Saturday, July 31, 2010

Four Planet Sunset

Saturday, July 31, 2010 0 comments

This mesmerizing sunset photo was taken from the summit of volcanic Mount Lawu, 3,265 meters above sea level, on July 21. The view looks west, toward the city lights of Surakarta (aka Solo), Central Java, Indonesia. Two other volcanic peaks, sharp Merapi (left) and Merbabu lie along the colorful horizon. Four planets shine in the twilight sky above them. Spread out near the plane of the ecliptic are Mercury, Venus, Mars, and Saturn, along with bright Regulus, alpha star of the constellation Leo. For help finding them, just put your cursor over the picture. In fact, these four planets still shine in western skies at sunset, with Venus, Mars, and Saturn grouped much more tightly this weekend and in early August. By August 12, a young crescent Moon will join the four planet sunset. 

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Friday, July 30, 2010

Eclipse on the Beach

Friday, July 30, 2010 0 comments

As the New Moon's shadow slid across the southern Pacific on July 11, people gathered along the white, sandy Anakena Beach on the north side of Easter Island to watch a total solar eclipse. The experience was captured in this tantalizing composite image, constructed from a sequence of 50 consecutive exposures. At their center is the totally eclipsed Sun surrounded by a shimmering solar corona. From the well chosen viewpoint, palm trees appear in silhouette against a darkened sky and the faint light reflected in the water. Of course, towering above the onlookers, at the boundaries of land, ocean, and sky are Moai, the island's mysterious monolithic statues

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Thursday, July 29, 2010

Sunset, Shadowrise

Thursday, July 29, 2010 0 comments

From central Australia, this serene 360 degree panorama follows a clear horizon as twilight began on May 28. At left, a bright western sky is still illuminated by the setting Sun. But sweeping right, toward a view centered on the countryside's dominating sandstone formation called Uluru or Ayers Rock, the sky takes on progressively darker hues and subtle colors. Behind Uluru is the shadow of planet Earth itself, a dark blue arch rising in the east. Cast through the dense atmosphere and still close to the horizon, Earth's long shadow is bounded above by a pinkish glow or antitwilight arch. Known as the Belt of Venus, the lovely color of the antitwilight arch is due to backscattering of reddened light from the setting Sun. On that night, a nearly full Moon also rose above Earth's shadow in the eastern sky.

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Wednesday, July 28, 2010

The Trifid Nebula is Stars and Dust

Wednesday, July 28, 2010 1 comments

Unspeakable beauty and unimaginable bedlam can be found together in the Trifid Nebula. Also known as M20, this photogenic nebula is visible with good binoculars towards the constellation of Sagittarius. The energetic processes of star formation create not only the colors but the chaos. The red-glowing gas results from high-energy starlight striking interstellar hydrogen gas. The dark dust filaments that lace M20 were created in the atmospheres of cool giant stars and in the debris from supernovae explosions. Which bright young stars light up the blue reflection nebula is still being investigated. The light from M20 we see today left perhaps 3,000 years ago, although the exact distance remains unknown. Light takes about 50 years to cross M20

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Tuesday, July 27, 2010

The Milky Way Over Bryce Canyon

Tuesday, July 27, 2010 0 comments

What are those strange rock structures? They are towers and walls of sedimentary rock that are particularly plentiful in Bryce Canyon in Utah, USA. The rock columns may rise higher than 50 meters and are called hoodoos. On the far left is Thor's Hammer, perhaps the most famous hoodoo. The tall rock columns were carved, most typically, when a unusually dense cap of rock provided a layer of protection to rock underneath from rain-based erosion. In the above panoramic picture taken earlier this month and compressed horizontally, the foreground rocks were momentarily illuminated by a roving spotlight. Visible in the background are a few water clouds a few kilometers away hovering over the nearby Earth. Visible well beyond that are thousands of individually discernible stars averaging a few hundred light years away in the nearby Milky Way Galaxy. Far in the distance lie billions of stars that are thousands of light years away and compose the faintly glowing arch that is the visible central band of the flat disk of our Milky Way. Over many years, wind and rain will eventually cause the tops of the hoodoos to topple, whereafter the underlying column will likely completely erode away. 

