vendredi 12 février 2016

SDO: Year 6 Ultra-HD

NASA - Solar Dynamics Observatory patch.

Feb. 12, 2016

SDO: Year 6 Ultra-HD

The sun is always changing and NASA's Solar Dynamics Observatory is always watching. Launched on Feb. 11, 2010, SDO keeps a 24-hour eye on the entire disk of the sun, with a prime view of the graceful dance of solar material coursing through the sun's atmosphere, the corona. SDO's sixth year in orbit was no exception. This video shows that entire sixth year -- from Jan. 1, 2015, to Jan. 28, 2016, as one time-lapse sequence. At full quality on YouTube, this video is ultra-high definition 3840x2160 and 29.97 frames per second. Each frame represents 2 hours. A downloadable version has a frame rate of 59.94 with each frame representing 1 hour.

See below for the link. SDO's Atmospheric Imaging Assembly (AIA) captures a shot of the sun every 12 seconds in 10 different wavelengths. The images shown here are based on a wavelength of 171 angstroms, which is in the extreme ultraviolet range and shows solar material at around 600,000 kelvins (about 1,079,540 degrees F). In this wavelength it is easy to see the sun's 25-day rotation. During the course of the video, the sun subtly increases and decreases in apparent size. This is because the distance between the SDO spacecraft and the sun varies over time.

Solar Dynamics Observatory (SDO) spacecraft

The image is, however, remarkably consistent and stable despite the fact that SDO orbits Earth at 6,876 mph, and Earth orbits the sun at 67,062 mph. Scientists study these images to better understand the complex electromagnetic system causing the constant movement on the sun, which can ultimately have an effect closer to Earth, too: Flares and another type of solar explosion called coronal mass ejections can sometimes disrupt technology in space. Moreover, studying our closest star is one way of learning about other stars in the galaxy.

NASA's Goddard Space Flight Center in Greenbelt, Maryland, built, operates and manages the SDO spacecraft for NASA's Science Mission Directorate in Washington, D.C.

Learn more about SDO and see more imagery: and

Image, Video, Text, Credits: NASA's Goddard Space Flight Center/Wiessinger Music: "Tides," a track available from Killer Tracks.


Particles in Love: Quantum Mechanics Explored in New Study

JPL - Jet Propulsion laboratory logo.

Feb. 12, 2016

This cartoon helps explain the idea of "entangled particles." Alice and Bob represent photon detectors, which NASA's Jet Propulsion Laboratory and the National Institute of Standards and Technology developed. Cartoon Credits: NASA/JPL-Caltech.

Here's a love story at the smallest scales imaginable: particles of light. It is possible to have particles that are so intimately linked that a change to one affects the other, even when they are separated at a distance.

This idea, called "entanglement," is part of the branch of physics called quantum mechanics, a description of the way the world works at the level of atoms and particles that are even smaller. Quantum mechanics says that at these very tiny scales, some properties of particles are based entirely on probability. In other words, nothing is certain until it happens.

Testing Bell's Theorem

Albert Einstein did not entirely believe that the laws of quantum mechanics described reality. He and others postulated that there must be some hidden variables at work, which would allow quantum systems to be predictable. In 1964, however, John Bell published the idea that any model of physical reality with such hidden variables also must allow for the instantaneous influence of one particle on another. While Einstein proved that information cannot travel faster than the speed of light, particles can still affect each other when they are far apart according to Bell.

Scientists consider Bell's theorem an important foundation for modern physics. While many experiments have taken place to try to prove his theorem, no one was able to run a full, proper test of the experiment Bell would have needed until recently. In 2015, three separate studies were published on this topic, all consistent with the predictions of quantum mechanics and entanglement.

"What's exciting is that in some sense, we're doing experimental philosophy," said Krister Shalm, physicist with the National Institute of Standards and Technology (NIST), Boulder, Colorado. Shalm is lead author on one of the 2015 studies testing Bell's theorem. "Humans have always had certain expectations of how the world works, and when quantum mechanics came along, it seemed to behave differently."

How 'Alice and Bob' Test Quantum Mechanics

The paper by Shalm, Marsili and colleagues was published in the journal Physical Review Letters, with the mind-bending title "Strong Loophole-Free Test of Local Realism."

“Our paper and the other two published last year show that Bell was right: any model of the world that contains hidden variables must also allow for entangled particles to influence one another at a distance," said Francesco Marsili of NASA's Jet Propulsion Laboratory in Pasadena, California, who collaborated with Shalm.

An analogy helps to understand the experiment, which was conducted at a NIST laboratory in Boulder:

Imagine that A and B are entangled photons. A is sent to Alice and B is sent to Bob, who are located 607 feet (185 meters) apart.

Alice and Bob poke and prod at their photons in all kinds of ways to get a sense of their properties. Without talking to each other, they then each randomly decide how to measure their photons, using random number generators to guide their decisions. When Alice and Bob compare notes, they are surprised to find that the results of their independent experiments are correlated. In other words, even at a distance, measuring one photon of the entangled pair affects the properties of the other photon.

Image above: Technology used to study the "love" between particles is also being used in research to improve communications between space and Earth. Image Credits: NASA/JPL-Caltech.

"It's as if Alice and Bob try to tear the two photons apart, but their love still persists," Shalm said. In other words, the entangled photons behave as if they are two parts of a single system, even when separated in space.

Alice and Bob -- representing actual photon detectors -- then repeat this with many other pairs of entangled photons, and the phenomenon persists.

In reality, the photon detectors are not people, but superconducting nanowire single photon detectors (SNSPDs). SNSPDs are metal strips that are cooled until they become "superconducting," meaning they lose their electric resistance. A photon hitting this strip causes it to turn into a normal metal again momentarily, so the resistance of the strip jumps from zero to a finite value. This change in resistance allows the researchers to record the event.

To make this experiment happen in a laboratory, the big challenge is to avoid losing photons as they get sent to the Alice and Bob detectors through an optical fiber. JPL and NIST developed SNSPDs with worldrecord performance, demonstrating more than 90 percent efficiency and low "jitter," or uncertainty on the time of arrival of a photon. This experiment would not have been possible without SNSPDs.

