2014 July 24
ALMA Milky Way
Image Credit & Copyright: Yuri Beletsky (Las Campanas Observatory, Carnegie Institution)
This alluring all-skyscape was taken 5,100 meters above sea level, from the Chajnantor Plateau in the Chilean Andes. Viewed through the site's rarefied atmosphere at about 50% sea level pressure, the gorgeous Milky Way stretches through the scene. Its cosmic rifts of dust, stars, and nebulae are joined by Venus, a brilliant morning star immersed in a strong band of predawn Zodiacal light. Still not completely dark even at this high altitude, the night sky's greenish cast is due to airglow emission from oxygen atoms. Around the horizon the dish antenna units of the Atacama Large Millimeter/submillimeter Array, ALMA, explore the universe at wavelengths over 1,000 times longer than visible light.
ALMA Milky Way
Image Credit & Copyright: Yuri Beletsky (Las Campanas Observatory, Carnegie Institution)
This alluring all-skyscape was taken 5,100 meters above sea level, from the Chajnantor Plateau in the Chilean Andes. Viewed through the site's rarefied atmosphere at about 50% sea level pressure, the gorgeous Milky Way stretches through the scene. Its cosmic rifts of dust, stars, and nebulae are joined by Venus, a brilliant morning star immersed in a strong band of predawn Zodiacal light. Still not completely dark even at this high altitude, the night sky's greenish cast is due to airglow emission from oxygen atoms. Around the horizon the dish antenna units of the Atacama Large Millimeter/submillimeter Array, ALMA, explore the universe at wavelengths over 1,000 times longer than visible light.
2014 July 25
Cosmic Crab Nebula
Image Credit: NASA, Chandra X-ray Observatory, SAO, DSS
The Crab Pulsar, a city-sized, magnetized neutron star spinning 30 times a second, lies at the center of this tantalizing wide-field image of the Crab Nebula. A spectacular picture of one of our Milky Way's supernova remnants, it combines optical survey data with X-ray data from the orbiting Chandra Observatory. The composite was created as part of a celebration of Chandra's 15 year long exploration of the high energy cosmos. Like a cosmic dynamo the pulsar powers the X-ray and optical emission from the nebula, accelerating charged particles to extreme energies to produce the jets and rings glowing in X-rays. The innermost ring structure is about a light-year across. With more mass than the Sun and the density of an atomic nucleus, the spinning pulsar is the collapsed core of the massive star that exploded, while the nebula is the expanding remnant of the star's outer layers. The supernova explosion was witnessed in the year 1054.
Cosmic Crab Nebula
Image Credit: NASA, Chandra X-ray Observatory, SAO, DSS
The Crab Pulsar, a city-sized, magnetized neutron star spinning 30 times a second, lies at the center of this tantalizing wide-field image of the Crab Nebula. A spectacular picture of one of our Milky Way's supernova remnants, it combines optical survey data with X-ray data from the orbiting Chandra Observatory. The composite was created as part of a celebration of Chandra's 15 year long exploration of the high energy cosmos. Like a cosmic dynamo the pulsar powers the X-ray and optical emission from the nebula, accelerating charged particles to extreme energies to produce the jets and rings glowing in X-rays. The innermost ring structure is about a light-year across. With more mass than the Sun and the density of an atomic nucleus, the spinning pulsar is the collapsed core of the massive star that exploded, while the nebula is the expanding remnant of the star's outer layers. The supernova explosion was witnessed in the year 1054.
2014 July 26
NGC 253: Dusty Island Universe
Image Credit & Copyright: László Francsics
Shiny NGC 253 is one of the brightest spiral galaxies visible, and also one of the dustiest. Some call it the Silver Dollar Galaxy for its appearance in small telescopes, or just the Sculptor Galaxy for its location within the boundaries of the southern constellation Sculptor. First swept up in 1783 by mathematician and astronomer Caroline Herschel, the dusty island universe lies a mere 10 million light-years away. About 70 thousand light-years across, NGC 253 is the largest member of the Sculptor Group of Galaxies, the nearest to our own Local Group of Galaxies. In addition to its spiral dust lanes, tendrils of dust seem to be rising from a galactic disk laced with young star clusters and star forming regions in this sharp color image. The high dust content accompanies frantic star formation, earning NGC 253 the designation of a starburst galaxy. NGC 253 is also known to be a strong source of high-energy x-rays and gamma rays, likely due to massive black holes near the galaxy's center.