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Monday, July 26, 2010

Lutetia: The Largest Asteroid Yet Visited

Monday, July 26, 2010 0 comments

As humans explore the universe, the record for largest asteroid visited by a spacecraft has increased yet again. Earlier this month, ESA's robotic Rosetta spacecraft zipped past the asteroid 21 Lutetia taking data and snapping images in an effort to better determine the history of the asteroid and the origin of its unusual colors. Although of unknown composition, Lutetia is not massive enough for gravity to pull it into a sphere. Pictured above on the upper right, the 100-kilometer across Lutetia is shown in comparison with the other nine asteroids and four comets that have been visited, so far, by human-launched spacecraft. Orbiting in the main asteroid belt, Lutetia shows itself to be a heavily cratered remnant of the early Solar System. The Rosetta spacecraft is now continuing onto comet Churyumov-Gerasimenko where a landing is planned for 2014. 

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Sunday, July 25, 2010

Happy People Dancing on Planet Earth

Sunday, July 25, 2010 0 comments

What are these humans doing? Dancing. Many humans on Earth exhibit periods of happiness, and one method of displaying happiness is dancing. Happiness and dancing transcend political boundaries and occur in practically every human society. Above, Matt Harding traveled through many nations on Earth, started dancing, and filmed the result. The video is perhaps a dramatic example that humans from all over planet Earth feel a common bond as part of a single species. Happiness is frequently contagious -- few people are able to watch the above video without smiling.

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Saturday, July 24, 2010

Diamond Ring and Shadow Bands

Saturday, July 24, 2010 0 comments

As the total phase of July 11's solar eclipse came to an end, sunlight streaming past the edge of the Moon's silhouette created the fleeting appearance of a glistening diamond ring in the sky. Seen through a thin cloud layer from the French Polynesian atoll of Hao it also produced remarkable shadow bands, flickering across the dramatic scene. Projected onto the cloud layer, the shadow bands are parallel to the sliver of sunlight emerging from behind the Moon's edge. Caused by turbulence in Earth's atmosphere refracting the sliver of sunlight, the narrow bands were captured in this brief, 1/400th second exposure. Shining through the cloud droplets, the sunlight also produced a luminous atmospheric corona, not to be confused with the solar corona seen during eclipse totality. The atmospheric corona is centered on the bright diamond of emerging sunlight.

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Friday, July 23, 2010

Messier 76

Friday, July 23, 2010 0 comments

"Nebula at the right foot of Andromeda ... " begins the description for the 76th object in Charles Messier's 18th century Catalog of Nebulae and Star Clusters. In fact, M76 is one of the fainter objects on the Messier list and is also known by the popular name of the "Little Dumbbell Nebula". Like its brighter namesake M27 (the Dumbbell Nebula), M76 is recognized as a planetary nebula - a gaseous shroud cast off by a dying sunlike star. The nebula itself is thought to be shaped more like a donut, while the box-like appearance of its brighter central region is due to our nearly edge-on view. Gas expanding more rapidly away from the donut hole produces the fainter loops of far flung material. The fainter material is emphasized in this composite image, highlighted by showing emission from hydrogen atoms in orange and oxygen atoms in complementary blue hues. The nebula's dying star can be picked out in the sharp false-color image as the blue-tinted star near the center of the box-like shape. Distance estimates place M76 about 3 to 5 thousand light-years away, making the nebula over a light-year in diameter.

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Thursday, July 22, 2010

The Meteor of 1860

Thursday, July 22, 2010 0 comments

Frederic Church (1826-1900), American landscape painter of the Hudson River School, painted what he saw in nature. And on July 20th, 1860, he saw a spectacular string of fireball meteors cross the Catskill evening sky, an extremely rare Earth-grazing meteor procession. From New York City, poet Walt Whitman (1819-1892) also wrote of the "... strange huge meteor procession, dazzling and clear, shooting over our heads" in his poem Year of Meteors (1859-60). But the inspiration for Whitman's words was forgotten. His astronomical reference became a mystery, the subject of scholarly debate until Texas State University physicists Donald Olson and Russell Doescher, English professor Marilynn Olson, and Honors Program student Ava Pope, located reports documenting the date and timing of the spectacular meteor procession. The breakthrough was spotting the connection with Church's relatively little-known painting. Fittingly, the forensic astronomy team's work was just published, on the 150th anniversary of the cosmic event that inspired both poet and painter. 

