samedi 19 septembre 2015

First launch of new Chinese rocket Long March 6

CASC - China Aerospace Science and Technology Corporation logo.

Sept. 19, 2015

 China Launches Long March 6 Carrier Rocket into Space

At 07:00 Beijing time on Saturday (23:00 UTC on Friday), China will perform the first ever launch of a Long March 6 rocket. Neither its size nor its payload – including a number of small amateur radio satellites – are notable, yet the event will mark a new era in Chinese spaceflight.

China’s established Long March series has helped the country go from putting its first satellite into space in 1970, to achieving human spaceflight in 2003, establish communications and navigation systems, Earth observation constellations, and put its first space lab into low Earth orbit.

Image above: Long March 6 rocket (CZ6) to launch at 23:00 UTC on 18 Sept 2015 from Taiyuan, delivering 20 satellites to 520 km.

However, after beginning development in the 2000s, the Long March 6 is the first of a long-waited new generation of Chinese launch vehicles, designed to take China’s space ambitions to the next level.

Together with the Long March 5 and 7 rocket families, Long March 6 has been designed to meet China’s future requirements for its space programs, providing increased reliability and adaptability, lower costs and preparation, and allow much heavier payloads to be put in orbit.

“The Long March 6 is for relatively light payloads and intended to give them a quick turnaround time capability. It gives them more flexibility in satellite launches, but it is the Long March 5 that will really signal a leap forward in Chinese capabilities,” says Joan Johnson-Freese, Professor of National Security Affairs at the US Naval War College, but expressing her own views.

New possibilities - including Moon mission?

Saturday’s launch will be the first real flight test of the YF-100 engine, based on Russia’s RD-120. The YF-100 will also power the heavy-lift Long March 5, which will be capable of lifting 25 tonnes to Low Earth Orbit.

Having a rocket comparable to the American Delta-IV Heavy will treble China’s payload lifting capacity, and bring many new possibilities, and possibly a trip to the Moon.

“China’s three step human spaceflight program, Shenzhou, relies on the Long March 5 to lift its large space station to orbit, and in order to do a human lunar mission - anticipated as their “next step” - the Long March 5 is needed as well,” Johnson-Freese explains.

China’s largest ever rocket, Long March 5 (CZ5)

The Long March 5 will also launch the ambitious Chang’e-5 lunar mission, which aims to put a lander on the Moon and return samples to Earth in 2017.

Long March 5 and medium-lift Long March 7 missions will lift off from a massive new space port constructed in Wenchang on the island province of Hainan.

The Wenchang Satellite Launch Centre, from which launches will take advantage of the Earth’s greater rotational speed at lower latitudes, took six years to construct and cost an estimated five billion yuan (US$800 million) and is another crucial component in China’s plans.

“What this means for the US and all space faring nations is another indicator that China is a long-term player in space with expanding capabilities. It cannot be denied or ignored, as the US has tended to do,” notes Johnson-Freese.

Technological advance

Professor Huang Jun at the Beijing University of Aeronautics and Astronautics told gbtimes that the new rockets mark a major technological development for China.

“My opinion is that, despite the fact that China has made great progress in its series rocket and space launches in the past few decades, there is still a big gap between China and the world's advanced level,” says Huang.

“Therefore, the development of these new launch vehicles is to meet the further space and deep space exploration on one hand, and to catch up the world's most sophisticated space technologies.”

Image above: A booster of the upcoming Long March 7 (CZ7), one of China's next generation rockets, in Tianjin, North China.

“This new generation of Chinese launch vehicle series uses universal modularized design which can be easily combined into new rocket variants for various missions. The reliability and launch preparation time are improved and the launching cost will be lowered.”

Huang also notes that the incendiary agents used for these rockets are kerosene and liquid hydrogen which are non-toxic, low or non-polluting compared with the highly toxic unsymmetrical dimethyl hydrazine (UDMH) used in the current Long March 2-4 series.

Long March series
Due to strategic concerns of the early days of the Cold War, China’s three operational launch centres are inland, meaning rocket debris – and remaining hydrazine fuel – poses a threat to those downrange of launches. The new rockets and launch centre will help reduce these risks.

For more information about China Aerospace Science and Technology Corporation (CASC), visit:

Images, Video, Text, Credits: CASC/CCTV/gbtimes/Andrew Jones/Wang Jie.


vendredi 18 septembre 2015

CAST explores the dark side of the universe

CERN - European Organization for Nuclear Research logo.

Sep. 18, 2015

Over the next 10 days, CERN's Axion Solar Telescope (CAST) will receive the Sun's rays. The Sun's course is visible from the window in the CAST experimental hall just twice a year, in March and September. The scientists will take advantage of these few days to improve the alignment of the detector with respect to the position of the Sun to within a thousandth of a radian.

CERN Axion Solar Telescope (CAST) solar tracking

Video above: Timelapse video of CAST following the Sun in the morning and in the evening. (Video: Madalin-Mihai Rosu/CERN).

Outside of this alignment operation, CAST tracks the Sun but does not see it. The astroparticle experiment is searching for solar axions, hypothetical particles that are thought to interact so weakly with ordinary matter that they pass through walls unimpeded. It is in order to catch these elusive particles that the CAST detector tracks the movement of the Sun for an hour and a half at dawn and an hour and a half at dusk.

Axions were postulated to solve the problem of a discrepancy between the theory of the infinitely small and what is actually observed. They were named after a brand of washing powder because their existence may allow the theory to be “cleaned up”. If they exist, axions could also be good candidates for the universe’s dark matter. Dark matter is thought to represent 80% of the matter of the universe, but its nature remains unknown.

After 12 years of research, CAST has not (yet) detected solar axions, but has established the most restrictive limit on their interaction strength. The experiment has therefore become a global reference on the subject.

Image above: Surveyors and members of the CAST collaboration install their equipment to align the telescope with the position of the Sun. (Image: Sophia Bennett/CERN).

