Kepler Mission patch.

June 6, 2013

Stars have an alluring pull on planets, especially those in a class called hot Jupiters, which are gas giants that form farther from their stars before migrating inward and heating up.

Now, a new study using data from NASA's Kepler Space Telescope shows that hot Jupiters, despite their close-in orbits, are not regularly consumed by their stars. Instead, the planets remain in fairly stable orbits for billions of years, until the day comes when they may ultimately get eaten.

"Eventually, all hot Jupiters get closer and closer to their stars, but in this study we are showing that this process stops before the stars get too close," said Peter Plavchan of NASA's Exoplanet Science Institute at the California Institute of Technology, Pasadena, Calif. "The planets mostly stabilize once their orbits become circular, whipping around their stars every few days."

On the Road Toward a Star, Planets Halt Their Migration

Image above: Researchers using data from NASA's Kepler space telescope have shown that migrating planets stop their inward journey before reaching their stars, as illustrated in this artist's concept. Image credit: NASA/JPL-Caltech.

The study, published recently in the Astrophysical Journal, is the first to demonstrate how the hot Jupiter planets halt their inward march on stars. Gravitational, or tidal, forces of a star circularize and stabilize a planet's orbit; when its orbit finally become circular, the migration ceases.

"When only a few hot Jupiters were known, several models could explain the observations," said Jack Lissauer, a Kepler scientist at NASA's Ames Research Center, Moffet Field, Calif., not affiliated with the study. "But finding trends in populations of these planets shows that tides, in combination with gravitational forces by often unseen planetary and stellar companions, can bring these giant planets close to their host stars."

Hot Jupiters are giant balls of gas that resemble Jupiter in mass and composition. They don't begin life under the glare of a sun, but form in the chilly outer reaches, as Jupiter did in our solar system. Ultimately, the hot Jupiter planets head in toward their stars, a relatively rare process still poorly understood.

The new study answers questions about the end of the hot Jupiters' travels, revealing what put the brakes on their migration. Previously, there were a handful of theories explaining how this might occur. One theory proposed that the star's magnetic field prevented the planets from going any farther. When a star is young, a planet-forming disk of material surrounds it. The material falls into the star -- a process astronomers call accretion -- but when it hits the magnetic bubble around it, called the magnetosphere, the material travels up and around the bubble, landing on the star from the top and bottom. This bubble could be halting migrating planets, so the theory went.

Another theory held that the planets stopped marching forward when they hit the end of the dusty portion of the planet-forming disk.

"This theory basically said that the dust road a planet travels on ends before the planet falls all the way into the star," said co-author Chris Bilinski of the University of Arizona, Tucson. "A gap forms between the star and the inner edge of its dusty disk where the planets are thought to stop their migration."

And yet a third theory, the one the researchers found to be correct, proposed that a migrating planet stops once the star's tidal forces have completed their job of circularizing its orbit.

To test these and other scenarios, the scientists looked at 126 confirmed planets and more than 2,300 candidates. The majority of the candidates and some of the known planets were identified via NASA's Kepler mission. Kepler has found planets of all sizes and types, including rocky ones that orbit where temperatures are warm enough for liquid water.

Kepler space telescope. Image credit: NASA/JPL-Caltech

The scientists looked at how the planets' distance from their stars varied depending on the mass of the star. It turns out that the various theories explaining what stops migrating planets differ in their predictions of how the mass of a star affects the orbit of the planet. The "tidal forces" theory predicted that the hot Jupiters of more massive stars would orbit farther out, on average.

The survey results matched the "tidal forces" theory and even showed more of a correlation between massive stars and farther-out orbits than predicted.

This may be the end of the road for the mystery of what halts migrating planets, but the journey itself still poses many questions. As gas giants voyage inward, it is thought that they sometimes kick smaller, rocky planets out of the way, and with them any chance of life evolving. Lucky for us, our Jupiter did not voyage toward the sun, and our Earth was left in peace. More studies like this one will help explain these and other secrets of planetary migration.

The technical paper is online at http://iopscience.iop.org/0004-637X/769/2/86/.

NASA Ames manages Kepler's ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, Calif., managed Kepler mission development. Ball Aerospace & Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with JPL at the Laboratory for Atmospheric and Space Physics at the University of Colorado in Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes the Kepler science data. Kepler is NASA's 10th Discovery Mission and is funded by NASA's Science Mission Directorate at the agency's headquarters in Washington.

NASA's Exoplanet Science Institute at Caltech manages time allocation on the Keck telescope for NASA. JPL manages NASA's Exoplanet Exploration program office. Caltech manages JPL for NASA.

More information about the Kepler mission is at http://www.nasa.gov/kepler.

More information about exoplanets and NASA's planet-finding program is at http://planetquest.jpl.nasa.gov.

Images (mentioned), Text, Credits: NASA / Ames Research Center / Michele Johnson / JPL / Whitney Clavin.

Greetings, Orbiter.ch

ALMA Discovers Comet Factory












ESO - European Southern Observatory logo.

6 June 2013

New observations of a “dust trap” around a young star solve long-standing planet formation mystery

 Artist’s impression of the comet factory seen by ALMA

Astronomers using the new Atacama Large Millimeter/submillimeter Array (ALMA) have imaged a region around a young star where dust particles can grow by clumping together. This is the first time that such a dust trap has been clearly observed and modelled. It solves a long-standing mystery about how dust particles in discs grow to larger sizes so that they can eventually form comets, planets and other rocky bodies. The results are published in the journal Science on 7 June 2013.