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Wednesday, July 21, 2010

The Crown of the Sun

Wednesday, July 21, 2010 0 comments

During a total solar eclipse, the Sun's extensive outer atmosphere, or corona, is an inspirational sight. Subtle shades and shimmering features that engage the eye span a brightness range of over 10,000 to 1, making them notoriously difficult to capture in a single photograph. But this composite of 7 consecutive digital images over a range of exposure times comes close to revealing the crown of the Sun in all its glory. The telescopic views were recorded from the Isla de Pascua (Easter Island) during July 11's total solar eclipse and also show solar prominences extending just beyond the edge of the eclipsed sun. Remarkably, features on the dim, near side of the New Moon can also be made out, illuminated by sunlight reflected from a Full Earth

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Tuesday, July 20, 2010

Lightning Over Athens

Tuesday, July 20, 2010 0 comments

Have you ever watched a lightning storm in awe? Join the crowd. Oddly, nobody knows exactly how lightning is produced. What is known is that charges slowly separate in some clouds causing rapid electrical discharges (lightning), but how electrical charges get separated in clouds remains a topic of much research. Lightning usually takes a jagged course, rapidly heating a thin column of air to about three times the surface temperature of the Sun. The resulting shock wave starts supersonically and decays into the loud sound known as thunder. Lightning bolts are common in clouds during rainstorms, and on average 6,000 lightning bolts occur between clouds and the Earth every minute. Pictured above, an active lightning storm was recorded over Athens, Greece earlier this month. 

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Monday, July 19, 2010

Dark River, Wide Field

Monday, July 19, 2010 0 comments

A Dark River of dust seems to run from our Galactic Center, then pool into a starfield containing photogenic sky wonders. Scrolling right will reveal many of these objects including (can you find?) the bright orange star Antares, a blue(-eyed) horsehead nebula, the white globular star cluster M4, the bright blue star system Rho Ophiuchi, the dark brown Pipe nebula, the red Lagoon nebula, the red and blue Trifid nebula, the red Cat's Paw Nebula, and the multicolored but still important center of our Galaxy. This wide view captures in exquisite detail about 50 degrees of the nighttime sky, 100 times the size of the full Moon, covering constellations from the Archer (Sagittarius) through the Snake Holder (Ophiuchus), to the Scorpion (Scorpius). The Dark River itself can be identified as the brown dust lane connected to Antares, and spans about 100 light years. Since the Dark River dust lane lies only about 500 light years away, it only appears as a bridge to the much more distant Galactic Center, that actually lies about 25,000 light years farther away. 

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Sunday, July 18, 2010

The Antennae Galaxies in Collision

Sunday, July 18, 2010 0 comments

Two galaxies are squaring off in Corvus and here are the latest pictures. But when two galaxies collide, the stars that compose them usually do not. That's because galaxies are mostly empty space and, however bright, stars only take up only a small amount of that space. During the slow, hundred million year collision, one galaxy can still rip the other apart gravitationally, and dust and gas common to both galaxies does collide. In this clash of the titans, dark dust pillars mark massive molecular clouds are being compressed during the galactic encounter, causing the rapid birth of millions of stars, some of which are gravitationally bound together in massive star clusters.

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Saturday, July 17, 2010

Galaxies in the River

Saturday, July 17, 2010 0 comments

 Large galaxies grow by eating small ones. Even our own galaxy practices galactic cannibalism, absorbing small galaxies that get too close and are captured by the Milky Way's gravity. In fact, the practice is common in the universe and illustrated by this striking pair of interacting galaxies from the banks of the southern constellation Eridanus (The River). Located over 50 million light years away, the large, distorted spiral NGC 1532 is seen locked in a gravitational struggle with dwarf galaxy NGC 1531, a struggle the smaller galaxy will eventually lose. Seen edge-on, spiral NGC 1532 spans about 100,000 light-years. Nicely detailed in this sharp image, the NGC 1532/1531 pair is thought to be similar to the well-studied system of face-on spiral and small companion known as M51.

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Friday, July 16, 2010

Shaping NGC 6188

Friday, July 16, 2010 0 comments
Dark shapes with bright edges winging their way through dusty NGC 6188 are tens of light-years long. The emission nebula is found near the edge of an otherwise dark large molecular cloud in the southern constellation Ara, about 4,000 light-years away. Formed in that region only a few million years ago, the massive young stars of the embedded Ara OB1 association sculpt the fantastic shapes and power the nebular glow with stellar winds and intense ultraviolet radiation. The recent star formation itself was likely triggered by winds and supernova explosions, from previous generations of massive stars, that swept up and compressed the molecular gas. A false-color Hubble palette was used to create this sharp close-up image and shows emission from sulfur, hydrogen, and oxygen atoms in red, green, and blue hues. At the estimated distance of NGC 6188, the picture spans about 200 light-years. 