NGC 253: Dusty Island Universe
Image Credit & Copyright: László Francsics
Shiny NGC 253 is one of the brightest spiral galaxies visible, and also one of the dustiest. Some call it the Silver Dollar Galaxy for its appearance in small telescopes, or just the Sculptor Galaxy for its location within the boundaries of the southern constellation Sculptor. First swept up in 1783 by mathematician and astronomer Caroline Herschel, the dusty island universe lies a mere 10 million light-years away. About 70 thousand light-years across, NGC 253 is the largest member of the Sculptor Group of Galaxies, the nearest to our own Local Group of Galaxies. In addition to its spiral dust lanes, tendrils of dust seem to be rising from a galactic disk laced with young star clusters and star forming regions in this sharp color image. The high dust content accompanies frantic star formation, earning NGC 253 the designation of a starburst galaxy. NGC 253 is also known to be a strong source of high-energy x-rays and gamma rays, likely due to massive black holes near the galaxy's center.
2014 July 27
Rho Ophiuchi Wide Field
Image Credit & Copyright: Rogelio Bernal Andreo
The clouds surrounding the star system Rho Ophiuchi compose one of the closest star forming regions. Rho Ophiuchi itself is a binary star system visible in the light-colored region on the image right. The star system, located only 400 light years away, is distinguished by its colorful surroundings, which include a red emission nebula and numerous light and dark brown dust lanes. Near the upper right of the Rho Ophiuchi molecular cloud system is the yellow star Antares, while a distant but coincidently-superposed globular cluster of stars, M4, is visible between Antares and the red emission nebula. Near the image bottom lies IC 4592, the Blue Horsehead nebula. The blue glow that surrounds the Blue Horsehead's eye -- and other stars around the image -- is a reflection nebula composed of fine dust. On the above image left is a geometrically angled reflection nebula cataloged as Sharpless 1. Here, the bright star near the dust vortex creates the light of surrounding reflection nebula. Although most of these features are visible through a small telescope pointed toward the constellations of Ophiuchus, Scorpius, and Sagittarius, the only way to see the intricate details of the dust swirls, as featured above, is to use a long exposure camera.
Rho Ophiuchi Wide Field
Image Credit & Copyright: Rogelio Bernal Andreo
The clouds surrounding the star system Rho Ophiuchi compose one of the closest star forming regions. Rho Ophiuchi itself is a binary star system visible in the light-colored region on the image right. The star system, located only 400 light years away, is distinguished by its colorful surroundings, which include a red emission nebula and numerous light and dark brown dust lanes. Near the upper right of the Rho Ophiuchi molecular cloud system is the yellow star Antares, while a distant but coincidently-superposed globular cluster of stars, M4, is visible between Antares and the red emission nebula. Near the image bottom lies IC 4592, the Blue Horsehead nebula. The blue glow that surrounds the Blue Horsehead's eye -- and other stars around the image -- is a reflection nebula composed of fine dust. On the above image left is a geometrically angled reflection nebula cataloged as Sharpless 1. Here, the bright star near the dust vortex creates the light of surrounding reflection nebula. Although most of these features are visible through a small telescope pointed toward the constellations of Ophiuchus, Scorpius, and Sagittarius, the only way to see the intricate details of the dust swirls, as featured above, is to use a long exposure camera.
2014 July 28
The Horsehead Nebula from Blue to Infrared
Image Credit & Copyright: Optical: Aldo Mottino & Carlos Colazo, OAC, C�rdoba; Infrared: Hubble Legacy Archive
One of the most identifiable nebulae in the sky, the Horsehead Nebula in Orion, is part of a large, dark, molecular cloud. Also known as Barnard 33, the unusual shape was first discovered on a photographic plate in the late 1800s. The red glow originates from hydrogen gas predominantly behind the nebula, ionized by the nearby bright star Sigma Orionis. The darkness of the Horsehead is caused mostly by thick dust, although the lower part of the Horsehead's neck casts a shadow to the left. Streams of gas leaving the nebula are funneled by a strong magnetic field. Bright spots in the Horsehead Nebula's base are young stars just in the process of forming. Light takes about 1,500 years to reach us from the Horsehead Nebula. The above image is a digital combination of images taken in blue, green, red, and hydrogen-alpha light from the Argentina, and an image taken in infrared light by the orbiting Hubble Space Telescope.