ALMA image of comet factory around Oph-IRS 48

Astronomers now know that planets around other stars are plentiful. But they do not fully understand how they form and there are many aspects of the formation of comets, planets and other rocky bodies that remain a mystery. However, new observations exploiting the power of ALMA are now answering one of the biggest questions: how do tiny grains of dust in the disc around a young star grow bigger and bigger — to eventually become rubble, and even boulders well beyond a metre in size?

Computer models suggest that dust grains grow when they collide and stick together. However, when these bigger grains collide again at high speed they are often smashed to pieces and sent back to square one. Even when this does not happen, the models show that the larger grains would quickly move inwards because of friction between the dust and gas and fall onto their parent star, leaving no chance that they could grow even further.

ALMA and VLT image of comet factory around Oph-IRS 48

Somehow the dust needs a safe haven where the particles can continue growing until they are big enough to survive on their own [1]. Such “dust traps” have been proposed, but there was no observational proof of their existence up to now.

Nienke van der Marel, a PhD student at Leiden Observatory in the Netherlands, and lead author of the article, was using ALMA along with her co-workers, to study the disc in a system called Oph-IRS 48 [2]. They found that the star was circled by a ring of gas with a central hole that was probably created by an unseen planet or companion star. Earlier observations using ESO’s Very Large Telescope had already shown that the small dust particles also formed a similar ring structure. But the new ALMA view of where the larger millimetre-sized dust particles were found was very different!

ALMA image of dust trap/comet factory around Oph-IRS 48 (annotated)

“At first the shape of the dust in the image came as a complete surprise to us,” says van der Marel. “Instead of the ring we had expected to see, we found a very clear cashew-nut shape! We had to convince ourselves that this feature was real, but the strong signal and sharpness of the ALMA observations left no doubt about the structure. Then we realised what we had found.”

What had been discovered was a region where bigger dust grains were trapped and could grow much larger by colliding and sticking together. This was a dust trap — just what the theorists were looking for.

The location of the system Oph-IRS 48 in the constellation of Ophiuchus

As van der Marel explains: “It’s likely that we are looking at a kind of comet factory as the conditions are right for the particles to grow from millimetre to comet size. The dust is not likely to form full-sized planets at this distance from the star. But in the near future ALMA will be able to observe dust traps closer to their parent stars, where the same mechanisms are at work. Such dust traps really would be the cradles for new-born planets.”

The dust trap forms as bigger dust particles move in the direction of regions of higher pressure. Computer modelling has shown that such a high pressure region can originate from the motions of the gas at the edge of a gas hole — just like the one found in this disc.

video
Dust trap animation 

“The combination of modelling work and high quality observations of ALMA makes this a unique project”, says Cornelis Dullemond from the Institute for Theoretical Astrophysics in Heidelberg, Germany, who is an expert on dust evolution and disc modelling, and a member of the team. “Around the time that these observations were obtained, we were working on models predicting exactly these kinds of structures: a very lucky coincidence.”

video
Zooming in on the Oph-IRS 48 system

The observations were made while the ALMA array was still being constructed. They made use of the ALMA Band 9 receivers [3] — European-made devices that allow ALMA to create its so far sharpest images.

video
Computer simulation of dust trap formation

“These observations show that ALMA is capable of delivering transformational science, even with less than half of the full array in use,” says Ewine van Dishoeck of the Leiden Observatory, who has been a major contributor to the ALMA project for more than 20 years. “The incredible jump in both sensitivity and image sharpness in Band 9 gives us the opportunity to study basic aspects of planet formation in ways that were simply not possible before.”

Notes:

[1] The cause of the dust trap, in this case a vortex in the disc's gas', has typical life spans of hundreds of thousand of years. Even when the dust trap ceases to work, the dust accumulated in the trap would take millions of years to disperse providing ample time for the dust grains to grow larger.

[2] The name is a combination of the constellation name of the star-forming region where the system is found and the type of source, so Oph stands for the constellation of Ophiuchus (The Serpent Bearer), and the IRS stands for infrared source. The distance from Earth to Oph-IRS 48 is about 400 light-years.

[3] ALMA can observe in different frequency bands. Band 9, operating at wavelengths of about 0.4–0.5 millimeters, is the mode that so far provides the sharpest images.

More information:

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of Europe, North America and East Asia in cooperation with the Republic of Chile. ALMA is funded in Europe by the European Southern Observatory (ESO), in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC) and the National Science Council of Taiwan (NSC) and in East Asia by the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Academia Sinica (AS) in Taiwan. ALMA construction and operations are led on behalf of Europe by ESO, on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI) and on behalf of East Asia by the National Astronomical Observatory of Japan (NAOJ). The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

This research was presented in a paper “A major asymmetric dust trap in a transition disk“, by van der Marel et al, to appear in the journal Science on 7 June 2013.

The team is composed of Nienke van der Marel (Leiden Observatory, Leiden, the Netherlands), Ewine F. van Dishoeck (Leiden Observatory; Max-Planck-Institut für Extraterrestrische Physik Garching, Germany [MPE]), Simon Bruderer (MPE), Til Birnstiel (Harvard-Smithsonian Center for Astrophysics, Cambridge, USA [CfA]), Paola Pinilla (Heidelberg University, Heidelberg, Germany), Cornelis P. Dullemond (Heidelberg University), Tim A. van Kempen (Leiden Observatory; Joint ALMA Offices, Santiago, Chile), Markus Schmalzl (Leiden Observatory), Joanna M. Brown (CfA), Gregory J. Herczeg (Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing, China), Geoffrey S. Mathews (Leiden Observatory) and Vincent Geers (Dublin Institute for Advanced Studies, Dublin, Ireland).

