by owlice » Tue Nov 15, 2011 1:46 am
_____________________________________________________________________
Please vote for the
two best APODs (image and text) for October, 2011. All titles are clickable and link to the original APOD page.
We ask for your help in choosing an APOM, as this helps Jerry and Robert create "year in APOD images" review lectures and a free PDF calendar at year's end, and provides feedback on which images and APODs were relatively well received.
We are very interested to know why you selected the APODs for which you voted; if you would like to tell us, please reply to this thread. Thank you!
Thank you!
_____________________________________________________________________
<- Previous month's poll
Also known as the Cigar Galaxy for its elongated visual appearance,
M82 is a starburst galaxy with a superwind.
In fact, through ensuing supernova explosions and powerful winds from massive stars, the burst of star formation in M82 is driving the prodigous outflow of material.
Evidence for the superwind from the galaxy's central regions is clear in
this sharp composite image, based on data from small telescopes
on planet Earth. The composite highlights emission from filaments of atomic hydrogen gas in reddish hues. The filaments extend for over 10,000 light-years. Some of the gas in the superwind, enriched in heavy elements
forged in the massive stars, will eventually escape into intergalactic space. Triggered by a close encounter with
nearby large galaxy M81, the furious burst of star formation in M82 should last about 100 million years or so. M82 is 12 million light-years distant, near the northern boundary of
Ursa Major.
One solar day on a planet is the length of time from noon to noon. A solar day lasts 24 hours on planet Earth.
On Mercury a solar day is about 176 Earth days long. And during its
first Mercury solar day in orbit the
MESSENGER spacecraft has imaged nearly the entire surface of the
innermost planet to generate a global monochrome map at 250 meters per pixel resolution and a 1 kilometer per pixel resolution color map. Examples of the maps, mosaics constructed from thousands of images made under uniform lighting conditions, are shown (monochrome at left), both centered along the planet's 75 degrees East longitude
meridian. The MESSENGER spacecraft's second Mercury solar day will likely include more high resolution
targeted observations of the planet's surface features. (
Editor's note: Due to
Mercury's 3:2 spin-orbit resonance, a Mercury solar day is 2
Mercury years long.)
Why would a rising Sun look so strange? No one is yet sure. What is clear is that the above unusual sunrise was captured last month from
Buenos Aires,
Argentina. The body of water in the foreground is
Rio de La Plata, considered by many to be the widest river in the world. Although the
above image is actually a combination of a normal and a very short exposure needed to avoid
oversaturating the bright Sun, the photographer saw this unusual structure with his own eyes, indicating that this effect was caused by neither
reflections nor
distortions in the camera or lens. What looks like arms on this
monster illusion might actually be, for example, low level clouds just thick enough to scatter sunlight without completely
blocking the Sun. Additionally, the distortion visible on the lower part of the Sun's image might indicate a
Etruscan Vase or
Fata Morgana mirage possibly created by a curious
refracting layer of air over the water. Unusual
atmospheric phenomena are frequently
thrilling to see personally, and although most can be
traced to well known phenomena, others, for lack of more data,
remain mysterious.
It's the bubble versus the cloud. NGC 7635, the
Bubble Nebula, is being pushed out by the
stellar wind of massive central star
BD+602522. Next door, though, lives a giant
molecular cloud, visible to the right. At this place in space, an
irresistible force meets an
immovable object in an interesting way. The
cloud is able to contain the expansion of the bubble gas, but gets blasted by the hot radiation from the
bubble's central star. The
radiation heats up dense regions of the
molecular cloud causing it to glow. The
Bubble Nebula,
pictured above in scientifically mapped colors to bring up contrast, is about 10
light-years across and part of a much
larger complex of stars and shells. The
Bubble Nebula can be seen with a small telescope towards the
constellation of the Queen of
Aethiopia (
Cassiopeia).
