Monday, May 30, 2011

NASA Shuttle Endeavour departs ISS for last time - Video



Endeavour undocked from the International Space Station at 11:55 p.m. EDT Sunday, ending a stay of 11 days, 17 hours and 41 minutes at the orbiting laboratory.

Pilot Greg Johnson, at the aft flight deck controls, flew Endeavour in a circle around the station at distances of about 450 to 650 feet. Crew members took still and video images of the station.

As Johnson was about to begin the flyaround, Commander Mark Kelly radioed mission control that he could see the $2 billion Alpha Magnetic Spectrometer particle physics detector Endeavour had brought to orbit. "It's a new day for science on the space station," he said to mission control.

After the flyaround and a separation burn, Kelly took the controls for a test of an automated rendezvous and docking system called STORRM, for Sensor Test for Orion Relative Navigation Risk Mitigation. Endeavour moved about 20,000 feet above and behind the station, then to a point below and behind it.

Kelly subsequently maneuvered the shuttle on a rendezvous-like course, winding up at a point about 950 feet below the station. There the shuttle did a separation burn, beginning its departure from the area with the STORRM sensors still tracking the station until contact was lost. Initial reports were that the test had produced good data. All Endeavour crew members, including Mission Specialists Mike Fincke, Roberto Vittori, Drew Feustel and Greg Chamitoff, were scheduled for almost four hours of STORRM work.

NASA Endeavour leaves ISS

The International Space Station is featured in this image photographed by an STS-134 crew member at an aft flight deck window of Space Shuttle Endeavour during rendezvous and docking operations on 18 May 2011.

Credits: NASA

Sunday, May 29, 2011

Confused Antibody production during long-term spaceflight

The trip to Mars just got a little more difficult now that French researchers have discovered that antibodies used to fight off disease might become seriously compromised during long-term space flight. In a new report published online in the FASEB Journal, the scientists show that antibodies produced in space are less effective than those produced on terra firma.

The reduced effectiveness of antibodies makes astronauts more susceptible to illness, while increasing the danger posed by bacteria and viruses likely to coexist with wayfaring astronauts.

"We hope to find efficient pharmacological and/or nutritional countermeasures to alterations of the immune system that could be useful to astronauts and to people who have weak immune systems on Earth because of infections, aging, or chronic stress exposure," said Jean-Pol Frippiat, a researcher involved in the work from the Faculty of Medicine, Development and Immunogenetics at the Universite Henri Poincare-Nancy, Vandoeuvre-les-Nancy, France.

To make their discovery, Frippiat and colleagues conducted studies using three groups of amphibians. Amphibians were chosen for the work because they use the same cellular mechanisms to produce antibodies as humans do. The first group of amphibians was immunized in space, the second was immunized on Earth, and the third was not immunized at all.

Comparison of the antibodies produced revealed that the quality of the antibodies generated by the group immunized in space was decreased. This suggests that spaceflight conditions alter the immune system and affect its ability to protect against infections and tumors, posing a serious risk for astronauts.

"This paper shows that somatic hypermutation occurs at a lower frequency in spaceflight and brings together yet more evidence that the immune system is dependent on gravity," said Millie Hughes-Fulford, Ph.D., NASA Science Astronaut; Professor, Department of Biochemistry and Biophysics, UCSF; Director, Laboratory of Cell Growth, VAMC/UCSF; and editorial board member of the FASEB Journal.

"Dependence on gravity should be no surprise since all of earth's jawed vertebrates developed in earth's gravity, and it would be logical to expect that some systems would require gravity for normal function."

"Outer space may be the final frontier, but this research shows that our inner space could pose the greatest threat to the success of a mission," said Gerald Weissmann, M.D., Editor-in-Chief of the FASEB Journal. "These explorers will have to be prepared not only for the challenges of extremely hostile environments, but also those posed by microbial stowaways, even those with which we peacefully co-exist on Earth."

Friday, May 27, 2011

NASA Endeavour: ISS EVA Andrew FeustalStation - Telegraph

Andrew Feustel enters the Quest airlock of the International Space Station as the mission's third session of extravehicular activity draws to a close


The spacewalk was Feustel's fifth and the seventh for Fincke, the 157th in support of space station assembly and maintenance and the 246th conducted by US astronauts

Picture: EPA / NASA

ESA ATV-4 to carry name Albert Einstein

With ATV Johannes Kepler in space and ATV Edoardo Amaldi almost built, the next Space Station supply craft coming off the production line has been named after the most famous scientist of all time: Albert Einstein. Launch is expected in early 2013.

With relativity and E=mc2, Albert Einstein is a major icon of 20th century science. His theories have been stringently tested in space and his work is used to guide spacecraft to other planets - and now he will fly into orbit. ESA has decided to name the fourth Automated Transfer Vehicle (ATV) after Albert Einstein.

ATVs are an essential contribution by Europe for supplying and maintaining the International Space Station.

The vessels are named after great European scientists and visionaries to highlight Europe's deep roots in science, technology and culture.

Naming ATV-4 after Albert Einstein, as proposed by the Swiss delegation to ESA, reflects this approach. Einstein's contributions to humanity and, in particular, science overturned our perception of the Universe.

ATV is also strongly linked to Switzerland: its structure is built by Swiss industry.

Thursday, May 26, 2011

NASA: Thermal control and Electronic Cooling pump

The more advanced the electronics, the more power they use. The more power they use, the hotter they get.

The hotter they get, the more likely they’ll overheat. It doesn’t take a rocket scientist to understand what typically happens next: The electronics fry.

In the world of electronics, thermal control is always one of the limiting factors -- particularly in space where there is no air to help cool down electronic components.

However, Jeffrey Didion, a thermal engineer at the NASA Goddard Space Flight Center in Greenbelt, Md., and Dr. Jamal Seyed-Yagoobi, a professor at the Illinois Institute of Technology in Chicago, Ill., have collaborated to develop a technology that may overcome current limitations. They have formed technical partnerships with the U.S. Air Force and National Renewable Energy Laboratory to address the thermal-control concerns.

Called electrohydrodynamic (EHD)-based thermal control, the technology promises to make it easier and more efficient to remove heat from small spaces -- a particular challenge for engineers building advanced space instruments and microprocessors that could fail if the heat they generate is not removed.

"Today, higher-power computer chips are available, but they generate too much heat," said Didion, who is leading the technology-development effort also involving Matthew Showalter, associate branch chief of Goddard’s Advanced Manufacturing Branch, and Mario Martins of Edge Space Systems, an engineering company specializing in thermal systems in Glenelg, Md. "If I can carry away more heat, engineers will be able to use higher-power components. In other words, they will be able to do more things."