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Thursday, July 15, 2010

Andes Sunset Eclipse

Thursday, July 15, 2010 0 comments

On July 11, after a long trek eastward across the southern Pacific Ocean, the Moon's shadow reached landfall in South America. In a total solar eclipse close to sunset, silhouetted Moon and Sun hugged the western horizon, seen here above the Andes mountains near the continent's southern tip. To enjoy a good vantage point, the photographer hiked to a windy spot about 400 meters above a lake, Lago Argentino, climbing into the picture after setting up his camera on a tripod. At left, the sky outside the shadow cone is still bright. Below, the lights of El Calafate, Patagonia, Argentina, shine by the lake shore.

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Wednesday, July 14, 2010

Functional/integration testing tool/frameworks for Flex/Flash based Rich Internet Applications.

Wednesday, July 14, 2010 0 comments
Given the emergence of Web 2.0, developers are pushing the limits of what browsers can do.  The original intent of a web browser was to deliver documents to end-users, not applications and thus, protocols and standards to meet this need where designed as such.  Request-Response patterns have moved from full-up page refresh models to incremental interactions similar to thick-client applications.  As users begin to demand more and more functionality delivered via web browsers, new challenges are emerging for developers.  To add further complexity, there is a lack of commonality between different browser vendors and browsers are being used in a manner in which they not originally intended to do.  Because of this, building browser-based applications with Flex is becoming a popular option for Rich Internet Application Development.

Rich Internet Applications (RIA) are web applications that run in web browsers but bypass the page refresh model just as AJAX does but require a Flash runtime.  Given the market penetration of the Flash Player in market-share leading browsers, this is highly available foundation to build solid RIA, especially in intranet applications which are commonly deployed within NASA.  The benefits of using Flex is that a developer can write and test code for one platform, the flash runtime, as opposed to a plethora of browsers/platforms which increase complexity, implementation time and drive up cost.

As with most software development, testing applications is very important to ensure software quality and user acceptance.  For Flex based applications, there are tools/frameworks readily available to do unit testing, but there are limited options for doing integration and functional testing.  For AJAX based RIA applications, released an excellent open source project called Selenium.  Selenium allows QA engineers to test modules written with AJAX technologies.  Given the popularity of the Flex application development, a good open source product to perform a similar function is lacking.

One COTS product that exists to do unctional/application testing is Mercury QuickTest Pro.  This is a valuable tool but very expensive.  Also, this tool only works in Internet Explorer as it is implemented as an ActiveX plug-in.

Another COTS product is iMacro from iOpus.  This is another available option that is far less expensive than Mercury QTP, but is not as robust.

Because of the widespread adoption of Flex based RIA development and the increasing importance of testing for applications, what is needed is a quality integration/functional testing framework such as Selenium for Flex RIA that is open-source and not tied to proprietary standards and protocols.

Relevant domain(s): Any Flex/Flash based RIA development effort within the agency.  Potentially the solution could address testing of Java and ActiveX applets as well but this is not as critical. 

Project(s) that would use the proposed tool/solution: Any Constellation project doing Flex web application development.  Currently, there are efforts underway within Constellation that are using Flex RIA approaches.

Current tool/solution in use and its shortcomings: Available tools to test Flash/Flex based apps are COTS, and tend to be very expensive such as Mercury QuickTest Pro.  Lesser expensive tools, such as iMacros tend to use non-robust techniques such as Image Recognition and XY coordinates to locate GUI elements.  Also, available tools tend to be proprietary.

Constraints that might influence the research work plan:
Timeline that the proposed tool/solution must support:
Language requirement: Flash, Flex, AIR

Size or scale requirements: Typically small to medium sized client applications

Required deliverables: A toolkit/framework similar to Selenium for recording macros to perform functional testing of Flex/Flash based applications

Other useful information: Flex Development and Programming services, Hire Flex Developers, Flex Programmers, Mobile Apps Programmer using Flex

Below is a selection of FLEX Test Point videos.

Test #1 - Droplet diameter of 4 mm, with no support fiber. Droplet deployment was successful with a brief burn before radiative extinction. An afterglow from condensing vapor cloud and scattered backlight occurred approximately 30 sec after extinction. This afterglow phenomena typically occurs following radiative extinction.

Test #2 - Droplet diameter of 4 mm, with support fiber and translation. Tethered deployment was successful with a brief burn before radiative extinction. Extinction occurred at “trailing surface ”after translation ceased.

Test #3 - Droplet diameter of 4 mm, with no support fiber. Droplet deployment was successful with very little droplet drift. The burn was very brief before radiative extinction. The afterglow phenomena occurred again similar to Test #1.

