2011 August 8
Seasonal Dark Streaks on Mars
Image Credit: HiRISE, MRO, LPL (U. Arizona), NASA
What is causing these dark streaks on Mars? A leading hypothesis is flowing -- but quickly evaporating -- water. The streaks, visible in dark brown near the image center, appear in the Martian spring and summer but fade in the winter months, only to reappear again the next summer. These are not the first markings on Mars that have been interpreted as showing the effects of running water, but they are the first to add the clue of a seasonal dependence. The above picture, taken in May, digitally combines several images from the the HiRISE instrument on the Mars Reconnaissance Orbiter (MRO). The image is color-enhanced and depicts a slope inside Newton crater in a mid-southern region of Mars. The streaks bolster evidence that water exists just below the Martian surface in several locations, and therefore fuels speculation that Mars might harbor some sort of water-dependent life. Future observations with robotic spacecraft orbiting Mars, such as MRO, Mars Express, and Mars Odyssey will continue to monitor the situation and possibly confirm -- or refute -- the exciting flowing water hypothesis.
Seasonal Dark Streaks on Mars
Image Credit: HiRISE, MRO, LPL (U. Arizona), NASA
What is causing these dark streaks on Mars? A leading hypothesis is flowing -- but quickly evaporating -- water. The streaks, visible in dark brown near the image center, appear in the Martian spring and summer but fade in the winter months, only to reappear again the next summer. These are not the first markings on Mars that have been interpreted as showing the effects of running water, but they are the first to add the clue of a seasonal dependence. The above picture, taken in May, digitally combines several images from the the HiRISE instrument on the Mars Reconnaissance Orbiter (MRO). The image is color-enhanced and depicts a slope inside Newton crater in a mid-southern region of Mars. The streaks bolster evidence that water exists just below the Martian surface in several locations, and therefore fuels speculation that Mars might harbor some sort of water-dependent life. Future observations with robotic spacecraft orbiting Mars, such as MRO, Mars Express, and Mars Odyssey will continue to monitor the situation and possibly confirm -- or refute -- the exciting flowing water hypothesis.
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2011 August 9
Juno Rockets Toward Jupiter
Video Credit: NASA
Next stop: Jupiter. Last week included one of the few times in history that humanity launched something completely off the Earth, moving away so fast that it will never return. Well, almost -- Juno's planned trajectory actually brings it homeward bound in about two years, zipping by, this time using the Earth's gravity to pull it to an even higher speed, high enough to reach Jupiter. The above video depicts the launch of Juno aboard a Atlas V rocket. When the robotic Juno spacecraft reaches Jupiter in 2016, it will spend just over a year circling the Solar System's largest planet, using its unique cadre of instruments to probe the planet, sending back clues of its structure and origin. Then Juno will be instructed to dive into the thick atmosphere of the Jovian giant, taking as much data as it can before it melts.
Juno Rockets Toward Jupiter
Video Credit: NASA
Next stop: Jupiter. Last week included one of the few times in history that humanity launched something completely off the Earth, moving away so fast that it will never return. Well, almost -- Juno's planned trajectory actually brings it homeward bound in about two years, zipping by, this time using the Earth's gravity to pull it to an even higher speed, high enough to reach Jupiter. The above video depicts the launch of Juno aboard a Atlas V rocket. When the robotic Juno spacecraft reaches Jupiter in 2016, it will spend just over a year circling the Solar System's largest planet, using its unique cadre of instruments to probe the planet, sending back clues of its structure and origin. Then Juno will be instructed to dive into the thick atmosphere of the Jovian giant, taking as much data as it can before it melts.
2011 August 10
The Summer Triangle Over Catalonia
Image Credit: Copyright: Juan Carlos Casado (TWAN)
Can you find the Summer Triangle? It's not hard to find this famous triangle of stars this time of year from northern locations. Just look straight up after sunset and find three of the brightest stars in the sky that nearly form a triangle. Then compare these stars to sky images like the one shown above, or hold up a smart phone running a good sky labelling application. The three stars that form the vertexes of the Summer Triangle are Vega, Deneb, and Altair. Pictured above is a 360 degree full sky projection framing not only the Summer Triangle but the great arch of our Milky Way Galaxy. The image was taken last week in front of a small river that encircles the historic town of Sant Lloren� de la Muga in Catalonia, northeastern Spain.