Why This is Useful

The design of this experiment could potentially be used in cryptography -- making information and communications secure -- as it involves generating random numbers.

"The same experiment that tells us something deep about how the world is constructed also can be used for these applications that require you to keep your information safe," Shalm said.

Cryptography isn't the only application of this research. Detectors similar to those used for the experiment, which were built by JPL and NIST, could eventually also be used for deep-space optical communication. With a high efficiency and low uncertainty about the time of signal arrival, these detectors are well-suited for transmitting information with pulses of light in the optical spectrum.

"Right now we have the Deep Space Network to communicate with spacecraft around the solar system, which encodes information in radio signals. With optical communications, we could increase the data rate of that network 10- to 100-fold," Marsili said.

Deep space optical communication using technology similar to the detectors in Marsili's experiment was demonstrated with NASA's Lunar Atmosphere Dust and Environment Explorer (LADEE) mission, which orbited the moon from October 2013 to April 2014. A technology mission called the Lunar Laser Communication Demonstration, with components on LADEE and on the ground, downlinked data encoded in laser pulses, and made use of ground receivers based on SNSPDs.

NASA's Space Technology Mission Directorate is working on the Laser Communications Relay Demonstration (LCRD) mission.  The mission proposes to revolutionize the way we send and receive data, video and other information, using lasers to encode and transmit data at rates 10 to 100 times faster than today's fastest radio-frequency systems, using significantly less mass and power.

"Information can never travel faster than the speed of light -- Einstein was right about that. But through optical communications research, we can increase the amount of information we send back from space," Marsili said. "The fact that the detectors from our experiment have this application creates great synergy between the two endeavors."

And so, what began as the study of "love" between particles is contributing to innovations in communications between space and Earth. "Love makes the world go 'round," and it may, in a sense, help us learn about other worlds.

Editor note:

This experiment was conducted by several laboratories including CERN and UNIGE (University of Geneva) used the photons to "teleport" data for several kilometers with quantum computers, Geneva physicists set quantum teleportation to 25 km.

Related article (from editor note):

Physicists Achieve Quantum Teleportation of Photon Over 25 Kilometers:

Related links:

Jet Propulsion Laboratory (JPL):

Quantum teleportation:

Université de Genève (University of Geneva):

CERN - European Organization for Nuclear Research:

Image (mentioned), Cartoon (mentioned), Text, Credits: NASA's Jet Propulsion Laboratory/Elizabeth Landau/Tony Greicius/ Aerospace/Roland Berga.

Best regards,

Hubble Watches the Icy Blue Wings of Hen 2-437

NASA - Hubble Space Telescope patch.

Feb. 12, 2016

In this cosmic snapshot, the spectacularly symmetrical wings of Hen 2-437 show up in a magnificent icy blue hue. Hen 2-437 is a planetary nebula, one of around 3,000 such objects known to reside within the Milky Way.

Located within the faint northern constellation of Vulpecula (The Fox), Hen 2-437 was first identified in 1946 by Rudolph Minkowski, who later also discovered the famous and equally beautiful M2-9 (otherwise known as the Twin Jet Nebula). Hen 2-437 was added to a catalog of planetary nebula over two decades later by astronomer and NASA astronaut Karl Gordon Henize.

Planetary nebulae such as Hen 2-437 form when an aging low-mass star — such as the sun — reaches the final stages of life. The star swells to become a red giant, before casting off its gaseous outer layers into space. The star itself then slowly shrinks to form a white dwarf, while the expelled gas is slowly compressed and pushed outwards by stellar winds. As shown by its remarkably beautiful appearance, Hen 2-437 is a bipolar nebula — the material ejected by the dying star has streamed out into space to create the two icy blue lobes pictured here.

For images and more information about Hubble, visit:

Image Credits: ESA (European Space Agency)/Hubble & NASA, Acknowledgement: Judy Schmidt/Text Credits: ESA/NASA/Rob Garner.


Rosetta's lander faces eternal hibernation

ESA - Rosetta Mission patch.

12 February 2016

Silent since its last call to mothership Rosetta seven months ago, the Philae lander is facing conditions on Comet 67P/Churyumov–Gerasimenko from which it is unlikely to recover.

Rosetta, which continues its scientific investigations at the comet until September before its own comet-landing finale, has in recent months been balancing science observations with flying dedicated trajectories optimised to listen out for Philae. But the lander has remained silent since 9 July 2015.

Reconstructing Philae’s flight

“The chances for Philae to contact our team at our lander control centre are unfortunately getting close to zero,” says Stephan Ulamec, Philae project manager at the German Aerospace Center, DLR. “We are not sending commands any more and it would be very surprising if we were to receive a signal again.”

Philae’s team of expert engineers and scientists at the German, French and Italian space centres and across Europe have carried out extensive investigations to try to understand the status of the lander, piecing together clues since it completed its first set of scientific activities after its historic landing on 12 November 2014.

Philae descends to the comet

A story with incredible twists and turns unfolded on that day. In addition to a faulty thruster, Philae also failed to fire its harpoons and lock itself onto the surface of the comet after its seven-hour descent, bouncing from its initial touchdown point at Agilkia, to a new landing site, Abydos, over 1 km away. The precise location of the lander has yet to be confirmed in high-resolution images.

A reconstruction of the flight of the lander suggested that it made contact with the comet four times during its two-hour additional flight across the small comet lobe. After bouncing from Agilkia it grazed the rim of the Hatmehit depression, bounced again, and then finally settled on the surface at Abydos.

Even after this unplanned excursion, the lander was still able to make an impressive array of science measurements, with some even as it was flying above the surface after the first bounce.

Once the lander had made its final touchdown, science and operations teams worked around the clock to adapt the experiments to make the most of the unanticipated situation. About 80% of its initial planned scientific activities were completed.

Reconstructing Philae’s trajectory

In the 64 hours following its separation from Rosetta, Philae took detailed images of the comet from above and on the surface, sniffed out organic compounds, and profiled the local environment and surface properties of the comet, providing revolutionary insights into this fascinating world.