Test #4 - Droplet diameter of 4 mm, with support fiber and translation. Tethered deployment was successful with a brief burn before radiative extinction. A small amount of residual fuel from previous test was still on the fiber, which caused a brief secondary “ignition flash” that lasted less than 1 sec. Extinction occurred (similar to Test #2) at “trailing surface.”

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Easter Island Eclipse 0 comments
Makemake, a god in Easter Island mythology, may have smiled for a moment as clouds parted long enough to reveal this glimpse of July 11's total solar eclipse to skygazers. In the foreground of the dramatic scene, the island's famous large, monolithic statues (Moai) share a beachside view of the shimmering solar corona and the darkened daytime sky. Other opportunities to see the total phase of this eclipse of the Sun were also hard to come by. Defined by the dark part of the Moon's shadow, the path of totality tracked eastward across the southern Pacific Ocean, only making significant landfall at Mangaia (Cook Islands) and Easter Island (Isla de Pascua), ending shortly after reaching southern Chile and Argentina. But a partial eclipse phase could be enjoyed over a broader region, including many southern Pacific islands and wide swath of South America.

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Tuesday, July 13, 2010

Mosaic: Welcome to Planet Earth

Tuesday, July 13, 2010 0 comments

Welcome to Planet Earth, the third planet from a star named the Sun. The Earth is shaped like a sphere and composed mostly of rock. Over 70 percent of the Earth's surface is water. The planet has a relatively thin atmosphere composed mostly of nitrogen and oxygen. This picture of Earth, dubbed Blue Marble, was taken from Apollo 17 in 1972 and features Africa and Antarctica. It is thought to be one of the most widely distributed photographs of any kind. Here, the world famous image has been recast as a spectacular photomosaic using over 5,000 archived images of Earth and space. With its abundance of liquid water, Earth supports a large variety of life forms, including potentially intelligent species such as dolphins and humans. Please enjoy your stay on Planet Earth. 

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Monday, July 12, 2010

Moons Beyond the Rings of Saturn

Monday, July 12, 2010 0 comments

What's happened to that moon of Saturn? Nothing -- Saturn's moon Rhea is just partly hidden behind Saturn's rings. In April, the robotic Cassini spacecraft now orbiting Saturn took this narrow-angle view looking across the Solar System's most famous rings. Rings visible in the foreground include the thin F ring on the outside and the much wider A and B rings just interior to it. Although it seems to be hovering over the rings, Saturn's moon Janus is actually far behind them. Janus is one of Saturn's smaller moons and measures only about 180 kilometers across. Farther out from the camera is the heavily cratered Rhea, a much larger moon measuring 1,500 kilometers across. The top of Rhea is visible only through gaps in the rings. The Cassini mission around Saturn has been extended to 2017 to better study the complex planetary system as its season changes from equinox to solstice

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Sunday, July 11, 2010

Warped Sky: Star Trails Panorama

Sunday, July 11, 2010 0 comments

What's happened to the sky? A time warp, of sorts, and a digital space warp too. The time warp occurs because this image captured in a single frame a four hour exposure of the night sky. As a result, prominent star trails are visible. The space warp occurs because the picture is actually a full 360 degree panorama, horizontally compressed to fit your browser. As the Earth rotated, stars appeared to circle both the South Celestial Pole, on the left, and the North Celestial Pole, just below the horizon on the right. The image captured the sky over Mudgee, New South Wales, Australia, including the domes of two large telescopes illuminated by red lighting. A horizontally unwarped image is visible by clicking on the image. 

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Saturday, July 10, 2010

Ecliptic New Zealand

Saturday, July 10, 2010 0 comments

Four bright celestial beacons and a faint triangle of light follow the plane of the ecliptic as it arcs high through this southern hemisphere night skyscape. Seen on a July winter night from Lake Taupo on New Zealand's North Island, the line-up features Venus, Regulus (alpha star of Leo), Mars, and Saturn from lower left to upper right. Just put your cursor over the picture to identify the planets and constellations. The delicate luminous glow of Zodiacal Light, sunlight scattered by dust along the ecliptic, also rises above the horizon from the lower left. Of course, defined by the path of the Sun through planet Earth's sky, the ecliptic plane rides low during July nights in the northern hemisphere's summer skies. Tomorrow, the Moon and Sun will meet on the ecliptic. Along a track across the southern Pacific Ocean, the daytime sky will feature a total solar eclipse.

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