The Summer Triangle Over Catalonia
Image Credit: Copyright: Juan Carlos Casado (TWAN)
Can you find the Summer Triangle? It's not hard to find this famous triangle of stars this time of year from northern locations. Just look straight up after sunset and find three of the brightest stars in the sky that nearly form a triangle. Then compare these stars to sky images like the one shown above, or hold up a smart phone running a good sky labelling application. The three stars that form the vertexes of the Summer Triangle are Vega, Deneb, and Altair. Pictured above is a 360 degree full sky projection framing not only the Summer Triangle but the great arch of our Milky Way Galaxy. The image was taken last week in front of a small river that encircles the historic town of Sant Lloren� de la Muga in Catalonia, northeastern Spain.
2011 August 11
The Snows of Paranal
Image Credit & Copyright: Yuri Beletsky (ESO)
Recorded last week, this dawn portrait of snowy mountain and starry sky captures a very rare scenario. The view does feature a pristine sky above the 2,600 meter high mountain Cerro Paranal, but clear skies over Paranal are not at all unusual. That's one reason the mountain is home to the European Southern Observatory's Very Large Telescope. Considering the number of satellites now in orbit, the near sunrise streak of a satellite glinting at the upper left isn't rare either. And the long, bright trail of a meteor can often be spotted this time of year too. The one at the far right is associated with the annual Perseid meteor shower whose peak is expected tomorrow (Friday, August 12). In fact, the rarest aspect of the picture is just the snow. Cerro Paranal rises above South America's Atacama desert, known as the driest place on planet Earth.
The Snows of Paranal
Image Credit & Copyright: Yuri Beletsky (ESO)
Recorded last week, this dawn portrait of snowy mountain and starry sky captures a very rare scenario. The view does feature a pristine sky above the 2,600 meter high mountain Cerro Paranal, but clear skies over Paranal are not at all unusual. That's one reason the mountain is home to the European Southern Observatory's Very Large Telescope. Considering the number of satellites now in orbit, the near sunrise streak of a satellite glinting at the upper left isn't rare either. And the long, bright trail of a meteor can often be spotted this time of year too. The one at the far right is associated with the annual Perseid meteor shower whose peak is expected tomorrow (Friday, August 12). In fact, the rarest aspect of the picture is just the snow. Cerro Paranal rises above South America's Atacama desert, known as the driest place on planet Earth.
2011 August 12
NGC 7331 and Beyond
Image Credit & Copyright: Ken Crawford (Rancho Del Sol Obs.)
Big, beautiful spiral galaxy NGC 7331 is often touted as an analog to our own Milky Way. About 50 million light-years distant in the northern constellation Pegasus, NGC 7331 was recognized early on as a spiral nebula and is actually one of the brighter galaxies not included in Charles Messier's famous 18th century catalog. Since the galaxy's disk is inclined to our line-of-sight, long telescopic exposures often result in an image that evokes a strong sense of depth. The effect is further enhanced in this sharp image by galaxies that lie beyond the gorgeous island universe. The background galaxies are about one tenth the apparent size of NGC 7331 and so lie roughly ten times farther away. Their close alignment on the sky with NGC 7331 occurs just by chance. Seen here through faint foreground dust clouds lingering above the plane of Milky Way, this visual grouping of galaxies is also known as the Deer Lick Group.
NGC 7331 and Beyond
Image Credit & Copyright: Ken Crawford (Rancho Del Sol Obs.)
