_______________________________________________________________
Please vote for the TWO best Astronomy Pictures of the Day (image and text) of December 4-10, 2011.
(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
What could create this unusual vein of rock on Mars? A leading hypothesis is that
this thin rock layer dubbed "Homestake" was deposited by a running liquid -- like most
mineral veins are here on Earth. And the
running liquid of choice is water. Therefore,
this mineral streak -- rich in calcium and sulfur -- is the latest in the growing body of evidence that part of
Mars had a watery past. This, in turn, increases the speculation that
Mars was once hospitable to life. Pictured above is a vista taken near the western rim of
Endeavour Crater by the
Opportunity rover currently exploring Mars. The
inset image shows a close up of the recently discovered mineral vein.
Strange shapes and textures can be found in neighborhood of the
Cone Nebula. The
unusual shapes originate from fine interstellar
dust reacting in complex ways with the energetic light and hot gas being expelled by the young stars. The brightest star on the right of the
above picture is
S Mon, while the region just below it has been nicknamed the
Fox Fur Nebula for its color and structure. The
blue glow directly surrounding S Mon results from
reflection, where neighboring dust reflects light from the bright star. The
red glow that encompasses the whole region results not only from dust reflection but also
emission from
hydrogen gas
ionized by starlight.
S Mon is part of a young open
cluster of stars named
NGC 2264, located about 2500
light years away toward the
constellation of the Unicorn (
Monoceros). The origin of the
mysterious geometric Cone Nebula, visible on the far left, remains
a mystery.
Our Moon turned red last week. The reason was that during December 10, a
total lunar eclipse occurred. The above digitally superimposed image mosaic captured the Moon many times during the eclipse, from before the
Moon entered Earth's shadow until after the Moon exited. The image sequence was recorded over a
Shanti Stupa Peace Pagota near the
center of
New Delhi,
India. The
red tint of the
eclipsed Moon was created by sunlight first passing through the Earth's atmosphere, which preferentially scatters blue light (making the
sky blue) but passes and refracts
red light, before reflecting back off the Moon. Differing amounts of clouds and
volcanic dust in the Earth's atmosphere make each
lunar eclipse appear differently. The next total lunar eclipse
will occur only in 2014.
The dark, inner shadow of planet Earth is called
the umbra. Shaped like a cone extending into space, it has a circular cross section most easily seen during a
lunar eclipse. For example, last Saturday the
Full Moon slid across the southern half of Earth's umbral shadow,
entertaining moonwatchers around much of the planet. In the total phase of the eclipse, the Moon was completely within the umbra for 51 minutes. Recorded from Beijing, China, this composite eclipse image uses
successive pictures from totality (center) and partial phases to trace out a large part of the umbra's
curved edge. Background stars are visible in the
darker eclipse phases. The result shows the relative size of the shadow's cross section at the distance of the Moon, as well as the Moon's path
through Earth's umbra.
This surreal, wintry scene is a composite picture
recorded on December 10 as the Moon rose behind the Zagros Mountains of Iran. A total lunar eclipse was already
in progress. The image combines nearly 500 successive frames taken over 1.5 hours beginning
in twilight as the eclipsed Moon steadily climbed above the rugged landscape. The reddened lunar disk and deep blue twilight make for a striking contrast, yet the contrasting colors have the same root cause. The eclipsed Moon is red because the
Earth's umbral shadow is suffused with
a faint red light. The ruddy illumination is from all the reddened sunsets and sunrises, as seen from a
lunar perspective. But the sunsets and sunrises are reddened because the Earth's atmosphere
scatters blue light more strongly than red, creating the twilight sky's dim, blue glow.
Like most other sungrazing comets, Comet Lovejoy (C/2011 W3) was not expected to survive its
close encounter with the Sun. But it did. This image
from a coronograph onboard the sun-staring SOHO spacecraft identifies the still
inbound remnants of the tail, with the brilliant head or coma
emerging from the solar glare on December 16. The Sun's position, behind an occulting disk to block the overwhelming glare, is indicated by the white circle. Separated from its tail, Comet Lovejoy's coma is so bright it saturates the camera's pixels creating the horizontal streaks. Based on their orbits,
sungrazer comets are thought to belong to the Kreutz family of comets, created by successive break ups from a single large parent comet that passed very near the Sun in the twelfth century. Most have been discovered with SOHO's cameras, but unlike many sungrazers, this one was first spotted by Australian
astronomer Terry Lovejoy from an earth-based observatory. Comet Lovejoy is estimated to have come within 120,000 kilometers of the Sun's surface and
likely had a large cometary nucleus to have survived its intense
perihelion passage. Remarkable videos of the encounter from the Solar Dynamics Observatory
can be found here.