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

Links:

Photos of ALMA: http://www.eso.org/public/images/archive/search/?adv=&subject_name=Atacama%20Large%20Millimeter/submillimeter%20Array

Images taken with ALMA: http://www.eso.org/public/images/archive/search/?adv=&facility=36

ALMA press releases: http://www.eso.org/public/news/archive/search/?adv=&facility=36

Images, Text, Credits: ESO/L. Calçada/ALMA (ESO/NAOJ/NRAO)/Nienke van der Marel/IAU and Sky & Telescope/Videos: ALMA/ESO/L. Calçada/P. Pinilla/NAOJ/NRAO/Nick Risinger (skysurvey.org)/Digitized Sky Survey 2/S. Guisard (www.eso.org/sguisard). Music: movetwo.

Best regards, Orbiter.ch

The floodwaters of Mars












ESA - Mars Express Mission patch.

6 June 2013

 Kasei Valles

Dramatic flood events carved this impressive channel system on Mars covering 1.55 million square kilometres, shown here in a stunning new mosaic from ESA’s Mars Express.

The mosaic, which features the spectacular Kasei Valles, comprises 67 images taken with the spacecraft’s high-resolution stereo camera and is released during the week of the 10th anniversary of the spacecraft’s launch to the Red Planet.

Kasei Valles is one of the largest outflow channel systems on Mars – from source to sink, it extends some 3000 km and descends by 3 km in altitude. The scene covered in the mosaic spans 987 km north–south (19–36°N) and 1550 km east–west (280–310°E).

The channel originates beyond the southern edge of this image near Valles Marineris, and empties into the vast plains of Chryse Planitia to the east (right).

Kasei Valles in context

Kasei Valles splits into two main branches that hug a broad island of fractured terrain – Sacra Mensa – rising 2 km above the channels that swerve around it. While weaker materials succumbed to the erosive power of the fast-flowing water, this hardier outcrop has stood the test of time.

Slightly further downstream, the flood waters did their best to erase the 100 km-wide Sharonov crater, crumpling its southern rim. Around Sharonov, many small streamlined islands form teardrop shapes rising from the riverbed, carved as water swept around these natural obstacles.

The region between Sacra Mensa and Sharonov is seen in close-up detail in the perspective view below, looking downstream from the northern flank of Kasai Valles.

Kasei Valles topography

Zooming into the valley floor reveals small craters with bright dust ‘tails’ seemingly flowing in the opposite direction to the movement of water. In fact, these craters were formed by impacts that took place after the catastrophic flooding, their delicate tails created by winds blowing in a westwards direction ‘up’ valley.

Their raised rims influence wind flow over the crater such that the dust immediately ‘behind’ the crater remains undisturbed in comparison to the surrounding, exposed, plains.

Kasei Valles has likely seen floods of many different sizes, brought about by the changing tectonic and volcanic activity in the nearby Tharsis region over 3 billion years ago.

Perspective view of Kasei Valles

The landscape was pulled apart under the strain of these forces, groundwater bursting from its ripped seams to create not only violent floods, but also the unique fracture patterns seen at Sacra Mensa and Sacra Fossae.

Snow and ice melted by volcanic eruptions also likely contributed to torrential, muddy outpourings, while glacial activity may have further shaped the channel system.

Now silent, one can only imagine from examples on Earth the roar of gushing water that once cascaded through Kasei Valles, undermining cliff faces and engulfing craters, and eventually flooding onto the plains of Chryse Planitia.

Related links:

Mars Epress - Looking at Mars: http://www.esa.int/Our_Activities/Space_Science/Mars_Express

Mars Express blog: http://blogs.esa.int/mex/

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

Mars Express overview: http://www.esa.int/Our_Activities/Space_Science/Mars_Express_overview

Mars Express 10 year brochure: http://esamultimedia.esa.int/multimedia/publications/BR-312/

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

Greetings, Orbiter.ch

Cassini Sees Precursors to Aerosol "Snow" on Titan












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

06 June 2013

Scientists have confirmed the presence of PAHs - Polycyclic Aromatic Hydrocarbons - in the upper atmosphere of Saturn's largest moon, Titan. The study, based on data from the VIMS instrument on the Cassini orbiter, provides an explanation of the origin of the aerosol particles found in the lowest haze layer that blankets Titan's surface. The PAHs, which form high up in the atmosphere, later grow into larger aggregates that drift down - much like snow flakes - and eventually give rise to aerosols.

 Of all the bodies in the Solar System, Saturn's largest moon, Titan, has the atmosphere most resembling that of Earth. Like that of our planet, Titan's atmosphere is largely composed of molecular nitrogen (N2); unlike Earth's atmosphere, however, Titan's contains only small traces of oxygen and water. Another molecule, methane (CH4), plays a similar role to that of water in Earth's atmosphere, and makes up about 2 per cent of Titan's atmosphere. Scientists have speculated that the atmosphere of this moon may resemble that of our planet in its early days, before primitive living organisms enriched it with oxygen via photosynthesis.

When sunlight or highly energetic particles from Saturn's magnetosphere hit the layers of Titan's atmosphere above 1000 km, the nitrogen and methane molecules there are broken up. This results in the formation of massive positive ions and electrons, which trigger a  chain of chemical reactions, producing a variety of hydrocarbons – a wide range of which have been detected in Titan's atmosphere. These reactions eventually lead to the production of carbon-based aerosols, large aggregates of atoms and molecules that are found in the lower layers of the haze that enshrouds Titan, well below 500 km.

Cassini image of Titan's haze. Credit: NASA / JPL / Space Science Institute.