Big, beautiful spiral galaxy NGC 7331 is often touted as an analog to our own Milky Way. About 50 million light-years distant in the northern constellation Pegasus, NGC 7331 was recognized early on as a spiral nebula and is actually one of the brighter galaxies not included in Charles Messier's famous 18th century catalog. Since the galaxy's disk is inclined to our line-of-sight, long telescopic exposures often result in an image that evokes a strong sense of depth. The effect is further enhanced in this sharp image by galaxies that lie beyond the gorgeous island universe. The background galaxies are about one tenth the apparent size of NGC 7331 and so lie roughly ten times farther away. Their close alignment on the sky with NGC 7331 occurs just by chance. Seen here through faint foreground dust clouds lingering above the plane of Milky Way, this visual grouping of galaxies is also known as the Deer Lick Group.
2011 August 13
Castle and Meteor by Moonlight
Image Credit & Copyright: Tamas Ladanyi (TWAN)
Each August, as planet Earth swings through dust trailing along the orbit of periodic comet Swift-Tuttle, skygazers enjoy the Perseid Meteor Shower. As Earth moves through the denser part of the comet's wide dust trail this year's shower peaks around 6:00 UT August 13 (this morning), when light from a nearly full Moon masks all but the brighter meteor streaks. Still, Perseid meteors can be spotted in the days surrounding the peak. Moonlight and a Perseid meteor created this gorgeous skyscape, recorded in a simple, single, 10 second long exposure on the morning of August 12. Below the moonlit clouds in the foreground are the ruins of a medieval castle near Veszprem, Hungary, seen against the Bakony mountain range. In the night sky above the clouds, the Perseid meteor's trail is joined by bright planet Jupiter near the center of the frame along with the lovely Pleiades star cluster at the left.
Castle and Meteor by Moonlight
Image Credit & Copyright: Tamas Ladanyi (TWAN)
Each August, as planet Earth swings through dust trailing along the orbit of periodic comet Swift-Tuttle, skygazers enjoy the Perseid Meteor Shower. As Earth moves through the denser part of the comet's wide dust trail this year's shower peaks around 6:00 UT August 13 (this morning), when light from a nearly full Moon masks all but the brighter meteor streaks. Still, Perseid meteors can be spotted in the days surrounding the peak. Moonlight and a Perseid meteor created this gorgeous skyscape, recorded in a simple, single, 10 second long exposure on the morning of August 12. Below the moonlit clouds in the foreground are the ruins of a medieval castle near Veszprem, Hungary, seen against the Bakony mountain range. In the night sky above the clouds, the Perseid meteor's trail is joined by bright planet Jupiter near the center of the frame along with the lovely Pleiades star cluster at the left.
2011 August 14
Tornado and Rainbow Over Kansas
Image Credit & Copyright: Eric Nguyen (Oklahoma U.), www.mesoscale.ws
The scene might have been considered serene if it weren't for the tornado. During 2004 in Kansas, storm chaser Eric Nguyen photographed this budding twister in a different light -- the light of a rainbow. Pictured above, a white tornado cloud descends from a dark storm cloud. The Sun, peeking through a clear patch of sky to the left, illuminates some buildings in the foreground. Sunlight reflects off raindrops to form a rainbow. By coincidence, the tornado appears to end right over the rainbow. Streaks in the image are hail being swept about by the high swirling winds. Over 1,000 tornadoes, the most violent type of storm known, occur on Earth every year, many in tornado alley. If you see a tornado while driving, do not try to outrun it -- park your car safely, go to a storm cellar, or crouch under steps in a basement.
Tornado and Rainbow Over Kansas
Image Credit & Copyright: Eric Nguyen (Oklahoma U.), www.mesoscale.ws
The scene might have been considered serene if it weren't for the tornado. During 2004 in Kansas, storm chaser Eric Nguyen photographed this budding twister in a different light -- the light of a rainbow. Pictured above, a white tornado cloud descends from a dark storm cloud. The Sun, peeking through a clear patch of sky to the left, illuminates some buildings in the foreground. Sunlight reflects off raindrops to form a rainbow. By coincidence, the tornado appears to end right over the rainbow. Streaks in the image are hail being swept about by the high swirling winds. Over 1,000 tornadoes, the most violent type of storm known, occur on Earth every year, many in tornado alley. If you see a tornado while driving, do not try to outrun it -- park your car safely, go to a storm cellar, or crouch under steps in a basement.