For two years, the collaboration, which involves around 70 researchers from 20 or so institutes, has also been searching for another type of hypothetical particle: chameleons. These were postulated to solve the problem of dark energy. Dark energy, which, as its name suggests, remains mysterious and undetectable, is thought to represent around 70% of the Universe's energy and to cause the acceleration of the expansion observed in the cosmos. Theories have postulated that this dark energy may be due to a fifth force and that chameleon particles could prove the existence of this force. They were named after the reptile because they are thought to interact differently according to the density of material encountered.

If chameleons exist, they could, like axions, be also produced by the Sun and be detected by CAST. The collaboration has therefore installed two new detectors at the end of its magnet. It is also preparing to install an innovative sensor with an ultra-thin membrane, capable of detecting a displacement of around 10-15 meters – the size of the nucleus of an atom!

More information in the CERN Bulletin article:


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:

CERN's Axion Solar Telescope (CAST):

Dark matter:

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

Image (mentioned), Video (mentioned), Text, Credits: CERN/Corinne Pralavorio.

Best regards,

The Fact and Fiction of Martian Dust Storms

NASA - Goddard Space Flight Center logo.

Sep. 18, 2015

For years, science fiction writers from Edgar Rice Burroughs to C. S. Lewis have imagined what it would be like for humans to walk on Mars. As mankind comes closer to taking its first steps on the Red Planet, authors’ depictions of the experience have become more realistic.

Andy Weir’s “The Martian” begins with a massive dust storm that strands fictional astronaut Mark Watney on Mars. In the scene, powerful wind rips an antenna out of a piece of equipment and destroys parts of the astronauts’ camp.

Mars is infamous for intense dust storms, which sometimes kick up enough dust to be seen by telescopes on Earth.

“Every year there are some moderately big dust storms that pop up on Mars and they cover continent-sized areas and last for weeks at a time,” said Michael Smith, a planetary scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

Beyond Mars’ large annual storms are massive storms that occur more rarely but are much larger and more intense.

“Once every three Mars years (about 5 ½ Earth years), on average, normal storms grow into planet-encircling dust storms, and we usually call those ‘global dust storms’ to distinguish them,” Smith said.

It is unlikely that even these dust storms could strand an astronaut on Mars, however. Even the wind in the largest dust storms likely could not tip or rip apart major mechanical equipment. The winds in the strongest Martian storms top out at about 60 miles per hour, less than half the speed of some hurricane-force winds on Earth.

Image above: A dust storm on Mars in 2008 temporarily cuts the amount of sunlight reaching the solar array on NASA's Mars Exploration Rover Spirit, leaving the rover in a vulnerable state. Image Credits: NASA/JPL-Caltech/Cornell.

Focusing on wind speed may be a little misleading, as well. The atmosphere on Mars is about 1 percent as dense as Earth’s atmosphere. That means to fly a kite on Mars, the wind would need to blow much faster than on Earth to get the kite in the air.

“The key difference between Earth and Mars is that Mars’ atmospheric pressure is a lot less,” said William Farrell, a plasma physicist who studies atmospheric breakdown in Mars dust storms at Goddard. “So things get blown, but it’s not with the same intensity.”

Challenges of Solar Power

Mars’ dust storms aren’t totally innocuous, however. Individual dust particles on Mars are very small and slightly electrostatic, so they stick to the surfaces they contact like Styrofoam packing peanuts.

“If you’ve seen pictures of Curiosity after driving, it’s just filthy,” Smith said. “The dust coats everything and it’s gritty; it gets into mechanical things that move, like gears.”

The possibility of dust settling on and in machinery is a challenge for engineers designing equipment for Mars. 

This dust is an especially big problem for solar panels. Even dust devils of only a few feet across -- which are much smaller than traditional storms -- can move enough dust to cover the equipment and decrease the amount of sunlight hitting the panels. Less sunlight means less energy created.

Image above: This artists concept illustrates a Martian dust storm, which might also crackle with electricity. Image Credits: NASA.

In “The Martian,” Watney spends part of every day sweeping dust off his solar panels to ensure maximum efficiency, which could represent a real challenge faced by future astronauts on Mars.

Global storms can also present a secondary issue, throwing enough dust into the atmosphere to reduce sunlight reaching the surface of Mars.

When faced with a larger dust storm in the book, Watney’s first hint is the decreased efficiency of his solar panels, caused by a slight darkening of the atmosphere. That’s a pretty accurate depiction of what large dust storms can do, Smith said.

When global storms hit, surface equipment often has to wait until the dust settles, either to conserve battery or to protect more delicate hardware.

“We really worry about power with the rovers; it’s a big deal,” Smith said. “The Spirit and Opportunity rovers landed in 2004, so they’ve only had one global dust storm to go through (in 2007) and they basically shut down operations and went into survival mode for a few weeks.”

Stirring Up Dust

Large global dust storms put enough dust in the air to completely cover the planet and block out the sun, but doing so ultimately dooms the storm itself. The radiative heat of sunlight reaching the surface of the planet is what drives these dust storms.

As sunlight hits the ground, it warms the air closest to the surface, leaving the upper air cooler.  As in thunderstorms on Earth, the warm and cool air together become unstable, with warm air rising up and taking dust with it.

Rising plumes of warm air create everything from small dust devils, similar to those that form in deserts on Earth, to larger continent-sized storms. These larger storms sometimes combine into the global storms, which cover the entire planet in atmospheric dust.

Image above: A towering dust devil casts a serpentine shadow over the Martian surface in this image acquired by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter.The scene is a late-spring afternoon in the Amazonis Planitia region of northern Mars. The view covers an area about four-tenths of a mile (644 meters) across. North is toward the top. The length of the dusty whirlwind's shadow indicates that the dust plume reaches more than half a mile (800 meters) in height. The plume is about 30 yards or meters in diameter. Image Credits: NASA/JPL-Caltech/University of Arizona.