Saturn's rings form one of the larger sundials known. This
sundial, however, determines only the
season of Saturn, not the time of day. In 2009, during
Saturn's last equinox, Saturn's thin rings threw
almost no shadows onto Saturn, since the ring plane pointed directly toward the Sun. As Saturn continued in its orbit around the Sun, however, the ring shadows become increasingly wider and cast further south. These shadows are not easily visible from the Earth because from our vantage point near the Sun, the rings
always block the shadows. The
above image was taken in August by the
robotic Cassini spacecraft currently orbiting Saturn. The rings themselves appear as a vertical bar on the image right. The Sun, far to the upper right, shines through the rings and casts captivatingly
complex shadows on south Saturn, on the image left. Cassini has been
exploring Saturn, its rings, and its moons since 2004, and is
expected to continue until at least the maximum elongation of Saturn's shadows occurs in 2017.
Cosmic clouds of gas and dust drift across this magnificent panorama, spanning some 17 degrees near the southern boundary of the heroic constellation
Perseus. The collaborative skyscape begins with bluish stars of Perseus at the left, but the eye is drawn to the striking,
red NGC 1499. Also known as the California Nebula, its
characteristic glow of atomic hydrogen gas is powered by ultraviolet light from luminous blue star Xi Persei immediately to the nebula's right. Farther along, intriguing young star cluster
IC 348 and neighboring Flying Ghost Nebula are right of center. Connected by dark and dusty tendrils on the outskirts of a giant
molecular cloud, another active star forming region,
NGC 1333, lies near the upper right edge of the wide field of view. Shining faintly, dust clouds
strewn throughout the scene are hovering hundreds of light-years above the galactic plane and reflect starlight from the
Milky Way.
On October 29 (UT), Jupiter,
the solar system's largest planet, will be at opposition,
opposite the Sun in planet Earth's sky, shining brightly and rising as the Sun sets.
That configuration results in Jupiter's almost annual closest approach to planet Earth, so near opposition the gas giant offers earthbound telescopes stunning views of its stormy, banded atmosphere and large
Galilean moons. This sharp snapshot of Jupiter was captured on October 13 with the
1 meter telescope at the
Pic Du Midi mountain top observatory in the
French Pyrenees. North is up in the image that shows off oval shaped vortices and planet girdling
dark belts and light zones. Also seen in remarkable detail, Jupiter's
icy Ganymede, the solar system's largest moon, is emerging from behind the planet (top) while
volcanic Io enters the frame near the lower left edge.
A fourth moon is visible on the
above image if you look hard enough. First -- and furthest in the background -- is
Titan, the largest moon of Saturn and one of the larger moons in the Solar System. The dark feature across the top of this perpetually cloudy world is the
north polar hood. The next most obvious moon is bright
Dione, visible in the foreground, complete with craters and long
ice cliffs. Jutting in from the left are several of Saturn's
expansive rings, including Saturn's A ring featuring the dark
Encke Gap. On the far right, just outside the rings, is
Pandora, a moon only 80-kilometers across that
helps shepherd Saturn's F ring. The fourth moon? If you look closely in the Encke Gap you'll find a speck that is actually
Pan. Although one of Saturn's smallest moons at 35-kilometers across, Pan is massive enough to help keep the
Encke gap relatively free of ring particles.
Spooky shapes seem to haunt
this starry expanse, drifting through the night in the royal constellation
Cepheus. Of course, the shapes are cosmic dust clouds faintly visible in dimly reflected starlight. Far from your
own neighborhood on planet Earth, they lurk at the edge of the
Cepheus Flare molecular cloud complex some 1,200 light-years away. Over 2 light-years across the ghostly nebula and relatively
isolated Bok globule, also known as
vdB 141 or
Sh2-136, is near the center of the field. The core of the dark cloud on the right is collapsing and is likely a binary star system in the
early stages of formation. Even so, if the spooky shapes could talk, they might well wish you a
happy Halloween.
<- Previous month's poll
[size=200][color=#FF0000]_____________________________________________________________________[/color][/size]
Please vote for the [b]two[/b] best APODs (image and text) for October, 2011. All titles are clickable and link to the original APOD page.