2011 August 15
Rover Arrives at Endeavour Crater on Mars
Image Credit: Mars Exploration Rover Mission, Cornell, JPL, NASA
What can the present-day terrain in and around large Endeavour crater tell us about ancient Mars? Starting three years ago, NASA sent a coffee-table sized robot named Opportunity on a mission rolling across the red planet's Meridiani Planum to find out. Last week, it finally arrived. Expansive Endeavour crater stretches 22 kilometers from rim to rim, making it the largest crater ever visited by a Mars Exploration Rover (MER). It is hypothesized that the impact that created the crater exposed ancient rock that possibly formed under wet conditions, and if so, this rock may yield unique clues to the watery past of Mars. Pictured above, the west rim of Endeavour looms just ahead of the Opportunity rover. Opportunity may well spend the rest of its operational life exploring Endeavour, taking pictures, spinning its wheels, and boring into intriguing rocks.
Rover Arrives at Endeavour Crater on Mars
Image Credit: Mars Exploration Rover Mission, Cornell, JPL, NASA
What can the present-day terrain in and around large Endeavour crater tell us about ancient Mars? Starting three years ago, NASA sent a coffee-table sized robot named Opportunity on a mission rolling across the red planet's Meridiani Planum to find out. Last week, it finally arrived. Expansive Endeavour crater stretches 22 kilometers from rim to rim, making it the largest crater ever visited by a Mars Exploration Rover (MER). It is hypothesized that the impact that created the crater exposed ancient rock that possibly formed under wet conditions, and if so, this rock may yield unique clues to the watery past of Mars. Pictured above, the west rim of Endeavour looms just ahead of the Opportunity rover. Opportunity may well spend the rest of its operational life exploring Endeavour, taking pictures, spinning its wheels, and boring into intriguing rocks.
2011 August 16
Shapley 1: An Annular Planetary Nebula
Image Credit: ESO
What happens when a star runs out of nuclear fuel? For stars about the mass of our Sun, the center condenses into a white dwarf while the outer atmospheric layers are expelled into space and appear as a planetary nebula. This particular planetary nebula, pictured above and designated Shapley 1 after the famous astronomer Harlow Shapley, has a very apparent annular ring like structure. Although some of these nebulas appear like planets on the sky (hence their name), they actually surround stars far outside our Solar System.
Shapley 1: An Annular Planetary Nebula
Image Credit: ESO
What happens when a star runs out of nuclear fuel? For stars about the mass of our Sun, the center condenses into a white dwarf while the outer atmospheric layers are expelled into space and appear as a planetary nebula. This particular planetary nebula, pictured above and designated Shapley 1 after the famous astronomer Harlow Shapley, has a very apparent annular ring like structure. Although some of these nebulas appear like planets on the sky (hence their name), they actually surround stars far outside our Solar System.
2011 August 17
Perseid Below
Credit: Ron Garan, ISS Expedition 28 Crew, NASA
Denizens of planet Earth watched this year's Perseid meteor shower by looking up into the moonlit night sky. But this remarkable view captured by astronaut Ron Garan looks down on a Perseid meteor. 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. Out of the frame, the Sun is on the horizon beyond one of the station's solar panel arrays at the upper right. Seen above the meteor near the horizon is bright star Arcturus and a star field that includes the constellations Bootes and Corona Borealis. The image was recorded on August 13 while the space station orbited above an area of China approximately 400 kilometers to the northwest of Beijing.
Perseid Below
Credit: Ron Garan, ISS Expedition 28 Crew, NASA
Denizens of planet Earth watched this year's Perseid meteor shower by looking up into the moonlit night sky. But this remarkable view captured by astronaut Ron Garan looks down on a Perseid meteor. 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. Out of the frame, the Sun is on the horizon beyond one of the station's solar panel arrays at the upper right. Seen above the meteor near the horizon is bright star Arcturus and a star field that includes the constellations Bootes and Corona Borealis. The image was recorded on August 13 while the space station orbited above an area of China approximately 400 kilometers to the northwest of Beijing.