But with insufficient sunlight falling on Philae’s new home to charge its secondary batteries, the race was on to collect and transmit the data to Rosetta and across 510 million kilometres of space back to Earth before the lander’s primary battery was exhausted as expected. Thus, on the evening of 14–15 November 2014, Philae fell into hibernation.

As the comet and the spacecraft moved closer to the Sun ahead of perihelion on 13 August 2015 – the closest point to the Sun along its orbit – there were hopes that Philae would wake up again.

Estimates of the thermal conditions at the landing site suggested that the lander might receive enough sunlight to start warming up to the minimum –45ºC required for it to operate on the surface even by the end of March 2015.

It is worth noting that if Philae had remained at its original landing site of Agilkia, it would have likely overheated by March, ending any further operations.

Welcome to a comet

On 13 June 2015, the lander finally hailed the orbiting Rosetta and subsequently transmitted housekeeping telemetry, including information from its thermal, power and computer subsystems.

Subsequent analysis of the data indicated that the lander had in fact already woken up on 26 April 2015, but had been unable to send any signals until 13 June.

The fact that the lander had survived the multiple impacts on 12 November and then unfavourable environmental conditions, greatly exceeding the specifications of its various electronic components, was quite remarkable.

After 13 June, Philae made a further seven intermittent contacts with Rosetta in the following weeks, with the last coming on 9 July. However, the communications links that were established were too short and unstable to enable any scientific measurements to be commanded.

Despite the improved thermal conditions, with temperatures inside Philae reaching 0ºC, no further contacts were made as the comet approached perihelion in August.

Approaching perihelion – Animation

However, the months around perihelion are also the comet’s most active. With increased levels of outflowing gas and dust, conditions were too challenging for Rosetta to operate safely close enough to the comet and within the 200 km where the signals had previously been detected from Philae.

In more recent months, the comet’s activity has subsided enough to make it possible to approach the nucleus again safely – this week the spacecraft reached around 45 km – and Rosetta has made repeated passes over Abydos.

No signal has been received, however. Attempts to send commands ‘in the blind’ to trigger a response from Philae have also not produced any results.

The mission engineers think that failures of Philae’s transmitters and receivers are the most likely explanation for the irregular contacts last year, followed by continued silence into this year.

Another difficulty that Philae may be facing is dust covering its solar panels, ejected by the comet during the active perihelion months, preventing the lander from powering up.

Also, the attitude and even location of Philae may have changed since November 2014 owing to cometary activity, meaning that the direction in which its antenna is sending signals to Rosetta is not as predicted, affecting the expected communication window.

Rosetta approaching comet

“The comet’s level of activity is now decreasing, allowing Rosetta to safely and gradually reduce its distance to the comet again,” says Sylvain Lodiot, ESA’s Rosetta spacecraft operations manager.

“Eventually we will be able to fly in ‘bound orbits’ again, approaching to within 10–20 km – and even closer in the final stages of the mission – putting us in a position to fly above Abydos close enough to obtain dedicated high-resolution images to finally locate Philae and understand its attitude and orientation.”

“Determining Philae’s location would also allow us to better understand the context of the incredible in situ measurements already collected, enabling us to extract even more valuable science from the data,” says Matt Taylor, ESA’s Rosetta project scientist.

“Philae is the cherry on the cake of the Rosetta mission, and we are eager to see just where the cherry really is!”

Rosetta mission selfie at 16 km

At the same time, Rosetta, Philae and the comet are heading back out towards the outer Solar System again. They have crossed the orbit of Mars and are now some 350 million km from the Sun. According to predictions, the temperatures should be falling far below those at which Philae is expected to be able to operate.

Nevertheless, while hopes of making contact again with Philae dwindle, Rosetta will continue to listen for signals from the lander as it flies alongside the comet ahead of its own comet landing in September.

“We would be very surprised to hear from Philae again after so long, but we will keep Rosetta’s listening channel on until it is no longer possible due to power constraints as we move ever further from the Sun towards the end of the mission,” says Patrick Martin, ESA’s Rosetta mission manager.

“Philae has been a tremendous challenge and for the lander teams to have achieved the science results that they have in the unexpected and difficult circumstances is something we can all be proud of.

“The combined achievements of Rosetta and Philae, rendezvousing with and landing on a comet, are historic high points in space exploration.”

Notes for Editors:

Lander contacts were made on 13, 14, 19, 20, 21, 23 and 24 June, and 9 July 2015. Housekeeping data were transferred from Philae to Rosetta on all but the 23 June contact. Background information about Philae’s wake-ups last year is discussed in our September blog post “Understanding Philae’s wake-up”:

Status reports were also published today by DLR, CNES and ASI.

Rosetta is an ESA mission with contributions from its Member States and NASA. Rosetta’s Philae lander was contributed by a consortium under the leadership of DLR, MPS, CNES and ASI.

Related links:

For more information about Rosetta mission, visit:

Rosetta overview:

Rosetta in depth:

Rosetta at Astrium:

Rosetta at DLR:

Ground-based comet observation campaign:

Rosetta factsheet:

Frequently asked questions:

Images, Animations, Text, Credits: ESA/Data: Auster et al. (2015)/Comet image: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA/Rosetta/Philae/CIVA/ATG medialab/ESA's scientists: Markus Bauer/Patrick Martin/Sylvain Lodiot/Matt Taylor/Stephan Ulamec/The video was prepared with inputs from the ROMAP, RPC-MAG, OSIRIS, ROLIS, CIVA CONSERT, SESAME and MUPUS instrument teams as well as from the Lander Control Centre at DLR and Science Operation and Navigation Center at CNES.

Best regards,

jeudi 11 février 2016

Putting Pluto’s Geology on the Map

NASA - New Horizons Mission logo.

Feb. 11, 2016

Image above: This map of the left side of Pluto’s heart-shaped feature uses colors to represent Pluto’s varied terrains, which helps scientists understand the complex geological processes at work. Image Credits: NASA/JHUAPL/SwRI.

How to make sense of Pluto’s surprising geological complexity? To help understand the diversity of terrain and to piece together how Pluto’s surface has formed and evolved over time, mission scientists construct geological maps like the one shown above. 

