________________________________________________________________
Please vote for the TWO best Astronomy Pictures of the Day (image and text) of January 23-29.
(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, creates APOM 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.
Thank you!
________________________________________________________________
<- Previous week's poll
The
Peekskill meteor of 1992 was captured on 16 independent
videos and then struck a car.
Documented as brighter than the
full Moon, the
spectacular fireball crossed parts of several
USA states during its 40 seconds of glory before landing in
Peekskill,
New York. A video of the fireball beyond a high school football game in
Johnstown, Pennsylvania, USA, is pictured above. The resulting meteorite is imaged
here, and was found to be composed of dense rock and has the size and mass of an extremely heavy
bowling ball. If you are lucky enough to find a
meteorite just after
impact, do not pick it up -- parts of it are likely to be either very hot or very cold. Tracking meteors origins and destinations might be easier in this modern digital age, but many security cameras videos that likely caught a bright fireball are not preserved. If you would like to volunteer to help meteor science by locating images and videos of newly occurring fireballs within 48 hours after they occur, here is a place to
sign up.
Where on this moon would you land? The moon
pictured above is not Earth's moon but
Phobos, the closest moon to the planet Mars.
Phobos is so close to Mars that it is expected to break up and crash into the red planet within the next 100 million years. Earlier just this year, however,
ESA's
Mars Express mission took detailed images of the area surrounding Phobos' South Pole. Visible on the small moon's
unusually dark surface are many
circular craters, long chains of craters, and strange streaks. Large
Stickney Crater, which looms on the far right, was also visible in the
corresponding North Polar image taken last year. This and other
similar images of Phobos are so
detailed, resolving items even 10-meters across, that they are useful for examining
proposed landing sites of the future Phobos-Grunt mission. The Russian
Phobos-Grunt robotic spacecraft is scheduled to launch toward
Phobos later this year and return surface samples in 2014.
What is causing the picturesque ripples of supernova remnant SNR 0509-67.5? The ripples, as well as the greater nebula, were
imaged in unprecedented detail by the
Hubble Space Telescope in 2006 and again late last year. The red color was recoded by a Hubble filter that left only the light emitted by
energetic hydrogen. The precise reason for the ripples remains unknown, with two considered origin hypotheses relating them to relatively dense portions of either ejected or impacted gas. The reason for the broader
red glowing ring is more clear, with expansion speed and light echos relating it to a classic
Type Ia supernova explosion that must have occurred about 400 years earlier.
SNR 0509 currently spans about 23
light years and lies about 160,000 light years away toward the constellation of the
dolphinfish (
Dorado) in the
Large Magellanic Cloud. The expanding ring carries with it another great mystery, however: why wasn't this
supernova seen 400 years ago when light from the initial blast should have passed the Earth?
How do spiral galaxies form stars? To help find out, the
Hubble Space Telescope imaged the nearby photogenic spiral
M51 in
infrared light to highlight the dust that traces the dense gas that best forms stars. To further isolate the
dust, much of the optical light from stars has also been
digitally removed. The
resulting unique image shows swirling and intricate patterns on the longest scales, while numerous bright clumps of previously hidden
open star clusters appear on the smaller scales. To see the
detailed optical light image for comparison, run your cursor over the above image. Anyone with a good pair of
binoculars can see the
Whirlpool toward the constellation of the
Hunting Dogs (
Canes Venatici). M51 lies about 30 million light years away, while the above imaged area spans about 15,000
light years from top to bottom. Astronomers speculate that M51's
spiral structure is primarily due to its gravitational interaction with
a neighboring smaller galaxy.
M78 isn't really hiding in planet Earth's night sky. About 1,600 light-years away and
nestled in the nebula rich
constellation Orion, the large, bright,
reflection nebula is well-known to telescopic skygazers. But this gorgeous image of M78 was selected as the winner of the
Hidden Treasures 2010 astrophotography competition. Held by the European Southern Observatory (ESO), the competition challenged amateur astronomers to process data from ESO's astronomical archive in search of hidden cosmic gems.
The winning entry shows off amazing details within
bluish M78 (center) embraced in dark, dusty clouds, along with a smaller reflection nebula in the region, NGC 2071 (top). Yellowish and even more compact, the recently discovered, variable
McNeil's Nebula is prominent in the scene below and right of center. Based on data from ESO's WFI camera and 2.2 meter telescope at
La Silla, Chile, this image spans just over 0.5 degrees on the sky. That corresponds to 15 light-years at the estimated distance of
M78.