We ask for your help in choosing an APOM, as this helps Jerry and Robert create "year in APOD images" review lectures and a free PDF calendar at year's end, and provides feedback on which images and APODs were relatively well received.
We are very interested to know why you selected the APODs for which you voted; if you would like to tell us, please reply to this thread. Thank you!
Thank you!
[size=200][color=#FF0000]_____________________________________________________________________[/color][/size]
[size=110][url=http://asterisk.apod.com/viewtopic.php?f=29&t=25536][color=#4040FF][b]<- Previous month's poll[/b][/color][/url][/size]
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[c][url=http://apod.nasa.gov/apod/ap111006.html][size=150][b]M82: Starburst Galaxy with a Superwind (2011 Oct 06)[/b][/size][/url][/c]
[float=left][img6="Image Credit & Copyright: Dietmar Hager, Torsten Grossmann"]http://apod.nasa.gov/apod/image/1110/M82_TorstenDietmar_Final900.jpg[/img6][hr][/hr][/float]Also known as the Cigar Galaxy for its elongated visual appearance, [url=http://messier.seds.org/m/m082.html]M82 is a starburst galaxy[/url] with a superwind. [url=http://messier.seds.org/m/m082.html]In fact[/url], through ensuing supernova explosions and powerful winds from massive stars, the burst of star formation in M82 is driving the prodigous outflow of material. [url=http://chandra.harvard.edu/photo/2006/m82/]Evidence for the superwind[/url] from the galaxy's central regions is clear in [url=http://www.stargazer-observatory.com/M%2082.html]this sharp composite image[/url], based on data from small telescopes [url=http://www.stargazer-observatory.com/]on planet Earth[/url]. The composite highlights emission from filaments of atomic hydrogen gas in reddish hues. The filaments extend for over 10,000 light-years. Some of the gas in the superwind, enriched in heavy elements [url=http://apod.nasa.gov/apod/ap050813.html]forged in the massive stars[/url], will eventually escape into intergalactic space. Triggered by a close encounter with [url=http://apod.nasa.gov/apod/ap080512.html]nearby large galaxy M81[/url], the furious burst of star formation in M82 should last about 100 million years or so. M82 is 12 million light-years distant, near the northern boundary of [url=http://en.wikipedia.org/wiki/Ursa_Major]Ursa Major[/url].
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[c][url=http://apod.nasa.gov/apod/ap111008.html][size=150][b]MESSENGER's First Day (2011 Oct 08)[/b][/size][/url][/c]
[float=left][img6="Credit: NASA/JHU APL/CIW"]http://apod.nasa.gov/apod/image/1110/mercuryMonoColorMap_messenger1000.jpg[/img6][hr][/hr][/float]One solar day on a planet is the length of time from noon to noon. A solar day lasts 24 hours on planet Earth. [url=http://messenger-education.org/elusive_planet/fastfact_4.php]On Mercury a solar day[/url] is about 176 Earth days long. And during its [url=http://messenger.jhuapl.edu/gallery/sciencePhotos/image.php?gallery_id=2&image_id=658]first Mercury solar day[/url] in orbit the [url=http://messenger.jhuapl.edu/]MESSENGER spacecraft has[/url] imaged nearly the entire surface of the [url=http://solarsystem.nasa.gov/planets/profile.cfm?Object=Mercury&Display=OverviewLong]innermost planet[/url] to generate a global monochrome map at 250 meters per pixel resolution and a 1 kilometer per pixel resolution color map. Examples of the maps, mosaics constructed from thousands of images made under uniform lighting conditions, are shown (monochrome at left), both centered along the planet's 75 degrees East longitude [url=http://en.wikipedia.org/wiki/Hun_Kal_%28crater%29]meridian[/url]. The MESSENGER spacecraft's second Mercury solar day will likely include more high resolution [url=http://apod.nasa.gov/apod/ap110622.html]targeted observations[/url] of the planet's surface features. ([i]Editor's note:[/i] Due to [url=http://en.wikipedia.org/wiki/Mercury_%28planet%29#Orbit_and_rotation]Mercury's 3:2 spin-orbit resonance[/url], a Mercury solar day is 2 [url=http://messenger-education.org/elusive_planet/around_sun.php]Mercury years[/url] long.)