The Horsehead Nebula from Blue to Infrared
Image Credit & Copyright: Optical: Aldo Mottino & Carlos Colazo, OAC, C�rdoba; Infrared: Hubble Legacy Archive
One of the most identifiable nebulae in the sky, the Horsehead Nebula in Orion, is part of a large, dark, molecular cloud. Also known as Barnard 33, the unusual shape was first discovered on a photographic plate in the late 1800s. The red glow originates from hydrogen gas predominantly behind the nebula, ionized by the nearby bright star Sigma Orionis. The darkness of the Horsehead is caused mostly by thick dust, although the lower part of the Horsehead's neck casts a shadow to the left. Streams of gas leaving the nebula are funneled by a strong magnetic field. Bright spots in the Horsehead Nebula's base are young stars just in the process of forming. Light takes about 1,500 years to reach us from the Horsehead Nebula. The above image is a digital combination of images taken in blue, green, red, and hydrogen-alpha light from the Argentina, and an image taken in infrared light by the orbiting Hubble Space Telescope.
2014 July 29
A Sky Portal in New Zealand
Image Credit & Copyright: Petr Hor�lek
To some, it may look like a portal into the distant universe. To others, it may appear as the eye of a giant. Given poetic license, both are correct. Pictured above is a standard fisheye view of the sky -- but with an unusual projection. The view is from a perch in New Zealand called Te Mata Peak, a name that translates from the Maori language as "Sleeping Giant". The wondrous panorama shows the band of our Milky Way Galaxy right down the center of the sky, with the Large and Small Magellanic Clouds visible to the right. The red hue is atmospheric airglow that surprised the photographer as it was better captured by the camera than the eye. The above image was taken two weeks ago as the photographer's sister, on the left, and an acquaintance peered into the sky portal.
A Sky Portal in New Zealand
Image Credit & Copyright: Petr Hor�lek
To some, it may look like a portal into the distant universe. To others, it may appear as the eye of a giant. Given poetic license, both are correct. Pictured above is a standard fisheye view of the sky -- but with an unusual projection. The view is from a perch in New Zealand called Te Mata Peak, a name that translates from the Maori language as "Sleeping Giant". The wondrous panorama shows the band of our Milky Way Galaxy right down the center of the sky, with the Large and Small Magellanic Clouds visible to the right. The red hue is atmospheric airglow that surprised the photographer as it was better captured by the camera than the eye. The above image was taken two weeks ago as the photographer's sister, on the left, and an acquaintance peered into the sky portal.
2014 July 30
M31: The Andromeda Galaxy
Image Credit & Copyright: Jacob Bers (Bersonic)
Andromeda is the nearest major galaxy to our own Milky Way Galaxy. Our Galaxy is thought to look much like Andromeda. Together these two galaxies dominate the Local Group of galaxies. The diffuse light from Andromeda is caused by the hundreds of billions of stars that compose it. The several distinct stars that surround Andromeda's image are actually stars in our Galaxy that are well in front of the background object. Andromeda is frequently referred to as M31 since it is the 31st object on Messier's list of diffuse sky objects. M31 is so distant it takes about two million years for light to reach us from there. Although visible without aid, the above image of M31 was taken with a standard camera through a small telescope. Much about M31 remains unknown, including how it acquired its unusual double-peaked center.
M31: The Andromeda Galaxy
Image Credit & Copyright: Jacob Bers (Bersonic)
Andromeda is the nearest major galaxy to our own Milky Way Galaxy. Our Galaxy is thought to look much like Andromeda. Together these two galaxies dominate the Local Group of galaxies. The diffuse light from Andromeda is caused by the hundreds of billions of stars that compose it. The several distinct stars that surround Andromeda's image are actually stars in our Galaxy that are well in front of the background object. Andromeda is frequently referred to as M31 since it is the 31st object on Messier's list of diffuse sky objects. M31 is so distant it takes about two million years for light to reach us from there. Although visible without aid, the above image of M31 was taken with a standard camera through a small telescope. Much about M31 remains unknown, including how it acquired its unusual double-peaked center.
2014 July 31
Veins of Heaven
Image Credit & Copyright: P-M Hedén (Clear Skies, TWAN)
Transfusing sunlight through a still dark sky, this exceptional display of noctilucent clouds was captured earlier this month above the island of Gotland, Sweden. From the edge of space, about 80 kilometers above Earth's surface, the icy clouds reflect sunlight even though the Sun itself is below the horizon as seen from the ground. Usually spotted at high latitudes in summer months the night shining clouds made a strong showing this July. Also known as polar mesopheric clouds they are understood to form as water vapor driven into the cold upper atmosphere condenses on the fine dust particles supplied by disintegrating meteors or volcanic ash. NASA's AIM mission provides daily projections of noctilucent clouds as seen from space.