This map covers a portion of Pluto’s surface that measures 1,290 miles (2,070 kilometers) from top to bottom, and includes the vast nitrogen-ice plain informally named Sputnik Planum and surrounding terrain.  As the key in the figure below indicates, the map is overlaid with colors that represent different geological terrains.  Each terrain, or unit, is defined by its texture and morphology – smooth, pitted, craggy, hummocky or ridged, for example.  How well a unit can be defined depends on the resolution of the images that cover it.  All of the terrain in this map has been imaged at a resolution of approximately 1,050 feet (320 meters) per pixel or better, meaning scientists can map units with relative confidence.

Image above: Pluto’s informally-named Sputnik Planum region is mapped, with the key indicating a wide variety of units or terrains. Image Credits: NASA/JHUAPL/SwRI.

The various blue and greenish units that fill the center of the map represent different textures seen across Sputnik Planum, from the cellular terrain in the center and north, to the smooth and pitted plains in the south.  The black lines represent troughs that mark the boundaries of cellular regions in the nitrogen ice.  The purple unit represents the chaotic, blocky mountain ranges that line Sputnik’s western border, and the pink unit represents the scattered, floating hills at its eastern edge.  The possible cryovolcanic feature informally named Wright Mons is mapped in red in the southern corner of the map.  The rugged highlands of the informally named Cthulhu Regio are mapped in dark brown along the western edge, pockmarked by many large impact craters, shown in yellow.

By studying how the boundaries between units crosscut one another, mission scientists can determine which units overlie others, and assemble a relative chronology for the different units. For example, the yellow craters (at left, on the western edge of the map) must have formed after their surrounding terrain. Producing such maps is important for gauging what processes have operated where on Pluto, and when they occurred relative to other processes at work. 

The base map for this geologic map is a mosaic of 12 images obtained by the Long Range Reconnaissance Imager (LORRI) at a resolution of 1,280 feet (about 390 meters) per pixel.  The mosaic was obtained at a range of approximately 48,000 miles (77,300 kilometers) from Pluto, about an hour and 40 minutes before New Horizons' closest approach on July 14, 2015.

For more information about New Horizons, visit:

Images (mentioned), Text, Credits: NASA/Tricia Talbert.


IXV spaceplane flight helped guide Irish firm to new business

ESA - Intermediate Experimental Vehicle (IXV) patch.

11 February 2016

Working with ESA – leading in turn to a key contribution to the IXV spaceplane – was the catalyst to help turn one Irish firm into a full-fledged space solution company, whose customers today include NASA, SpaceX, Boeing and Airbus Defence and Space.

The 100-minute flight of ESA’s Intermediate eXperimental Vehicle (IXV) one year ago today was keenly followed all across Europe, but especially in the crowded lunch canteen of Curtiss-Wright in Dublin.

Vega rocket carrying IXV launch

“It was a fantastic day, witnessing the launch on a large screen,” recalls Danny Gleeson, the company’s Space Business Development Manager. “I felt like an expectant father! Our company had put years of work into IXV, making a mission-critical contribution.

“The whole point of IXV was to get as full a picture as possible of the impact of the extreme conditions of atmospheric reentry on the spacecraft, and it was our systems that were gathering all the data from the hundreds of sensors on board, to be transmitted back to the ground.

“In the event it all worked perfectly, and we hope to be playing a similar part in the follow-up Programme for Reusable In-orbit Demonstrator in Europe, PRIDE, mission.”

The company was founded back in 1991 by a quartet of Dublin City University graduates, originally named ‘Acra’ – from the Gaelic for ‘utensil’  – and specialising in data acquisition systems for test flights. Acra was acquired by Curtiss-Wright in 2011.

Test flight instrumentation

Each time a new aircraft is first sent aloft, its test pilots are accompanied by a multitude of sensors capturing data on every aspect of its performance, in terms of acceleration, vibration, shock, temperature extremes and so on, usually in tandem with video.

“The key aspect is that these systems have to be rugged, because test flights are all about exploring the extremes of the aircraft performance envelope,” adds Mr Gleeson. “So when we were thinking about markets to expand into, the thought came: what about space missions?”

To operate in the space environment involves significant challenges, including exposure to vacuum, a still wider range of temperature and vibration extremes and increased radiation exposure above Earth’s atmosphere.

ESA is the European authority on working in space, and in 2002 an initial contract to subject the Acra equipment to the space environment was arranged through the Enterprise Ireland development agency. On the ESA side, the attraction was the prospect of ‘spin in’ – transferring an existing, well-proven technological solution to the space sector.

“There’s been a lot of interest in making use of what’s called ‘commercial off-the-shelf’, COTS, products for space in recent years,” comments Mr Gleeson.

IXV recovery

“For space missions you get to shorten the development cycle, starting with existing products and adapting them, rather than starting from a blank piece of paper. What is needed is to ‘qualify’ them – to carry out the exhaustive tests to prove the products, once suitably modified, can perform as required. This is a process we call ‘space-qualified COTS’

“So the testing ESA carried out, and the resulting documentation, opened up other opportunities, not only for IXV – which we began to work on in 2009 – but with other space companies.”

Curtiss-Wright Dublin began working with SpaceX in 2006, supplying equipment to the Falcon family of launchers and the Dragon reentry spacecraft while also contributing to experimental SpaceX ‘DragonEye’ payloads flown on some of the final Space Shuttle flights in 2009 and 2011.

Micro-sections for electronics testing

The company is also supplying sensor data acquisition systems to the Boeing-CST crew vehicle. It has also won contracts with Airbus Defence and Space to supply data handling systems: the most recent  as part of the Advanced Closed Loop System (ACLS) ISS Life Support System payload– converting waste carbon dioxide into breathable air.

Curtiss-Wright was also selected by ESA as prime contractor for an ISS payload to monitor the micro-gravity environment for experimental payloads, destined for the European Columbus module of the International Space Station.

Columbus module

“Our success in the space sector has led us to forge a local supply chain here in Ireland, with a variety of partner companies, including Realtime and Schivo,” adds Mr Gleeson. “Our needs include quality electronics and mechanical parts – one supplier, Schivo is actually primarily a medical device company, so they understand the reliability and quality we need.