Featured in this artist's illustration,
NASA's NanoSail-D finally unfurled a very thin, 10 square meter reflective sail on January 20th, becoming the first solar sail spacecraft in low Earth orbit. Often considered the
stuff of science fiction, sailing through space
was suggested 400 years ago by astronomer Johannes Kepler who observed comet tails blown by the solar wind.
Modern solar sail spacecraft designs, like NanoSail-D or the Japanese interplanetary
spacecraft IKAROS, rely on the small but
continuous pressure from sunlight itself for thrust. Glinting in the sunlight as it circles planet Earth, the NanoSail-D solar sail will periodically be bright and easily visible to the eye. In fact, skygazers are urged to participate in an ongoing
contest to capture images of NanoSail-D. The images will help NASA monitor the satellite before it reenters the atmosphere in April or May.
Celebrating 7 years on the surface of
the Red Planet, Mars exploration rover Opportunity now stands near the rim of 90 meter wide
Santa Maria crater. Remarkably, Opportunity and its fellow
rover Spirit were initially
intended for a 3 month long primary mission. Still exploring, the golf cart-sized robot and shadow (far right) appear in the foreground of this panoramic view of its
current location. The mosaic was constructed using images from the rover's navigation camera. On its
7 year anniversary, Opportunity can boast
traversing a total of 26.7 kilometers
along the martian surface. After investigating Santa Maria crater, controllers plan to have Opportunity resume a long-term trek toward Endurance crater, a large, 22 kilometer diameter crater about 6 kilometers from Santa Maria. During coming days, communication with the rover will be more difficult as Mars moves close to alignment with the Sun as seen from planet Earth's
perspective.
<- Previous week's poll
[size=200][color=#FF0000]________________________________________________________________[/color][/size]
Please vote for the TWO best Astronomy Pictures of the Day (image and text) of January 23-29.
(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, creates APOM 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.
Thank you!
[size=200][color=#FF0000]________________________________________________________________[/color][/size]
[size=110][url=http://asterisk.apod.com/viewtopic.php?f=29&t=22748][color=#4040FF][b]<- Previous week's poll[/b][/color][/url][/size]
[c][url=http://apod.nasa.gov/apod/ap110123.html][size=150][b]Peekskill Fireball Video: Johnstown (2011 Jan 23)[/b][/size][/url][/c]
[float=left][youtube]http://www.youtube.com/watch?v=5S3WfNDD59Y&feature=player_embedded[/youtube][/float] The [url=http://uregina.ca/~astro/mb_5.html]Peekskill meteor[/url] of 1992 was captured on 16 independent [url=http://aquarid.physics.uwo.ca/~pbrown/Videos/peekskill.htm]video[/url]s and then struck a car. [url=http://nyrockman.com/peekskill.htm]Documented[/url] as brighter than the [url=http://apod.nasa.gov/apod/ap020316.html]full Moon[/url], the [url=http://starchild.gsfc.nasa.gov/docs/StarChild/shadow/solar_system_level2/peekskill.html]spectacular fireball[/url] crossed parts of several [url=https://www.cia.gov/library/publications/the-world-factbook/geos/us.html]USA[/url] states during its 40 seconds of glory before landing in [url=http://en.wikipedia.org/wiki/Peekskill,_New_York]Peekskill[/url], [url=http://en.wikipedia.org/wiki/New_York]New York[/url]. A video of the fireball beyond a high school football game in [url=http://en.wikipedia.org/wiki/Johnstown,_Pennsylvania]Johnstown, Pennsylvania[/url], USA, is pictured above. The resulting meteorite is imaged [url=http://apod.nasa.gov/apod/ap061119.html]here[/url], and was found to be composed of dense rock and has the size and mass of an extremely heavy [url=http://www.youtube.com/watch?v=yyUmEgvq3B0]bowling[/url] ball. If you are lucky enough to find a [url=http://en.wikipedia.org/wiki/Meteorite]meteorite[/url] just after [url=http://apod.nasa.gov/apod/ap990711.html]impact[/url], do not pick it up -- parts of it are likely to be either very hot or very cold. Tracking meteors origins and destinations might be easier in this modern digital age, but many security cameras videos that likely caught a bright fireball are not preserved. If you would like to volunteer to help meteor science by locating images and videos of newly occurring fireballs within 48 hours after they occur, here is a place to [url=http://asterisk.apod.com/viewtopic.php?f=32&t=22715]sign up[/url].