Veins of Heaven
Image Credit & Copyright: P-M Hedén (Clear Skies, TWAN)
Transfusing sunlight through a still dark sky, this exceptional display of noctilucent clouds was captured earlier this month above the island of Gotland, Sweden. From the edge of space, about 80 kilometers above Earth's surface, the icy clouds reflect sunlight even though the Sun itself is below the horizon as seen from the ground. Usually spotted at high latitudes in summer months the night shining clouds made a strong showing this July. Also known as polar mesopheric clouds they are understood to form as water vapor driven into the cold upper atmosphere condenses on the fine dust particles supplied by disintegrating meteors or volcanic ash. NASA's AIM mission provides daily projections of noctilucent clouds as seen from space.
2014 August 1
Tetons and Snake River, Planet Earth
Image Credit & Copyright: Babak Tafreshi (TWAN)
An alluring night skyscape, this scene looks west across the Grand Teton National Park, Wyoming, USA, Planet Earth. The Snake River glides through the foreground, while above the Tetons' rugged mountain peaks the starry sky is laced with exceptionally strong red and green airglow. That night, the luminous atmospheric glow was just faintly visible to the eye, its color and wavey structure captured only by a sensitive digital camera. In fact, this contemporary digital photograph matches the location and perspective of a well-known photograph from 1942 - The Tetons and The Snake River , by Ansel Adams, renowned photographer of the American West. Adams' image is one of 115 images stored on the Voyager Golden Record. Humanity's message in a bottle, golden records were onboard both Voyager 1 and Voyager 2 spacecraft, launched in 1977 and now headed toward interstellar space.
Tetons and Snake River, Planet Earth
Image Credit & Copyright: Babak Tafreshi (TWAN)
An alluring night skyscape, this scene looks west across the Grand Teton National Park, Wyoming, USA, Planet Earth. The Snake River glides through the foreground, while above the Tetons' rugged mountain peaks the starry sky is laced with exceptionally strong red and green airglow. That night, the luminous atmospheric glow was just faintly visible to the eye, its color and wavey structure captured only by a sensitive digital camera. In fact, this contemporary digital photograph matches the location and perspective of a well-known photograph from 1942 - The Tetons and The Snake River , by Ansel Adams, renowned photographer of the American West. Adams' image is one of 115 images stored on the Voyager Golden Record. Humanity's message in a bottle, golden records were onboard both Voyager 1 and Voyager 2 spacecraft, launched in 1977 and now headed toward interstellar space.
2014 August 2
NGC 7023: The Iris Nebula
Image Credit & Copyright: Jimmy Walker
These clouds of interstellar dust and gas have blossomed 1,300 light-years away in the fertile star fields of the constellation Cepheus. Sometimes called the Iris Nebula, NGC 7023 is not the only nebula in the sky to evoke the imagery of flowers, though. Still, this deep telescopic view shows off the Iris Nebula's range of colors and symmetries in impressive detail. Within the Iris, dusty nebular material surrounds a hot, young star. The dominant color of the brighter reflection nebula is blue, characteristic of dust grains reflecting starlight. Central filaments of the dusty clouds glow with a faint reddish photoluminesence as some dust grains effectively convert the star's invisible ultraviolet radiation to visible red light. Infrared observations indicate that this nebula may contain complex carbon molecules known as PAHs. The pretty blue petals of the Iris Nebula span about six light-years.
NGC 7023: The Iris Nebula
Image Credit & Copyright: Jimmy Walker
These clouds of interstellar dust and gas have blossomed 1,300 light-years away in the fertile star fields of the constellation Cepheus. Sometimes called the Iris Nebula, NGC 7023 is not the only nebula in the sky to evoke the imagery of flowers, though. Still, this deep telescopic view shows off the Iris Nebula's range of colors and symmetries in impressive detail. Within the Iris, dusty nebular material surrounds a hot, young star. The dominant color of the brighter reflection nebula is blue, characteristic of dust grains reflecting starlight. Central filaments of the dusty clouds glow with a faint reddish photoluminesence as some dust grains effectively convert the star's invisible ultraviolet radiation to visible red light. Infrared observations indicate that this nebula may contain complex carbon molecules known as PAHs. The pretty blue petals of the Iris Nebula span about six light-years.
2014 August 3
Dark Shuttle Approaching
Image Credit: Space Station Expedition 22 Crew, NASA
What's that approaching? Astronauts on board the International Space Station first saw it in early 2010 far in the distance. Soon it enlarged to become a dark silhouette. As it came even closer, the silhouette appeared to be a spaceship. Finally, the object revealed itself to be the Space Shuttle Endeavour, and it soon docked as expected with the Earth-orbiting space station. Pictured above, Endeavour was imaged near Earth's horizon as it approached, where several layers of the Earth's atmosphere were visible. Directly behind the shuttle is the mesosphere, which appears blue. The atmospheric layer that appears white is the stratosphere, while the orange layer is Earth's Troposphere. This shuttle mission, began with a dramatic night launch. Tasks completed during this shuttle's visit to the ISS included the delivery of the Tranquility Module which contained a cupola bay window complex that allows even better views of spaceships approaching and leaving the space station.
