Partial Solar Eclipse with Airplane Image Credit & Copyright: Phillip Calais Explanation: It was just eight minutes after sunrise, last week, and already there were four things in front of the Sun. The largest and most notable was Earth’s Moon, obscuring a big chunk of the Sun’s lower limb as it moved across the solar disk, as viewed from Fremantle, Australia. This was expected as the image was taken during a partial solar eclipse — an eclipse that left sunlight streaming around all sides of the Moon from some locations. Next, a band of clouds divided the Sun horizontally while showing interesting internal structure vertically. The third intervening body might be considered to be theEarth’s atmosphere, as it dimmed the Sun from its higher altitude brightness while density fluctuations caused the Sun’s edges to appear to shimmer. Although closest to the photographer, the least expectedsolar occulter was an airplane. Quite possibly, passengers on both sides of that airplane were contemplating the unusual view only visible out the eastern-facing windows.
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Partial Solar Eclipse with Airplane 
Image Credit & Copyright: Phillip Calais

Explanation: It was just eight minutes after sunrise, last week, and already there were four things in front of the Sun. The largest and most notable was Earth’s Moon, obscuring a big chunk of the Sun’s lower limb as it moved across the solar disk, as viewed from Fremantle, Australia. This was expected as the image was taken during a partial solar eclipse — an eclipse that left sunlight streaming around all sides of the Moon from some locations. Next, a band of clouds divided the Sun horizontally while showing interesting internal structure vertically. The third intervening body might be considered to be theEarth’s atmosphere, as it dimmed the Sun from its higher altitude brightness while density fluctuations caused the Sun’s edges to appear to shimmer. Although closest to the photographer, the least expectedsolar occulter was an airplane. Quite possibly, passengers on both sides of that airplane were contemplating the unusual view only visible out the eastern-facing windows.

Clouds, Birds, Moon, Venus Image Credit & Copyright: Isaac Gutiérrez Pascual (Spain) Explanation: Sometimes the sky above can become quite a show. In early September of 2010, for example, the Moon and Venus converged, creating quite a sight by itself for sky enthusiasts around the globe.   From some locations, though, the sky was even more picturesque. In the above image taken in Spain, a crescent Moon and the planet Venus, on the far right, were captured during sunset posing against a deep blue sky.  In the foreground, dark storm clouds loom across the image bottom, while a white anvil cloud shape appears above. Black specks dot the frame, caused by a flock of birds taking flight. Very soon after this picture was taken, however, the birds passed by, the storm ended, and Venus and the Moon set.   Bright Venus again becomes visible just after sunset this 2013 May and will appear near Jupiter toward the end of the month.
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Clouds, Birds, Moon, Venus 
Image Credit & Copyright: Isaac Gutiérrez Pascual (Spain)

Explanation: Sometimes the sky above can become quite a show. In early September of 2010, for example, the Moon and Venus converged, creating quite a sight by itself for sky enthusiasts around the globe.   From some locations, though, the sky was even more picturesque. In the above image taken in Spain, a crescent Moon and the planet Venus, on the far right, were captured during sunset posing against a deep blue sky.  In the foreground, dark storm clouds loom across the image bottom, while a white anvil cloud shape appears above. Black specks dot the frame, caused by a flock of birds taking flight. Very soon after this picture was taken, however, the birds passed by, the storm ended, and Venus and the Moon set.   Bright Venus again becomes visible just after sunset this 2013 May and will appear near Jupiter toward the end of the month.

Source: apod.nasa.gov

A Supercell Thunderstorm Cloud Over Montana Image Credit & Copyright: Sean R. Heavey Explanation: Is that a spaceship or a cloud? Although it may seem like an alien mothership, it’s actually a impressive thunderstorm cloud called a supercell. Such colossal storm systems center onmesocyclones — rotating updrafts that can span several kilometers and deliver torrential rain and high winds including tornadoes. Jagged sculptured clouds adorn the supercell’s edge, while wind swept dust and rain dominate the center. A tree waits patiently in the foreground. The above supercell cloud was photographed in July west of Glasgow, Montana, USA, caused minor damage, and lasted several hours before moving on.
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A Supercell Thunderstorm Cloud Over Montana 
Image Credit & Copyright: Sean R. Heavey

Explanation: Is that a spaceship or a cloud? Although it may seem like an alien mothership, it’s actually a impressive thunderstorm cloud called a supercell. Such colossal storm systems center onmesocyclones — rotating updrafts that can span several kilometers and deliver torrential rain and high winds including tornadoes. Jagged sculptured clouds adorn the supercell’s edge, while wind swept dust and rain dominate the center. A tree waits patiently in the foreground. The above supercell cloud was photographed in July west of Glasgow, Montana, USA, caused minor damage, and lasted several hours before moving on.