Aerosols in this lower haze have been studied using data from the descent of the Huygens probe, which reached the surface in 2005, but their origin remained unclear. A new study of Titan's upper atmosphere might have solved the puzzle with the detection of Polycyclic Aromatic Hydrocarbons (PAHs), which are large carbon-based molecules that form from the aggregation of smaller hydrocarbons. The detected PAHs appear to be the precursors to  aerosols, triggering the first reactions that cause these large, solid particles to sink, like snow flakes, into Titan's lower atmosphere. The study is based on data collected with the Visible and Infrared Mapping Spectrometer (VIMS) on board the Cassini mission.

"We can finally confirm that PAHs play a major role in the production of Titan's lower haze, and that the chemical reactions leading to the formation of the haze start high up in the atmosphere," comments Manuel López-Puertas from the Instituto de Astrofísica de Andalucía (CSIC) in Granada, Spain. López-Puertas is the first author of a paper, published in The Astrophysical Journal, describing these results.

"This finding is surprising: we had long suspected that PAHs and aerosols were linked in Titan's atmosphere, but didn't expect we could prove this with current instruments," he adds.

The team of scientists had been studying the emission from various molecules in Titan's atmosphere when they stumbled upon a peculiar feature in the data. One of the characteristic lines in the spectrum, due to emission by methane, had a slightly anomalous shape, and the scientists suspected it was hiding something.

"We subtracted from the observed spectra the signal caused by methane, which is very strong because this molecule is quite abundant in Titan's atmosphere. And that's when we found out that it was covering up something else," explains co-author Bianca Maria Dinelli from the Istituto di Scienze dell'Atmosfera e del Clima (CNR) in Bologna, Italy. "We found an additional emission feature. But we had no idea what it was," she adds.


Image above: The role of Polycyclic Aromatic Hydrocarbons (PAHs) in the formation of aerosols in Titan's haze. Credit: ESA / ATG medialab.

Painstaking investigation followed to identify the chemical species responsible for this emission. The additional signal was found only during daytime, so it clearly had something to do with solar irradiation.

"The central wavelength of this signal – about 3.28 microns – is the typical one of the emission from aromatic compounds – hydrocarbon molecules in which the carbon atoms are bound in ring-like structures," explains Dinelli.

The scientists tested whether the unidentified emission could be produced by benzene (C6H6), the simplest aromatic compound consisting of one ring only, which had been earlier detected in Titan's atmosphere. However, the relatively low abundances of benzene are not sufficient to explain the emission that had been observed.

After they ruled benzene out, the scientists tried to reproduce the observed emission with PAHs, which are more complex aromatic molecules containing several rings. And they were successful: the data can be explained as emission by a mixture of many different PAHs, which contain an average of 34 carbon atoms and about 10 rings each.


Image above: Two of the most likely abundant PAHs found in Titan's atmosphere: C10H8N (left) and C48H22 (right). Credit: ESA / ATG medialab / NASA Ames PAH IR Spectral Database.

"Although less abundant than benzene, PAHs are very efficient in absorbing ultraviolet radiation from the Sun, redistributing the energy within the molecule and finally emitting it at infrared wavelengths," explains co-author Alberto Adriani from the Istituto di Astrofisica e Planetologia Spaziali (INAF) in Rome, Italy. Adriani is part of the Cassini-VIMS co-investigator team based at INAF, Italy, that collected and processed the data.

"It is not only this 'solar pumping', but also the peculiar characteristics of PAHs that cause these molecules to radiate so profusely, after having absorbed ultraviolet photons from the Sun, even in the rarefied environment of Titan's upper atmosphere, where the collisions between molecules are not very frequent," comments López-Puertas.

The PAHs themselves are a product of photoionisation of smaller molecules in the upper atmosphere of Titan – and the first step in a sequence of increasingly larger compounds. Models show how PAHs can coagulate and form large aggregates, which tend to sink, due to their greater weight, into the lower atmospheric layers. The higher densities in Titan's lower atmosphere favour the further growth of these large conglomerates of atoms and molecules, leading to the eventual formation of aerosols.

"The direct detection of PAHs in Titan's atmosphere is an important step in understanding the role of carbon compounds in another body in the Solar System," says Nicolas Altobelli, Cassini-Huygens Project Scientist at ESA. "In the future, we plan to study how these compounds behave with the seasons in the data from Cassini: aerosols in the lower haze are known to undergo seasonal variations, so finding a similar trend in the PAHs would be a further proof of their close connection."

Notes for editors:

The study presented here is based on observations performed with the Visible and Infrared Mapping Spectrometer (VIMS) on board the Cassini orbiter of the NASA/ESA/ASI Cassini-Huygens mission. The data were gathered during two of Cassini's flybys of Titan in July and August 2007.

The study is based on data collected and processed by the Cassini-VIMS co-investigator team based at INAF, Italy and on further detailed atmospheric modelling performed by collaborators from the Italian CNR and the Spanish CSIC institutes.

The study focuses on a strong emission feature detected at 3.28 microns in Titan's upper atmosphere during daytime. The emission is produced at altitudes between 600 and 1250 km, and has a peak around 950 km.

The attribution of the emission to Polycyclic Aromatic Hydrocarbons (PAHs) was done using the  NASA Ames PAH IR Spectral Database. The emission is caused by a mixture of PAHs containing a number of carbon atoms that ranges from 9 to 96, and an average of 10-11 rings. The two most likely abundant PAHs in this mixture are C48H22 and C10H8N.

Related publications:

M. López-Puertas, et al., "Large abundances of Polycyclic Aromatic Hydrocarbons in Titan's upper atmosphere", 2013, Astrophysical Journal. DOI: 10.1088/0004-637X/770/2/132
- López-Puertas, M., et al. [2013]: http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=51869

B.M. Dinelli, et al., "An unidentified emission in Titan's upper atmosphere", 2013, Geophysical Research Letters, Vol. 40, Pag. 1-5. DOI: 10.1002/grl.50332
- Dinelli, B. M., et al. [2013]: http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=51868

Related Link:

The NASA Ames PAH IR Spectral Database: http://www.astrochem.org/pahdb/

Images, Text, Credits: ESA / ATG medialab / NASA / JPL / Space Science Institute / NASA Ames PAH IR Spectral Database.