Larger storms typically only happen during summer in Mars’ southern hemisphere. Seasons on Mars are caused by the tilt of the planet, like on Earth. But Mars’ orbit is less circular than Earth’s; for part of a Martian year, the planet is closer to the sun and therefore significantly hotter. This warmer time is during the southern hemisphere’s summer, so radiative heat forces are strongest then. Once started, bigger storms can last weeks to months.

Scientists aren’t really sure why the years’ long gaps between storms exist.

“It could be that it just takes a while for the sources to replenish themselves,” Smith said. “Maybe there’s some kind of cycle that the dust has to go through to get back into the right places to trigger a new one, or maybe it’s just kind of luck.”

Scientists have been tracking these global dust storms on Mars for more than a century, using both telescopes on Earth and spacecraft orbiting Mars. The storms have been observed a number of times since 1909, most recently in 2007. Now, more than eight years later, Smith is hopeful he’ll get the chance to study a major storm soon.

“We’re overdue for a global dust storm and it could be saving up a really big one this year, so that would kind of fun,” he said. “I like the dust storms.”

Related links:


Journey to Mars:

Images (mentioned), Text, Credits: NASA Goddard Space Flight Center/Kathryn Mersmann/Karl Hille.


jeudi 17 septembre 2015

Pluto ‘Wows’ in Spectacular New Backlit Panorama

NASA - New Horizons Mission logo.

Sep. 17, 2015

The latest images from NASA’s New Horizons spacecraft have scientists stunned – not only for their breathtaking views of Pluto’s majestic icy mountains, streams of frozen nitrogen and haunting low-lying hazes, but also for their strangely familiar, arctic look.

Image above: Pluto’s Majestic Mountains, Frozen Plains and Foggy Hazes: Just 15 minutes after its closest approach to Pluto on July 14, 2015, NASA’s New Horizons spacecraft looked back toward the sun and captured this near-sunset view of the rugged, icy mountains and flat ice plains extending to Pluto’s horizon. The smooth expanse of the informally named icy plain Sputnik Planum (right) is flanked to the west (left) by rugged mountains up to 11,000 feet (3,500 meters) high, including the informally named Norgay Montes in the foreground and Hillary Montes on the skyline. To the right, east of Sputnik, rougher terrain is cut by apparent glaciers. The backlighting highlights over a dozen layers of haze in Pluto’s tenuous but distended atmosphere. The image was taken from a distance of 11,000 miles (18,000 kilometers) to Pluto; the scene is 780 miles (1,250 kilometers) wide. Image Credits: NASA/JHUAPL/SwRI.

This new view of Pluto’s crescent -- taken by New Horizons’ wide-angle Ralph/Multispectral Visual Imaging Camera (MVIC) on July 14 and downlinked to Earth on Sept. 13 -- offers an oblique look across Plutonian landscapes with dramatic backlighting from the sun. It spectacularly highlights Pluto’s varied terrains and extended atmosphere. The scene measures 780 miles (1,250 kilometers) across.

Image above: Closer Look: Majestic Mountains and Frozen Plains: Just 15 minutes after its closest approach to Pluto on July 14, 2015, NASA’s New Horizons spacecraft looked back toward the sun and captured this near-sunset view of the rugged, icy mountains and flat ice plains extending to Pluto’s horizon. The smooth expanse of the informally named Sputnik Planum (right) is flanked to the west (left) by rugged mountains up to 11,000 feet (3,500 meters) high, including the informally named Norgay Montes in the foreground and Hillary Montes on the skyline. The backlighting highlights more than a dozen layers of haze in Pluto’s tenuous but distended atmosphere. The image was taken from a distance of 11,000 miles (18,000 kilometers) to Pluto; the scene is 230 miles (380 kilometers) across. Image Credits: NASA/JHUAPL/SwRI.

“This image really makes you feel you are there, at Pluto, surveying the landscape for yourself,” said New Horizons Principal Investigator Alan Stern, of the Southwest Research Institute, Boulder, Colorado. “But this image is also a scientific bonanza, revealing new details about Pluto’s atmosphere, mountains, glaciers and plains.”

Image above: Near-Surface Haze or Fog on Pluto: In this small section of the larger crescent image of Pluto, taken by NASA’s New Horizons just 15 minutes after the spacecraft’s closest approach on July 14, 2015, the setting sun illuminates a fog or near-surface haze, which is cut by the parallel shadows of many local hills and small mountains. The image was taken from a distance of 11,000 miles (18,000 kilometers), and the width of the image is 115 miles (185 kilometers). Image Credits: NASA/JHUAPL/SwRI.

Owing to its favorable backlighting and high resolution, this MVIC image also reveals new details of hazes throughout Pluto’s tenuous but extended nitrogen atmosphere. The image shows more than a dozen thin haze layers extending from near the ground to at least 60 miles (100 kilometers) above the surface. In addition, the image reveals at least one bank of fog-like, low-lying haze illuminated by the setting sun against Pluto’s dark side, raked by shadows from nearby mountains.

"In addition to being visually stunning, these low-lying hazes hint at the weather changing from day to day on Pluto, just like it does here on Earth," said Will Grundy, lead of the New Horizons Composition team from Lowell Observatory, Flagstaff, Arizona.

Combined with other recently downloaded pictures, this new image also provides evidence for a remarkably Earth-like “hydrological” cycle on Pluto – but involving soft and exotic ices, including nitrogen, rather than water ice.

Image above: Pluto’s ‘Heart’: Sputnik Planum is the informal name of the smooth, light-bulb shaped region on the left of this composite of several New Horizons images of Pluto. The brilliantly white upland region to the right may be coated by nitrogen ice that has been transported through the atmosphere from the surface of Sputnik Planum, and deposited on these uplands. The box shows the location of the glacier detail images below. Image Credits: NASA/JHUAPL/SwRI.