Dark Shuttle Approaching
Image Credit: Space Station Expedition 22 Crew, NASA
What's that approaching? Astronauts on board the International Space Station first saw it in early 2010 far in the distance. Soon it enlarged to become a dark silhouette. As it came even closer, the silhouette appeared to be a spaceship. Finally, the object revealed itself to be the Space Shuttle Endeavour, and it soon docked as expected with the Earth-orbiting space station. Pictured above, Endeavour was imaged near Earth's horizon as it approached, where several layers of the Earth's atmosphere were visible. Directly behind the shuttle is the mesosphere, which appears blue. The atmospheric layer that appears white is the stratosphere, while the orange layer is Earth's Troposphere. This shuttle mission, began with a dramatic night launch. Tasks completed during this shuttle's visit to the ISS included the delivery of the Tranquility Module which contained a cupola bay window complex that allows even better views of spaceships approaching and leaving the space station.
2014 August 4
Shadows and Plumes Across Enceladus
Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA
Why does Enceladus have ice plumes? The discovery of jets spewing water vapor and ice was detected by the Saturn-orbiting Cassini spacecraft in 2005. The origin of the water feeding the jets, however, remained a topic of research. A leading hypothesis held that the source might originate from a deep underground sea, but another hypothesis indicated that it might just be ice melted off walls of deep rifts by the moon's tidal flexing and heating. Pictured above, the textured surface of Enceladus is visible in the foreground, while rows of plumes rise from ice fractures in the distance. These jets are made more visible by the Sun angle and the encroaching shadow of night. Recent study of over a hundred images like this -- of geysers crossing Enceladus' South Pole, together with regional heat maps, indicate that these plumes likely originate from a hidden sea, incresaing the chance that this frosty globe might be harboring life.
Shadows and Plumes Across Enceladus
Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA
Why does Enceladus have ice plumes? The discovery of jets spewing water vapor and ice was detected by the Saturn-orbiting Cassini spacecraft in 2005. The origin of the water feeding the jets, however, remained a topic of research. A leading hypothesis held that the source might originate from a deep underground sea, but another hypothesis indicated that it might just be ice melted off walls of deep rifts by the moon's tidal flexing and heating. Pictured above, the textured surface of Enceladus is visible in the foreground, while rows of plumes rise from ice fractures in the distance. These jets are made more visible by the Sun angle and the encroaching shadow of night. Recent study of over a hundred images like this -- of geysers crossing Enceladus' South Pole, together with regional heat maps, indicate that these plumes likely originate from a hidden sea, incresaing the chance that this frosty globe might be harboring life.
2014 August 5
Four Billion BCE: Battered Earth
Illustration Credit: Simone Marchi (SwRI), SSERVI, NASA
No place on Earth was safe. Four billion years ago, during the Hadean eon, our Solar System was a dangerous shooting gallery of large and dangerous rocks and ice chunks. Recent examination of lunar and Earth bombardment data indicate that the entire surface of the Earth underwent piecemeal upheavals, hiding our globe's ancient geologic history, and creating a battered world with no remaining familiar land masses. The rain of devastation made it difficult for any life to survive, although bacteria that could endure high temperatures had the best chance. Oceans thought to have formed during this epoch would boil away after particularly heavy impacts, only to reform again. The above artist's illustration depicts how Earth might have looked during this epoch, with circular impact features dotting the daylight side, and hot lava flows visible in the night. One billion years later, in a calmer Solar System, Earth's first supercontinent formed.
Four Billion BCE: Battered Earth
Illustration Credit: Simone Marchi (SwRI), SSERVI, NASA
No place on Earth was safe. Four billion years ago, during the Hadean eon, our Solar System was a dangerous shooting gallery of large and dangerous rocks and ice chunks. Recent examination of lunar and Earth bombardment data indicate that the entire surface of the Earth underwent piecemeal upheavals, hiding our globe's ancient geologic history, and creating a battered world with no remaining familiar land masses. The rain of devastation made it difficult for any life to survive, although bacteria that could endure high temperatures had the best chance. Oceans thought to have formed during this epoch would boil away after particularly heavy impacts, only to reform again. The above artist's illustration depicts how Earth might have looked during this epoch, with circular impact features dotting the daylight side, and hot lava flows visible in the night. One billion years later, in a calmer Solar System, Earth's first supercontinent formed.