“We’ve also built up an indigenous skill base. We’re one of about 20 Irish companies with common training needs that are participating in the national Space Industry Skillnet, the only space industry skills training network in Europe – building up the expertise we will need to go on making inroads into space markets and growing the space sector in Ireland.”

Related links:


European space laboratory Columbus:


Enterprise Ireland:

Space Industry Skillnet:

Images, Text, Credits: ESA/S. Corvaja/Tommaso Javidi/Sergi Ferreté Aymerich/Curtiss-Wright/NASA.

Best regards,

The sleeping giant

ESA - Hubble Space Telescope logo.

11 February 2016

The sleeping giant NGC 4889

The placid appearance of NGC 4889 can fool the unsuspecting observer. But the elliptical galaxy, pictured in this new image from the NASA/ESA Hubble Space Telescope, harbours a dark secret. At its heart lurks one of the most massive black holes ever discovered.

Located about 300 million light-years away in the Coma Cluster, the giant elliptical galaxy NGC 4889, the brightest and largest galaxy in this image, is home to a record-breaking supermassive black hole. Twenty-one billion times the mass of the Sun, this black hole has an event horizon — the surface at which even light cannot escape its gravitational grasp — with a diameter of approximately 130 billion kilometres. This is about 15 times the diameter of Neptune’s orbit from the Sun. By comparison, the supermassive black hole at the centre of our galaxy, the Milky Way, is believed to have a mass about four million times that of the Sun and an event horizon just one fifth the orbit of Mercury.

Wide-field view of NGC 4889 (ground-based view)

But the time when NGC 4889’s black hole was swallowing stars and devouring dust is past. Astronomers believe that the gigantic black hole has stopped feeding, and is currently resting after feasting on NGC 4889’s cosmic cuisine. The environment within the galaxy is now so peaceful that stars are forming from its remaining gas and orbiting undisturbed around the black hole.

When it was active, NGC 4889’s supermassive black hole was fuelled by the process of hot accretion. When galactic material — such as gas, dust and other debris — slowly fell inwards towards the black hole, it accumulated and formed an accretion disc. Orbiting the black hole, this spinning disc of material was accelerated by the black hole’s immense gravitational pull and heated to millions of degrees. This heated material also expelled gigantic and very energetic jets. During its active period, astronomers would have classified NGC 4889 as a quasar and the disc around the supermassive black hole would have emitted up to a thousand times the energy output of the Milky Way.

Zooming onto the galaxy NGC 4889

The accretion disc sustained the supermassive black hole’s appetite until the nearby supply of galactic material was exhausted. Now, napping quietly as it waits for its next celestial snack, the supermassive black hole is dormant. However its existence allows astronomers to further their knowledge of how and where quasars, these still mysterious and elusive objects, formed in the early days of the Universe.

Although it is impossible to directly observe a black hole — as light cannot escape its gravitational pull — its mass can be indirectly determined. Using instruments on the Keck II Observatory and Gemini North Telescope, astronomers measured the velocity of the stars moving around NGC 4889’s centre. These velocities — which depend on the mass of the object they orbit — revealed the immense mass of the supermassive black hole.

Panning across the elliptical galaxy NGC 4889

More information:

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

Related links:

Keck II Observatory:

Gemini North Telescope:


Images of Hubble:

Image credit: NASA/ESA/Hubble/Digitized Sky Survey 2/Acknowledgement: Davide De Martin/Videos: Akira Fujii/David Malin Images, DSS, ESA/Hubble/Music: Johan B. Monell.


ESA congratulations on gravitational wave discovery

ESA - European Space Agency logo.

11 February 2016

ESA is thrilled to learn that gravitational waves have been detected, and is looking forward to starting its mission to test technologies that could extend the study of these exotic waves to space.

Gravitational waves are elusive no more: an exciting breakthrough that has been 100 years in the making.

Gravitational waves

In November 1915, Albert Einstein presented his general theory of relativity, introducing a dramatic change of perspective in the physical understanding of one of the four fundamental interactions of nature: gravity.

This theory describes gravity as the way matter interacts with the flexible ‘spacetime’ it is embedded in. Massive bodies deform spacetime, changing its curvature as they move.

When accelerated, massive bodies produce tiny fluctuations in the fabric of spacetime – gravitational waves – which were first predicted in a further study published by Einstein in 1918. These minuscule cosmic perturbations have finally been revealed, after almost a century of theoretical investigations and experimental searches.

The discovery was announced today by scientists from the Laser Interferometer Gravitational-Wave Observatory (LIGO) collaboration.

LIGO comprises two gravitational wave detectors in Livingston, Louisiana and Hanford, Washington, USA, and involves over a thousand scientists from across the world. The experiment uses laser beams to monitor two perpendicular arms, each extending 4 km, to look for tiny changes in their length that might be caused by passing gravitational waves.

Recently upgraded to become Advanced LIGO, the experiment obtained this historic result during the first observation run in the new configuration, which collected data between September 2015 and January 2016.

LISA Pathfinder in space

“This is tremendous news for everyone studying gravity and general relativity, and we send our warmest congratulations to colleagues in the LIGO collaboration for their outstanding result,” says Paul McNamara, LISA Pathfinder project scientist at ESA.

LISA Pathfinder is ESA’s technology demonstration mission for possible future missions to observe gravitational waves from space. Launched on 3 December 2015, the spacecraft reached its operational orbit in January and is undergoing final checks before starting its science mission on 1 March.

“With LISA Pathfinder, we will be testing the underlying technology to observe gravitational waves from space, and it is even more encouraging to know that these long-mysterious fluctuations have now been directly detected,” adds Paul.

A first, indirect confirmation that gravitational waves exist came in the late 1970s, with observations of a pair of neutron stars – the dead cores of massive stars – rapidly orbiting each other.

One of the two neutron stars appears as a pulsating radio source, or pulsar, which allowed precise timing measurements of the system. As the two stellar remnants circle each other, scientists noticed that they move into tighter and faster orbits, and the rate of acceleration was just as it was expected if they were to lose energy by emitting gravitational waves.

But today’s announcement by the LIGO collaboration provides the direct detection of gravitational waves that scientists had been seeking for decades.