<- 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 December 4-10, 2011.
(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 "[url=http://www.youtube.com/watch?v=NAQXYYbBa1s]year in APOD images[/url]" review lectures, create APOM and [url=http://asterisk.apod.com/viewtopic.php?f=29&t=22695&p=141942#p141942]APOY polls[/url] 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!
[size=200][color=#FF0000]_______________________________________________________________[/color][/size]
[size=110][url=http://asterisk.apod.com/viewtopic.php?f=29&t=26161][color=#4040FF][b]<- Previous week's poll[/b][/color][/url][/size]
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[c][url=http://apod.nasa.gov/apod/ap111212.html][size=150][b]An Unusual Vein of Deposited Rock on Mars (2011 Dec 12)[/b][/size][/url][/c]
[float=left][img6="Image Credit: Mars Exploration Rover Mission, NASA, JPL, Cornell; Image Processing: Kenneth Kremer, Marco Di Lorenzo"]http://apod.nasa.gov/apod/image/1112/marsvein_opportunity_900.jpg[/img6][hr][/hr][/float]What could create this unusual vein of rock on Mars? A leading hypothesis is that [url=http://www.jpl.nasa.gov/news/news.cfm?release=2011-377&rn=news.xml&rst=3220]this thin rock layer[/url] dubbed "Homestake" was deposited by a running liquid -- like most [url=http://en.wikipedia.org/wiki/Mineral_vein]mineral veins[/url] are here on Earth. And the [url=http://www.youtube.com/watch?v=ZRlNOyxWWf8]running liquid[/url] of choice is water. Therefore, [url=http://science.nasa.gov/science-news/science-at-nasa/2011/08dec_slamdunk/]this mineral streak[/url] -- rich in calcium and sulfur -- is the latest in the growing body of evidence that part of [url=http://apod.nasa.gov/apod/ap050401.html]Mars had a watery[/url] past. This, in turn, increases the speculation that [url=http://en.wikipedia.org/wiki/Life_on_Mars]Mars was once hospitable to life[/url]. Pictured above is a vista taken near the western rim of [url=http://en.wikipedia.org/wiki/Endeavour_(crater)]Endeavour Crater[/url] by the [url=http://apod.nasa.gov/apod/ap051214.html]Opportunity rover[/url] currently exploring Mars. The [url=http://photojournal.jpl.nasa.gov/catalog/PIA15033]inset image[/url] shows a close up of the recently discovered mineral vein.
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[c][url=http://apod.nasa.gov/apod/ap111213.html][size=150][b]In the Vicinity of the Cone Nebula (2011 Dec 13)[/b][/size][/url][/c]
[float=left][img6="Image Credit & Copyright: Dieter Willasch (Astro-Cabinet)"]http://apod.nasa.gov/apod/image/1112/cone_willasch_900.jpg[/img6][hr][/hr][/float]Strange shapes and textures can be found in neighborhood of the [url=http://apod.nasa.gov/apod/ap040529.html]Cone Nebula[/url]. The [url=http://apod.nasa.gov/apod/ap081228.html]unusual shapes[/url] originate from fine interstellar [url=http://apod.nasa.gov/apod/ap990509.html]dust[/url] reacting in complex ways with the energetic light and hot gas being expelled by the young stars. The brightest star on the right of the [url=http://astro-cabinet.com/showimage.php?image=NGC2264-60m-Ha_45RGB_crop_ss_1.jpg〈=english#]above picture[/url] is [url=http://apod.nasa.gov/apod/ap010424.html]S Mon[/url], while the region just below it has been nicknamed the [url=http://apod.nasa.gov/apod/ap080422.html]Fox Fur Nebula[/url] for its color and structure. The [url=http://www.youtube.com/watch?v=EN1Yxq8KMsw]blue glow[/url] directly surrounding S Mon results from [url=http://apod.nasa.gov/apod/reflection_nebulae.html]reflection[/url], where neighboring dust reflects light from the bright star. The [url=http://apod.nasa.gov/apod/ap111106.html]red glow[/url] that encompasses the whole region results not only from dust reflection but also [url=http://en.wikipedia.org/wiki/Emission_nebula]emission[/url] from [url=http://apod.nasa.gov/apod/ap010113.html]hydrogen[/url] gas [url=http://csep10.phys.utk.edu/astr162/lect/light/ionization.html]ionized[/url] by starlight. [url=http://en.wikipedia.org/wiki/S_Monocerotis]S Mon[/url] is part of a young open [url=http://asterisk.apod.com/viewtopic.php?f=24&t=18009]cluster of stars[/url] named [url=http://adsabs.harvard.edu/abs/2002AAS...200.7002L]NGC 2264[/url], located about 2500 [url=http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980211a.html]light years[/url] away toward the [url=http://www.astro.wisc.edu/~dolan/constellations/extra/constellations.html]constellation[/url] of the Unicorn ([url=http://www.hawastsoc.org/deepsky/mon/index.html]Monoceros[/url]). The origin of the [url=http://apod.nasa.gov/apod/ap020107.html]mysterious geometric Cone Nebula[/url], visible on the far left, remains [url=http://www.grassrootsinternetstrategy.com.au/wp-content/uploads/2011/06/cute-dog.jpg]a mystery[/url].