Best regards, Orbiter.ch

mercredi 5 juin 2013

South-Up Moon Phase and Libration 2013

NASA - Lunar Reconnaissance Orbiter (LRO) patch.

June 5, 2013

video
 South-Up Moon Phase and Libration 2013

This visualization shows the moon's phase and libration at hourly intervals throughout 2013, as viewed from the Southern Hemisphere. Each frame represents one hour. In addition, this visualization shows the moon’s orbit position, sub-Earth and subsolar points, and distance from Earth at true scale. Credit: NASA's Goddard Space Flight Center.

The jagged, cratered, airless lunar terrain casts sharp shadows that clearly outline the Moon's surface features for observers on Earth. This is especially true near the terminator, the line between day and night, where surface features appear in high relief. Elevation measurements by the Lunar Orbiter Laser Altimeter (LOLA) aboard the Lunar Reconnaissance Orbiter (LRO) make it possible to simulate shadows on the Moon's surface with unprecedented accuracy and detail.

The Moon always keeps the same face to us, but not exactly the same face. Because of the tilt and shape of its orbit, we see the Moon from slightly different angles over the course of a month. When a month is compressed into 24 seconds, as it is in this animation, our changing view of the Moon makes it look like it's wobbling. This wobble is called libration.

The word comes from the Latin for "balance scale" (as does the name of the zodiac constellation Libra) and refers to the way such a scale tips up and down on alternating sides. The sub-Earth point gives the amount of libration in longitude and latitude. The sub-Earth point is also the apparent center of the Moon's disk and the location on the Moon where the Earth is directly overhead.

Lunar Reconnaissance Orbiter (LRO)

The Moon is subject to other motions as well. It appears to roll back and forth around the sub-Earth point. The roll angle is given by the position angle of the axis, which is the angle of the Moon's north pole relative to celestial north. The Moon also approaches and recedes from us, appearing to grow and shrink. The two extremes, called perigee (near) and apogee (far), differ by more than 10%.

The most noticed monthly variation in the Moon's appearance is the cycle of phases, caused by the changing angle of the Sun as the Moon orbits the Earth. The cycle begins with the waxing (growing) crescent Moon visible in the west just after sunset. By first quarter, the Moon is high in the sky at sunset and sets around midnight. The full Moon rises at sunset and is high in the sky at midnight. The third quarter Moon is often surprisingly conspicuous in the daylit western sky long after sunrise.

Celestial south is up in these images, corresponding to the view from the southern hemisphere. The descriptions of the print resolution stills also assume a southern hemisphere orientation.

For more information about Lunar Reconnaissance Orbiter (LRO), visit: http://lunar.gsfc.nasa.gov/

See unlabeled and HD versions of this video: http://svs.gsfc.nasa.gov/vis/a000000/a004000/a004067/index.html

Image, Video, Text, Credit: Credit: NASA's Goddard Space Flight Center.

Greetings, Orbiter.ch

NASA's Curiosity Mars Rover Nears Turning Point










NASA - Mars Science Laboratory (MSL) logo.

June 5, 2013

Drilled Hole and ChemCam Marks at 'Cumberland'

Image above: The Chemistry and Camera (ChemCam) instrument on NASA's Mars rover Curiosity was used to check the composition of gray tailings from the hole in rock target "Cumberland" that the rover drilled on May 19, 2013. Image credit: NASA/JPL-Caltech/MSSS.

NASA's Mars Science Laboratory mission is approaching its biggest turning point since landing its rover, Curiosity, inside Mars' Gale Crater last summer.

Curiosity is finishing investigations in an area smaller than a football field where it has been working for six months, and it will soon shift to a distance-driving mode headed for an area about 5 miles (8 kilometers) away, at the base Mount Sharp.

In May, the mission drilled a second rock target for sample material and delivered portions of that rock powder into laboratory instruments in one week, about one-fourth as much time as needed at the first drilled rock.

"We're hitting full stride," said Mars Science Laboratory Project Manager Jim Erickson of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We needed a more deliberate pace for all the first-time activities by Curiosity since landing, but we won't have many more of those."

No additional rock drilling or soil scooping is planned in the "Glenelg" area that Curiosity entered last fall as the mission's first destination after landing. To reach Glenelg, the rover drove east about a third of a mile (500 meters) from the landing site. To reach the next destination, Mount Sharp, Curiosity will drive toward the southwest for many months.

'Point Lake' Outcrop in Gale Crater, Raw Color

Image above: One priority target for a closer look by NASA's Mars rover Curiosity before the rover departs the "Glenelg" area east of its landing site is the pitted outcrop called "Point Lake," in the upper half of this image. Image credit: NASA/JPL-Caltech/MSSS.

"We don't know when we'll get to Mount Sharp," Erickson said. "This truly is a mission of exploration, so just because our end goal is Mount Sharp doesn't mean we're not going to investigate interesting features along the way."

Images of Mount Sharp taken from orbit and images Curiosity has taken from a distance reveal many layers where scientists anticipate finding evidence about how the ancient Martian environment changed and evolved.

While completing major first-time activities since landing, the mission has also already accomplished its main science objective. Analysis of rock powder from the first drilled rock target, "John Klein," provided evidence that an ancient environment in Gale Crater had favorable conditions for microbial life: the essential elemental ingredients, energy and ponded water that was neither too acidic nor too briny.