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[c][url=http://apod.nasa.gov/apod/ap111010.html][size=150][b]A Strange Sunrise Over Argentina (2011 Oct 10)[/b][/size][/url][/c]
[float=left][img6="Image Credit & Copyright: Luis Argerich"]http://apod.nasa.gov/apod/image/1110/strangesunrise_argerich_900.jpg[/img6][hr][/hr][/float][url=http://asterisk.apod.com/discuss_apod.php?date=111010]Why would a rising Sun look so strange?[/url] No one is yet sure. What is clear is that the above unusual sunrise was captured last month from [url=http://en.wikipedia.org/wiki/Buenos_Aires]Buenos Aires[/url], [url=http://en.wikipedia.org/wiki/Argentina]Argentina[/url]. The body of water in the foreground is [url=http://en.wikipedia.org/wiki/Rio_de_La_Plata]Rio de La Plata[/url], considered by many to be the widest river in the world. Although the [url=http://www.luisargerich.com/optiscapes/h1b5f4fbc#h1b5f4fbc]above image[/url] is actually a combination of a normal and a very short exposure needed to avoid [url=http://farm1.static.flickr.com/13/15029998_fb5890e7d1.jpg]oversaturating[/url] the bright Sun, the photographer saw this unusual structure with his own eyes, indicating that this effect was caused by neither [url=http://apod.nasa.gov/apod/ap090804.html]reflections[/url] nor [url=http://apod.nasa.gov/apod/ap101207.html]distortions[/url] in the camera or lens. What looks like arms on this [url=http://apod.nasa.gov/apod/ap110425.html]monster illusion[/url] might actually be, for example, low level clouds just thick enough to scatter sunlight without completely [url=http://apod.nasa.gov/apod/ap110115.html]blocking the Sun[/url]. Additionally, the distortion visible on the lower part of the Sun's image might indicate a [url=http://apod.nasa.gov/apod/ap090223.html]Etruscan Vase[/url] or [url=http://en.wikipedia.org/wiki/Fata_Morgana_%28mirage%29]Fata Morgana[/url] mirage possibly created by a curious [url=http://apod.nasa.gov/apod/%20http://physics.stackexchange.com/questions/10464/why-does-the-road-look-like-its-wet-on-hot-days]refracting layer of air[/url] over the water. Unusual [url=http://www.atoptics.co.uk/opod.htm]atmospheric phenomena[/url] are frequently [url=http://www.youtube.com/watch?v=Rh2tzXvBlJg]thrilling to see[/url] personally, and although most can be [url=http://apod.nasa.gov/apod/ap041207.html]traced to well known phenomena[/url], others, for lack of more data, [url=http://apod.nasa.gov/apod/ap070815.html]remain mysterious[/url].