Source: apod.nasa.gov

Milky Way and Stone Tree Image Credit & Copyright: Daniel López (El Cielo de Canarias) Explanation: What’s that next to the Milky Way? An unusual natural rock formation known as Roque Cinchado or Stone Tree found on the Spanish Canary Island of Tenerife. A famous icon, Roque Cinchado is likely a dense plug of cooled volcanic magma that remains after softer surrounding rock eroded away. Majestically, the central band of our Milky Way Galaxy is visible arcing across the right of the above seven image panoramic mosaic taken during the summer of 2010. On the far right is the Teide volcano complete with a lenticular cloud hovering near its peak.
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Milky Way and Stone Tree 
Image Credit & Copyright: Daniel López (El Cielo de Canarias)

Explanation: What’s that next to the Milky Way? An unusual natural rock formation known as Roque Cinchado or Stone Tree found on the Spanish Canary Island of Tenerife. A famous icon, Roque Cinchado is likely a dense plug of cooled volcanic magma that remains after softer surrounding rock eroded away. Majestically, the central band of our Milky Way Galaxy is visible arcing across the right of the above seven image panoramic mosaic taken during the summer of 2010. On the far right is the Teide volcano complete with a lenticular cloud hovering near its peak.

Horsehead: A Wider View Composition and Processing: Robert Gendler Image Data: ESO, VISTA, HLA, Hubble Heritage Team (STScI/AURA) Explanation: Combined image data from the massive, ground-based VISTA telescope and the Hubble Space Telescope was used to create this wide perspective of the interstellar landscape surrounding the famous Horsehead Nebula. Captured at near-infrared wavelengths, the region’s dusty molecular cloud sprawls across the scene that covers an angle about two-thirds the size of the Full Moon on the sky. Left to right the frame spans just over 10 light-years at the Horsehead’s estimated distance of 1,600 light-years. Also known as Barnard 33, the still recognizable Horsehead Nebula stands at the upper right, the near-infrared glow of a dusty pillar topped with newborn stars. Below and left, the bright reflection nebula NGC 2023 is itself the illuminated environs of a hot young star. Obscuring clouds below the base of the Horsehead and on the outskirts of NGC 2023 show the tell-tale far red emission of energetic jets, known as Herbig-Haro objects, also associatedwith newborn stars.
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Horsehead: A Wider View 
Composition and Processing: Robert Gendler 
Image Data: ESO, VISTA, HLA, Hubble Heritage Team (STScI/AURA)

Explanation: Combined image data from the massive, ground-based VISTA telescope and the Hubble Space Telescope was used to create this wide perspective of the interstellar landscape surrounding the famous Horsehead Nebula. Captured at near-infrared wavelengths, the region’s dusty molecular cloud sprawls across the scene that covers an angle about two-thirds the size of the Full Moon on the sky. Left to right the frame spans just over 10 light-years at the Horsehead’s estimated distance of 1,600 light-years. Also known as Barnard 33, the still recognizable Horsehead Nebula stands at the upper right, the near-infrared glow of a dusty pillar topped with newborn stars. Below and left, the bright reflection nebula NGC 2023 is itself the illuminated environs of a hot young star. Obscuring clouds below the base of the Horsehead and on the outskirts of NGC 2023 show the tell-tale far red emission of energetic jets, known as Herbig-Haro objects, also associatedwith newborn stars.

Source: apod.nasa.gov

Airglow, Gegenschein, and Milky Way Image Credit & Copyright: Yuri Beletsky (Las Campanas Observatory, Carnegie Institution) Explanation: As far as the eye could see, it was a dark night at Las Campanas Observatory in the southern Atacama desert of Chile. But near local midnight on April 11, this mosaic of 3 minute long exposures revealed a green, unusually intense, atmospheric airglow stretching over thin clouds. Unlike aurorae powered by collisions with energetic charged particles and seen at high latitudes, the airglow is due to chemiluminescence, the production of light in a chemical reaction, and found around the globe. The chemical energy is provided by the Sun’s extreme ultraviolet radiation. Like aurorae, the greenish hue of this airglow does originate at altitudes of 100 kilometers or so dominated by emission from excited oxygen atoms. The gegenschein, sunlight reflected by dust along the solar system’s ecliptic plane was still visible on that night, a faint bluish cloud just right of picture center. At the far right, the Milky Way seems to rise from the mountain top perch of the Magellan telescopes. Left are the OGLE project and du Pont telescope domes.  
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Airglow, Gegenschein, and Milky Way 
Image Credit & Copyright: Yuri Beletsky (Las Campanas Observatory, Carnegie Institution)