The project, a joint activity between NASA Goddard and its partners, received support from the Goddard Internal Research and Development (IRAD) program, which funds the development of promising new technologies that could advance NASA’s scientific and exploration goals. It is being demonstrated in June on a Terrier-Improved Orion sounding rocket mission, which also is flying the Small Rocket/Spacecraft Technology (SMART) platform, a microsatellite also developed at Goddard. This new microsatellite measures about 16 inches in diameter and was specifically designed to give scientific users less expensive access to space. (Read the related press release.)

NASA-Funded Scientists Make Lunar Discovery of Water

A team of NASA-funded researchers has measured for the first time water from the moon in the form of tiny globules of molten rock, which have turned to glass-like material trapped within crystals.

Data from these newly-discovered lunar melt inclusions indicate the water content of lunar magma is 100 times higher than previous studies suggested.

The inclusions were found in lunar sample 74220, the famous high-titanium "orange glass soil" of volcanic origin collected during the Apollo 17 mission in 1972.

The scientific team used a state-of-the-art ion microprobe instrument to measure the water content of the inclusions, which were formed during explosive eruptions on the moon approximately 3.7 billion years ago.

The results, published in the May 26 issue of Science Express, raise questions about aspects of the "giant impact theory" of how the moon was created.

That theory predicted very low water content of lunar rock due to catastrophic degassing during the collision of Earth with a Mars-sized body very early in its history. The study also provides additional scientific justification for returning similar samples from other planetary bodies in the solar system.

"Water plays a critical role in determining the tectonic behavior of planetary surfaces, the melting point of planetary interiors and the location and eruptive style of planetary volcanoes," said Erik Hauri, a geochemist with the Carnegie Institution of Washington and lead author of the study.

"I can conceive of no sample type that would be more important to return to Earth than these volcanic glass samples ejected by explosive volcanism, which have been mapped not only on the moon but throughout the inner solar system."

In contrast to most volcanic deposits, the lunar melt inclusions are encased in crystals that prevent the escape of water and other volatiles during eruption.

"These samples provide the best window we have on the amount of water in the interior of the moon where the orange glass came from," said science team member James Van Orman of Case Western Reserve University in Cleveland.

NASA EVA: Orbiter Boom Sensor System

The space shuttle's robotic arm released the Orbiter Boom Sensor System at 12:50 a.m., and it was stowed as a permanent part of the space station at 1:42 a.m.

Mike Fincke will connect two grounding connectors, while Greg Chamitoff installs a foot restraint on the station’s robotic arm for use later in the spacewalk.

Currently, a grapple fixture in the middle of the boom is the only one the station arm is able to use, which halves the reach of the boom when on the station’s arm.

To remedy this, the spacewalkers will replace an electrical flight grapple fixture currently on one end of the boom with a power and data grapple fixture the station arm can use.

Once the power and data grapple fixture is added, it will be known as the Enhanced International Space Station Boom Assembly.

Both Mike Fincke and Greg Chamitoff will make their way to the P6 segment of the station’s truss to retrieve the power and data grapple fixture. To retrieve it, Fincke and Chamitoff will work together to release four bolts holding it in place. Chamitoff will then climb onto the station’s robotic arm for a ride back to boom on the starboard side of the station’s truss.

Chamitoff, with assistance from Fincke, will release the six bolts holding the electrical flight grapple fixture to the boom and cut its cable. Then he will install an adapter assembly on the boom, using six bolts and slide the power and data grapple fixture into place on it. Four bolts will hold it in place.

Tree-Climbing Robot - Video



TreeBot’s creators, Tin Lun Lam and Yangsheng Xu from The Chinese University of Hong Kong, presented their research at the International Conference on Robotics and Animation. In this video, you can see Treebot inch its way up thin stalks of bamboo as well as trees with much thicker diameters.

You see it tackle trees that lean like the Tower of Pisa, and you hold your breath as it makes 90-degree turns onto branches. While it would best most humans any day, it appears to have the unfair advantage of eight appendages as opposed to our measly four.

Socially Awkward Robotic Blimp Stalks People

Meet Ollie, the DIY autonomous robotic blimp. He (yes, the blimp is apparently a "he") floats on Helium; has flapping wings made of wire, mylar, and servos; and he reacts to his surroundings--often socially awkwardly.

Created by Pritika Nilaratna, a user experience designer and programmer in New York City, Ollie floats around and tries to get attention from people. He is observant and reacts to voices by "excitedly flapping his wings. Ollie is meant to be friendly and eager to be noticed, but also unobtrusive--you could just just push him out of your way if he gets annoying.

In the video of Ollie below, you see that he actually kind of stalks people to get their attention. According to Pritikia "machine-human interaction has the potential to be both poetic and ubiquitous," and Ollie "is a demonstration of the creative capabilities of robots as inhabitants of our society, breaking the stereotype of the servile robot." In other words, Ollie is meant to break the standard that we're so used to. It's definitely funny watching some people's responses to Ollie.


Ollie from Pritika Nilaratna on Vimeo.

So how do you get your own? You make it! Ollie is under a Creative Commons Attribution-ShareAlike 3.0 Unported License which means that you can copy and modify Ollie's design so long as you give credit to the author (Pritika) and that you only distribute the resulting work under the same kind or similar license.

You can make your very own Ollie with an Arduino board, some servos, a mylar balloon envelope, and some other basic electronics supplies. Pritika posted instructions for Ollie on the main Ollie site and also as an Instructables project. To learn more about Ollie check out the abstract.
[Ollie via Hackaday / Video: Pritika Nilaratna (at Vimeo)]

ESA: Satellite observations show potential to improve ash cloud forecasts

video

Predicting the exact dispersal of a volcanic ash cloud is never going to be easy. However, satellite data are showing that the eruption from Iceland's Grímsvötn volcano this week was unlikely to have posed a significant threat to airspace over central Europe.

The Icelandic Met Office reports that eruption from Grímsvötn has subsided and that there is now virtually no ash being produced from the volcano.

This major eruption began during the evening of 21 May and led to the disruption of around a thousand flights across Europe.

Although this is minor compared to the chaos caused last year when Eyjafjallajoekull erupted, satellite data are showing that this week's eruption did not pose a serious threat to aircraft flying over central Europe.

Satellite measurements offer an excellent means with which to follow the spread, extension, concentration and movement of volcanic plumes.

The most useful information is provided by satellites in geostationary orbit, such as the Meteosat series operated by Eumetsat, as they deliver data every 15 minutes.