Bright areas east of the vast icy plain informally named Sputnik Planum appear to have been blanketed by these ices, which may have evaporated from the surface of Sputnik and then been redeposited to the east. The new Ralph imager panorama also reveals glaciers flowing back into Sputnik Planum from this blanketed region; these features are similar to the frozen streams on the margins of ice caps on Greenland and Antarctica.

Image above: Valley Glaciers on Pluto: Ice (probably frozen nitrogen) that appears to have accumulated on the uplands on the right side of this 390-mile (630-kilometer) wide image is draining from Pluto’s mountains onto the informally named Sputnik Planum through the 2- to 5-mile (3- to 8- kilometer) wide valleys indicated by the red arrows. The flow front of the ice moving into Sputnik Planum is outlined by the blue arrows. The origin of the ridges and pits on the right side of the image remains uncertain. Image Credits: NASA/JHUAPL/SwRI.

"We did not expect to find hints of a nitrogen-based glacial cycle on Pluto operating in the frigid conditions of the outer solar system,” said Alan Howard, a member of the mission’s Geology, Geophysics and Imaging team from the University of Virginia, Charlottesville. “Driven by dim sunlight, this would be directly comparable to the hydrological cycle that feeds ice caps on Earth, where water is evaporated from the oceans, falls as snow, and returns to the seas through glacial flow.”

Image above: Intricate Valley Glaciers on Pluto: This image covers the same region as the image above, but is re-projected from the oblique, backlit view shown in the new crescent image of Pluto. The backlighting highlights the intricate flow lines on the glaciers. The flow front of the ice moving into the informally named Sputnik Planum is outlined by the blue arrows. The origin of the ridges and pits on the right side of the image remains uncertain. This image is 390 miles (630 kilometers) across. Image Credits: NASA/JHUAPL/SwRI.

“Pluto is surprisingly Earth-like in this regard,” added Stern, “and no one predicted it.”

For more information about New Horizons mission, visit:

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


mercredi 16 septembre 2015

Funky Light Signal From Colliding Black Holes Explained

NASA - Galaxy Evolution Explorer (GALEX) logo / NASA - Hubble Space Telescope patch.

Sep. 16, 2015

Entangled by gravity and destined to merge, two candidate black holes in a distant galaxy appear to be locked in an intricate dance. Researchers using data from NASA's Galaxy Evolution Explorer (GALEX) and NASA's Hubble Space Telescope have come up with the most compelling confirmation yet for the existence of these merging black holes and have found new details about their odd, cyclical light signal.

Images above: This simulation helps explain an odd light signal thought to be coming from a close-knit pair of merging black holes, PG 1302-102, located 3.5 billion light-years away. Images Credits: Columbia University.

The candidate black hole duo, called PG 1302-102, was first identified earlier this year using ground-based telescopes. The black holes are the tightest orbiting pair detected so far, with a separation not much bigger than the diameter of our solar system. They are expected to collide and merge in less than a million years, triggering a titanic blast with the power of 100 million supernovae.

Researchers are studying this pair to better understand how galaxies and the monstrous black holes at their cores merge -- a common occurrence in the early universe. But as common as these events were, they are hard to spot and confirm.

PG 1302-102 is one of only a handful of good binary black hole candidates. It was discovered and reported earlier this year by researchers at the California Institute of Technology in Pasadena, after they scrutinized an unusual light signal coming from the center of a galaxy. The researchers, who used telescopes in the Catalina Real-Time Transient Survey, demonstrated that the varying signal is likely generated by the motion of two black holes, which swing around each other every five years. While the black holes themselves don't give off light, the material surrounding them does.

In the new study, published in the Sept. 17 issue of Nature, researchers found more evidence to support and confirm the close-knit dance of these black holes. Using ultraviolet data from GALEX and Hubble, they were able to track the system's changing light patterns over the past 20 years.

Galaxy Evolution Explorer (GALEX). Image Credit: NASA

"We were lucky to have GALEX data to look through," said co-author David Schiminovich of Columbia University in New York. "We went back into the GALEX archives and found that the object just happened to have been observed six times."

Hubble, which sees ultraviolet light in addition to visible and other wavelengths of light, had likewise observed the object in the past.

The ultraviolet light was important to test a prediction of how the black holes generate a cyclical light pattern. The idea is that one of the black holes in the pair is giving off more light -- it is gobbling up more matter than the other one, and this process heats up matter that emits energetic light. As this black hole orbits around its partner every five years, its light changes and appears to brighten as it heads toward us.

"It's as if a 60-Watt light bulb suddenly appears to be 100 Watts," explained Daniel D'Orazio, lead author of the study from Columbia University. "As the black hole light speeds away from us, it appears as a dimmer 20-Watt bulb."

What's causing the changes in light? One set of changes has to do with the "blue shifting" effect, in which light is squeezed to shorter wavelengths as it travels toward us in the same way that a police car's siren squeals at higher frequencies as it heads toward you. Another reason has to do with the enormous speed of the black hole.

The brighter black hole is, in fact, traveling at nearly seven percent the speed of light -- in other words, really fast. Though it takes the black hole five years to orbit its companion, it is traveling vast distances. It would be as if a black hole lapped our entire solar system from the outer fringes, where the Oort cloud of comets lies, in just five years. At speeds as high as this, which are known as relativistic, the light becomes boosted and brighter.

D'Orazio and colleagues modeled this effect based on a previous Caltech paper and predicted how it should look in ultraviolet light. They determined that, if the periodic brightening and dimming previously seen in the visible light is indeed due to the relativistic boosting effect, then the same periodic behavior should be present in ultraviolet wavelengths, but amplified 2.5 times. Sure enough, the ultraviolet light from GALEX and Hubble matched their predictions

Hubble Space Telescope. Image Credit: NASA

"We are strengthening our ideas of what's going on in this system and starting to understand it better," said Zoltán Haiman, a co-author from Columbia University who conceived the project.