Explanation: As far as the eye could see, it was a dark night at Las Campanas Observatory in the southern Atacama desert of Chile. But near local midnight on April 11, this mosaic of 3 minute long exposures revealed a green, unusually intense, atmospheric airglow stretching over thin clouds. Unlike aurorae powered by collisions with energetic charged particles and seen at high latitudes, the airglow is due to chemiluminescence, the production of light in a chemical reaction, and found around the globe. The chemical energy is provided by the Sun’s extreme ultraviolet radiation. Like aurorae, the greenish hue of this airglow does originate at altitudes of 100 kilometers or so dominated by emission from excited oxygen atoms. The gegenschein, sunlight reflected by dust along the solar system’s ecliptic plane was still visible on that night, a faint bluish cloud just right of picture center. At the far right, the Milky Way seems to rise from the mountain top perch of the Magellan telescopes. Left are the OGLE project and du Pont telescope domes.

 

Grand Spiral Galaxy M81 and Arp’s Loop Image Credit & Copyright: Bernard Miller Explanation: One of the brightest galaxies in planet Earth’s sky is similar in size to our Milky Way Galaxy: big, beautiful M81. This grand spiral galaxy lies 11.8 million light-years away toward the northern constellation of the Great Bear (Ursa Major). The deep image of the region reveals details in the bright yellow core, but at the same time follows fainter features along the galaxy’s gorgeous blue spiral arms and sweeping dust lanes. It also follows the expansive, arcing feature, known as Arp’s loop, that seems to rise from the galaxy’s disk at the upper right. Studied in the 1960s, Arp’s loop has been thought to be a tidal tail, material pulled out of M81 by gravitational interaction with its large neighboring galaxy M82. But a subsequent investigation demonstrates that at least some of Arp’s loop likely lies within our own galaxy. The loop’s colors in visible and infrared light match the colors of pervasive clouds of dust, relatively unexplored galactic cirrus only a few hundred light-years above the plane of the Milky Way. Along with the Milky Way’s stars, the dust clouds lie in the foreground of this remarkable view. M81’s dwarf companion galaxy, Holmberg IX, can be seen just above the large spiral. On the sky, this image spans about 0.5 degrees, about the size of the Full Moon.
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Grand Spiral Galaxy M81 and Arp’s Loop 
Image Credit & Copyright: Bernard Miller

Explanation: One of the brightest galaxies in planet Earth’s sky is similar in size to our Milky Way Galaxy: big, beautiful M81. This grand spiral galaxy lies 11.8 million light-years away toward the northern constellation of the Great Bear (Ursa Major). The deep image of the region reveals details in the bright yellow core, but at the same time follows fainter features along the galaxy’s gorgeous blue spiral arms and sweeping dust lanes. It also follows the expansive, arcing feature, known as Arp’s loop, that seems to rise from the galaxy’s disk at the upper right. Studied in the 1960s, Arp’s loop has been thought to be a tidal tail, material pulled out of M81 by gravitational interaction with its large neighboring galaxy M82. But a subsequent investigation demonstrates that at least some of Arp’s loop likely lies within our own galaxy. The loop’s colors in visible and infrared light match the colors of pervasive clouds of dust, relatively unexplored galactic cirrus only a few hundred light-years above the plane of the Milky Way. Along with the Milky Way’s stars, the dust clouds lie in the foreground of this remarkable view. M81’s dwarf companion galaxy, Holmberg IX, can be seen just above the large spiral. On the sky, this image spans about 0.5 degrees, about the size of the Full Moon.

Source: apod.nasa.gov

Wringing out Water on the ISS - for Science!

Video Credit: CSA, ASC, Expedition 35

Explanation: What happens if you wring out a wet towel while floating in space? The water shouldn’t fall toward the floor because while orbiting the Earth, free falling objects will appear to float. But will the water fly out from the towel, or what? The answer may surprise you. To find out and to further exhibit how strange being in orbit can be, Expedition 35 Commander Chris Hadfield did just this experiment last week in the microgravity of the Earth orbiting International Space Station. As demonstrated in the above video, although a few drops do go flying off, most of the water sticks together and forms a unusual-looking cylindrical sheath in and around the towel. The self-sticking surface tensionof water is well known on Earth, for example being used to create artistic water cascades and, more generally, raindrops.

Woah….