The rover team chose a similar rock, "Cumberland," as the second drilling target to provide a check for the findings at John Klein. Scientists are analyzing laboratory-instrument results from portions of the Cumberland sample. One new capability being used is to drive away while still holding rock powder in Curiosity's sample-handling device to supply additional material to instruments later if desired by the science team.

Checking Contact Points for Curiosity's Drill

Image above: This image demonstrates how engineers place the drill carried by NASA's Mars rover Curiosity onto rock targets. Image credit: NASA/JPL-Caltech/MSSS.

For the drill campaign at Cumberland, steps that each took a day or more at John Klein could be combined into a single day's sequence of commands. "We used the experience and lessons from our first drilling campaign, as well as new cached sample capabilities, to do the second drill campaign far more efficiently," said sampling activity lead Joe Melko of JPL. "In addition, we increased use of the rover's autonomous self-protection. This allowed more activities to be strung together before the ground team had to check in on the rover."

The science team has chosen three targets for brief observations before Curiosity leaves the Glenelg area: the boundary between bedrock areas of mudstone and sandstone, a layered outcrop called "Shaler" and a pitted outcrop called "Point Lake."

Mars Science Laboratory (MSL) "Curiosity". Image credit: NASA / JPL-Caltech

JPL's Joy Crisp, deputy project scientist for Curiosity, said "Shaler might be a river deposit. Point Lake might be volcanic or sedimentary. A closer look at them could give us better understanding of how the rocks we sampled with the drill fit into the history of how the environment changed."

JPL, a division of the California Institute of Technology, Pasadena, manages the Mars Science Laboratory Project for NASA's Science Mission Directorate in Washington. For more about the mission, visit: http://www.nasa.gov/msl and http://mars.jpl.nasa.gov/msl .

You can follow the mission on Facebook and Twitter at: http://www.facebook.com/marscuriosity and http://www.twitter.com/marscuriosity .

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

Greetings, Orbiter.ch

NASA'S Spitzer Sees Milky Way's Blooming Countryside












NASA - Spitzer Space Telescope patch.

June 5, 2013

 Stars Shoot Jets in Cosmic Playground

Image above: Dozens of newborn stars sprouting jets from their dusty cocoons have been spotted in images from NASA's Spitzer Space Telescope. Image credit: NASA/JPL-Caltech/University of Wisconsin.

New views from NASA's Spitzer Space Telescope show blooming stars in our Milky Way galaxy's more barren territories, far from its crowded core.

The images are part of the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (Glimpse 360) project, which is mapping the celestial topography of our galaxy. The map and a full, 360-degree view of the Milky Way plane will be available later this year. Anyone with a computer may view the Glimpse images and help catalog features.

We live in a spiral collection of stars that is mostly flat, like a vinyl record, but it has a slight warp. Our solar system is located about two-thirds of the way out from the Milky Way's center, in the Orion Spur, an offshoot of the Perseus spiral arm. Spitzer's infrared observations are allowing researchers to map the shape of the galaxy and its warp with the most precision yet.

Bubbles Within Bubbles

Image above: This infrared image shows a striking example of what is called a hierarchical bubble structure, in which one giant bubble, carved into the dust of space by massive stars, has triggered the formation of smaller bubbles. Image credit: NASA/JPL-Caltech/University of Wisconsin.

While Spitzer and other telescopes have created mosaics of the galaxy's plane looking in the direction of its center before, the region behind us, with its sparse stars and dark skies, is less charted.

"We sometimes call this flyover country," said Barbara Whitney, an astronomer from the University of Wisconsin at Madison who uses Spitzer to study young stars. "We are finding all sorts of new star formation in the lesser-known areas at the outer edges of the galaxy."

Whitney and colleagues are using the data to find new sites of youthful stars. For example, they spotted an area near Canis Major with 30 or more young stars sprouting jets of material, an early phase in their lives. So far, the researchers have identified 163 regions containing these jets in the Glimpse 360 data, with some of the young stars highly clustered in packs and others standing alone.

Life and Death Intermingled

Image above: In what may look to some like an undersea image of coral and seaweed, a new image from NASA's Spitzer Space Telescope is showing the birth and death of stars. Image credit: NASA/JPL-Caltech/University of Wisconsin.

Robert Benjamin is leading a University of Wisconsin team that uses Spitzer to more carefully pinpoint the distances to stars in the galaxy's hinterlands. The astronomers have noticed a distinct and rapid drop-off of red giants, a type of older star, at the edge of the galaxy. They are using this information to map the structure of the warp in the galaxy's disk.

"With Spitzer, we can see out to the edge of the galaxy better than before," said Robert Benjamin of the University of Wisconsin, who presented the results Wednesday at the 222nd meeting of the American Astronomical Society in Indianapolis. "We are hoping this will yield some new surprises."

Thanks to Spitzer's infrared instruments, astronomers are capturing improved images of those remote stellar lands. Data from NASA's Wide-field Infrared Survey Explorer (WISE) are helping fill in gaps in the areas Spitzer did not cover. WISE was designed to survey the entire sky twice in infrared light, completing the job in early 2011, while Spitzer continues to probe the infrared sky in more detail. The results are helping to canvas our galaxy, filling in blanks in the outer expanses where not much is known.

Galaxies in Hiding

Image above: There are nearly 200 galaxies within the marked circles in this image from NASA's Spitzer Space Telescope. Image credit: NASA/JPL-Caltech/University of Wisconsin.

Glimpse 360 already has mapped 130 degrees of the sky around the galactic center. Four new views from the area looking away from the galactic center are online at: http://www.nasa.gov/mission_pages/spitzer/multimedia/index.html .