The results will also help researchers understand how to find even closer-knit merging black holes in the future, what some consider the holy grail of physics and the search for gravitational waves. In the final moments before the ultimate union of two black holes, when they are tightly spinning around each other like ice skaters in a "death spiral," they are predicted to send out ripples in space and time. These so-called gravitational waves, whose existence follows from Albert Einstein’s gravity theory published 100 years ago, hold clues about the fabric of our universe.

The findings are also a doorway to understanding other merging black holes across the universe, a widespread population that is only now beginning to yield its secrets.

The California Institute of Technology in Pasadena led the Galaxy Evolution Explorer mission, which ended in 2013 after more than a decade of scanning the skies in ultraviolet light. NASA's Jet Propulsion Laboratory, also in Pasadena, managed the mission and built the science instrument. JPL is managed by Caltech for NASA.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington.

For more information about GALEX, visit:

For more information on the Hubble Space Telescope, visit:

Images (mentioned), Text, Credits: NASA/JPL/Whitney Clavin/Martin Perez.


A Shy Galactic Neighbour

ESO - European Southern Observatory logo.

16 September 2015

Sculptor Dwarf Galaxy

The Sculptor Dwarf Galaxy, pictured in this new image from the Wide Field Imager camera, installed on the 2.2-metre MPG/ESO telescope at ESO’s La Silla Observatory, is a close neighbour of our galaxy, the Milky Way. Despite their close proximity, both galaxies have very distinct histories and characters. This galaxy is much smaller and older than the Milky Way, making it a valuable subject for studying both star and galaxy formation in the early Universe. However, due to its faintness, studying this object is no easy task.

The Sculptor Dwarf Galaxy — also known as the Sculptor Dwarf Elliptical or the Sculptor Dwarf Spheroidal — is a dwarf spheroidal galaxy, and is one of the fourteen known satellite galaxies orbiting the Milky Way [1]. These galactic hitchhikers are located close by in the Milky Way’s extensive halo, a spherical region extending far beyond our galaxy’s spiral arms. As indicated by its name, this galaxy is located in the southern constellation of Sculptor and lies about 280 000 light-years away from Earth. Despite its proximity, the galaxy was only discovered in 1937, as its stars are faint and spread thinly across the sky.

Location of the Sculptor Dwarf Galaxy

Although difficult to pick out, the Sculptor Dwarf Galaxy was among the first faint dwarf galaxies found orbiting the Milky Way. The tiny galaxy’s shape intrigued astronomers at the time of its discovery, but nowadays dwarf spheroidal galaxies play a more important role in allowing astronomers to dig deeply into the Universe’s past.

The Milky Way, like all large galaxies, is thought to have formed from the build-up of smaller galaxies during the early days of the Universe. If some of these small galaxies still remain today, they should now contain many extremely old stars. The Sculptor Dwarf Galaxy fits the bill as a primordial galaxy, thanks to a large number of ancient stars, visible in this image.

Astronomers can determine the age of stars in the galaxy because their light carries the signatures of only a small quantity of heavy chemical elements. These heavy elements accumulate in galaxies with successive generations of stars. A low level of heavy elements thus indicates that the average age of the stars in the Sculptor Dwarf Galaxy is high.

Wide-field image of the sky around the Sculptor Dwarf Galaxy

This quantity of old stars makes the Sculptor Dwarf Galaxy a prime target for studying the earliest periods of star formation. In a recent study, astronomers combined all the data available for the galaxy to create the most accurate star formation history ever determined for a dwarf spheroidal galaxy. This analysis revealed two distinct groups of stars in the galaxy. The first, predominant group is the older population, which is lacking in heavier elements. The second, smaller population, in contrast, is rich with heavy elements. Like young people crowding into city centres, this youthful stellar population is concentrated toward the galaxy’s core.

The stars within dwarf galaxies like the Sculptor Dwarf Galaxy can exhibit complex star formation histories. But as most of these dwarf galaxies’ stars have been isolated from each other and have not interacted for billions of years, each collection of stars has charted its own evolutionary course. Studying the similarities in dwarf galaxies’ histories, and explaining the occasional outliers, will help to explain the development of all galaxies, from the most unassuming dwarf to the grandest spirals. There is indeed much for astronomers to learn from the Milky Way’s shy neighbours.

A close-up look at the Sculptor Dwarf Galaxy


[1] This faint galaxy should not be confused with the much brighter Sculptor Galaxy (NGC 253) in the same constellation:

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”.


Photos of the MPG/ESO.2.2-metre telescope:

Photos taken with the MPG/ESO.2.2-metre telescope:

Images, Text, Credits: ESO/IAU and Sky & Telescope/Digitized Sky Survey 2/Video: Credits: ESO/DSS.

Best regards,

International Space Station (ISS) orbit correction

ROSCOSMOS - Russian Vehicles patch.

Sept. 16, 2015

The International Space Station (ISS) orbit has been increased by 3.7 kilometers with the help Russia’s Progress M-28M cargo vehicle, the Mission Control Center said on Monday.

"The maneuver on raising the orbit was carried out with the help of thrusters of the Progress M-28M cargo craft," a representative of the center based outside Moscow told TASS.

ISS re-boost by Progress-M cargo

As a result, the orbit’s altitude now amounts to 405 kilometers in average. Russia’s space agency Roscosmos said the spacecraft’s thrusters operated for 146 seconds, increasing the station’s velocity by 2.2 m/s.

The ISS now has a crew of six: Russia’s Mikhail Korniyenko, Oleg Kononenko and Sergey Volkov, the United States’ Scott Kelly and Kjell Lindgren and Japan’s Kimiya Yui.

ROSCOSMOS Press Release:

Image, Text, Credits: ROSCOSMOS/TASS/NASA.


mardi 15 septembre 2015

LRO Discovers Earth's Pull is "Massaging" our Moon

NASA - Lunar Reconnaissance Orbiter (LRO) patch.