“Hats off to the LIGO collaboration for their remarkable achievement, having mastered the experimental facilities to reach the exquisite sensitivity required to detect gravitational waves from ground,” says César García Marirrodriga, ESA’s LISA Pathfinder project manager.

Pair of coalescing black holes

The recorded signal is very strong, and it appears to come from a pair of coalescing black holes about 1.3 billion light-years away. The two monstrous bodies, with masses equivalent to 36 and 29 times the mass of the Sun, respectively, merged to form a single, even more gigantic black hole of 62 solar masses, releasing the remaining 3 solar masses in gravitational waves.

“Now that gravitational waves have been found, we can start delving into the physics of their sources. That’s where the move to space will make the difference,” says Oliver Jennrich, LISA Pathfinder deputy project scientist at ESA.

Like light, gravitational waves also span a broad spectrum of frequencies, and different astronomical objects are expected to emit these waves all across the spectrum. Ground-based experiments like LIGO are sensitive to high-frequency waves, like those coming from coalescing pairs of black holes or neutron stars, with frequencies of 10–1000 Hz.

To detect gravitational waves with lower frequencies, such as those from the merging of supermassive black holes at the centre of massive galaxies, scientists need to investigate changes in length of much longer arms – about one million kilometres. This can only be achieved in space, using laser beams to monitor the distance between three freely falling masses separated by much larger distances than can be achieved on Earth.

ESA has identified the gravitational Universe as the scientific theme for its L3 mission, the third Large-class mission in the Cosmic Vision science programme, resulting in a large gravitational wave observatory in space in the coming years.

Test masses on LISA Pathfinder

Today’s LISA Pathfinder is a step towards L3, because it will test whether it is possible to put test masses in pure free fall, unperturbed by any external forces, at the level needed for the future space-based gravitational wave observatory.

On 3 February, the two masses at the heart of the spacecraft – a pair of identical gold-platinum cubes, 46 mm on each side – were unlocked from one of the two mechanisms that kept them secure during launch and cruise.

The final release will take place next week, leaving the two cubes with no physical contact with the spacecraft, ahead of the start of science operations.

To compensate for other forces acting on the cubes, LISA Pathfinder will measure their position and orientation to exquisite accuracy and manoeuvre itself by tiny amounts to remain centred on one of them.

“LISA Pathfinder has a challenging task ahead, and we are honoured to contribute to this new era of gravitational wave research inaugurated today by the LIGO discovery,” concludes Paul.

For more information about LISA Pathfinder, visit:

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Images, Animation, Text, Credits: ESA/C.Carreau/ATG medialab/NASA/C. Henze.

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mercredi 10 février 2016

United Launch Alliance Successfully Launches NROL-45 Payload for the National Reconnaissance Office

ULA - Delta IV / NROL-45 launch poster.

Feb. 10, 2016

Second ULA Mission for the U.S. Air Force Launched In Just Five Days

Mission Overview

Delta IV rocket carrying a payload for the National Reconnaissance Office (NRO) liftoff

A United Launch Alliance (ULA) Delta IV rocket carrying a payload for the National Reconnaissance Office (NRO) lifted off from Space Launch Complex-6  on Feb. 10 at 3:40 a.m. PST. Designated NROL-45, the mission is in support of national defense. This is ULA’s second launch in 2016 and the 105th successful launch since the company was formed in December 2006.

“Congratulations to the ULA team and our U.S. Air Force and NRO partners on the launch of NROL-45,” said Laura Maginnis, ULA vice president of Custom Services. “This is our second successful launch within five days for our U.S. government customer, a testament to our outstanding teamwork and focus on 100 percent mission success, one launch at a time. ULA is proud to be entrusted with safely and reliably delivering our nation’s most critical space assets to orbit.”

This mission was launched aboard a Delta IV Medium+ (5,2) configuration Evolved Expendable Launch Vehicle (EELV) using a single ULA common booster core powered by an Aerojet Rocketdyne RS-68A main engine along with two Orbital ATK GEM-60 solid rocket motors. The upper stage was powered by an Aerojet Rocketdyne RL10B-2 engine with the satellite encapsulated in a 5-meter-diameter composite payload fairing.

Launch of Delta IV Rocket with NROL-45 from Vandenberg

ULA's next launch is the Atlas V OA-6 Cygnus International Space Station resupply mission, flown for Orbital ATK under NASA’s Commercial Resupply Services contract. The launch is targeted for March 22 from Space Launch Complex-41 from Cape Canaveral Air Force Station, Florida.

The EELV program was established by the U.S. Air Force to provide assured access to space for Department of Defense and other government payloads. The commercially developed EELV program supports the full range of government mission requirements, while delivering on schedule and providing significant cost savings over the heritage launch systems.

With more than a century of combined heritage, United Launch Alliance is the nation’s most experienced and reliable launch service provider. ULA has successfully delivered more than 100 satellites to orbit that provide critical capabilities for troops in the field, aid meteorologists in tracking severe weather, enable personal device-based GPS navigation and unlock the mysteries of our solar system.

For more information on ULA, visit the ULA website at Join the conversation at, and

Image, Video, Text, Credit: United Launch Alliance (ULA).


A Star’s Moment in the Spotlight

ESO - European Southern Observatory logo.

10 February 2016

Young star lights up reflection nebula IC 2631

A newly formed star lights up the surrounding cosmic clouds in this new image from ESO’s La Silla Observatory in Chile. Dust particles in the vast clouds that surround the star HD 97300 diffuse its light, like a car headlight in enveloping fog, and create the reflection nebula IC 2631. Although HD 97300 is in the spotlight for now, the very dust that makes it so hard to miss heralds the birth of additional, potentially scene-stealing, future stars.

The glowing region in this new image from the MPG/ESO 2.2-metre telescope is a reflection nebula known as IC 2631. These objects are clouds of cosmic dust that reflect light from a nearby star into space, creating a stunning light show like the one captured here. IC 2631 is the brightest nebula in the Chamaeleon Complex, a large region of gas and dust clouds that harbours numerous newborn and still-forming stars. The complex lies about 500 light-years away in the southern constellation of Chamaeleon.