Yuri’s Planet Image Credit: ISS Expedition 30, NASA Explanation: On another April 12th, in 1961, Soviet cosmonaut Yuri Alexseyevich Gagarin became the first human to see planet Earth from space. Commenting on his view from orbit he reported, “The sky is very dark; the Earth is bluish. Everything is seen very clearly”. On yet another April 12th, in 1981 NASA launched the first space shuttle. To celebrate in 2013, consider this image from the orbiting International Space Station, a stunning view of the planet at night from low Earth orbit. Constellations of lights connecting the densely populated cities along the Atlantic east coast of the United States are framed by two Russian spacecraft docked at the space station. Easy to recognize cities include New York City and Long Island at the right. From there, track toward the left for Philadelphia, Baltimore, and then Washington DC near picture center.
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Yuri’s Planet 
Image Credit: ISS Expedition 30, NASA

Explanation: On another April 12th, in 1961, Soviet cosmonaut Yuri Alexseyevich Gagarin became the first human to see planet Earth from space. Commenting on his view from orbit he reported, “The sky is very dark; the Earth is bluish. Everything is seen very clearly”. On yet another April 12th, in 1981 NASA launched the first space shuttle. To celebrate in 2013, consider this image from the orbiting International Space Station, a stunning view of the planet at night from low Earth orbit. Constellations of lights connecting the densely populated cities along the Atlantic east coast of the United States are framed by two Russian spacecraft docked at the space station. Easy to recognize cities include New York City and Long Island at the right. From there, track toward the left for Philadelphia, Baltimore, and then Washington DC near picture center.

Source: apod.nasa.gov

Darkened City Image Credit & Copyright: Photo Thierry Cohen / Courtesy Danziger Gallery, New York Explanation: In a haunting vista you can never see, bright stars and the central Milky Way rise over the dark skyline of metropolitan Pudong in Shanghai, China. Looking east across the Huangpu River, the cityscape includes Pudong’s 470 meter tall Oriental Pearl Tower. The night sky stretches from Antares and the stars of Scorpius at the far right, to Altair in Aquila at the left. To create the vision of an unseen reality, part of a series of Darkened Cities, photographer Thierry Cohen has combined a daytime image of the city skyline with an image matched in orientation from a dark sky region at the same latitude, just west of Merzouga, Morocco. The result finds the night sky that hours earlier also arced over Shanghai, but drowned in the lights of a city upon the sea.
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Darkened City 
Image Credit & Copyright: Photo Thierry Cohen / Courtesy Danziger Gallery, New York

Explanation: In a haunting vista you can never see, bright stars and the central Milky Way rise over the dark skyline of metropolitan Pudong in Shanghai, China. Looking east across the Huangpu River, the cityscape includes Pudong’s 470 meter tall Oriental Pearl Tower. The night sky stretches from Antares and the stars of Scorpius at the far right, to Altair in Aquila at the left. To create the vision of an unseen reality, part of a series of Darkened Cities, photographer Thierry Cohen has combined a daytime image of the city skyline with an image matched in orientation from a dark sky region at the same latitude, just west of Merzouga, Morocco. The result finds the night sky that hours earlier also arced over Shanghai, but drowned in the lights of a city upon the sea.

Source: apod.nasa.gov

A Horizon Rainbow in Paris Image Credit & Copyright: Bertrand Kulik Explanation: Why is this horizon so colorful? Because, opposite the Sun, it is raining. What is pictured above is actually just a common rainbow. It’s uncommon appearance is caused by the Sun being unusually high in the sky during the rainbow’s creation. Since every rainbow’s center must be exactly opposite the Sun, a high Sun reflecting off of a distant rain will produce a low rainbow where only the very top is visible — because the rest of the rainbow is below the horizon. Furthermore, no two observers can see exactly the same rainbow — every person finds themselves exactly between the Sun and rainbow’s center, and every observer sees the colorful circular band precisely 42 degrees from rainbow’s center. The above image featuring the Eiffel Tower was taken in Paris, France last week. Although the intermittent thunderstorms lasted for much of the day, the horizon rainbow lasted for only a few minutes.
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A Horizon Rainbow in Paris 
Image Credit & Copyright: Bertrand Kulik

Explanation: Why is this horizon so colorful? Because, opposite the Sun, it is raining. What is pictured above is actually just a common rainbow. It’s uncommon appearance is caused by the Sun being unusually high in the sky during the rainbow’s creation. Since every rainbow’s center must be exactly opposite the Sun, a high Sun reflecting off of a distant rain will produce a low rainbow where only the very top is visible — because the rest of the rainbow is below the horizon. Furthermore, no two observers can see exactly the same rainbow — every person finds themselves exactly between the Sun and rainbow’s center, and every observer sees the colorful circular band precisely 42 degrees from rainbow’s center. The above image featuring the Eiffel Tower was taken in Paris, France last week. Although the intermittent thunderstorms lasted for much of the day, the horizon rainbow lasted for only a few minutes.