2014 August 6
Saturn's Swirling Cloudscape
Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA
Acquiring its first sunlit views of far northern Saturn in late 2012, the Cassini spacecraft's wide-angle camera recorded this stunning, false-color image of the ringed planet's north pole. The composite of near-infrared image data results in red hues for low clouds and green for high ones, giving the Saturnian cloudscape a vivid appearance. Enormous by terrestrial standards, Saturn's north polar hurricane-like storm is deep, red, and about 2,000 kilometers wide. Clouds at its outer edge travel at over 500 kilometers per hour. Other atmospheric vortices also swirl inside the large, yellowish green, six-sided jet stream known as the hexagon. Beyond the cloud tops at the upper right, arcs of the planet's eye-catching rings appear bright blue.
Saturn's Swirling Cloudscape
Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA
Acquiring its first sunlit views of far northern Saturn in late 2012, the Cassini spacecraft's wide-angle camera recorded this stunning, false-color image of the ringed planet's north pole. The composite of near-infrared image data results in red hues for low clouds and green for high ones, giving the Saturnian cloudscape a vivid appearance. Enormous by terrestrial standards, Saturn's north polar hurricane-like storm is deep, red, and about 2,000 kilometers wide. Clouds at its outer edge travel at over 500 kilometers per hour. Other atmospheric vortices also swirl inside the large, yellowish green, six-sided jet stream known as the hexagon. Beyond the cloud tops at the upper right, arcs of the planet's eye-catching rings appear bright blue.
2014 August 7
Rosetta's Rendezvous
Image Credit: ESA / Rosetta / MPS for OSIRIS Team; MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
On August 3rd, the Rosetta spacecraft's narrow angle camera captured this stunning image of the nucleus of Comet 67P/Churyumov-Gerasimenko. After 10 years and 6.5 billion kilometers of travel along gravity assist trajectories looping through interplanetary space, Rosetta had approached to within 285 kilometers of its target. The curious double-lobed shape of the nucleus is revealed in amazing detail at an image resolution of 5.3 meters per pixel. About 4 kilometers across, the comet nucleus is presently just over 400 million kilometers from Earth, between the orbits of Jupiter and Mars. Now the first spacecraft to achieve a delicate orbit around a comet, Rosetta will swing to within 50 kilometers and closer in the coming weeks, identifiying candidate sites for landing its probe Philae later this year.
Rosetta's Rendezvous
Image Credit: ESA / Rosetta / MPS for OSIRIS Team; MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
On August 3rd, the Rosetta spacecraft's narrow angle camera captured this stunning image of the nucleus of Comet 67P/Churyumov-Gerasimenko. After 10 years and 6.5 billion kilometers of travel along gravity assist trajectories looping through interplanetary space, Rosetta had approached to within 285 kilometers of its target. The curious double-lobed shape of the nucleus is revealed in amazing detail at an image resolution of 5.3 meters per pixel. About 4 kilometers across, the comet nucleus is presently just over 400 million kilometers from Earth, between the orbits of Jupiter and Mars. Now the first spacecraft to achieve a delicate orbit around a comet, Rosetta will swing to within 50 kilometers and closer in the coming weeks, identifiying candidate sites for landing its probe Philae later this year.
2014 August 8
Spiral Galaxy NGC 6744
Image Credit & Copyright: Don Goldman
Big, beautiful spiral galaxy NGC 6744 is nearly 175,000 light-years across, larger than our own Milky Way. It lies some 30 million light-years distant in the southern constellation Pavo. We see the disk of the nearby island universe tilted towards our line of sight. Orientation and composition give a strong sense of depth to this colorful galaxy portrait that covers an area about the angular size of the full moon. This giant galaxy's yellowish core is dominated by the light from old, cool stars. Beyond the core, spiral arms filled with young blue star clusters and pinkish star forming regions sweep past a smaller satellite galaxy at the lower left, reminiscent of the Milky Way's satellite galaxy the Large Magellanic Cloud.
Spiral Galaxy NGC 6744
Image Credit & Copyright: Don Goldman
Big, beautiful spiral galaxy NGC 6744 is nearly 175,000 light-years across, larger than our own Milky Way. It lies some 30 million light-years distant in the southern constellation Pavo. We see the disk of the nearby island universe tilted towards our line of sight. Orientation and composition give a strong sense of depth to this colorful galaxy portrait that covers an area about the angular size of the full moon. This giant galaxy's yellowish core is dominated by the light from old, cool stars. Beyond the core, spiral arms filled with young blue star clusters and pinkish star forming regions sweep past a smaller satellite galaxy at the lower left, reminiscent of the Milky Way's satellite galaxy the Large Magellanic Cloud.