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[c][url=http://apod.nasa.gov/apod/ap110124.html][size=150][b]Phobos' South Pole from Mars Express (2011 Jan 24)[/b][/size][/url][/c]
[float=left][img2]http://apod.nasa.gov/apod/image/1101/phobos2_marsexpress.jpg[/img2][/float]Where on this moon would you land? The moon [url=http://webservices.esa.int/blog/post/7/1317]pictured above[/url] is not Earth's moon but [url=http://en.wikipedia.org/wiki/Phobos_%28moon%29]Phobos[/url], the closest moon to the planet Mars. [url=http://apod.nasa.gov/apod/ap080414.html]Phobos[/url] is so close to Mars that it is expected to break up and crash into the red planet within the next 100 million years. Earlier just this year, however, [url=http://en.wikipedia.org/wiki/ESA]ESA[/url]'s [url=http://en.wikipedia.org/wiki/Mars_Express]Mars Express[/url] mission took detailed images of the area surrounding Phobos' South Pole. Visible on the small moon's [url=http://apod.nasa.gov/apod/ap101201.html]unusually dark surface[/url] are many [url=http://www.youtube.com/watch?v=XzIw0c_MjTc]circular craters[/url], long chains of craters, and strange streaks. Large [url=http://apod.nasa.gov/apod/ap080410.html]Stickney Crater[/url], which looms on the far right, was also visible in the [url=http://apod.nasa.gov/apod/%20ap100317.html]corresponding North Polar image[/url] taken last year. This and other [url=http://webservices.esa.int/blog/post/7/1317]similar images[/url] of Phobos are so [url=http://planetary.org/blog/article/00002888/]detailed[/url], resolving items even 10-meters across, that they are useful for examining [url=http://www.esa.int/SPECIALS/Mars_Express/SEMIPY6SXIG_1.html#subhead4]proposed landing sites[/url] of the future Phobos-Grunt mission. The Russian [url=http://en.wikipedia.org/wiki/Fobos-Grunt]Phobos-Grunt robotic spacecraft[/url] is scheduled to launch toward [url=http://www.youtube.com/watch?v=vkBPeGLDKS4]Phobos[/url] later this year and return surface samples in 2014.
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[c][url=http://apod.nasa.gov/apod/ap110125.html][size=150][b]The Rippled Red Ribbons of SNR 0509 (2011 Jan 25)[/b][/size][/url][/c]
[float=left][img2]http://apod.nasa.gov/apod/image/1101/snr0509_hubble.jpg[/img2][/float]What is causing the picturesque ripples of supernova remnant SNR 0509-67.5? The ripples, as well as the greater nebula, were [url=http://hubblesite.org/newscenter/archive/releases/2010/27/image/]imaged[/url] in unprecedented detail by the [url=http://hubblesite.org/the_telescope/hubble_essentials/]Hubble Space Telescope[/url] in 2006 and again late last year. The red color was recoded by a Hubble filter that left only the light emitted by [url=http://en.wikipedia.org/wiki/H-alpha]energetic hydrogen[/url]. The precise reason for the ripples remains unknown, with two considered origin hypotheses relating them to relatively dense portions of either ejected or impacted gas. The reason for the broader [url=http://hubblesite.org/newscenter/archive/releases/2010/27/]red glowing ring[/url] is more clear, with expansion speed and light echos relating it to a classic [url=http://en.wikipedia.org/wiki/Type_1a_supernova]Type Ia supernova[/url] explosion that must have occurred about 400 years earlier. [url=http://adsabs.harvard.edu/abs/2008ApJ...680.1149B]SNR 0509[/url] currently spans about 23 [url=http://chandra.harvard.edu/photo/cosmic_distance.html]light years[/url] and lies about 160,000 light years away toward the constellation of the [url=http://en.wikipedia.org/wiki/Coryphaenidae]dolphinfish[/url] ([url=http://www.ianridpath.com/startales/dorado.htm]Dorado[/url]) in the [url=http://apod.nasa.gov/apod/ap100514.html]Large Magellanic Cloud[/url]. The expanding ring carries with it another great mystery, however: why wasn't this [url=http://www.youtube.com/watch?v=5YZkAoR3WLE&f]supernova[/url] seen 400 years ago when light from the initial blast should have passed the Earth?