The animation at the top, produced by the Royal Netherlands Meteorological Institute KNMI, uses data from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on Europe's MSG-2 satellite. It shows how the ash cloud spewed from Grímsvötn drifted towards Scotland and Scandinavia over the last few days.

ESA Portal - Satellite observations show potential to improve ash cloud forecasts

Wednesday, May 25, 2011

NASA WISE: Galaxy Menagerie

A new, colourful collection of galaxy specimens has been released by NASA's Wide-field Infrared Survey Explorer, or WISE, mission. 

It showcases galaxies of several types, from elegant grand design spirals to more patchy flocculent spirals.

Some of the galaxies have roundish centers, while others have elongated central bars. 

The orientation of the galaxies varies as well, with some seeming to peer straight back at us in the face-on configuration while others point to the side, appearing edge-on. 

Infrared light has been translated into colours we see with our eyes, such that the shortest wavelengths are blue and the longest are red. 

The oldest stars appear blue, while pockets of newly formed stars have yellow or reddish hues. Below is more information about each member of WISE's galaxy collection. The order is from top left to right; middle left to right; and bottom left to right.

The Whirpool Galaxy, or Messier 51 (M51)
Known by astronomers as M51, this beauty is a grand design spiral, which are galaxies with well-defined spiral arms. Its smaller companion, a dwarf galaxy called NGC 5195, is thought to have helped define and shape the arms due to its gravitational "dance" with its larger partner. 

M51 is also known as "The Lord Ross Galaxy," after the astronomer who was the first to study its spiral structure in the 1840s. It is located 25 million light-years away in the constellation Canes Venatici, and is 81,000 light-years across.

Bode's Galaxy, or Messier 81 (M81)
M81 is another grand design spiral galaxy, with pronounced arms spiraling into its core. WISE highlights areas where gas and dust have been compressed in the arms, leading to the formation of new stars. 

This compression has been enhanced by the galaxy's interaction with its partner galaxy, Messier 82 (not pictured here). That galaxy is bursting with new stars, and is therefore known as a "starburst." M81 is 12 million light-years away in the constellation Ursa Major, and 94,000 light-years across.

Southern Pinwheel Galaxy, or Messier 83 (M83)
At about 55,500 light-years across, M83 is s a bit more than half the size of our Milky Way Galaxy, but it has a similar overall structure. Like the Milky Way, most of M83's stars, dust, and gas lie in a thin disk decorated with grand spiral arms.

This galaxy is classified as a barred spiral because, in addition to a central bulge of stars, it has a central bar-shaped region of stars. It is 15 million light-years away in the constellation Hydra.

NGC 628, or Messier 74 (M74)
Some astronomers call the grand design spiral Messier 74 the "perfect spiral," for its exceptional symmetry. It is suspected to have a black hole at its center, with a mass equal to 10,000 suns. 

It is one of only a handful of known black holes with masses intermediate between the relatively smaller ones that form from collapsing stars and the supermassive black holes millions of times more massive than the sun. 

Supermassive black holes are more typically found at the centers of galaxies. Messier 74 is located between 24.5 and 36 million light-years away in the constellation Pisces, and is 100,000 light-years across.

NGC 1398
This barred spiral has a dense inner ring that surrounds a bright, central core. The ring is actually two spiral arms that are closed in on each other. In contrast to its well-defined center, this galaxy's arms are patchy, or flocculent.

It is inclined about 43 degrees away from an edge-on orientation, and has a diameter of 135,000 light-years. NGC 1398 is 65 million light-years away in the Fornax constellation, and is part of the Fornax cluster of galaxies.

NGC 2403
This fuzzy-looking galaxy is a flocculent, or patchy, spiral. It is largely veiled by gas and dust at visible-light wavelengths, but when viewed with WISE, its arms are clearly revealed. 

In 2004, NGC 2403 was host to one of the largest supernova in recent decades -- SN 2004dj was first observed in 2004 in Japan and was visible for 8 months. NGC 2403 is located 11.4 million-light years away in the constellation Camelopardalis, and is about 73,000 light-years across.

Splinter or Knife Edge Galaxy, or NGC 5907
This galaxy's face is angled about 90 degrees from our view, so it appears edge-on and thin as a splinter, or knife. It was discovered by the astronomer William Herschel in 1788. 

There is a large complex of stellar streams surrounding the galaxy, which can't be seen in the WISE image. These are the torn-up shreds of smaller galaxies that were consumed. 

The faint green hue seen in the WISE composite is due to the "halo" of old stars that encircles the central region of the galaxy. The Splinter Galaxy is about 53 million light-years away in the constellation Draco, and is nearly 200,000 light-years across.

Barnard's Galaxy, or IC 4895 or NGC 6822
Barnard's Galaxy is known as a dwarf for its small size -- it has only about one percent of the mass of the Milky Way. The galaxy's irregular shape is dominated by a central bar of stars, whose appearance resembles that of the nearby satellite galaxy, the Large Magellanic Cloud. 

It is therefore given a classification of "Magellanic type." The prominent yellow blobs seen against the blue stellar background are sites of recent star formation. Barnard's Galaxy is 1.6 million light-years away in the Sagittarius constellation, and is about 7,000 light-years across.

Hidden Galaxy, or IC342
Sometimes called the Hidden Galaxy, this spiral beauty is shrouded behind our own galaxy, the Milky Way. Stargazers and professional astronomers have a hard time seeing the galaxy through the Milky Way's bright band of stars, dust and gas. 

WISE's infrared vision cuts through this veil, offering a crisp view. The nucleus is very bright at infrared wavelengths, due to a burst of new stars forming there. The Hidden Galaxy is located about 10 million light-years away in the constellation Camelopardalis, and is 62,000 light-years across.
The colours used in all of these image represent specific wavelengths of infrared light. Blue and cyan represent 3.4- and 4.6-micron light, mainly emitted by hot stars. Green and red represent 12- and 22-micron wavelengths, primarily light emitted from warm dust.

Image Credit: NASA/JPL-Caltech/WISE Team

NASA's Hubble Finds Rare 'Blue Straggler' Stars in Milky Way

NASA's Hubble Space Telescope has found a rare class of oddball stars called blue stragglers in the hub of our Milky Way, the first detected within our galaxy's bulge.

Blue stragglers are so named because they seemingly lag behind in the aging process, appearing younger than the population from which they formed. While they have been detected in many distant star clusters, and among nearby stars, they never have been seen inside the core of our galaxy.