Sep. 15, 2015

Earth's gravity has influenced the orientation of thousands of faults that form in the lunar surface as the moon shrinks, according to new results from NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft.

Animation above: The gravitational forces the Moon and Sun exert are responsible for Earth’s rising and falling tides. Earth’s gravity also exerts forces on the Moon in the form of solid body tides that distort its shape. The Moon is slowly receding away from Earth and forces build as the Moon’s tidal distortion diminishes with distance and its rotation period slows with time. These tidal forces combined with the shrinking of the Moon from cooling of its interior have influenced the pattern of orientations in the network of young fault scarps. Animation Credits: NASA/LRO.

In August, 2010, researchers using images from LRO's Narrow Angle Camera (NAC) reported the discovery of 14 cliffs known as "lobate scarps" on the moon's surface, in addition to about 70 previously known from the limited high-resolution Apollo Panoramic Camera photographs. Due largely to their random distribution across the surface, the science team concluded that the moon is shrinking.

These small faults are typically less than 6.2 miles (10 kilometers) long and only tens of yards or meters high. They are most likely formed by global contraction resulting from cooling of the moon's still hot interior. As the interior cools and portions of the liquid outer core solidify, the volume decreases; thus the moon shrinks and the solid crust buckles.

Image above: Thousands of young, lobate thrust fault scarps have been revealed in Reconnaissance Orbiter Camera images (LROC). Lobate scarps like the one shown here are like stair-steps in the landscape formed when crustal materials are pushed together, break and are thrust upward along a fault forming a cliff. Cooling of the still hot lunar interior is causing the Moon to shrink, but the pattern of orientations of the scarps indicate that tidal forces are contributing to the formation of the young faults. Image Credits: NASA/LRO.

Now, after more than six years in orbit, the Lunar Reconnaissance Orbiter Camera (LROC) has imaged nearly three-fourths of the lunar surface at high resolution, allowing the discovery of over 3,000 more of these features. These globally distributed faults have emerged as the most common tectonic landform on the moon. An analysis of the orientations of these small scarps yielded a surprising result: the faults created as the moon shrinks are being influenced by an unexpected source—gravitational tidal forces from Earth.

Global contraction alone should generate an array of thrust faults with no particular pattern in the orientations of the faults, because the contracting forces have equal magnitude in all directions. "This is not what we found," says Smithsonian senior scientist Thomas Watters of the National Air and Space Museum in Washington. "There is a pattern in the orientations of the thousands of faults and it suggests something else is influencing their formation, something that's also acting on a global scale -- 'massaging' and realigning them." Watters is lead author of the paper describing this research published in the October issue of the journal Geology.

Image above: The map shows the locations of over 3,200 lobate thrust fault scarps (red lines) on the Moon. The black double arrows show the average orientations of the lobate scarps sampled in areas with dimensions of 40° longitude by 20° latitude and scaled by the total length of the fault scarps in the sampled areas. The pattern of the black double arrows (orientation vectors) indicates that the fault scarps do not have random orientations as would be expected if the forces that formed them were from global contraction alone. Mare basalt units are shown in tan. Image Credits: NASA/LRO.

The other forces acting on the moon come not from its interior, but from Earth. These are tidal forces. When the tidal forces are superimposed on the global contraction, the combined stresses should cause predictable orientations of the fault scarps from region to region. "The agreement between the mapped fault orientations and the fault orientations predicted by the modeled tidal and contractional forces is pretty striking," says Watters.

"The discovery of so many previously undetected tectonic features as our LROC high-resolution image coverage continues to grow is truly remarkable," said Mark Robinson of Arizona State University, coauthor and LROC principal investigator. "Early on in the mission we suspected that tidal forces played a role in the formation of tectonic features, but we did not have enough coverage to make any conclusive statements. Now that we have NAC images with appropriate lighting for more than half of the moon, structural patterns are starting to come into focus."

Image above: A prominent lobate fault scarp in the Vitello Cluster is one of thousands discovered in Lunar Reconnaissance Orbiter Camera images (LROC). Topography derived from the LROC Narrow Angle Camera (NAC) stereo images shows a degraded crater has been uplift as the fault scarp has formed (blues are lower elevations and reds are higher elevations). Boulders in the crater have aligned in rows that parallel the orientation of the fault scarp. Image Credits: NASA/LRO.

The fault scarps are very young – so young that they are likely still actively forming today. The team's modeling shows that the peak stresses are reached when the moon is farthest from Earth in its orbit (at apogee). If the faults are still active, the occurrence of shallow moonquakes related to slip events on the faults may be most frequent when the moon is at apogee. This hypothesis can be tested with a long-lived lunar seismic network.

"With LRO we've been able to study the moon globally in detail not yet possible with any other body in the solar system beyond Earth, and the LRO data set enables us to tease out subtle but important processes that would otherwise remain hidden," said John Keller, LRO Project Scientist at NASA's Goddard Space Flight Center, Greenbelt, Maryland.

Image above: A nadir (top) and perspective view (bottom) of a prominent lobate fault scarp in the Vitello Cluster, one of thousands discovered in Lunar Reconnaissance Orbiter Camera images (LROC). In the perspective view, the Narrow Angle Camera (NAC) image is draped over topography derived from NAC stereo images. A degraded crater has been uplift as the fault scarp has formed. Boulders in the crater have aligned in rows that parallel the orientation of the fault scarp. Image Credits: NASA/LRO.

Launched on June 18, 2009, LRO has collected a treasure trove of data with its seven powerful instruments, making an invaluable contribution to our knowledge about the moon. LRO is managed by NASA's Goddard Space Flight Center in Greenbelt, Maryland, under the Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville for the Science Mission Directorate at NASA Headquarters in Washington, DC.

For more information about Lunar Reconnaissance Orbiter (LRO), visit:

Animation (mentioned), Images (mentioned), Text, Credits: NASA Goddard Space Flight Center/Nancy Neal-Jones / William Steigerwald/ Karl Hille.