2014 August 9
A Luminous Night
Image Credit & Copyright: Phil Hart
What shines in the world at night? Just visible to the eye, a rare electric blue glow spread along the shores of Victoria Lake on January 16, 2013. Against reflections of a light near the horizon, this digitally stacked long exposure recorded the bioluminescence of Noctiluca scintillans, plankton stimulated by the lapping waves. Above, the night skies of the Gippsland Lakes region, Victoria, Australia shine with a fainter greenish airglow. Oxygen atoms in the upper atmosphere, initially excited by ultraviolet sunlight, produce the more widely seen fading atmospheric chemiluminescence. Washed out by the Earth's rotation, the faint band of the southern summer Milky Way stretches from the horizon as star trails circle the South Celestial Pole.
A Luminous Night
Image Credit & Copyright: Phil Hart
What shines in the world at night? Just visible to the eye, a rare electric blue glow spread along the shores of Victoria Lake on January 16, 2013. Against reflections of a light near the horizon, this digitally stacked long exposure recorded the bioluminescence of Noctiluca scintillans, plankton stimulated by the lapping waves. Above, the night skies of the Gippsland Lakes region, Victoria, Australia shine with a fainter greenish airglow. Oxygen atoms in the upper atmosphere, initially excited by ultraviolet sunlight, produce the more widely seen fading atmospheric chemiluminescence. Washed out by the Earth's rotation, the faint band of the southern summer Milky Way stretches from the horizon as star trails circle the South Celestial Pole.
2014 August 10
A Perseid Below
Image Credit: Ron Garan, ISS Expedition 28 Crew, NASA
Denizens of planet Earth typically watch meteor showers by looking up. But this remarkable view, captured on August 13, 2011 by astronaut Ron Garan, caught a Perseid meteor by looking down. From Garan's perspective onboard the International Space Station orbiting at an altitude of about 380 kilometers, the Perseid meteors streak below, swept up dust left from comet Swift-Tuttle heated to incandescence. The glowing comet dust grains are traveling at about 60 kilometers per second through the denser atmosphere around 100 kilometers above Earth's surface. In this case, the foreshortened meteor flash is right of frame center, below the curving limb of the Earth and a layer of greenish airglow, just below bright star Arcturus. Want to look up at a meteor shower? You're in luck, as the 2014 Perseids meteor shower peaks this week. Unfortunately, the fainter meteors in this year's shower will be hard to see in a relatively bright sky lit by the glow of a nearly full Moon.
A Perseid Below
Image Credit: Ron Garan, ISS Expedition 28 Crew, NASA
Denizens of planet Earth typically watch meteor showers by looking up. But this remarkable view, captured on August 13, 2011 by astronaut Ron Garan, caught a Perseid meteor by looking down. From Garan's perspective onboard the International Space Station orbiting at an altitude of about 380 kilometers, the Perseid meteors streak below, swept up dust left from comet Swift-Tuttle heated to incandescence. The glowing comet dust grains are traveling at about 60 kilometers per second through the denser atmosphere around 100 kilometers above Earth's surface. In this case, the foreshortened meteor flash is right of frame center, below the curving limb of the Earth and a layer of greenish airglow, just below bright star Arcturus. Want to look up at a meteor shower? You're in luck, as the 2014 Perseids meteor shower peaks this week. Unfortunately, the fainter meteors in this year's shower will be hard to see in a relatively bright sky lit by the glow of a nearly full Moon.
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2014 August 11
Rosetta Approaches Comet Churyumov-Gerasimenko
Image Credit & Copyright: ESA, Rosetta spacecraft, NavCam imager; Music: Eine kleine Nachtmusik (Mozart)
What does it look like to approach a comet? Early this month humanity received a new rendition as the robotic Rosetta spacecraft went right up to -- and began orbiting -- the nucleus of Comet 67P/Churyumov-Gerasimenko. This approach turned out to be particularly fascinating because the comet nucleus first revealed itself to have an unexpected double structure, and later showed off an unusual and craggily surface. The above 101-frame time-lapse video details the approach of the spacecraft from August 1 through August 6. The icy comet's core is the size of a mountain and rotates every 12.7 hours. Rosetta's images and data may shed light on the origin of comets and the early history of our Solar System. Later this year, Rosetta is scheduled to release the Philae lander, which will attempt to land on Comet Churyumov�Gerasimenko's periphery and harpoon itself to the surface.