It is not clear how blue stragglers form. A common theory is that they emerge from binary pairs. As the more massive star evolves and expands, the smaller star gains material from its companion. This stirs up hydrogen fuel and causes the growing star to undergo nuclear fusion at a faster rate. It burns hotter and bluer, like a massive young star.

Woodpecker Fills Antenna With Acorns [VIDEO]

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NASA Messenger Mercury: Image

At first glance, Mercury seems remarkably similar to the Moon - a grey, airless world dominated by craters.

As the smallest of the four terrestrial planets, Mercury cooled fairly rapidly, losing heat and slowing its geological activity several billion years ago.

Since then, the Sun's tidal forces have slowed Mercury's rotation so that it rotates three times in every two 88-day orbits around the Sun.

This unique arrangement means that most parts of Mercury only see a sunrise every two years, and creates an extreme range of temperatures, varying from -190ºC (-342ºF) to 430ºC (806ºF).

Picture: Image produced by NASA/Johns Hopkins University Applied Physics Laboratory/Arizona State University/Carnegie Institution of Washington. Image reproduced courtesy of Science/AAAS

Mars: Victoria Crater in Meridiani Planum

At 730 m (2,400 ft) wide, Victoria crater is a relatively insignificant feature in the landscape of the Meridiani Planum region close to the Martian equator.

However, it is one of the most intensively studied regions of the red planet's surface thanks to its location close to the landing site of the NASA's Opportunity Mars Rover.

Photographs from the Mars Reconnaissance Orbiter satellite have helped to put Victoria in context - they reveal a crater edged with numerous landslips and filled with fine Martian dust that piles up in dunes near the centre of its floor.

Picture: NASA/ JPL/Cornell

Stuck Solar Array Threatens Telesats South America Push

The Telstar 14R/Estrela do Sul 2 telecommunications satellite launched May 21 has failed to deploy one of its two solar arrays, a defect that, if permanent, will curtail owner Telesat Canada’s growth plans in South America, Telesat and satellite builder Space Systems/Loral announced May 25.

The satellite’s south array has fully deployed and is providing power, but the north array has not. Ottawa-based Telesat said that if the situation is not corrected, Telstar 14R will be able to provide “at a minimum” the same level of service of the satellite it is replacing, the Telstar 14/Estrela do Sol spacecraft launched in 2004.

Telesat has been counting on Telstar 14R to do much more than replace its predecessor at 63 degrees west. Arriving on station at a time of substantial unmet demand for satellite bandwidth in Latin America, particularly Brazil, the satellite was seen as a source of growth for Telesat. The company is weighing several options for selling its equity, either through an outright purchase by private-equity investors, or through an initial public offering of stock.

In a May 5 conference call with investors, Telesat Chief Executive Daniel S. Goldberg said Telstar 14 is just about filled given the strong demand in Latin America, and that Telstar 14R’s arrival would enable Telesat to pick up new business.

Telstar 14R has the equivalent of 58 Ku-band transponders, compared to 41 on Telstar 14.

The satellite, a Loral 1300 model, weighed about 5,000 kilograms at launch and was expected to operate for at least 15 years in orbit. It was launched aboard an International Launch Services (ILS) Proton rocket from Russia’s Baikonur Cosmodrome in Kazakhstan, a launch that ILS and Telesat said went smoothly.

Palo Alto, Calif.-based Space Systems/Loral said in a May 25 statement that it is “analyzing data from the satellite to determine what steps can be taken to maximize the satellite’s lifespan and capability.”

NASA's Kepler: Astounding haul of multiple-planet systems

NASA’s Kepler spacecraft is proving itself to be a prolific planet hunter. Within just the first four months of data, astronomers have found evidence for more than 1,200 planetary candidates.

Of those, 408 reside in systems containing two or more planets, and most of those look very different than our solar system.

In particular, the Kepler systems with multiple planets are much flatter than our solar system. They have to be for Kepler to spot them. Kepler watches for a planet to cross in front of its star, blocking a tiny fraction of the star’s light.

By measuring how much the star dims during such a transit, astronomers can calculate the planet’s size, and by observing the time between successive events they can derive the orbital period – how long it takes the planet to revolve around its star.

To see a transit, the planet’s orbit must be edge-on to our line of sight. To see multiple transiting planets, they all must be edge-on (or nearly so).

“We didn’t anticipate that we would find so many multiple-transit systems. We thought we might see two or three. Instead, we found more than 100,” said Smithsonian astronomer David Latham (Harvard-Smithsonian Center for Astrophysics).

Latham presented the findings today in a press conference at the 218th meeting of the American Astronomical Society.

In our solar system, some planet orbits are tilted by up to 7 degrees, meaning that an alien astronomer looking for transits wouldn’t be able to detect all eight planets. (In particular, they would miss Mercury and Venus.) The systems spotted by Kepler are much flatter, with orbits tilted less than 1 degree.

Why are they so flat? One clue comes from the planets themselves. The multiplanet systems found by Kepler are dominated by planets smaller than Neptune. They lack Jupiter-sized gas giants. Scientists believe that a gas giant’s powerful gravity tends to disrupt planetary systems, tilting the orbits of neighboring worlds.

“Jupiters are the 800-pound gorillas stirring things up during the early history of these systems,” explained Latham. “Other studies have found plenty of systems with big planets, but they’re not flat.”

Multiple-planet systems may offer a chance for confirming the densities of small, rocky worlds. The more massive a planet, the easier it is to detect using radial velocity measurements (essentially the star’s wobble as a planet’s gravity tugs it).

Earth-sized worlds in Earth-sized orbits aren’t massive enough to make a radial velocity signal that’s detectable with present technology.

ESA: Sentinel-1offers new ways of monitoring crops

A simulated Sentinel-1 image of Indian Head in Canada, one the three major sites investigated intensively during the AgriSAR 2009 campaign.

The various colours reflect the radar brightness of each field at different times.

Fields growing the same crops generally display the same colour radar data.

These data can therefore be used for crop classification.

Credits: ESA/MDA

Sentinel-1
Sustainable food production remains a pressing challenge, so scientists have been assessing the potential of the future Sentinel-1 mission to deliver new methods of monitoring crops grown around the world from space.

Sentinel-1, expected to be launched in 2013, is one of the five missions that ESA is developing for Europe's Global Monitoring for Environment and Security programme.

While the design of the Sentinel-1 mission is primarily based on marine applications such as ship detection and sea-ice mapping, there is increasing interest in using it for land applications.

To this end, ESA carried out the major international AgriSAR field campaign in 2009 as part of the mission's preparatory activities. 