2011 August 18
A Sun Pillar Over Ontario
Image Credit & Copyright: Rick Stankiewicz (Peterborough Astronomical Association)
What is that on the horizon? No, it's not an alien starship battling distant Earthlings, but rather a sun pillar. When driving across Ontario, Canada in early June, the photographer was surprised to encounter such an "eerie and beautiful" vista, and immediately took pictures. When the atmosphere is cold, ice sometimes forms flat six-sided crystals as it falls from high-level clouds. Air resistance then causes these crystals to lie nearly flat much of the time as they flutter to the ground. If viewed toward a rising or setting Sun, these flat crystals will reflect sunlight and create an unusual column of light -- a sun pillar as seen above. Such columns of light are not uncommon to see, and a retrospective of past APODs that have featured picturesque sun pillars can be found here.
A Sun Pillar Over Ontario
Image Credit & Copyright: Rick Stankiewicz (Peterborough Astronomical Association)
What is that on the horizon? No, it's not an alien starship battling distant Earthlings, but rather a sun pillar. When driving across Ontario, Canada in early June, the photographer was surprised to encounter such an "eerie and beautiful" vista, and immediately took pictures. When the atmosphere is cold, ice sometimes forms flat six-sided crystals as it falls from high-level clouds. Air resistance then causes these crystals to lie nearly flat much of the time as they flutter to the ground. If viewed toward a rising or setting Sun, these flat crystals will reflect sunlight and create an unusual column of light -- a sun pillar as seen above. Such columns of light are not uncommon to see, and a retrospective of past APODs that have featured picturesque sun pillars can be found here.
2011 August 19
Herschel's Cocoon
Credit: ESA, SPIRE & PACS Consortia, Doris Arzoumanian (CEA Saclay), et al.
In this remarkable infrared skyscape of interstellar clouds adrift in the high flying constellation Cygnus, the eye is drawn to the Cocoon Nebula. Also known as IC5146, the dusty star forming region is shown in blue hues in the Herschel Space Observatory false color image, at wavelengths more than 100 times longer than visible red light. And while visible light images show the Cocoon nebula at the end of long dark nebula Barnard 168, Hershel's infrared view finds the cosmic Cocoon punctuating a trail of filamentary clouds of glowing dust. The filaments have widths that suggest they are formed as shockwaves from exploding stars travel through the medium, sweeping up and compressing the interstellar dust and gas. Herschel data also indicate stars are forming along the dusty filaments. The Cocoon Nebula itself is about 15 light-years wide and 4,000 light-years away.
Herschel's Cocoon
Credit: ESA, SPIRE & PACS Consortia, Doris Arzoumanian (CEA Saclay), et al.
In this remarkable infrared skyscape of interstellar clouds adrift in the high flying constellation Cygnus, the eye is drawn to the Cocoon Nebula. Also known as IC5146, the dusty star forming region is shown in blue hues in the Herschel Space Observatory false color image, at wavelengths more than 100 times longer than visible red light. And while visible light images show the Cocoon nebula at the end of long dark nebula Barnard 168, Hershel's infrared view finds the cosmic Cocoon punctuating a trail of filamentary clouds of glowing dust. The filaments have widths that suggest they are formed as shockwaves from exploding stars travel through the medium, sweeping up and compressing the interstellar dust and gas. Herschel data also indicate stars are forming along the dusty filaments. The Cocoon Nebula itself is about 15 light-years wide and 4,000 light-years away.
2011 August 20
Stereo Vesta
Image Credit: NASA, JPL-Caltech, UCLA, MPS, DLR, IDA
Get out your red/blue glasses and float next to 4 Vesta. A 500 kilometer diameter world, Vesta lies in the main asteroid belt between the orbits of Mars and Jupiter. This stereo anaglyph was constructed from two separate images recorded on July 24 by the just arrived Dawn spacecraft's framing camera with a resolution of about 500 meters per pixel. The 3D view features Vesta's newly discovered terrain, including long equatorial ridges and troughs and the prominent string of three craters at the upper right dubbed Snowman. Highlighted in 3D, steep sides of many of the craters show streaks of both bright and dark material. Of course, the ion-driven Dawn spacecraft is not marooned off Vesta. After a year exploring the asteroid from orbit, Dawn is scheduled to depart, beginning its journey to Ceres.