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[c][url=http://apod.nasa.gov/apod/ap110126.html][size=150][b]The Whirlpool Galaxy in Infrared Dust (2011 Jan 26)[/b][/size][/url][/c]
[float=left][img2]http://apod.nasa.gov/apod/image/1101/m51op_hubble.jpg[/img2][/float]How do spiral galaxies form stars? To help find out, the [url=http://apod.nasa.gov/apod/ap090525.html]Hubble Space Telescope[/url] imaged the nearby photogenic spiral [url=http://en.wikipedia.org/wiki/Whirlpool_Galaxy]M51[/url] in [url=http://science.hq.nasa.gov/kids/imagers/ems/infrared.html]infrared light[/url] to highlight the dust that traces the dense gas that best forms stars. To further isolate the [url=http://apod.nasa.gov/apod/ap030706.html]dust[/url], much of the optical light from stars has also been [url=http://apod.nasa.gov/apod/ap091101.html]digitally removed[/url]. The [url=http://hubblesite.org/newscenter/archive/releases/2011/03/image/a/]resulting unique image[/url] shows swirling and intricate patterns on the longest scales, while numerous bright clumps of previously hidden [url=http://apod.nasa.gov/apod/open_clusters.html]open star clusters[/url] appear on the smaller scales. To see the [url=http://apod.nasa.gov/apod/ap080614.html]detailed optical light image[/url] for comparison, run your cursor over the above image. Anyone with a good pair of [url=http://www.birdwatching.com/optics/how_binoculars_work.html]binoculars[/url] can see the [url=http://www.youtube.com/watch?v=sx8vA9jBEFk]Whirlpool[/url] toward the constellation of the [url=http://en.wikipedia.org/wiki/Hunting_dog]Hunting Dogs[/url] ([url=http://seds.org/Maps/Stars_en/Fig/canesvenatici.html]Canes Venatici[/url]). M51 lies about 30 million light years away, while the above imaged area spans about 15,000 [url=http://www.physlink.com/education/askexperts/ae502.cfm]light years[/url] from top to bottom. Astronomers speculate that M51's [url=http://asterisk.apod.com/viewtopic.php?f=24&t=18005]spiral[/url] structure is primarily due to its gravitational interaction with [url=http://apod.nasa.gov/apod/ap100611.html]a neighboring smaller galaxy[/url].
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[c][url=http://apod.nasa.gov/apod/ap110127.html][size=150][b]Hidden Treasures of M78 (2011 Jan 27)[/b][/size][/url][/c]
[float=left][img2]http://apod.nasa.gov/apod/image/1101/M78WFI_chekalin900.jpg[/img2][/float][url=http://apod.nasa.gov/apod/ap051104.html]M78[/url] isn't really hiding in planet Earth's night sky. About 1,600 light-years away and [url=http://apod.nasa.gov/apod/ap090211.html]nestled[/url] in the nebula rich [url=http://apod.nasa.gov/apod/ap101023.html]constellation Orion[/url], the large, bright, [url=http://apod.nasa.gov/apod/ap011228.html]reflection nebula[/url] is well-known to telescopic skygazers. But this gorgeous image of M78 was selected as the winner of the [url=http://www.eso.org/public/news/eso1102/]Hidden Treasures 2010[/url] astrophotography competition. Held by the European Southern Observatory (ESO), the competition challenged amateur astronomers to process data from ESO's astronomical archive in search of hidden cosmic gems. [url=http://www.flickr.com/photos/igorfp/5164928669/lightbox/#/photos/igorfp/5164928669/]The winning entry[/url] shows off amazing details within [url=http://www.leosondra.cz/en/mix-your-own-reflection-nebula/]bluish[/url] M78 (center) embraced in dark, dusty clouds, along with a smaller reflection nebula in the region, NGC 2071 (top). Yellowish and even more compact, the recently discovered, variable [url=http://apod.nasa.gov/apod/ap040219.html]McNeil's Nebula[/url] is prominent in the scene below and right of center. Based on data from ESO's WFI camera and 2.2 meter telescope at [url=http://www.eso.org/public/teles-instr/lasilla.html]La Silla[/url], Chile, this image spans just over 0.5 degrees on the sky. That corresponds to 15 light-years at the estimated distance of [url=http://seds.org/messier/m/m078.html]M78[/url].