Messenger: Mercury Surface

MLA coverage (left) of Mercury as May 21, 2011, shown as a polar orthographic projection extending to the equator. 

The altimetric profile (obtained on April 30, 2011) for the MLA track highlighted on the left is shown in detail on the right. 

The length of this profile is about 6000 km (or about 3700 miles).

MESSENGER’s Mercury Laser Altimeter (MLA) in its first 2 months of operation has already built up a grid of ground tracks that span most of Mercury’s surface north of the equator (picture).

These data will provide a very good measure of the shape of the planet’s northern hemisphere. The shape of a planet carries a record of all of the interior dynamical and geological processes that have modified the surface.

Signals from MLA’s laser reflected from the surface can be recovered whenever the spacecraft is within a range of about 1,800 km (about 1,100 miles) from the ground track.

Because of MESSENGER’s highly elliptical orbit, MLA can make measurements only for a portion of each orbit approximately centered on closest approach (Figure 2).

By far the most accurate instrument on MESSENGER for determining the shape of Mercury, MLA is yielding precise topographic measurements of Mercury’s northern hemisphere, but other techniques must be employed to measure the shape of the southern hemisphere.

These complementary techniques include the creation of three-dimensional terrain models from stereo images obtained with MESSENGER’s Mercury Dual Imaging System (MDIS), radio occultations, and MDIS profiling of the planet’s

Spacewalkers Andrew Feustel and Mike Fincke

Spacewalkers Andrew Feustel and Mike Fincke
Image above: STS-134 Mission Specialists Andrew Feustel and Mike Fincke participate in the mission's third spacewalk as construction and maintenance continue on the International Space Station. Photo credit: NASA

The crew members for space shuttle Endeavour's STS-134 mission are Commander Mark Kelly, Pilot Gregory H. Johnson and Mission Specialists Michael Fincke, Greg Chamitoff, Andrew Feustel and European Space Agency astronaut Roberto Vittori.

Astronauts Drew Feustel and Mike Fincke completed a six-hour, 54-minute spacewalk at 8:37 a.m. EDT.

They completed all planned tasks, installing cables to increase redundancy for the power system on the Russian segment of the station, completing the external wireless antenna system work Feustel and Greg Chamitoff began during the first spacewalk, and installing a power and data grapple fixture to Zarya. The fixture will allow the station's robotic arm to "walk" to the Russian segment, extending its reach by using that grapple fixture as a base.

This was the third of the four STS-134 spacewalks, for a mission total of 21 hours 20 minutes. It was the 247th spacewalk conducted by U.S. astronauts, the 117th from space station airlocks, and the 158th in support of space station assembly and maintenance, totaling 995 hours, 13 min. If all goes as planned, the 1,000th hour of space station assembly and maintenance will be logged Friday.

It was Feustel's sixth spacewalk for a total time of 42 hours and 18 minutes; he is 14th on the all-time list. This was his last spacewalk for the mission.

It was Fincke's eighth spacewalk for a total time of 41 hours and 13 minutes; he is tied for 18th on the all-time list with cosmonaut Talgat Musabayev. On Friday, when Fincke conducts the mission's final spacewalk, he also will be doing so on the same day he will surpass Peggy Whitson as the U.S. astronaut who has spent the most days in space. She spent 377 days in space.

NASA Television will air a mission status briefing with STS-134 Lead Flight Director Derek Hassmann and STS-134 Lead Spacewalk Officer Allison Bolinger to discuss the spacewalk. The briefing is scheduled to begin at 10 a.m.

NASA Soyuz Expedition 28: Crew Departs Star City

Expedition 28 crew members, Flight Engineer Satoshi Furukawa, left, Soyuz commander Sergei Volkov, centre, and Flight Engineer Mike Fossum, answer reporters questions during a crew departure press conference held on the grounds of the Gagarin Cosmonaut Training Center, Wednesday, May 25, 2011 in Star City, Russia.

The crew later departed for Baikonur, Kazakhstan in preparation for their June launch onboard a Soyuz rocket.

Photo Credit: (NASA/Bill Ingalls)

NASA Flame Extinguishing Experimen: Combustion of liquid fuel in microgravity

Because of the absence of gravity, fuels burning in space behave very differently than they do on Earth.

In this image, a 3-millimeter diameter droplet of heptane fuel burns in microgravity, producing soot.

When a bright, uniform backlight is placed behind the droplet and flame and recorded by a video camera, the soot appears as a dark cloud. Image processing techniques can then quantify the soot concentration at each point in the image.

On the International Space Station, the Flame Extinguishing Experiment examines the combustion of such liquid fuel droplets.

This colorised gray-scale image is a composite of the individual video frames of the backlit fuel droplet.

The bright yellow structure in the middle is the path of the droplet, which becomes smaller as it burns. Initial soot structures (in green) tend to form near the liquid fuel.

These come together into larger and larger particles which ultimately spiral out of the flame zone in long, twisting streamers.

Image Credit: NASA

The illusion: Mask of Love

Face_lovers.jpg
(Image: Gianni Sarcone, Courtney Smith & Marie-Jo Waeber)

At first, it looks like a pensive face in a Venetian mask (see photo above) but take a closer look at its features and you'll see that it conceals a couple kissing.

Aptly named Mask of Love, the illusion was created by Gianni Sarcone, Courtney Smith and Marie-Jo Waeber from Archimedes' Laboratory in Genoa, Italy, after discovering the blurry photograph.

NASA’s Mars Rover: Farewell Spirit, you served us well

NASA’s Spirit rover looks like it is going to fade away due to the harsh Martian winter.

The space agency said it has ended attempts to gain contact with the Spirit rover.

According to NASA, the Spirit rover last communicated on March 22, 2010. NASA said it will make one final attempt to day.

The hope was that the Spirit may reawaken once it got more solar energy. It appears that components were damaged without its heaters.

NASA statement:
Engineers’ assessments in recent months have shown a very low probability for recovering communications with Spirit.

Communications assets that have been used by the Spirit mission in the past, including NASA’s Deep Space Network of antennas on Earth, plus two NASA Mars orbiters that can relay communications, now are needed to prepare for NASA’s Mars Science Laboratory mission. MSL is scheduled to launch later this year.

Spirit landed in early 2004 amid much fanfare. The rover was designed to last three months. Spirit’s twin, Opportunity, continues to explore Mars.

The Future
NASA is planning to launch a new rover called Curiosity in November.

Spirit has returned a ton of data to NASA about Mars, including photos, soil samples, thermal readings and other items.