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[c][url=http://apod.nasa.gov/apod/ap111011.html][size=150][b]NGC 7635: The Bubble Nebula (2011 Oct 11)[/b][/size][/url][/c]
[float=left][img6="Image Credit & Copyright: Larry Van Vleet"]http://apod.nasa.gov/apod/image/1110/bubble_vanvleet_900.jpg[/img6][hr][/hr][/float]It's the bubble versus the cloud. NGC 7635, the [url=http://apod.nasa.gov/apod/ap091030.html]Bubble Nebula[/url], is being pushed out by the [url=http://apod.nasa.gov/apod/ap000318.html]stellar wind[/url] of massive central star [url=http://adsabs.harvard.edu/abs/2002AJ....124.3305M]BD+602522[/url]. Next door, though, lives a giant [url=http://apod.nasa.gov/apod/ap090623.html]molecular cloud[/url], visible to the right. At this place in space, an [url=http://en.wikipedia.org/wiki/Irresistible_force_paradox]irresistible force[/url] meets an [url=http://1.bp.blogspot.com/-s8wPzTQVHwk/TZ23dhVwPTI/AAAAAAAAARY/1SsZ9s_A_J4/s1600/big+pumpkin.jpg]immovable object[/url] in an interesting way. The [url=http://heritage.stsci.edu/1998/31/index.html]cloud[/url] is able to contain the expansion of the bubble gas, but gets blasted by the hot radiation from the [url=http://www.exploratorium.edu/ronh/bubbles/bubbles.html]bubble[/url]'s central star. The [url=http://imagine.gsfc.nasa.gov/docs/science/know_l1/emspectrum.html]radiation[/url] heats up dense regions of the [url=http://en.wikipedia.org/wiki/Molecular_cloud]molecular cloud[/url] causing it to glow. The [url=http://apod.nasa.gov/apod/ap030617.html]Bubble Nebula[/url], [url=http://apod.nasa.gov/apod/]pictured above[/url] in scientifically mapped colors to bring up contrast, is about 10 [url=http://chandra.harvard.edu/photo/cosmic_distance.html]light-years[/url] across and part of a much [url=http://apod.nasa.gov/apod/ap100909.html]larger complex[/url] of stars and shells. The [url=http://apod.nasa.gov/apod/ap000118.html]Bubble Nebula[/url] can be seen with a small telescope towards the [url=http://www.astro.wisc.edu/~dolan/constellations/extra/constellations.html]constellation[/url] of the Queen of [url=http://en.wikipedia.org/wiki/Ethiopia_(mythology)]Aethiopia[/url] ([url=http://www.astronomical.org/portal/modules/wfsection/article.php?articleid=18]Cassiopeia[/url]).
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[c][url=http://apod.nasa.gov/apod/ap111012.html][size=150][b]Saturn: Shadows of a Seasonal Sundial (2011 Oct 12)[/b][/size][/url][/c]
[float=left][img6="Image Credit: Cassini Imaging Team, ISS, JPL, ESA, NASA"]http://apod.nasa.gov/apod/image/1110/saturn9_cassini_900.jpg[/img6][hr][/hr][/float]Saturn's rings form one of the larger sundials known. This [url=http://en.wikipedia.org/wiki/Sundial]sundial[/url], however, determines only the [url=http://apod.nasa.gov/apod/ap030405.html]season[/url] of Saturn, not the time of day. In 2009, during [url=http://apod.nasa.gov/apod/ap090825.html]Saturn's last equinox[/url], Saturn's thin rings threw [url=http://apod.nasa.gov/apod/ap091110.html]almost no shadows[/url] onto Saturn, since the ring plane pointed directly toward the Sun. As Saturn continued in its orbit around the Sun, however, the ring shadows become increasingly wider and cast further south. These shadows are not easily visible from the Earth because from our vantage point near the Sun, the rings [url=http://addictedtoinsight.com/aihome/wp-content/uploads/2011/08/frustration1.png]always block[/url] the shadows. The [url=http://photojournal.jpl.nasa.gov/catalog/PIA14576]above image[/url] was taken in August by the [url=http://saturn.jpl.nasa.gov/spacecraft/overview/]robotic Cassini spacecraft[/url] currently orbiting Saturn. The rings themselves appear as a vertical bar on the image right. The Sun, far to the upper right, shines through the rings and casts captivatingly [url=http://apod.nasa.gov/apod/ap101012.html]complex shadows[/url] on south Saturn, on the image left. Cassini has been [url=http://apod.nasa.gov/apod/ap110613.html]exploring Saturn[/url], its rings, and its moons since 2004, and is [url=http://saturn.jpl.nasa.gov/news/newsreleases/newsrelease20100203/]expected to continue[/url] until at least the maximum elongation of Saturn's shadows occurs in 2017.