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[c][url=http://apod.nasa.gov/apod/ap110128.html][size=150][b]NanoSail-D (2011 Jan 28)[/b][/size][/url][/c]
[float=left][img2]http://apod.nasa.gov/apod/image/1101/NanoSailD900.jpg[/img2][/float]Featured in this artist's illustration, [url=http://www.nasa.gov/mission_pages/smallsats/nanosaild.html]NASA's NanoSail-D[/url] [url=http://science.nasa.gov/science-news/science-at-nasa/2011/24jan_solarsail/]finally unfurled[/url] a very thin, 10 square meter reflective sail on January 20th, becoming the first solar sail spacecraft in low Earth orbit. Often considered the [url=http://240plan.ovh.net/~upngmmxw/imag/bd/bd_a.htm]stuff of science fiction[/url], sailing through space [url=http://apod.nasa.gov/apod/ap040821.html]was suggested[/url] 400 years ago by astronomer Johannes Kepler who observed comet tails blown by the solar wind. [url=http://en.wikipedia.org/wiki/Solar_sail]Modern solar sail[/url] spacecraft designs, like NanoSail-D or the Japanese interplanetary [url=http://www.jaxa.jp/projects/sat/ikaros/index_e.html]spacecraft IKAROS[/url], rely on the small but [url=http://www.phy6.org/stargaze/Solsail.htm]continuous pressure from sunlight[/url] itself for thrust. Glinting in the sunlight as it circles planet Earth, the NanoSail-D solar sail will periodically be bright and easily visible to the eye. In fact, skygazers are urged to participate in an ongoing [url=http://www.nanosail.org/]contest to capture images of NanoSail-D[/url]. The images will help NASA monitor the satellite before it reenters the atmosphere in April or May.
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[c][url=http://apod.nasa.gov/apod/ap110129.html][size=150][b]Opportunity at Santa Maria Crater (2011 Jan 29)[/b][/size][/url][/c]
[float=left][img2]http://apod.nasa.gov/apod/image/1101/OpportunitySol2476_Kremer600hc.jpg[/img2][/float][url=http://www.nasa.gov/mission_pages/mer/news/mer20110120.html]Celebrating 7 years[/url] on the surface of [url=http://solarsystem.nasa.gov/planets/profile.cfm?Object=Mars]the Red Planet[/url], Mars exploration rover Opportunity now stands near the rim of 90 meter wide [url=http://photojournal.jpl.nasa.gov/catalog/PIA13794]Santa Maria crater[/url]. Remarkably, Opportunity and its fellow [url=http://www.nasa.gov/mission_pages/mer/spirit-update.html]rover Spirit[/url] were initially [url=http://xkcd.com/695/]intended[/url] for a 3 month long primary mission. Still exploring, the golf cart-sized robot and shadow (far right) appear in the foreground of this panoramic view of its [url=http://hirise.lpl.arizona.edu/releases/oppy-santa-maria.php]current location[/url]. The mosaic was constructed using images from the rover's navigation camera. On its [url=http://www.universetoday.com/82784/7-years-of-opportunity-on-mars-and-a-science-bonanza/]7 year anniversary[/url], Opportunity can boast [url=http://marsrovers.jpl.nasa.gov/mission/traverse_maps.html]traversing[/url] a total of 26.7 kilometers [url=http://beamartian.jpl.nasa.gov/welcome]along the martian surface[/url]. After investigating Santa Maria crater, controllers plan to have Opportunity resume a long-term trek toward Endurance crater, a large, 22 kilometer diameter crater about 6 kilometers from Santa Maria. During coming days, communication with the rover will be more difficult as Mars moves close to alignment with the Sun as seen from planet Earth's [url=http://www.jpl.nasa.gov/missions/mer/images.cfm?id=2673]perspective[/url].
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[size=110][url=http://asterisk.apod.com/viewtopic.php?f=29&t=22748][color=#4040FF][b]<- Previous week's poll[/b][/color][/url][/size]