Meanwhile, NASA has captured Spirit’s entire project log via an update page. The last year has been disappointing, but Spirit had an extended life and notched up a lot of small victories.

ISS Image: Soyuz shuttle leaving for Earth

Astronaut Paolo Nespoli can be seen taking pictures of the International Space Station and space shuttle Endeavour, through the window of the Soyuz capsule as he heads back to Earth.

This image was taken from the International Space Station by astronaut Ron Garan.

Picture: AP / NASA / RON GARAN

Tuesday, May 24, 2011

NASA Astronauts to try spacewalk 'hokey pokey'

US astronauts on Tuesday will try out a new set of exercises to prepare them for the change in pressure they encounter on their spacewalk outside the International Space Station, NASA said.

Known in part as the "slow motion hokey pokey," the exercises are designed to prevent decompression sickness known as the bends, the type scuba divers can face if they rise to the surface too quickly, the US space agency said.

To prevent the bends, astronauts typically get their spacesuits on early and take a series of steps, such as breathing pure oxygen through a mask, in order to get rid of nitrogen in the bloodstream.

Otherwise they could form gas bubbles in their bodies as they stroll in space, causing pain in the joints, or in rare cases, paralysis or death.

On the eve of the past 70 spacewalks, astronauts have camped out overnight in an airlock where the pressure is 10.2 pounds per square inch, in between that of the space station (around 14 psi) and the spacesuits (about 4 psi).

The new combination of breathing and low-effort exercises, known officially as ILE, or in-suit light exercise prebreathe protocol, aims to skip the campout but still gradually purge nitrogen from the bloodstream.

On a perceived exertion scale of six to 20 -- where six is "sitting there not doing anything, we are asking crew members to target seven," said lead spacewalk officer Allison Bollinger.

"This is equivalent to walking a mile in about 70 minutes, so this is very light exercise," she explained.

Bollinger showed reporters a video of astronauts in their spacesuits, kicking one leg from the knee down, followed by a long pause, then the other leg kicking, then another long pause, then a brief flailing of the arms.

"This is what we call the slow motion hokey-pokey," she said.

After that they are scheduled to do a "50-minute resting pre-breathe," though they will break up that resting session into two separate parts for extra tests this time around.

It's a far cry from past days when astronauts would strap on an oxygen mask and pedal furiously on a stationary bicycle before stepping out on a spacewalk.

"The effort all along has been to save time and go out earlier, and to help conserve oxygen," explained Kylie Clem, a spokeswoman for mission control in Houston.

But like anyone who tries to squeeze in some exercise before work, the effort has already fallen short of one of its main goals.

Eliminating range anxiety in Electric Cars

The ultimate cure for the “range anxiety” that afflicts electric car drivers worried they’ll run out of juice mid-trip could come when road-embedded wireless charging strips power up cars as they motor down the highway.

HaloIPT, a London-based developer of cable-free charging systems, took a small step in that direction yesterday, as it signed an agreement with another UK company, Chargemaster plc, to manufacture HaloIPT’s wireless transmitting pads.

On the surface, the deal is not huge- Chargemaster will make “dozens” of charging pads, according to a joint press release. But the “strategic partnership” is significant because it calls for Chargemaster to help develop and deploy a wireless charging infrastructure and billing system in Britain.

Chargemaster is already the largest provider of cabled charging bays in the UK, where it has installed posts in parking lots, supermarkets and other public spaces. It has done the same across Europe, where it has about 500 charging posts. It should be a key ally for HaloIPT, a company owned by international engineering firm Arup, by the University of Auckland in New Zealand, and by Australian venture capital firm Trans-Tasman Commercialization.

Lightning Strikes Grimsvotn volcano






Lightning strikes in the erupting Grimsvotn volcano, as seen from Sprengisandur, in the central highlands of Iceland, 60km away from the eruption...

Picture: ORVAR ATLI THORGEIRSSON / BARCROFT MEDIA

Stratospheric UAV Payloads Provide New Ways to Chase Terrorism





This illustration shows the Persistent UAVs networking, and collaborating with a satellite while providing video surveillance services.
The classic special operations success in hunting and killing Osama bin Laden was certainly supported by Unmanned Aerial Vehicles (UAVs). That was undoubtedly a difficult operation given the limited endurance by conventional UAVs compared to the months of observation necessary. It's quite likely that ground-based surveillance capabilities were both more relevant and far riskier to American intelligence operatives in Pakistan.

In the near future, payloads flying on Stratospheric UAVs will be far more relevant to such operations than will today's Conventional UAVs, even with similar payload capabilities.

This is one of the conclusions of a new "Stratospheric UAV Payloads - Markets and Technologies Forecast 2012-2021", available on ASDReports.com.

The new report examines, analyses and predicts the evolution of technologies, markets and outlays for the payloads that will serve aboard extremely enduring or persistent UAVs flying above the Jet Stream. While flying in the atmosphere, they will behave much like stationary satellites.

Today, persistence means maintaining a Predator orbit by replacing the on-station aircraft once or twice a day. That's a huge effort requiring at least three functioning aircraft and all their support.

They also risk giving away the operator's intent, a strong motivation to risk people hiding nearby rather than flying unmanned aircraft constantly. Conventional UAVs are hard to detect when flying very high, but certainly not impossible. Their presence over weeks to months will certainly be noticed.

Field of Regard or camera coverage area is another problem. Flying 20 - 30,000' above the ground, a camera can only be used over a relatively small footprint. Double that altitude and the footprint increases by a factor of four. In the illustration, you can see Persistent UAVs networking, and collaborating with a satellite while providing video surveillance services.

So, the next hunt for an elusive, very high value targets may benefit from Stratospheric UAV Payloads flying on the new Stratospheric UAVs being prototyped now. Those payloads will revolutionise the hunt by flying at twice Conventional UAV altitudes to see areas at least four times as large, all while being much harder to detect and remaining on-station for months or longer.

Grimsvotn May 2011 eruption seen by the US GOES-13 satellite




The start of the Grimsvotn May 2011 eruption as seen by the US GOES-13 satellite.

The volcanic plume was apparent on the very edge of GOES-east imagery, which can be seen in the animation of visible channel images. 

The oblique viewing angle from this satellite helped to emphasise the large vertical extent of the erupted plume. 

Credits: Cooperative Institute for Meteorological Satellite Studies.

Monday, May 23, 2011

NASA: Soyuz TMA-20 Returns to Earth

The Soyuz TMA-20 spacecraft is seen as it lands with Expedition 27 Commander Dmitry Kondratyev and Flight Engineers Paolo Nespoli and Cady Coleman in a remote area southeast of the town of Zhezkazgan, Kazakhstan, on Tuesday, May 24, 2011.