Members of the public continue scouring images from earlier Glimpse data releases in search of cosmic bubbles indicative of hot, massive stars. Astronomers' knowledge of how massive stars influence the formation of other stars is benefitting from this citizen science activity, called The Milky Way Project. For instance, volunteers identified a striking multiple bubble structure in a star-forming region called W39. Followup work by the researchers showed the smaller bubbles were spawned by a larger bubble that had been carved out by massive stars.

"This crowdsourcing approach really works," said Charles Kerton of Iowa State University at Ames, who also presented results. "We are examining more of the hierarchical bubbles identified by the volunteers to understand the prevalence of triggered star formation in our galaxy."

For more information about the Milky Way project and to learn how to participate, visit: http://www.milkywayproject.org .

NASA's Jet Propulsion Laboratory, Pasadena, Calif., manages the Spitzer Space Telescope mission for NASA's Science Mission Directorate, Washington. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA. For more information about Spitzer, visit http://spitzer.caltech.edu and http://www.nasa.gov/spitzer .

Images (mentioned), Text, Credits: NASA / J.D. Harrington / Jet Propulsion Laboratory / Whitney Clavin.

Best regards, Orbiter.ch

NASA Chandra, Spitzer Study Suggests Black Holes Abundant Among The Earliest Stars














NASA - Chandra X-ray Observatory patch / NASA - Spitzer Space Telescope patch.

June 5, 2013

By comparing infrared and X-ray background signals across the same stretch of sky, an international team of astronomers has discovered evidence of a significant number of black holes that accompanied the first stars in the universe.

Using data from NASA's Chandra X-ray Observatory and NASA's Spitzer Space Telescope, which observes in the infrared, researchers have concluded one of every five sources contributing to the infrared signal is a black hole.



Image above: The cosmic microwave background, shown at left in this illustration, is a flash of light that occurred when the young universe cooled enough for electrons and protons to form the first atoms. It contains slight temperature fluctuations that correspond to regions of slightly different densities, representing the seeds of all cosmic structure we see around us today. The universe then went dark for hundreds of millions of years until the first stars shone and the first black holes began accreting gas. A portion of the infrared and X-ray signals from these sources is preserved in the cosmic infrared background, or CIB, and its X-ray equivalent, the CXB. At least 20 percent of the structure in these backgrounds changes in concert, indicating that black hole activity was hundreds of times more intense in the early universe than it is today. Credit: Karen Teramura, UHIfA.

"Our results indicate black holes are responsible for at least 20 percent of the cosmic infrared background, which indicates intense activity from black holes feeding on gas during the epoch of the first stars," said Alexander Kashlinsky, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Md.

The cosmic infrared background (CIB) is the collective light from an epoch when structure first emerged in the universe. Astronomers think it arose from clusters of massive suns in the universe's first stellar generations, as well as black holes, which produce vast amounts of energy as they accumulate gas.

Even the most powerful telescopes cannot see the most distant stars and black holes as individual sources. But their combined glow, traveling across billions of light-years, allows astronomers to begin deciphering the relative contributions of the first generation of stars and black holes in the young cosmos. This was at a time when dwarf galaxies assembled, merged and grew into majestic objects like our own Milky Way galaxy.

"We wanted to understand the nature of the sources in this era in more detail, so I suggested examining Chandra data to explore the possibility of X-ray emission associated with the lumpy glow of the CIB," said Guenther Hasinger, director of the Institute for Astronomy at the University of Hawaii in Honolulu, and a member of the study team.

Hasinger discussed the findings Tuesday at the 222nd meeting of the American Astronomical Society in Indianapolis. A paper describing the study was published in the May 20 issue of The Astrophysical Journal.

Chandra X-ray Observatory. Image credit: NASA / JPL-Caltech.

The work began in 2005, when Kashlinsky and his colleagues studying Spitzer observations first saw hints of a remnant glow. The glow became more obvious in further Spitzer studies by the same team in 2007 and 2012. The 2012 investigation examined a region known as the Extended Groth Strip, a single well-studied slice of sky in the constellation Bootes. In all cases, when the scientists carefully subtracted all known stars and galaxies from the data, what remained was a faint, irregular glow. There is no direct evidence this glow is extremely distant, but telltale characteristics lead researchers to conclude it represents the CIB.

In 2007, Chandra took especially deep exposures of the Extended Groth Strip as part of a multiwavelength survey. Along a strip of sky slightly larger than the full moon, the deepest Chandra observations overlap with the deepest Spitzer observations. Using Chandra observations, lead researcher Nico Cappelluti, an astronomer with the National Institute of Astrophysics in Bologna, Italy, produced X-ray maps with all of the known sources removed in three wavelength bands. The result, paralleling the Spitzer studies, was a faint, diffuse X-ray glow that constitutes the cosmic X-ray background (CXB).

Comparing these maps allowed the team to determine whether the irregularities of both backgrounds fluctuated independently or in concert. Their detailed study indicates fluctuations at the lowest X-ray energies are consistent with those in the infrared maps.

"This measurement took us some five years to complete and the results came as a great surprise to us," said Cappelluti, who also is affiliated with the University of Maryland, Baltimore County in Baltimore.

Spitzer Space Telescope. Image credit: NASA / JPL-Caltech.

The process is similar to standing in Los Angeles while looking for signs of fireworks in New York. The individual pyrotechnics would be too faint to see, but removing all intervening light sources would allow the detection of some unresolved light. Detecting smoke would strengthen the conclusion at least part of this signal came from fireworks.

In the case of the CIB and CXB maps, portions of both infrared and X-ray light seem to come from the same regions of the sky. The team reports black holes are the only plausible sources that can produce both energies at the intensities required. Regular star-forming galaxies, even those that vigorously form stars, cannot do this.