Source: apod.nasa.gov

Mt. Hood and a Lenticular Cloud Image Credit & Copyright: Ben Canales Explanation: What kind of cloud is next to that mountain? A lenticular. This type of cloud forms in air that passes over a mountain, rises up again, and cools past the dew point — so what molecular water carried in the air condenses into droplets. The layered nature of some lenticular clouds may make them appear, to some, as large alien spaceships. In this case, the mountain pictured is Mt. Hood located in Oregon, USA. Lenticular clouds can only form when conditions are right — for example this is first time this astrophotographer has seen a lenticular cloud at night near Mt. Hood. The above image was taken in mid-March about two hours before dawn.
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Mt. Hood and a Lenticular Cloud 
Image Credit & Copyright: Ben Canales

Explanation: What kind of cloud is next to that mountain? A lenticular. This type of cloud forms in air that passes over a mountain, rises up again, and cools past the dew point — so what molecular water carried in the air condenses into droplets. The layered nature of some lenticular clouds may make them appear, to some, as large alien spaceships. In this case, the mountain pictured is Mt. Hood located in Oregon, USA. Lenticular clouds can only form when conditions are right — for example this is first time this astrophotographer has seen a lenticular cloud at night near Mt. Hood. The above image was taken in mid-March about two hours before dawn.

Source: apod.nasa.gov

Lenticular Clouds Over Washington Credit & Copyright: Tim Thompson Explanation: Are those UFOs near that mountain? No — they are multilayered lenticular clouds. Moist air forced to flow upward around mountain tops can create lenticular clouds. Water droplets condense from moist air cooled below the dew point, and clouds are opaque groups of water droplets. Waves in the air that would normally be seen horizontally can then be seen vertically, by the different levels where clouds form. On some days the city of Seattle, Washington, USA, is treated to an unusual sky show when lenticular clouds form near Mt. Rainier, a large mountain that looms just under 100 kilometers southeast of the city. This imageof a spectacular cluster of lenticular clouds was taken in 2008 December.
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Lenticular Clouds Over Washington 
Credit & Copyright: Tim Thompson

Explanation: Are those UFOs near that mountain? No — they are multilayered lenticular clouds. Moist air forced to flow upward around mountain tops can create lenticular clouds. Water droplets condense from moist air cooled below the dew point, and clouds are opaque groups of water droplets. Waves in the air that would normally be seen horizontally can then be seen vertically, by the different levels where clouds form. On some days the city of Seattle, Washington, USA, is treated to an unusual sky show when lenticular clouds form near Mt. Rainier, a large mountain that looms just under 100 kilometers southeast of the city. This imageof a spectacular cluster of lenticular clouds was taken in 2008 December.

Source: apod.nasa.gov

Goat Aurora Over Greenland Image Credit & Copyright: Juan Carlos Casado (TWAN) Explanation: Sometimes it’s hard to believe what you see in the sky. During the Shelios Expedition to Greenland in late August, even veteran sky enthusiasts saw auroras so colorful, so fast changing, and so unusual in form that they could remember nothing like it. As the ever changing auroras evolved, huge shapes spread across the sky morphed from one familiar form into another, including what looked to be the head of a goat (shown above), the head of an elephant, a strange green-tailed comet, and fingers on a celestial hand. Even without the aurora, the sky would be notable for the arching band of our Milky Way Galaxy and the interesting field of stars, nebulas, and galaxies. In contrast, in the foreground is a farm house inTasiusaq, Kujalleq. Greenland. The Shelios project exists not only to observe auroras but to motivate students to consider a career in science.
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Goat Aurora Over Greenland 
Image Credit & Copyright: Juan Carlos Casado (TWAN)

Explanation: Sometimes it’s hard to believe what you see in the sky. During the Shelios Expedition to Greenland in late August, even veteran sky enthusiasts saw auroras so colorful, so fast changing, and so unusual in form that they could remember nothing like it. As the ever changing auroras evolved, huge shapes spread across the sky morphed from one familiar form into another, including what looked to be the head of a goat (shown above), the head of an elephant, a strange green-tailed comet, and fingers on a celestial hand. Even without the aurora, the sky would be notable for the arching band of our Milky Way Galaxy and the interesting field of stars, nebulas, and galaxies. In contrast, in the foreground is a farm house inTasiusaq, Kujalleq. Greenland. The Shelios project exists not only to observe auroras but to motivate students to consider a career in science.

Source: apod.nasa.gov