NASA Astronaut Coleman, Russian Cosmonaut Kondratyev and Italian Astronaut Nespoli are returning from more than five months onboard the International Space Station where they served as members of the Expedition 26 and 27 crews.

NASA Astronaut Coleman climbs out of the Soyuz capsule.

Photo Credit: NASA/Bill Ingalls

Soyuz Module Undocks and Astronauts Land safely



Soyuz module undocks and backs away from the ISS. On board are 3 astronauts, returning to Earth.


A view of the Soyuz module from the ISS and in the foreground is the NASA Shuttle Endeavour on it's last mission.


The Soyuz module lands safely and awaits attention on the ground in Kazakhstan.



ESA astronaut Paolo Nespoli (@Astro_Paolo) and astronaut Dmitri Kondratyev, pose for an historic photo and experience the pull of Earth's gravity, once more.


Expedition 27 crew, @astro_paolo, @Astro_Cady and Dmitri Kondratyev at landing site after 159 days in space.

NASA ISS EVA: Feustal Finishes EVA Space walk

Astronaut Andrew Feustel reenters the space station after completing n 8-hour, 7-minute spacewalk at 10:12 a.m. EDT Sunday, May 22, 2011.

He and fellow spacewalker Mike Fincke completed this, the second of the four STS-134 spacewalks, for a mission total of 14 hours 26 minutes.

It was the 246th spacewalk conducted by U.S. astronauts, the 116th from space station airlocks, and the 157th in support of space station assembly and maintenance.

It was Feustel's fifth spacewalk and Fincke's seventh spacewalk.

Image Credit: NASA

ESA Galileo: Europe prepares for October launch

The European Space Agency (ESA), Arianespace and the European Commission announced today that the launch of the first two satellites of Europe's global navigation satellite system is planned to take place on 20 October.

This will be the first of a series of Galileo satellite launches by Arianespace from Europe's Spaceport in French Guiana.

The announcement follows a detailed review held on 12 May, under the chairmanship of the Director General of the European Space Agency (ESA) and with the participation of Arianespace and industrial prime contractors, which concluded that the space and ground elements will be ready for a launch in October.

The two Galileo satellites will be deployed using a Soyuz launcher. The October launch will mark the inaugural Soyuz flight from its new launch facilities in French Guiana, built in the framework of a programme of the European Space Agency.


Soyuz from French Guiana

Soyuz launching from French Guiana
Jean-Jacques Dordain, Director General of ESA, pointed out the significance of this launch: "The October launch will be a perfect example of European and international cooperation. On one side we will have the first operational Galileo satellites in orbit, resulting from the cooperation between the European Union and ESA.

"On the other side, this is the first launch of Soyuz from French Guiana, a programme made possible through the cooperation between ESA and Russia."

"Arianespace is both proud and honoured to be contributing to this innovative project, reflecting the innovative technologies that are constantly being developed in Europe for the benefit of all citizens," said Jean-Yves Le Gall, Chairman and CEO of Arianespace.

Grimsvoetn Volcanic Ash


An image released by NASA shows smoke billowing from Grimsvoetn, Iceland's most active volcano. Authorities shut Iceland's airspace after the country's most active volcano began spewing ash cloud 20 kilometres into the sky, raising fears of a repeat of last year's flights chaos.

Picture: AFP/NASA

This aerial view shows the volcano Grimsvoetn in the south-east of Iceland, which began to erupt on Saturday

Picture: EPA

Gas-powered diesel engine may double fuel efficiency

Recently, it seems like car engine innovation has become about moving away from the internal combustion engine and toward more environmentally-friendly alternatives like electric motors.

Unfortunately, the truth is gasoline engines, which have been with us for well over a century, aren’t headed for the junk yard any time soon.

With that in mind, engineers at the U.S. Department of Energy’s Argonne National Laboratory have been hard at work on a project to improve the fuel efficiency of gas-powered engines.

Their approach has been to figure out a way to take advantage of the highly fuel efficient technologies found in diesel engine while also keeping harmful emissions to a minimum.

So far, the result is a gas-powered prototype that’s cleaner than a diesel engine and almost twice as efficient as a typical gasoline-powered engine.

The major difference between gas and diesel engines is the technology used to ignite the fuel. Gasoline engines are designed to mix air with the fuel prior to compressing and igniting the mixture. But in a diesel engine, the air is compressed first and then the fuel is injected.

This makes it so the air is hot enough to ignite the fuel without spark plugs or the use of an air-restricting throttle, which allows the fuel to mix more evenly with air so that more of can be burned.

The drawback is that the process produces unacceptably high levels of nitrous oxides and soot. This is because diesel fuel is so easy to auto-ignite that it begins to react the moment it’s introduced—long before all of the fuel is in the chamber.

Nitrous oxides are created when the flame jet created by the diesel injection burns so hot that nearby nitrogen and oxygen molecules in the air start to break apart and react. Meanwhile, soot is created inside the hot jet because the fuel doesn’t have enough oxygen to fully burn, creating soot instead.

“What we want to do is combine the efficiency of diesel with the cleanliness of gas,” said Steve Ciatti, an engineer working on the project. “So we lose the throttle and spark plugs, because those create inefficiencies. We start with a diesel engine and inject gasoline instead.

Sunday, May 22, 2011

NASA/University Japan Quake Study Yields Surprises

An overhead model of the estimated fault slip due to the earthquake.

The fault responsible for this earthquake dips under Japan, starting at the Japan Trench indicated by the barbed line, the point of contact between the subducting Pacific Plate and the overriding Okhotsk Plate.

The magnitude of fault slip is indicated by the colour and the contours, at 8-meter intervals.

The question mark indicates the general region where researchers currently lack information about future seismic potential.

Credit: Mark Simons/Caltech Seismological Laboratory

NASA Chandra: Capture Best-Ever Snapshot of Black Hole Jets

Merging X-ray data (blue) from NASA's Chandra X-ray Observatory with microwave (orange) and visible images reveals the jets and radio-emitting lobes emanating from Centaurus A's central black hole.

Credit: ESO/WFI (visible); MPIfR/ESO/APEX/A.Weiss et al. (microwave); NASA/CXC/CfA/R.Kraft et al. (X-ray)

NASA Galaxy Evolution Explorer: Confirms Nature of Dark Energy

A five-year survey of 200,000 galaxies, stretching back seven billion years in cosmic time, has led to one of the best independent confirmations that dark energy is driving our universe apart at accelerating speeds. The survey used data from NASA's space-based Galaxy Evolution Explorer and the Anglo-Australian Telescope on Siding Spring Mountain in Australia.