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[c][url=http://apod.nasa.gov/apod/ap111021.html][size=150][b]Clouds of Perseus (2011 Oct 21)[/b][/size][/url][/c]
[float=left][img6="Credit & Copyright: Image Data - Bob Caton, Al Howard, Eric Zbinden, Rogelio Bernal Andreo; Processing - Rogelio Bernal Andreo"]http://apod.nasa.gov/apod/image/1110/mbz_2011-09_Clouds_Of_Perseus600h.jpg[/img6][hr][/hr][/float]Cosmic clouds of gas and dust drift across this magnificent panorama, spanning some 17 degrees near the southern boundary of the heroic constellation [url=http://hawastsoc.org/deepsky/per/index.html]Perseus[/url]. The collaborative skyscape begins with bluish stars of Perseus at the left, but the eye is drawn to the striking, [url=http://www.atlasoftheuniverse.com/nebulae/ngc1499.html]red NGC 1499[/url]. Also known as the California Nebula, its [url=http://apod.nasa.gov/apod/ap111013.html]characteristic glow[/url] of atomic hydrogen gas is powered by ultraviolet light from luminous blue star Xi Persei immediately to the nebula's right. Farther along, intriguing young star cluster [url=http://cdsads.u-strasbg.fr/cgi-bin/nph-bib_query?2006AJ....132..467W&db_key=AST&nosetcookie=1]IC 348 and[/url] neighboring Flying Ghost Nebula are right of center. Connected by dark and dusty tendrils on the outskirts of a giant [url=http://en.wikipedia.org/wiki/Perseus_molecular_cloud]molecular cloud[/url], another active star forming region, [url=http://apod.nasa.gov/apod/ap090418.html]NGC 1333[/url], lies near the upper right edge of the wide field of view. Shining faintly, dust clouds [url=http://apod.nasa.gov/apod/ap080512.html]strewn throughout[/url] the scene are hovering hundreds of light-years above the galactic plane and reflect starlight from the [url=http://apod.nasa.gov/apod/ap110924.html]Milky Way[/url].
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[c][url=http://apod.nasa.gov/apod/ap111022.html][size=150][b]Jupiter Near Opposition (2011 Oct 22)[/b][/size][/url][/c]
[float=left][img6="Image Credit & Copyright: S2P/IMCCE/Obs. Midi Pyrénées, Jean-Luc Dauvergne, Francois Colas"]http://apod.nasa.gov/apod/image/1110/jupiter20111013225714couleu900.jpg[/img6][hr][/hr][/float][url=http://earthsky.org/tonight/on-october-28-jupiters-closest-opposition-until-2022]On October 29 (UT)[/url], Jupiter, [url=http://solarsystem.nasa.gov/planets/profile.cfm?Object=Jupiter&Display=OverviewLong]the solar system's largest planet[/url], will be at opposition, [url=http://apod.nasa.gov/apod/ap100918.html]opposite the Sun[/url] in planet Earth's sky, shining brightly and rising as the Sun sets. [url=http://astronomy.swin.edu.au/cosmos/O/Opposition]That configuration[/url] results in Jupiter's almost annual closest approach to planet Earth, so near opposition the gas giant offers earthbound telescopes stunning views of its stormy, banded atmosphere and large [url=http://solarsystem.nasa.gov/planets/profile.cfm?Object=Jupiter&Display=Moons]Galilean moons[/url]. This sharp snapshot of Jupiter was captured on October 13 with the [url=http://www.youtube.com/watch?v=Dm3h2e_mOjI]1 meter telescope[/url] at the [url=http://www.bagn.obs-mip.fr/webcamV2/]Pic Du Midi[/url] mountain top observatory in the [url=http://apod.nasa.gov/apod/ap080125.html]French Pyrenees[/url]. North is up in the image that shows off oval shaped vortices and planet girdling [url=http://en.wikipedia.org/wiki/Atmosphere_of_Jupiter#Zones.2C_belts_and_jets]dark belts and light zones[/url]. Also seen in remarkable detail, Jupiter's [url=http://apod.nasa.gov/apod/ap990304.html]icy Ganymede[/url], the solar system's largest moon, is emerging from behind the planet (top) while [url=http://apod.nasa.gov/apod/ap080817.html]volcanic Io[/url] enters the frame near the lower left edge.