By teasing out additional information from this background light, the astronomers are providing the first census of sources at the dawn of structure in the universe.

"This is an exciting and surprising result that may provide a first look into the era of initial galaxy formation in the universe," said another contributor to the study, Harvey Moseley, a senior astrophysicist at Goddard. "It is essential that we continue this work and confirm it."

NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass. Data are archived at the Chandra X-ray Center in Cambridge.

NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., manages the Spitzer Space Telescope mission. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology (Caltech) in Pasadena. Data are archived at the Infrared Science Archive housed at the Infrared Processing and Analysis Center at Caltech. Caltech manages JPL for NASA.

Related Links:

Paper: Cross-Correlating Cosmic Infrared and X-ray Background Fluctuations: Evidence of Significant Black Hole Populations Among the CIB Sources: http://arxiv.org/abs/1210.5302

"NASA's Spitzer Finds First Objects Burned Furiously" (06.07.12): http://www.nasa.gov/mission_pages/spitzer/news/spitzer20120607.html

"NASA Telescope Picks Up Glow of Universe's First Objects" (12.18.06): http://www.nasa.gov/mission_pages/spitzer/news/spitzer-20061218.html

NASA’s Chandra website: http://www.nasa.gov/chandra

NASA’s Spitzer website: http://www.nasa.gov/spitzer

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

Cheers, Orbiter.ch

Europe's Heaviest Cargo Ship Launched to Space Station





















ESA / Arianespace - ATV-4 "Albert Einstein" Mission Launch poster / ESA - ATV-4 Mission patch.

5 June 2013

 Liftoff!

ESA’s fourth Automated Transfer Vehicle, Albert Einstein, was launched into orbit last evening from Europe’s Spaceport in Kourou, French Guiana. Europe’s autonomous supply ship will perform a series of manoeuvres to dock with the International Space Station on 15 June.

video
Ariane 5 ES with ATV-4 liftoff

The Ariane 5 rocket, operated by Arianespace, lifted off at 21:52:11 GMT (23:52:11 CEST, 18:52:11 local time) and delivered ATV-4 into the planned circular parking orbit at 260 km altitude about 64 minutes later. ATV then deployed its four power-generating solar wings and antenna boom.

The ship is being monitored by the ATV Control Centre, jointly operated by ESA and CNES, the French space agency, in Toulouse. It will complete the Launch and Early Orbit Phase in some six hours after launch and is due to rendezvous and dock automatically with the Station at 13:46 GMT (15:46 CEST) on 15 June.

Heaviest spacecraft ever launched by Ariane

At 20 190 kg, ATV Albert Einstein is the heaviest spacecraft ever launched by Ariane, beating predecessor ATV Edoardo Amaldi by some 150 kg. ESA’s resupply and reboost vehicle is the largest, most advanced and most capable of the vehicles servicing the orbital outpost.

The solar panels and antennas are deployed, the electrical power on board is normal

“With another successful launch of the ATV, and another record in lifting capacity, European industry demonstrates its capacity to produce unique spacecrafts, providing ESA with a key role among the partners of the International Space Station,” noted Jean-Jacques Dordain, ESA Director General.

“This adventure is still in the making – ATV-4 is flying but ATV-5 is following and ATV technologies will survive beyond them in promising new programmes, such as NASA’s Orion Multipurpose Crew Vehicle, for which ESA is developing the service module.

Orion

"From ATV to Orion, ESA is building up capabilities which will provide Europe the capacity to be a key partner in future international exploration programmes," said Thomas Reiter, ESA Director of Human Spaceflight and Operations.

“Today, we’re supporting long-term settlement and scientific research in low orbit. Tomorrow, we will take this expertise beyond Earth orbit together with our partners.”

Delivering record payload

ATV-4 is carrying a record payload of 2480 kg dry cargo, including 620 kg of ‘last minute’ items, which were installed while on top of Ariane, less than two weeks before launch. Stored in ATV’s pressurised section, this cargo is also the most diverse ever, with more than 1400 items.

Loading cargo before launch

In addition, ATV-4 has 2580 kg of propellants for reboosting the Station’s orbit and 860 kg more to refill the tanks of the Zvezda module. It will also pump 570 kg of drinking water and 100 kg of gases (two tanks of oxygen, one of air) into the Station’s tanks.

Fully autonomous docking
ATV was developed for ESA by European industry, with Astrium as prime contractor, to deliver goods and propellants under a barter agreement with NASA to support Europe’s share of the Station’s operating costs. It features high-precision navigation systems, highly redundant flight software and a fully autonomous self-monitoring and collision-avoidance system with independent power supplies, control and thrusters.

No other spaceship approaching the Station has demonstrated such a level of autonomous control.

ATV approaching Station

Albert Einstein is the fourth in a series of five ATVs. It will spend over 4 months docked to the Zvezda module, during which it will provide extra storage room and a quiet rest area for the astronauts. It also offers a powerful manoeuvring capability to raise the Station’s altitude to combat natural orbital decay and, if required, to steer it out of the way of dangerous space debris.

At the end of its mission, filled with waste, it will undock on 28 October and make a safe controlled reentry over the South Pacific.

The last ATV, Georges Lemaître, is being prepared for launch in 2014.

For more information about Automated Transfer Vehicle (ATV), visit: http://www.esa.int/Our_Activities/Human_Spaceflight/ATV

ATV blog: http://blogs.esa.int/atv

ATV Control Centre: http://www.esa.int/Our_Activities/Human_Spaceflight/ATV/ATV_Control_Centre

Images, Video, Text, Credits: ESA / Arianespace / NASA / Screen captures by Orbiter.ch Aerospace.

Greetings, Orbiter.ch