The findings offer new support for the favored theory of how dark energy works - as a constant force, uniformly affecting the universe and propelling its runaway expansion. They contradict an alternate theory, where gravity, not dark energy, is the force pushing space apart. According to this alternate theory, with which the new survey results are not consistent, Albert Einstein's concept of gravity is wrong, and gravity becomes repulsive instead of attractive when acting at great distances.

"The action of dark energy is as if you threw a ball up in the air, and it kept speeding upward into the sky faster and faster," said Chris Blake of the Swinburne University of Technology in Melbourne, Australia. Blake is lead author of two papers describing the results that appeared in recent issues of the Monthly Notices of the Royal Astronomical Society.

"The results tell us that dark energy is a cosmological constant, as Einstein proposed. If gravity were the culprit, then we wouldn't be seeing these constant effects of dark energy throughout time."

Dark energy is thought to dominate our universe, making up about 74 percent of it. Dark matter, a slightly less mysterious substance, accounts for 22 percent. So-called normal matter, anything with atoms, or the stuff that makes up living creatures, planets and stars, is only approximately four percent of the cosmos.

The idea of dark energy was proposed during the previous decade, based on studies of distant exploding stars called supernovae. Supernovae emit constant, measurable light, making them so-called "standard candles," which allows calculation of their distance from Earth. Observations revealed dark energy was flinging the objects out at accelerating speeds.

NASA ISS EVA: Astronauts encounter bolt trouble

A spacewalking astronaut ran into trouble Sunday while trying to lubricate a joint in the life-sustaining solar power system of the International Space Station, losing one bolt and getting a washer stuck in a crevice.

Mission Control told veteran spaceflier Mike Fincke that he'd have to settle for a partial lube job, after the bolts holding down covers on the joint started popping off unexpectedly.

The spacewalk — the second of four scheduled duringt the shuttle Endeavour's final space station visit — started out well, with Fincke and partner Andrew Feustel topping off a leaky radiator line.

They successfully added ammonia to the space station's coolant system, after rerouting jumper cables and opening valves. One line leaks slightly, and the astronauts needed to recharge it.

Ammonia is extremely hazardous, and the two did their best to avoid contaminating their spacesuits while replenishing the system with about 5 pounds of the substance.

Some frozen ammonia flakes floated toward Feustel as well as a small icy chunk, but he didn't think any of it got him.

Fincke moved on to preventive maintenance on the massive joint that rotates the space station's solar wings on the left side. He was removing his first cover when a bolt popped out and got away from him.

He caught it, but another bolt ended up floating away, and a washer got stuck between the cover and an attachment.

Mission Control worried that the washer might get into the gear mechanisms of the joint and damage them.

Fincke was advised to use "gentle backhand sweeping motions" to get the washer away from the gears, and the astronaut replied he could try to coax it out.

All this came as a surprise, and Mission Control later told the astronauts that the washers might be bent and flimsy from previous repair efforts.

"Sorry you're having such a hard time with those bolts, buddy," Feustel called out to Fincke.

"Yeah, man, I was being really careful, too," replied Fincke, one of NASA's most experienced spacemen.

NASA ISS EVA: All in a Day's Work

Astronaut Greg Chamitoff made his way inside the station as Andrew Feustel awaited his turn at the end of the STS-134 mission's first spacewalk.

The Endeavour astronauts completed a 6-hour, 19-minute spacewalk at the International Space Station Friday, May 20, 2011, retrieving materials experiments and installing another, and installing an antenna.

They also installed a light on a station handcart, set up equipment for adding ammonia to a cooling loop and installed a cover on a rotary joint for solar arrays.

Image Credit: NASA

NASA AMS - Exploring the Wonders of the Universe

The newly-installed Alpha Magnetic Spectrometer-2 is visible at center of the International Space Station's starboard truss.

The Alpha Magnetic Spectrometer, or AMS, is the largest scientific collaboration to use the orbital laboratory.

This investigation is sponsored by the U.S. Department of Energy and made possible by funding from 16 nations.

Led by Nobel Laureate Samuel Ting, more than 600 physicists from around the globe will be able to participate in the data generated from this particle physics detector. The mission of the AMS is, in part, to seek answers to the mysteries of antimatter, dark matter and cosmic ray propagation in the universe.

Image Credit: NASA

Iceland Volcano Erupts: Reykjavík-Keflavik International Airport Closed

Iceland’s most active volcano began erupting over the weekend, sending billows of ash up to 11 miles into the air on Sunday, and prompting the island nation to close its main international airport to commercial air traffic as a precaution, aviation officials said.

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The Icelandic authorities said that as of 8:30 a.m. local time, Reykjavík-Keflavik International Airport was closed to all inbound and outbound air traffic.

"The ash is covering up all of Iceland,” said Hjordís Gudmundsdottir, a spokeswoman for Isavia, Iceland’s air navigation services provider. "We are trying to identify some holes in it and to use them to allow some flights, but it’s not looking very good right now.”

Overnight, Iceland’s civil protection agency said it had imposed a no-fly zone of 120 nautical miles around the Grimsvötn volcano in southeast Iceland.

Meteorologists said the prevailing winds were expected to blow the volcanic ash in a generally westward direction through the rest of this week — most likely avoiding a repeat of the widespread shutdowns of European airports that grounded more than 100,000 flights in April and May 2010.

Eurocontrol, the Brussels-based agency that coordinates air traffic management across the region, said it was monitoring the situation but it appeared there would be no wider threat to trans-Atlantic or European air travel at least for the next 24 hours.

Ms. Gudmundsdottir of Isavia said Iceland’s aviation authorities planned an update on the situation at around noon. For the time being, Iceland’s three other international airports remained open, she said.Iceland officials said roughly 30 flight arrivals and departures had originally been scheduled at Keflavik airport on Sunday.Iceland’s Met Office weather agency reported heavy ash fall near the volcano itself.

Grimsvötn, a volcano of 1,725 meters, is located beneath an uninhabited icecap, Vatnajokull, in southeast Iceland.

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The entire night sky

In this photograph provided by Nick Risinger of Skysurvey.org, the entire night sky is shown in a composite photograph made from more than 37,000 exposures taken in different locations all over the world.

Risinger traveled more than 60,000 miles by air and land and spent more than a year to produce the photo.

Picture: AP Photo/Skysurvey.org, Nick Risinger