Cassini Finds Global Ocean in Saturn's Moon Enceladus

NASA - Cassini Mission to Saturn patch.

Sep. 15, 2015

A global ocean lies beneath the icy crust of Saturn's geologically active moon Enceladus, according to new research using data from NASA's Cassini mission.

Researchers found the magnitude of the moon's very slight wobble, as it orbits Saturn, can only be accounted for if its outer ice shell is not frozen solid to its interior, meaning a global ocean must be present.

Image above: Illustration of the interior of Saturn's moon Enceladus showing a global liquid water ocean between its rocky core and icy crust. Thickness of layers shown here is not to scale. Image Credits: NASA/JPL-Caltech.

The finding implies the fine spray of water vapor, icy particles and simple organic molecules Cassini has observed coming from fractures near the moon's south pole is being fed by this vast liquid water reservoir. The research is presented in a paper published online this week in the journal Icarus.

Previous analysis of Cassini data suggested the presence of a lens-shaped body of water, or sea, underlying the moon's south polar region. However, gravity data collected during the spacecraft's several close passes over the south polar region lent support to the possibility the sea might be global. The new results -- derived using an independent line of evidence based on Cassini's images -- confirm this to be the case.

"This was a hard problem that required years of observations, and calculations involving a diverse collection of disciplines, but we are confident we finally got it right," said Peter Thomas, a Cassini imaging team member at Cornell University, Ithaca, New York, and lead author of the paper.

Cassini scientists analyzed more than seven years' worth of images of Enceladus taken by the spacecraft, which has been orbiting Saturn since mid-2004. They carefully mapped the positions of features on Enceladus -- mostly craters -- across hundreds of images, in order to measure changes in the moon's rotation with extreme precision.

As a result, they found Enceladus has a tiny, but measurable wobble as it orbits Saturn. Because the icy moon is not perfectly spherical -- and because it goes slightly faster and slower during different portions of its orbit around Saturn -- the giant planet subtly rocks Enceladus back and forth as it rotates.

The team plugged their measurement of the wobble, called a libration, into different models for how Enceladus might be arranged on the inside, including ones in which the moon was frozen from surface to core.

"If the surface and core were rigidly connected, the core would provide so much dead weight the wobble would be far smaller than we observe it to be," said Matthew Tiscareno, a Cassini participating scientist at the SETI Institute, Mountain View, California, and a co-author of the paper. "This proves that there must be a global layer of liquid separating the surface from the core," he said.

The mechanisms that might have prevented Enceladus' ocean from freezing remain a mystery. Thomas and his colleagues suggest a few ideas for future study that might help resolve the question, including the surprising possibility that tidal forces due to Saturn's gravity could be generating much more heat within Enceladus than previously thought.

"This is a major step beyond what we understood about this moon before, and it demonstrates the kind of deep-dive discoveries we can make with long-lived orbiter missions to other planets," said co-author Carolyn Porco, Cassini imaging team lead at Space Science Institute (SSI), Boulder, Colorado, and visiting scholar at the University of California, Berkeley. "Cassini has been exemplary in this regard."

Cassini Spacecraft Animation

The unfolding story of Enceladus has been one of the great triumphs of Cassini's long mission at Saturn. Scientists first detected signs of the moon's icy plume in early 2005, and followed up with a series of discoveries about the material gushing from warm fractures near its south pole. They announced strong evidence for a regional sea in 2014, and more recently, in 2015, they shared results that suggest hydrothermal activity is taking place on the ocean floor.

Cassini is scheduled to make a close flyby of Enceladus on Oct. 28, in the mission's deepest-ever dive through the moon's active plume of icy material. The spacecraft will pass a mere 30 miles (49 kilometers) above the moon's surface.

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA's Jet Propulsion Laboratory (JPL) in Pasadena, California, manages the mission for the agency's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena, California. The Cassini imaging operations center is based at Space Science Institute.

For more information about Cassini, visit: and and

Image (mentioned), Video, Text, Credits: NASA/Dwayne Brown/Laurie Cantillo/JPL/Preston Dyches/European Space Agency (ESA).

Best regards,

ESA/NASA Solar Observatory Discovers Its 3,000th Comet

ESA / NASA - SOHO Mission patch.

Sep. 15, 2015

On Sept. 13, 2015, the Solar and Heliospheric Observatory -- a joint project of the European Space Agency and NASA -- discovered its 3,000th comet, cementing its standing as the greatest comet finder of all time. Prior to the 1995 launch of the observatory, commonly known as SOHO, only a dozen or so comets had ever even been discovered from space, while some 900 had been discovered from the ground.

3,000 Comets for SOHO

Video above: This narrated video shows an artist's representation of the paths of almost 2,000 comets either discovered or seen by SOHO. Different colors represent different families of comets. Red represents the Kreutz family of comets, which count for 85 percent of all the comets found by the Solar and Heliospheric Observatory. Video Credits: NASA's Goddard Space Flight Center/Bridgman/Duberstein.

The 3,000th comet was originally spotted in the data by Worachate Boonplod, of Samut Songkhram, Thailand.

"I am very happy to be part of a great milestone for SOHO's comet project," said Boonplod. "I would like to thank SOHO, ESA and NASA for making this opportunity possible, including other fellow comet hunters who I have learned a lot from.”

 ESA/NASA SOHO Solar Observatory spacecraft. Image Credits: ESA/NASA

SOHO's mission is to observe the sun and interplanetary space, above Earth's atmosphere that blocks so much of the sun's radiation. From there, SOHO watches the solar disk itself and its surrounding environment, tracking the constant outward flow of particles known as the solar wind, as well as giant explosions of escaping gas called coronal mass ejections, or CMEs. In its two decades in orbit, SOHO has opened up a new era of solar observations, dramatically extending our understanding of the star we live with.

