APOD Collection: Sun Pillars

A nostalgic look back at Astronomy Picture of the Day
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owlice
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APOD Collection: Sun Pillars

Post by owlice » Wed Aug 17, 2011 2:37 am


2010 March 6 Reddened light from the setting Sun illuminates the cloud banks hugging this snowy, rugged terrain. Inspiring a moment of quiet contemplation, the sunset scene included a remarkable pillar of light that seemed to connect the clouds in the sky with the mountains below. Known as a Sun pillar, the luminous column was produced by sunlight reflecting from flat, six-sided ice crystals formed high in the cold atmosphere and fluttering toward the ground. Last Monday, astronomers watched this Sun pillar slowly fade, as the twilight deepened and clearing, dark skies came to Mt. Jelm and the Wyoming Infrared Observatory.

2008 December 15 Have you ever seen a sun pillar? When the air is cold and the Sun is rising or setting, falling ice crystals can reflect sunlight and create an unusual column of light. Ice sometimes forms flat, six-sided shaped crystals as it falls from high-level clouds. Air resistance causes these crystals to lie nearly flat much of the time as they flutter to the ground. Sunlight reflects off crystals that are properly aligned, creating the sun-pillar effect. In the above picture taken in 2007 January, a sun-pillar reflects light from a Sun setting over Lake Norman, North Carolina, USA.

2006 September 23 Today, the Sun rises due east at the Equinox, a geocentric astronomical event that occurs twice a year. To celebrate, consider this view of the rising Sun and a lovely set of ice halos recorded on a cold winter morning near Green Bay, Wisconsin, USA, planet Earth. Produced by sunlight shining through common atmospheric ice crystals with hexagonal cross-sections, such halos can actually be seen more often than rainbows. The remarkable sunrise picture captures a beautiful assortment of the types most frequently seen, including a sun pillar (center) just above the rising Sun surrounded by a 22 degree halo arc. Completing a triple sunrise illusion, sundogs appear at the far left and far right edges of the 22 degree arc. An upper tangent arc is also just visible at the very top of the view.

2006 February 5 Sometimes the unknown is beautiful. In 2000 February near Lake Tahoe, Nevada, two amateur photographers noticed an unusual red column of light rise mysteriously from a setting sun. During the next few minutes, they were able to capture the pillar and a photogenic sunset on film. Pictured above, the red column is seen above a serene Lake Tahoe and snow-capped mountains across from Lake Tahoe-Nevada State Park. The mysterious column, they learned later, is a Sun Pillar, a phenomenon where sunlight reflects off of distant falling ice crystals.

2006 January 2 Have you ever seen a sun pillar? When the air is cold and the Sun is rising or setting, falling ice crystals can reflect sunlight and create an unusual column of light. Ice sometimes forms flat, six-sided shaped crystals as it falls from high-level clouds. Air resistance causes these crystals to lie nearly flat much of the time as they flutter to the ground. Sunlight reflects off crystals that are properly aligned, creating the sun-pillar effect. In the above picture taken late last month, a sun-pillar reflects light from a Sun setting over Bangor, Maine, USA.

2003 January 23 On January 16, NASA's space shuttle Columbia roared into blue morning skies above Kennedy Space Center on STS-107, the first shuttle mission of 2003. But this is not a picture of that launch! It was taken on the morning of January 16 though, at sunrise, looking eastward toward Lake Ontario from just outside of Caledon, Ontario, Canada. In the picture a sun pillar, sunlight reflecting from ice crystals gently falling through the cold air, seems to shoot above the fiery Sun still low on the horizon. By chance, fog and clouds forming over the relatively warm lake look like billowing smoke from a rocket's exhaust plume and complete the launch illusion. Amateur photographer Lauri Kangas stopped on his way to work to record the eye-catching sun pillar launch.

2002 December 30 Have you ever seen a sun pillar? When the air is cold and the Sun is rising or setting, falling ice crystals can reflect sunlight and create an unusual column of light. Ice sometimes forms flat, stop-sign shaped crystals as it falls from high-level clouds. Air resistance causes these crystals to lie nearly flat much of the time as they flutter to the ground. Sunlight reflects off crystals that are properly aligned, creating the sun-pillar effect. In the above picture, a sun-pillar reflects light from a setting Sun.

2001 March 13 Have you ever seen a sun pillar? When the air is cold and the Sun is rising or setting, falling ice crystals can reflect sunlight and create an unusual column of light. Ice sometimes forms flat, stop-sign shaped crystals as it falls from high-level clouds. Air resistance causes these crystals to lie nearly flat much of the time as they flutter to the ground. Sunlight reflects off crystals that are properly aligned, creating the sun-pillar effect. In the above picture, a sun-pillar reflects light from a setting Sun.

July 6, 1999 Have you ever seen a sun pillar? When the air is cold and the Sun is rising or setting, falling ice crystals can reflect sunlight and create an unusual column of light. Ice sometimes forms flat, stop-sign shaped crystals as it falls from high-level clouds. Air resistance causes these crystals to lie nearly flat much of the time as they flutter to the ground. Sunlight reflects off crystals that are properly aligned, creating the sun-pillar effect. In the above picture, the sun-pillar can be traced up to the cloud that is raining the reflecting ice-crystals.
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APOD Collection: Sun Pillars

Post by Doc Cherokee » Thu Aug 18, 2011 4:56 pm

:drgreen: :drgreen: I'd love to see the mathematics behind Sun Pillars; glorious!

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Re: APOD Collection: Sun Pillars

Post by ernvl@yahoo.com » Sat Aug 20, 2011 12:54 am

The mathematics behind sun pillars is outlined in R.Greenler "Rainbows, Haloes and Glories" Probably out of print but may be available in a science library.
I donot have the book and cannot recall whether the detailed mathematics is actually given.
Ernest Loewenstein

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bystander
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Re: APOD Collection: Sun Pillars

Post by bystander » Sat Aug 20, 2011 1:07 am

Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

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Re: APOD Collection: Sun Pillars

Post by gthroop » Tue Aug 23, 2011 7:53 pm

The ancient history of astronomy documented! For a truly enjoyable read try "Witness of the Stars" by E.W. Bullinger, just fascinating! The sun pillar pictures are great.

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Re: APOD Collection: Sun Pillars

Post by xpesos » Fri Dec 09, 2011 12:37 pm

that was superb and awesome, i never knew why sun pillars showed up,
also thank to bystander for giving useful links, now i can tell sun pillars are due to tiny ice fragments in air, Oo

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