The location of the reflection nebula IC 2631 in the constellation of Chameleon

IC 2631 is illuminated by the star HD 97300, one of the youngest — as well as most massive and brightest — stars in its neighbourhood. This region is full of star-making material, which is made evident by the presence of dark nebulae noticeable above and below IC 2631 in this picture. Dark nebulae are so dense with gas and dust that they prevent the passage of background starlight.

Despite its dominating presence, the heft of HD 97300 should be kept in perspective. It is a T Tauri star, the youngest visible stage for relatively small stars. As these stars mature and reach adulthood they will lose mass and shrink. But during the T Tauri phase these stars have not yet contracted to the more modest size that they will maintain for billions of years as main sequence stars.

The sky around reflection nebula IC 2631

These fledging stars already have surface temperatures similar to their main sequence phase and accordingly, because T Tauri-phase objects are essentially jumbo versions of their later selves, they look brighter in their oversized youth than in maturity. They have not yet started to fuse hydrogen into helium in their cores, like normal main sequence stars, but are just starting to flex their thermal muscles by generating heat from contraction.

Zooming in on the young star in the reflection nebula IC 2631

Reflection nebula, like the one spawned by HD 97300, merely scatter starlight back out into space. Starlight that is more energetic, such as the ultraviolet radiation pouring forth from very hot new stars, can ionise nearby gas, making it emit light of its own. These emission nebulae indicate the presence of hotter and more powerful stars, which in their maturity can be observed across thousands of light-years. HD 97300 is not so powerful, and its moment in the spotlight is destined not to last.

Close-up of the reflection nebula IC 2631

More information:

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 16 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Poland, Portugal, Spain, Sweden, Switzerland and the United Kingdom, along with the host state of Chile. 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 a major partner in ALMA, the largest astronomical project in existence. And on Cerro Armazones, close to Paranal, ESO is building the 39-metre European Extremely Large Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Related link:

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Images of the MPG/ESO 2.2-metre telescope at La Silla:

Photos taken with the MPG/ESO 2.2-metre telescope at La Silla:

Images, Text, Credits: ESO/IAU and Sky & Telescope/Digitized Sky Survey 2/Acknowledgement: Davide De Martin/Richard Hook/Videos: ESO/N. Risinger ( Sky Survey 2. Music: Johan B Monell.

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mardi 9 février 2016

Study: Long-Term Global Warming Needs External Drivers

NASA logo.

Feb. 9, 2016

A study by scientists at NASA’s Jet Propulsion Laboratory in Pasadena, California, and Duke University in Durham, North Carolina, shows, in detail, the reason why global temperatures remain stable in the long run unless they are pushed by outside forces, such as increased greenhouse gases due to human impacts.

Lead author Patrick Brown, a doctoral student at Duke’s Nicholas School of the Environment, and his JPL colleagues combined global climate models with satellite measurements of changes in the energy approaching and leaving Earth at the top of the atmosphere over the past 15 years. The satellite data were from the Clouds and the Earth’s Radiant Energy System (CERES) instruments on NASA’s Aqua and Terra spacecraft. Their work reveals in new detail how Earth cools itself back down after a period of natural warming.

Image above: Earth's atmosphere viewed from the International Space Station. A NASA/Duke University study provides new evidence that natural cycles alone aren't sufficient to explain the global atmospheric warming observed over the last century. Image Credit: NASA.

Scientists have long known that as Earth warms, it is able to restore its temperature equilibrium through a phenomenon known as the Planck Response. The phenomenon is an overall increase in infrared energy that Earth emits as it warms. The response acts as a safety valve of sorts, allowing more of the accumulating heat to be released through the top of Earth's atmosphere into space.

The new research, however, shows it’s not quite as simple as that.

“Our analysis confirmed that the Planck Response plays the dominant role in restoring global temperature stability, but to our surprise, we found that it tends to be overwhelmed locally by heat-trapping changes in clouds, water vapor, and snow and ice,” Brown said. “This initially suggested that the climate system might be able to create large, sustained changes in temperature all by itself.”

A more detailed investigation of the satellite observations and climate models helped the researchers finally reconcile what was happening globally versus locally.

“While global temperature tends to be stable due to the Planck Response, there are other important, previously less appreciated, mechanisms at work, too,” said Wenhong Li, assistant professor of climate at Duke. These mechanisms include the net release of energy over anomalously cool regions and the transport of energy to continental and polar regions.  In those regions, the Planck Response overwhelms positive, heat-trapping local energy feedbacks.

“This emphasizes the importance of large-scale energy transport and atmospheric circulation changes in reconciling local versus global energy feedbacks and, in the absence of external drivers, restoring Earth’s global temperature equilibrium,” Li said.

The researchers say the findings may finally help put the chill on skeptics’ belief that long-term global warming occurs in an unpredictable manner, independently of external drivers such as human impacts.

“This study underscores that large, sustained changes in global temperature like those observed over the last century require drivers such as increased greenhouse gas concentrations,” said Brown.

“Scientists have long believed that increasing greenhouse gases played a major role in determining the warming trend of our planet,” added JPL co-author Jonathan Jiang. “This study provides further evidence that natural climate cycles alone are insufficient to explain the global warming observed over the last century.”

The research is published this month in the Journal of Climate. The study was funded by the National Science Foundation and NASA.

NASA uses the vantage point of space to increase our understanding of our home planet, improve lives and safeguard our future. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records. The agency freely shares this unique knowledge and works with institutions around the world to gain new insights into how our planet is changing.

For more information about NASA's Earth science activities, visit:

Image (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Alan Buis/Duke University/Tim Lucas.


CERN - Has the magic gone from Calcium-52?

CERN - European Organization for Nuclear Research logo.

Feb. 9, 2016

For the first time scientists have measured the radius of a calcium nucleus with 32 neutrons – indicating that nuclear physics theories don’t describe atomic nuclei as well as previously thought.

The study, conducted by CERN scientists at the ISOLDE facility and published in the latest issue of the journal Nature Physics (link is external), aimed to understand whether calcium has more than two magic numbers.

