Poll: Astronomy Picture of the Week for 2012 February 12-18
Posted: Tue Feb 21, 2012 2:58 pm
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Please vote for the TWO best Astronomy Pictures of the Day (image and text) of February 12-18, 2012.
(Repeated APODs are not included in the poll.)
All titles are clickable and link to the original APOD page.
We ask for your help in choosing an APOW as this helps Jerry and Robert create "year in APOD images" review lectures, create APOM and APOY polls that can be used to create a free PDF calendar at year's end, and provides feedback on which images and APODs were relatively well received. You can select two top images for the week.
We are very interested in why you selected the APODs you voted for, and enthusiastically welcome your telling us why by responding to this thread.
Thank you!
_______________________________________________________________
<- Previous week's poll
Why would Venus appear oval? Venus has been seen countless times from the surface of the Earth, and every time the Earth's atmosphere has dispersed its light to some degree. When the air has just the right amount of dust or water droplets, small but distant objects like Venus appear spread out into an angularly large aureole. Aureoles are not unusual to see and are frequently noted as circular coronas around the Sun or Moon. Recently, however, aureoles have been imaged that are not circular but distinctly oval. The above oval Venusian aureole was imaged by the astrophotographer who first noted the unusual phenomenon three years ago. Initially disputed, the unusual distortion has now been confirmed multiple times by several different astrophotographers. What causes the ellipticity is currently unknown, and although several hypotheses hold that horizontally oriented ice crystals are responsible, significant discussions about it are still taking place.
The Rosette Nebula is not the only cosmic cloud of gas and dust to evoke the imagery of flowers -- but it is the most famous. At the edge of a large molecular cloud in Monoceros, some 5,000 light years away, the petals of this rose are actually a stellar nursery whose lovely, symmetric shape is sculpted by the winds and radiation from its central cluster of hot young stars. The stars in the energetic cluster, cataloged as NGC 2244, are only a few million years old, while the central cavity in the Rosette Nebula, cataloged as NGC 2237, is about 50 light-years in diameter. The nebula can be seen firsthand with a small telescope toward the constellation of the Unicorn (Monoceros).
Reflection nebulas reflect light from a nearby star. Many small carbon grains in the nebula reflect the light. The blue color typical of reflection nebula is caused by blue light being more efficiently scattered by the carbon dust than red light. The brightness of the nebula is determined by the size and density of the reflecting grains, and by the color and brightness of the neighboring star(s). NGC 1435, pictured above, surrounds Merope (23 Tau), one of the brightest stars in the Pleiades (M45). The Pleiades nebulosity is caused by a chance encounter between an open cluster of stars and a dusty molecular cloud.
These two spiral galaxies make a photogenic pair, found within the boundaries of the northern constellation Draco. Contrasting in color and orientation, NGC 5965 is nearly edge-on to our line of sight and dominated by yellow hues, while bluish NGC 5963 is closer to face-on. Of course, even in this well-framed cosmic snapshot the scene is invaded by other galaxies, including small elliptical NGC 5969 at the lower left. Brighter, spiky stars in our own Milky Way are scattered through the foreground. Though they seem to be close and of similar size, galaxies NGC 5965 and NGC 5963 are far apart and unrelated, by chance appearing close on the sky. NGC 5965 is about 150 million light-years distant and over 200,000 light-years across. Much smaller, NGC 5963 is a mere 40 million light-years away and so is not associated with the edge-on spiral. Difficult to follow, NGC 5963's extraordinarily faint blue spiral arms mark it as a low surface brightness galaxy.
Aristarchus Plateau is anchored in the vast lava flows of the Moon's Oceanus Procellarum. At the plateau's southeastern edge lies the spectacular Aristarchus Crater, an impact crater 40 kilometers wide and 3 kilometers deep. Scan along this remarkable panorama and you will find yourself gazing directly at the crater's west wall for some 25 kilometers. Features along the terraced wall include dark impact melt and debris deposits, bright excavated material, and boulders over 100 meters wide. At a full resolution of 1.6 meters per pixel, the sharp mosaic was created from images recorded by the Lunar Reconnaissance Orbiter's narrow angle camera in November of 2011. The orbiter's vantage point was 70 kilometers east of the crater's center and only 26 kilometers above the lunar surface.
This rugged road through the dark Atacama Desert seems to lead skyward toward the bright stars and glowing nebulae of the southern Milky Way. If you follow the road you will get to Cerro Armazones peak in Chile, future construction site for the 40-meter class European Extremely Large Telescope. For now though, sliding your cursor across the image will identify wonders of the southern skies in view. The scene is dominated by the reddish glow of the Great Carina Nebula, one of our galaxy's largest star forming regions. In fact, the remarkable skyscape is not a composite of varying exposures or a photomontage. Far from sources of light pollution, the landscape illuminated by starlight and the Milky Way above were recorded by a modified digital camera and fast lens. The sensitive system captured both planet Earth and deep sky in a relatively short exposure.