The telescope’s comet prowess, however, was unplanned and has turned out to be an unexpected benefit. With its clear view of the sun's surroundings, SOHO can easily spot a special kind of comet called a sungrazer, because of its close approach to the sun.

Image above: The dot in the cross-hairs is a comet streaming toward the sun, as seen on Sept. 14, 2015, by the ESA/NASA Solar and Heliospheric Observatory. This is the 3,000th comet discovered in the data from that space telescope since it launched in 1995. The comet was originally spotted by by Worachate Boonplod person of Samut Songkhram,Thailand. Image Credits: ESA/NASA/SOHO.

"SOHO has a view of about 12-and-a-half million miles beyond the sun," said Joe Gurman, mission scientist for SOHO at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "So we expected it might from time to time see a bright comet near the sun. But nobody dreamed we'd approach 200 a year."

SOHO's great success as a comet finder is dependent on the people who sift through its data – a task open to the world as the data is publicly available online in near-real time. A cadre of volunteer amateur astronomers dedicate themselves to searching the data via the NASA-funded Sungrazer Project. While scientists often search SOHO imagery for very specific events, various members of the astronomy community choose to comb through all the imagery in fine detail. The result: 95 percent of SOHO comets have been found by these citizen scientists.

"The people who have found comets represent a very broad cross section as the program is open to anyone who has interest," said Karl Battams, a solar scientist at the Naval Research Laboratory in Washington, D.C. Battams has been charged with running the SOHO comet-sighting website since 2003. "There are scientists, teachers, writers. We have even had two 13-year-olds."

Image above: SOHO and comet-finding infographic. Image Credits: NASA's Goddard Space Flight Center/Duberstein.

More than just a celebrated bright vision in the night sky, comets can tell scientists a great deal about the place and time where they originated. Comets are essentially a clump of frozen gases mixed with dust. They are often pristine relics that can hold clues about the very formation of our solar system. On the other hand, if they have made previous trips around the sun, they can hold information about the distant reaches of the solar system through which they've traveled.

Watching these sungrazing comets also help us learn about our sun. Their tails of ionized gas illuminate magnetic fields around the sun, so they can act as a tracer that helps scientists observe these invisible fields. Such fields have even ripped off comet tails allowing astronomers to watch the lost tails blowing in the steady outpouring of solar particles streaming off our closest star. The tails act as giant windsocks in this solar wind, showing researchers the details of the wind's movement.

At almost 20 years old, the SOHO mission is a respected elder in NASA's Heliophysics System Observatory – the fleet of spacecraft that both watches the sun and measure its effects near Earth and throughout the solar system. SOHO is a cooperative effort between ESA and NASA. Mission control is based at NASA Goddard. SOHO’s Large Angle and Spectrometric Coronagraph Experiment, or LASCO, which is the instrument that provides most of the comet imagery, was built by an international consortium, led the Naval Research Lab in Washington, D.C. 

Related Links:

Feature: “Nearing 3,000 Comets: SOHO Solar Observatory Greatest Comet Hunter of All Time” (July 30, 2015):

NASA’s SOHO website:
ESA's SOHO website:

NRL’s SOHO Sungrazer Project website:

Images (mentioned), Video (mentioned), Text, Credits: NASA's Goddard Space Flight Center/Karen C. Fox/Rob Garner.


Proba-2’s partial eclipse

ESA - Proba-2 Mission logo.

Sept. 15, 2015

Proba-2 eclipse

ESA’s Sun-watching Proba-2 satellite experienced three partial solar eclipses on 13 September 2015. On Earth, a single partial eclipse occurred over South Africa, the southern Indian Ocean and Antarctica.

During a total solar eclipse, the Moon moves in front of the Sun as seen from Earth, their alignment and separation such that the Moon, situated much closer to Earth, appears large enough to block out the light from the much more distant Sun.

But, like yesterday, sometimes the alignment is such that the Moon only partially covers the Sun’s disc.

Meanwhile, ESA’s Proba-2 orbits Earth about 14.5 times per day, dipping in and out of the Moon’s shadow around the time of a solar eclipse. The constant change in viewing angle of Proba-2 meant that the satellite passed through the shadow three times during the eclipse yesterday.

ESA’s Sun-watching Proba-2 satellite

One of these partial eclipses is presented here – it was captured at 06:32 GMT on 13 September – but all three, along with a fourth passage of the Moon close to the edge of the Sun, can be seen in this movie.

The image was taken with Proba-2’s SWAP imager, which views the solar disc at extreme ultraviolet wavelengths to capture the turbulent surface of the Sun and its swirling corona – a glimpse of which can be seen in the background.

For more information about Proba-2 mission, visit:

Images, Text, Credits: ESA / Royal Observatory of Belgium.


lundi 14 septembre 2015

Khrunichev Center: Proton-M was successfully launched from Baikonur



Proton-M night launch (illustration)

September 14 at 22:00 MSK from Launch Complex 81 area Baikonur Cosmodrome starting calculations Roskosmos MV. Khrunichev Center and other enterprises of rocket-space industry of Russia conducted a successful launch of the carrier rocket Proton-M with the upper stage DM-03 and the telecommunications spacecraft EXPRESS AM8. After the regular separation from the third stage of the launch vehicle orbital unit as part of the Republic of Belarus DM-03 and Express-AM8 continues autonomous flight.

Launch of Russian Proton rocket carrying Express-AM8 from Baikonur

Further injection into the target orbit carried the upper stage DM-03 on the scheme RB trip with three inclusions sustainer engine. The total duration of excretion from the start of the launcher before separation of the spacecraft will be 6 hours and 37 minutes, the separation of the Express-AM8 scheduled September 15, 2015 at 04:37 MSK.

EXPRESS AM8 telecommunications satellite

Today's launch - 406 minutes in the history of space launches of Proton and the fifth this year.

ROSCOSMOS Press Release:

Images, Video, Text, Credits: ROSCOSMOS/Tsenki/ Aerospace.