Image above: The laser launch stations at COLLAPS at the ISOLDE facility where the new discovery was made. (Image: Samuel Morier-Genoud/CERN).

Magic numbers appear in nuclei when they have the right number of protons and neutrons to make them particularly strongly bound. This in turn has an influence on their nuclear charge radii.

Previous indications suggested that 52Ca, an isotope with 20 protons and 32 neutrons, is doubly-magic, having magic numbers of both protons and neutrons. To test this, the team of researchers set out to measure how the radii of calcium isotopes change as neutrons are added. Calcium with the magic proton number 20 already has two doubly-magic isotopes when it also has 20 or 28 neutrons. Scientists found evidence that other doubly-magic isotopes might exist for 32 and 34 neutrons.

“The previously known doubly-magic isotopes, 40Ca and 48Ca, have similar and smaller charge radii than their neighbours because they are particularly strongly bound. When we measured charge radii for larger neutron numbers they kept growing. Based on observations from other doubly-magic nuclei, we would have expected a relative drop in the charge radius if 52Ca were doubly-magic, too. However, it increases as other non-magic nuclei in this region of the nuclear chart,” explains Ronald Fernando Garcia Ruiz, the lead researcher on the project.

Several nuclear models had already computed what would happen, but none predicted the radius growing as much as the experiment found. First-principles computations using state-of-the-art nuclear interactions and the supercomputer Titan at Oak Ridge National Laboratory in the US reproduced the similarity of the charge radii for 40,48Ca, and showed an increase of radii beyond 48Ca. However, to understand the unexpectedly large difference between the charge radii of 52Ca and 48Ca still poses a theoretical challenge.

“Theory before this was happy, because it described other aspects of neutron-rich calcium isotopes. But all of the theoretical models employed underestimated this growth in charge radii. We’ve shown there are missing components in our knowledge,” says Garcia Ruiz.

The ISOLDE researchers used lasers to measure how the electrons surrounding the nucleus shifted in energy depending on the neutron number of the calcium isotope.  The amount of shift, combined with their understanding of electromagnetic forces, enabled them to determine the charge radius of the nucleus.

Interview to Ronald Fernando Garcia Ruiz, lead scientist COLLAPS experiment at ISOLDE

Video above: Ronald Fernando Garcia Ruiz, scientist of COLLAPS experiment at ISOLDE, explains the latest results.(Video: Christoph Madsen - Paola Catapano/CERN).

Since the shift from one isotope to the next is so tiny the study was only able to show the change in nucleus radius by using high-resolution techniques.

The study, at the COLLAPS installation at ISOLDE, was able to measure this to very high precision and sensitivity: one of the highest ever reached with optical detection techniques.

The team are now developing a higher sensitivity technique that will allow them to extend their research to study the radii of calcium nuclei beyond 52Ca, to 53,54Ca.


CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States.

Related links:

Latest issue of the journal Nature Physics:



For more information about the European Organization for Nuclear Research (CERN), visit:

Image (mentioned), Video (mentioned), Text, Credits: CERN/Harriet Jarlett/James Gillies/Corinne Pralavorio.

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New Satellite-Based Maps to Aid in Climate Forecasts

NASA patch.

Feb. 9, 2016

New, detailed maps of the world’s natural landscapes created using NASA satellite data could help scientists better predict the impacts of future climate change.

The maps of forests, grasslands and other productive ecosystems provide the most complete picture yet of how carbon from the atmosphere is reused and recycled by Earth’s natural ecosystems.

Image above: Global map of the average amount of time that live biomass carbon and dead organic carbon spend in carbon reservoirs around the world, in years. Image Credit: A. Anthony Bloom.

Scientists at the University of Edinburgh, Scotland, United Kingdom; NASA’s Jet Propulsion Laboratory, Pasadena, California; and Wageningen University, Netherlands, used a computer model to analyze a decade of satellite and field study data from 2001 to 2010. The existing global maps of vegetation and fire activity they studied were produced from data from NASA’s Terra, Aqua and ICESat spacecraft. The researchers then constructed maps that show where -- and for how long -- carbon is stored in plants, trees and soils.

The maps reveal how the biological properties of leaves, roots and wood in different natural habitats affect their ability to store carbon across the globe, and show that some ecosystems retain carbon longer than others. For example, large swaths of the dry tropics store carbon for a relatively short time due to frequent fires, while in warm, wet climates, carbon is stored longer in vegetation than in soils.

Although it is well known that Earth’s natural ecosystems absorb and process large amounts of carbon dioxide, much less is known about where the carbon is stored or how long it remains there. Improved understanding about how carbon is stored will allow researchers to more accurately predict the impacts of climate change.

Study first author Anthony Bloom, a JPL postdoctoral scientist, said: “Our findings are a major step toward using satellite imagery to decipher how carbon flows through Earth’s natural ecosystems from satellite images. These results will help us understand how Earth’s natural carbon balance will respond to human disturbances and climate change.”

Professor Mathew Williams of the University of Edinburgh’s School of GeoSciences, who led the study, said, “Recent studies have highlighted the disagreement among Earth system models in the way they represent the current global carbon cycle. “Our results constitute a useful, modern benchmark to help improve these models and the robustness of global climate projections.”

Image above: Nature’s color abounds in the Hiawatha National Forest on the Upper Peninsula of Michigan during the fall. Image Credits: USDA Photo by Bob Nichols.

To generate values for each of the 13,000 cells on each map, a supercomputer at the Edinburgh Compute and Data Facility ran the model approximately 1.6 trillion times.

New data can be added to the maps as it becomes available. The impact of major events such as forest fires on the ability of ecosystems to store carbon can be determined within three months of their occurrence, the researchers say.

The study, published Feb. 2 in the Proceedings of the National Academy of Sciences, was funded by the Natural Environment Research Council. The California Institute of Technology in Pasadena manages JPL for NASA.

NASA uses the vantage point of space to increase our understanding of our home planet, improve lives and safeguard our future. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records. The agency freely shares this unique knowledge and works with institutions around the world to gain new insights into how our planet is changing.

For more information about NASA's Earth science activities, visit:

Images (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Alan Buis/University of Edinburgh/Corin Campbell.