<- Previous week's poll
Please vote for the TWO best Astronomy Pictures of the Day (image and text) of February 12-18, 2012.
(Repeated APODs are not included in the poll.)
All titles are clickable and link to the original APOD page.
We ask for your help in choosing an APOW as this helps Jerry and Robert create "year in APOD images" review lectures, create APOM and APOY polls that can be used to create a free PDF calendar at year's end, and provides feedback on which images and APODs were relatively well received. You can select two top images for the week.
We are very interested in why you selected the APODs you voted for, and enthusiastically welcome your telling us why by responding to this thread.
Thank you!
_______________________________________________________________
<- Previous week's poll
Why would Venus appear oval? Venus has been seen countless times from the surface of the Earth, and every time the Earth's atmosphere has dispersed its light to some degree. When the air has just the right amount of dust or water droplets, small but distant objects like Venus appear spread out into an angularly large aureole. Aureoles are not unusual to see and are frequently noted as circular coronas around the Sun or Moon. Recently, however, aureoles have been imaged that are not circular but distinctly oval. The above oval Venusian aureole was imaged by the astrophotographer who first noted the unusual phenomenon three years ago. Initially disputed, the unusual distortion has now been confirmed multiple times by several different astrophotographers. What causes the ellipticity is currently unknown, and although several hypotheses hold that horizontally oriented ice crystals are responsible, significant discussions about it are still taking place.
The Rosette Nebula is not the only cosmic cloud of gas and dust to evoke the imagery of flowers -- but it is the most famous. At the edge of a large molecular cloud in Monoceros, some 5,000 light years away, the petals of this rose are actually a stellar nursery whose lovely, symmetric shape is sculpted by the winds and radiation from its central cluster of hot young stars. The stars in the energetic cluster, cataloged as NGC 2244, are only a few million years old, while the central cavity in the Rosette Nebula, cataloged as NGC 2237, is about 50 light-years in diameter. The nebula can be seen firsthand with a small telescope toward the constellation of the Unicorn (Monoceros).
Reflection nebulas reflect light from a nearby star. Many small carbon grains in the nebula reflect the light. The blue color typical of reflection nebula is caused by blue light being more efficiently scattered by the carbon dust than red light. The brightness of the nebula is determined by the size and density of the reflecting grains, and by the color and brightness of the neighboring star(s). NGC 1435, pictured above, surrounds Merope (23 Tau), one of the brightest stars in the Pleiades (M45). The Pleiades nebulosity is caused by a chance encounter between an open cluster of stars and a dusty molecular cloud.
These two spiral galaxies make a photogenic pair, found within the boundaries of the northern constellation Draco. Contrasting in color and orientation, NGC 5965 is nearly edge-on to our line of sight and dominated by yellow hues, while bluish NGC 5963 is closer to face-on. Of course, even in this well-framed cosmic snapshot the scene is invaded by other galaxies, including small elliptical NGC 5969 at the lower left. Brighter, spiky stars in our own Milky Way are scattered through the foreground. Though they seem to be close and of similar size, galaxies NGC 5965 and NGC 5963 are far apart and unrelated, by chance appearing close on the sky. NGC 5965 is about 150 million light-years distant and over 200,000 light-years across. Much smaller, NGC 5963 is a mere 40 million light-years away and so is not associated with the edge-on spiral. Difficult to follow, NGC 5963's extraordinarily faint blue spiral arms mark it as a low surface brightness galaxy.
Aristarchus Plateau is anchored in the vast lava flows of the Moon's Oceanus Procellarum. At the plateau's southeastern edge lies the spectacular Aristarchus Crater, an impact crater 40 kilometers wide and 3 kilometers deep. Scan along this remarkable panorama and you will find yourself gazing directly at the crater's west wall for some 25 kilometers. Features along the terraced wall include dark impact melt and debris deposits, bright excavated material, and boulders over 100 meters wide. At a full resolution of 1.6 meters per pixel, the sharp mosaic was created from images recorded by the Lunar Reconnaissance Orbiter's narrow angle camera in November of 2011. The orbiter's vantage point was 70 kilometers east of the crater's center and only 26 kilometers above the lunar surface.
This rugged road through the dark Atacama Desert seems to lead skyward toward the bright stars and glowing nebulae of the southern Milky Way. If you follow the road you will get to Cerro Armazones peak in Chile, future construction site for the 40-meter class European Extremely Large Telescope. For now though, sliding your cursor across the image will identify wonders of the southern skies in view. The scene is dominated by the reddish glow of the Great Carina Nebula, one of our galaxy's largest star forming regions. In fact, the remarkable skyscape is not a composite of varying exposures or a photomontage. Far from sources of light pollution, the landscape illuminated by starlight and the Milky Way above were recorded by a modified digital camera and fast lens. The sensitive system captured both planet Earth and deep sky in a relatively short exposure.
<- Previous week's poll