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[c][url=http://apod.nasa.gov/apod/ap111214.html][size=150][b]A Lunar Eclipse Over an Indian Peace Pagoda (2011 Dec 14)[/b][/size][/url][/c]
[float=left][img6="Image Credit & Copyright: Chander Devgun (SPACE)"]http://apod.nasa.gov/apod/image/1112/lunareclipse_devgun_900.jpg[/img6][hr][/hr][/float]Our Moon turned red last week. The reason was that during December 10, a [url=http://eclipse.gsfc.nasa.gov/OH/OHfigures/OH2011-Fig06.pdf]total lunar eclipse[/url] occurred. The above digitally superimposed image mosaic captured the Moon many times during the eclipse, from before the [url=http://www.youtube.com/watch?v=B5J3hyvzmkY]Moon entered Earth's shadow[/url] until after the Moon exited. The image sequence was recorded over a [url=http://en.wikipedia.org/wiki/Shanti_Stupa]Shanti Stupa[/url] [url=http://en.wikipedia.org/wiki/Peace_Pagoda]Peace Pagota[/url] near the [url=http://shantistupa.org/]center[/url] of [url=http://en.wikipedia.org/wiki/New_Delhi]New Delhi[/url], [url=http://en.wikipedia.org/wiki/India]India[/url]. The [url=http://apod.nasa.gov/apod/ap041029.html]red tint[/url] of the [url=http://apod.nasa.gov/apod/ap080820.html]eclipsed Moon[/url] was created by sunlight first passing through the Earth's atmosphere, which preferentially scatters blue light (making the [url=http://spaceplace.nasa.gov/blue-sky/]sky blue[/url]) but passes and refracts [url=http://apod.nasa.gov/apod/ap090128.html]red light[/url], before reflecting back off the Moon. Differing amounts of clouds and [url=http://apod.nasa.gov/apod/ap100419.html]volcanic dust[/url] in the Earth's atmosphere make each [url=http://earthsky.org/space/why-does-the-moon-look-red-during-a-total-lunar-eclipse]lunar eclipse appear differently[/url]. The next total lunar eclipse [url=http://eclipse.gsfc.nasa.gov/LEplot/LEplot2001/LE2014Apr15T.pdf]will occur[/url] only in 2014.
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[c][url=http://apod.nasa.gov/apod/ap111215.html][size=150][b]The Umbra of Earth (2011 Dec 15)[/b][/size][/url][/c]
[float=left][img6="Image Credit & Copyright: Wang, Letian"]http://apod.nasa.gov/apod/image/1112/TLE2011Dec10WangLetian900c.jpg[/img6][hr][/hr][/float]The dark, inner shadow of planet Earth is called [url=http://apod.nasa.gov/apod/ap060909.html]the umbra[/url]. Shaped like a cone extending into space, it has a circular cross section most easily seen during a [url=http://www.mreclipse.com/Special/LEprimer.html]lunar eclipse[/url]. For example, last Saturday the [url=http://apod.nasa.gov/apod/ap080220.html]Full Moon slid[/url] across the southern half of Earth's umbral shadow, [url=http://asterisk.apod.com/viewtopic.php?f=29&t=26135]entertaining moonwatchers[/url] around much of the planet. In the total phase of the eclipse, the Moon was completely within the umbra for 51 minutes. Recorded from Beijing, China, this composite eclipse image uses [url=http://apod.nasa.gov/apod/ap070901.html]successive[/url] pictures from totality (center) and partial phases to trace out a large part of the umbra's [url=http://apod.nasa.gov/apod/ap080820.html]curved edge[/url]. Background stars are visible in the [url=http://apod.nasa.gov/apod/ap110621.html]darker[/url] eclipse phases. The result shows the relative size of the shadow's cross section at the distance of the Moon, as well as the Moon's path [url=http://www.nasa.gov/mission_pages/LRO/news/dec2011-eclipse.html]through Earth's umbra[/url].