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[c][url=http://apod.nasa.gov/apod/ap111026.html][size=150][b]In, Through, and Beyond Saturn's Rings (2011 Oct 26)[/b][/size][/url][/c]
[float=left][img6="Image Credit: Cassini Imaging Team, ISS, JPL, ESA, NASA"]http://apod.nasa.gov/apod/image/1110/fourmoons_cassini_900.jpg[/img6][hr][/hr][/float]A fourth moon is visible on the [url=http://photojournal.jpl.nasa.gov/catalog/PIA14579]above image[/url] if you look hard enough. First -- and furthest in the background -- is [url=http://apod.nasa.gov/apod/ap110401.html]Titan[/url], the largest moon of Saturn and one of the larger moons in the Solar System. The dark feature across the top of this perpetually cloudy world is the [url=http://saturn.jpl.nasa.gov/photos/imagedetails/index.cfm?imageId=3689]north polar hood[/url]. The next most obvious moon is bright [url=http://en.wikipedia.org/wiki/Dione_%28moon%29]Dione[/url], visible in the foreground, complete with craters and long [url=http://apod.nasa.gov/apod/ap060905.html]ice cliffs[/url]. Jutting in from the left are several of Saturn's [url=http://apod.nasa.gov/apod/ap050525.html]expansive rings[/url], including Saturn's A ring featuring the dark [url=http://en.wikipedia.org/wiki/Encke_Division#Encke_Gap]Encke Gap[/url]. On the far right, just outside the rings, is [url=http://en.wikipedia.org/wiki/Pandora_%28moon%29]Pandora[/url], a moon only 80-kilometers across that [url=http://www.youtube.com/watch?v=fdUlpeUFfxI]helps shepherd[/url] Saturn's F ring. The fourth moon? If you look closely in the Encke Gap you'll find a speck that is actually [url=http://en.wikipedia.org/wiki/Pan_%28moon%29]Pan[/url]. Although one of Saturn's smallest moons at 35-kilometers across, Pan is massive enough to help keep the [url=http://planetary.org/explore/topics/saturn/pan.html]Encke gap[/url] relatively free of ring particles.
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[c][url=http://apod.nasa.gov/apod/ap111031.html][size=150][b]Ghost of the Cepheus Flare (2011 Oct 31)[/b][/size][/url][/c]
[float=left][img6="Image Credit & Copyright: Adam Block, Mt. Lemmon SkyCenter, University of Arizona"]http://apod.nasa.gov/apod/image/1110/sh2136s_block900.jpg[/img6][hr][/hr][/float]Spooky shapes seem to haunt [url=http://www.caelumobservatory.com/gallery/sh2136.shtml]this starry expanse[/url], drifting through the night in the royal constellation [url=http://www.dibonsmith.com/cep_con.htm]Cepheus[/url]. Of course, the shapes are cosmic dust clouds faintly visible in dimly reflected starlight. Far from your [url=http://earthobservatory.nasa.gov/]own neighborhood[/url] on planet Earth, they lurk at the edge of the [url=http://arxiv.org/abs/0809.4761]Cepheus Flare[/url] molecular cloud complex some 1,200 light-years away. Over 2 light-years across the ghostly nebula and relatively [url=http://arxiv.org/abs/1004.0869]isolated Bok globule[/url], also known as [url=http://www.noao.edu/image_gallery/html/im1060.html]vdB 141[/url] or [url=http://galaxymap.org/cgi-bin/details.py?id=21415&t=hii&s=4_p34.0xp31.0&name=S136]Sh2-136[/url], is near the center of the field. The core of the dark cloud on the right is collapsing and is likely a binary star system in the [url=http://arxiv.org/abs/0910.1894]early stages[/url] of formation. Even so, if the spooky shapes could talk, they might well wish you a [url=http://apod.nasa.gov/apod/ap101031.html]happy Halloween[/url].
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[size=110][url=http://asterisk.apod.com/viewtopic.php?f=29&t=25536][color=#4040FF][b]<- Previous month's poll[/b][/color][/url][/size]