Stereo Vesta
Image Credit: NASA, JPL-Caltech, UCLA, MPS, DLR, IDA
Get out your red/blue glasses and float next to 4 Vesta. A 500 kilometer diameter world, Vesta lies in the main asteroid belt between the orbits of Mars and Jupiter. This stereo anaglyph was constructed from two separate images recorded on July 24 by the just arrived Dawn spacecraft's framing camera with a resolution of about 500 meters per pixel. The 3D view features Vesta's newly discovered terrain, including long equatorial ridges and troughs and the prominent string of three craters at the upper right dubbed Snowman. Highlighted in 3D, steep sides of many of the craters show streaks of both bright and dark material. Of course, the ion-driven Dawn spacecraft is not marooned off Vesta. After a year exploring the asteroid from orbit, Dawn is scheduled to depart, beginning its journey to Ceres.
2011 August 21
The Fairy of Eagle Nebula
Image Credit: The Hubble Heritage Team, (STScI/AURA), ESA, NASA
The dust sculptures of the Eagle Nebula are evaporating. As powerful starlight whittles away these cool cosmic mountains, the statuesque pillars that remain might be imagined as mythical beasts. Pictured above is one of several striking dust pillars of the Eagle Nebula that might be described as a gigantic alien fairy. This fairy, however, is ten light years tall and spews radiation much hotter than common fire. The greater Eagle Nebula, M16, is actually a giant evaporating shell of gas and dust inside of which is a growing cavity filled with a spectacular stellar nursery currently forming an open cluster of stars. The above image in scientifically re-assigned colors was released in 2005 as part of the fifteenth anniversary celebration of the launch of the Hubble Space Telescope.
The Fairy of Eagle Nebula
Image Credit: The Hubble Heritage Team, (STScI/AURA), ESA, NASA
The dust sculptures of the Eagle Nebula are evaporating. As powerful starlight whittles away these cool cosmic mountains, the statuesque pillars that remain might be imagined as mythical beasts. Pictured above is one of several striking dust pillars of the Eagle Nebula that might be described as a gigantic alien fairy. This fairy, however, is ten light years tall and spews radiation much hotter than common fire. The greater Eagle Nebula, M16, is actually a giant evaporating shell of gas and dust inside of which is a growing cavity filled with a spectacular stellar nursery currently forming an open cluster of stars. The above image in scientifically re-assigned colors was released in 2005 as part of the fifteenth anniversary celebration of the launch of the Hubble Space Telescope.
2011 August 22
TrES-2b: Dark Planet
Illustration Credit: David A. Aguilar (CfA), TrES, Kepler, NASA
Why is this planet so dark? Planet TrES-2b reflects back less than one percent of the light it receives, making it darker than any known planet or moon, darker even than coal. Jupiter-sized TrES-2b orbits extremely close to a sun-like star 750 light years away, and was discovered producing slight eclipses in 2006 using the modest 10-cm telescopes of the Trans-Atlantic Exoplanet Survey (TrES). The alien world's strange darkness, however, was only uncovered recently by observations indicating its slight reflective glow by the Sun-orbiting Kepler satellite. An artist's drawing of planet is shown above, complete with unsubstantiated speculation on possible moons. Reasons for TrES-2b's darkness remain unknown and are an active topic of research.
TrES-2b: Dark Planet
Illustration Credit: David A. Aguilar (CfA), TrES, Kepler, NASA
Why is this planet so dark? Planet TrES-2b reflects back less than one percent of the light it receives, making it darker than any known planet or moon, darker even than coal. Jupiter-sized TrES-2b orbits extremely close to a sun-like star 750 light years away, and was discovered producing slight eclipses in 2006 using the modest 10-cm telescopes of the Trans-Atlantic Exoplanet Survey (TrES). The alien world's strange darkness, however, was only uncovered recently by observations indicating its slight reflective glow by the Sun-orbiting Kepler satellite. An artist's drawing of planet is shown above, complete with unsubstantiated speculation on possible moons. Reasons for TrES-2b's darkness remain unknown and are an active topic of research.