Rosetta Approaches Comet Churyumov-Gerasimenko
Image Credit & Copyright: ESA, Rosetta spacecraft, NavCam imager; Music: Eine kleine Nachtmusik (Mozart)
What does it look like to approach a comet? Early this month humanity received a new rendition as the robotic Rosetta spacecraft went right up to -- and began orbiting -- the nucleus of Comet 67P/Churyumov-Gerasimenko. This approach turned out to be particularly fascinating because the comet nucleus first revealed itself to have an unexpected double structure, and later showed off an unusual and craggily surface. The above 101-frame time-lapse video details the approach of the spacecraft from August 1 through August 6. The icy comet's core is the size of a mountain and rotates every 12.7 hours. Rosetta's images and data may shed light on the origin of comets and the early history of our Solar System. Later this year, Rosetta is scheduled to release the Philae lander, which will attempt to land on Comet Churyumov�Gerasimenko's periphery and harpoon itself to the surface.
2014 August 12
Collapse in Hebes Chasma on Mars
Image Credit & Copyright: ESA/DLR/FU Berlin (G. Neukum)
What's happened in Hebes Chasma on Mars? Hebes Chasma is a depression just north of the enormous Valles Marineris canyon. Since the depression is unconnected to other surface features, it is unclear where the internal material went. Inside Hebes Chasma is Hebes Mensa, a 5 kilometer high mesa that appears to have undergone an unusual partial collapse -- a collapse that might be providing clues. The above image, taken by the robotic Mars Express spacecraft currently orbiting Mars, shows great details of the chasm and the unusual horseshoe shaped indentation in the central mesa. Material from the mesa appears to have flowed onto the floor of the chasm, while a possible dark layer appears to have pooled like ink on a downslope landing. A recent hypothesis holds that salty rock composes some lower layers in Hebes Chasma, with the salt dissolving in melted ice flows that drained through holes into an underground aquifer.
Collapse in Hebes Chasma on Mars
Image Credit & Copyright: ESA/DLR/FU Berlin (G. Neukum)
What's happened in Hebes Chasma on Mars? Hebes Chasma is a depression just north of the enormous Valles Marineris canyon. Since the depression is unconnected to other surface features, it is unclear where the internal material went. Inside Hebes Chasma is Hebes Mensa, a 5 kilometer high mesa that appears to have undergone an unusual partial collapse -- a collapse that might be providing clues. The above image, taken by the robotic Mars Express spacecraft currently orbiting Mars, shows great details of the chasm and the unusual horseshoe shaped indentation in the central mesa. Material from the mesa appears to have flowed onto the floor of the chasm, while a possible dark layer appears to have pooled like ink on a downslope landing. A recent hypothesis holds that salty rock composes some lower layers in Hebes Chasma, with the salt dissolving in melted ice flows that drained through holes into an underground aquifer.
2014 August 13
Rings Around the Ring Nebula
Image Credit: Hubble, Large Binocular Telescope, Subaru Telescope; Composition & Copyright: Robert Gendler
It is a familiar sight to sky enthusiasts with even a small telescope. There is much more to the Ring Nebula (M57), however, than can be seen through a small telescope. The easily visible central ring is about one light-year across, but this remarkably deep exposure - a collaborative effort combining data from three different large telescopes - explores the looping filaments of glowing gas extending much farther from the nebula's central star. This remarkable composite image includes narrowband hydrogen image, visible light emission, and infrared light emission. Of course, in this well-studied example of a planetary nebula, the glowing material does not come from planets. Instead, the gaseous shroud represents outer layers expelled from a dying, sun-like star. The Ring Nebula is about 2,000 light-years away toward the musical constellation Lyra.
Rings Around the Ring Nebula
Image Credit: Hubble, Large Binocular Telescope, Subaru Telescope; Composition & Copyright: Robert Gendler
It is a familiar sight to sky enthusiasts with even a small telescope. There is much more to the Ring Nebula (M57), however, than can be seen through a small telescope. The easily visible central ring is about one light-year across, but this remarkably deep exposure - a collaborative effort combining data from three different large telescopes - explores the looping filaments of glowing gas extending much farther from the nebula's central star. This remarkable composite image includes narrowband hydrogen image, visible light emission, and infrared light emission. Of course, in this well-studied example of a planetary nebula, the glowing material does not come from planets. Instead, the gaseous shroud represents outer layers expelled from a dying, sun-like star. The Ring Nebula is about 2,000 light-years away toward the musical constellation Lyra.