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[c][url=http://apod.nasa.gov/apod/ap111216.html][size=150][b]Red Moon Rising (2011 Dec 16)[/b][/size][/url][/c]
[float=left][img6="Image Credit & Copyright: Oshin Zakarian (TWAN)"]http://apod.nasa.gov/apod/image/1112/TLE2011Dec10_901oshin_600h.jpg[/img6][hr][/hr][/float]This surreal, wintry scene is a composite picture [url=http://asterisk.apod.com/viewtopic.php?f=29&t=26135]recorded on December 10[/url] as the Moon rose behind the Zagros Mountains of Iran. A total lunar eclipse was already [url=http://apod.nasa.gov/apod/ap111214.html]in progress[/url]. The image combines nearly 500 successive frames taken over 1.5 hours beginning [url=http://apod.nasa.gov/apod/ap071227.html]in twilight[/url] as the eclipsed Moon steadily climbed above the rugged landscape. The reddened lunar disk and deep blue twilight make for a striking contrast, yet the contrasting colors have the same root cause. The eclipsed Moon is red because the [url=http://www.mreclipse.com/Special/LEprimer.html]Earth's umbral shadow[/url] is suffused with [url=http://apod.nasa.gov/apod/ap070830.html]a faint red light[/url]. The ruddy illumination is from all the reddened sunsets and sunrises, as seen from a [url=http://science.nasa.gov/science-news/science-at-nasa/2003/04nov_lunareclipse2105/]lunar perspective[/url]. But the sunsets and sunrises are reddened because the Earth's atmosphere [url=http://www.webexhibits.org/causesofcolor/14.html]scatters blue[/url] light more strongly than red, creating the twilight sky's dim, blue glow.
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[c][url=http://apod.nasa.gov/apod/ap111217.html][size=150][b]Comet Lovejoy: Sungrazing Survivor (2011 Dec 17)[/b][/size][/url][/c]
[float=left][img6="Credit: LASCO, SOHO Consortium, NRL, ESA, NASA"]http://apod.nasa.gov/apod/image/1112/Lovejoy_loses_tail900.jpg[/img6][hr][/hr][/float]Like most other sungrazing comets, Comet Lovejoy (C/2011 W3) was not expected to survive its [url=http://science.nasa.gov/science-news/science-at-nasa/2011/16dec_cometlovejoy/]close encounter with the Sun[/url]. But it did. This image [url=http://sohowww.nascom.nasa.gov/pickoftheweek/old/03dec2011/]from a coronograph[/url] onboard the sun-staring SOHO spacecraft identifies the still [url=http://sungrazer.nrl.navy.mil/index.php?p=news/birthday_comet_c1]inbound[/url] remnants of the tail, with the brilliant head or coma [url=http://sungrazer.nrl.navy.mil/index.php?p=news/birthday_comet]emerging from[/url] the solar glare on December 16. The Sun's position, behind an occulting disk to block the overwhelming glare, is indicated by the white circle. Separated from its tail, Comet Lovejoy's coma is so bright it saturates the camera's pixels creating the horizontal streaks. Based on their orbits, [url=http://apod.nasa.gov/apod/ap090322.html]sungrazer comets[/url] are thought to belong to the Kreutz family of comets, created by successive break ups from a single large parent comet that passed very near the Sun in the twelfth century. Most have been discovered with SOHO's cameras, but unlike many sungrazers, this one was first spotted by Australian [url=http://tech.groups.yahoo.com/group/comets-ml/message/18445]astronomer Terry Lovejoy[/url] from an earth-based observatory. Comet Lovejoy is estimated to have come within 120,000 kilometers of the Sun's surface and [i]likely had[/i] a large cometary nucleus to have survived its intense [url=http://www.windows2universe.org/physical_science/physics/mechanics/orbit/perihelion_aphelion.html]perihelion passage[/url]. Remarkable videos of the encounter from the Solar Dynamics Observatory [url=http://sdo.gsfc.nasa.gov/gallery/potw.php?v=item&id=79]can be found here[/url].
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[size=110][url=http://asterisk.apod.com/viewtopic.php?f=29&t=26161][color=#4040FF][b]<- Previous week's poll[/b][/color][/url][/size]