2011 August 23
Aurora Over Greenland
Image Credit: Copyright: Juan Carlos Casado (TWAN)
This aurora arched from horizon to horizon. During the current Shelios expedition to observe and learn about the northern lights, the sky last weekend did not disappoint. After sunset and some careful photographic planning, the above image was taken from the expedition's Qaleraliq campsite in southern Greenland. Visible straight through the center of the aurora, found with a careful eye, is the Big Dipper and the surrounding constellation of the Big Bear (Ursa Major). The brightest orb on the far right is the Moon, while Jupiter can be seen even further to the right. The Shelios expedition is scheduled to last until the end of August and include live broadcasts of ongoing auroras.
Aurora Over Greenland
Image Credit: Copyright: Juan Carlos Casado (TWAN)
This aurora arched from horizon to horizon. During the current Shelios expedition to observe and learn about the northern lights, the sky last weekend did not disappoint. After sunset and some careful photographic planning, the above image was taken from the expedition's Qaleraliq campsite in southern Greenland. Visible straight through the center of the aurora, found with a careful eye, is the Big Dipper and the surrounding constellation of the Big Bear (Ursa Major). The brightest orb on the far right is the Moon, while Jupiter can be seen even further to the right. The Shelios expedition is scheduled to last until the end of August and include live broadcasts of ongoing auroras.
2011 August 24
A Pileus Iridescent Cloud Over Ethiopia
Image Credit & Copyright: Esther Havens (Light the World)
Yes, but how many dark clouds have a multicolored lining? Pictured, behind this darker cloud, is a pileus iridescent cloud, a group of water droplets that have a uniformly similar size and so together diffract different colors of sunlight by different amounts. The above image was taken just after the picturesque sight was noticed by chance by a photographer in Ethiopia. A more detailed picture of the same cloud shows not only many colors, but unusual dark and wavy bands whose origins are thought related to wave disturbances in the cloud.
A Pileus Iridescent Cloud Over Ethiopia
Image Credit & Copyright: Esther Havens (Light the World)
Yes, but how many dark clouds have a multicolored lining? Pictured, behind this darker cloud, is a pileus iridescent cloud, a group of water droplets that have a uniformly similar size and so together diffract different colors of sunlight by different amounts. The above image was taken just after the picturesque sight was noticed by chance by a photographer in Ethiopia. A more detailed picture of the same cloud shows not only many colors, but unusual dark and wavy bands whose origins are thought related to wave disturbances in the cloud.
2011 August 25
Portrait of NGC 281
Image Credit & Copyright: J-P Metsävainio (Astro Anarchy)
Look through the cosmic cloud cataloged as NGC 281 and it's almost easy to miss stars of open cluster IC 1590. But, formed within the nebula, that cluster's young, massive stars ultimately power the pervasive nebular glow. The eye-catching shapes looming in this portrait of NGC 281 are sculpted columns and dense dust globules seen in silhouette, eroded by intense, energetic winds and radiation from the hot cluster stars. If they survive long enough, the dusty structures could also be sites of future star formation. Playfully called the Pacman Nebula because of its overall shape, NGC 281 is about 10,000 light-years away in the constellation Cassiopeia. This composite image was made through narrow-band filters, but combines emission from the nebula's hydrogen, sulfur, and oxygen atoms in a visible spectrum palette. It spans over 80 light-years at the estimated distance of NGC 281.
Portrait of NGC 281
Image Credit & Copyright: J-P Metsävainio (Astro Anarchy)
Look through the cosmic cloud cataloged as NGC 281 and it's almost easy to miss stars of open cluster IC 1590. But, formed within the nebula, that cluster's young, massive stars ultimately power the pervasive nebular glow. The eye-catching shapes looming in this portrait of NGC 281 are sculpted columns and dense dust globules seen in silhouette, eroded by intense, energetic winds and radiation from the hot cluster stars. If they survive long enough, the dusty structures could also be sites of future star formation. Playfully called the Pacman Nebula because of its overall shape, NGC 281 is about 10,000 light-years away in the constellation Cassiopeia. This composite image was made through narrow-band filters, but combines emission from the nebula's hydrogen, sulfur, and oxygen atoms in a visible spectrum palette. It spans over 80 light-years at the estimated distance of NGC 281.
2011 August 26
A Young Supernova in the Nearby Pinwheel Galaxy
Image Credit: D. Andrew Howell & BJ Fulton (LCOGT) et al., Faulkes Telescope North, LCOGT
A nearby star has exploded and telescopes all over the world are turning to monitor it. The supernova, dubbed PTF 11kly, was discovered by computer only two days ago as part of the Palomar Transient Factory (PTF) sky survey utilizing the wide angle 1.2-meter Samuel Oschin Telescope in California. Its rapid recovery makes it one of the supernovas caught most soon after ignition. PTF 11kly occurred in the photogenic Pinwheel galaxy (M101), which, being only about 21 million light years away, makes it one of the closest supernovas seen in decades. Rapid follow up observations have already given a clear indication that PTF 11kly is a Type Ia supernova, a type of white dwarf detonation that usually progresses in such a standard manner than it has helped to calibrate the expansion history of the entire universe. Studying such a close and young Type Ia event, however, may yield new and unique clues. If early indications are correct, PTF 11kly should brighten to about visual magnitude 10 in the coming weeks, making it possible to monitor with even moderately sized telescopes.
A Young Supernova in the Nearby Pinwheel Galaxy
Image Credit: D. Andrew Howell & BJ Fulton (LCOGT) et al., Faulkes Telescope North, LCOGT
A nearby star has exploded and telescopes all over the world are turning to monitor it. The supernova, dubbed PTF 11kly, was discovered by computer only two days ago as part of the Palomar Transient Factory (PTF) sky survey utilizing the wide angle 1.2-meter Samuel Oschin Telescope in California. Its rapid recovery makes it one of the supernovas caught most soon after ignition. PTF 11kly occurred in the photogenic Pinwheel galaxy (M101), which, being only about 21 million light years away, makes it one of the closest supernovas seen in decades. Rapid follow up observations have already given a clear indication that PTF 11kly is a Type Ia supernova, a type of white dwarf detonation that usually progresses in such a standard manner than it has helped to calibrate the expansion history of the entire universe. Studying such a close and young Type Ia event, however, may yield new and unique clues. If early indications are correct, PTF 11kly should brighten to about visual magnitude 10 in the coming weeks, making it possible to monitor with even moderately sized telescopes.
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2011 August 27
Hurricane Irene Forms
Image Credit: GOES 13 satellite, NASA, NOAA
How does a hurricane form? Although a complete picture is still being researched, insight into this process might be gleaned by watching the above time lapse movie of the formation of Hurricane Irene, a large storm system currently threatening the eastern seaboard of the USA. Starting as a slight pressure difference visible as nondescript clouds on the lower right, Hurricane Irene is shown growing into large spiraling storm system of low pressure off the coast of South Carolina. A hurricane is powered by evaporating ocean water, and so typically gains strength over warm water and loses strength over land. Besides Earth, other planets that have hurricane-like storm systems include Venus, Saturn, Jupiter, Uranus, and Neptune. Much remains unknown about hurricanes and cyclones, including the exact path they will take.
Hurricane Irene Forms
Image Credit: GOES 13 satellite, NASA, NOAA
How does a hurricane form? Although a complete picture is still being researched, insight into this process might be gleaned by watching the above time lapse movie of the formation of Hurricane Irene, a large storm system currently threatening the eastern seaboard of the USA. Starting as a slight pressure difference visible as nondescript clouds on the lower right, Hurricane Irene is shown growing into large spiraling storm system of low pressure off the coast of South Carolina. A hurricane is powered by evaporating ocean water, and so typically gains strength over warm water and loses strength over land. Besides Earth, other planets that have hurricane-like storm systems include Venus, Saturn, Jupiter, Uranus, and Neptune. Much remains unknown about hurricanes and cyclones, including the exact path they will take.