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APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Wed Jul 25, 2012 4:09 am
by APOD Robot
Image Pink Aurora Over Crater Lake

Explanation: Why is this aurora strikingly pink? When photographing picturesque Crater Lake in Oregon, USA last month, the background sky lit up with auroras of unusual colors. Although much is known about the physical mechanisms that create auroras, accurately predicting the occurrence and colors of auroras remains a topic of investigation. Typically, it is known, the lowest auroras appear green. These occur at about 100 kilometers high and involve atmospheric oxygen atoms excited by fast moving plasma from space. The next highest auroras -- at about 200 kilometers up -- appear red, and are also emitted by resettling atmospheric oxygen. Some of the highest auroras visible -- as high as 500 kilometers up -- appear blue, and are caused by sunlight-scattering nitrogen ions. When looking from the ground through different layers of distant auroras, their colors can combine to produce unique and spectacular hues, in this case rare pink hues seen above. As Solar Maximum nears over the next two years, particle explosions from the Sun are sure to continue and likely to create even more memorable nighttime displays.

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Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Wed Jul 25, 2012 7:43 am
by Boomer12k
It was a great night here in the Pacific Northwest....I have personally stood in about that same spot as the picture was taken... :D Crater lake is an awesome place...

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Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Wed Jul 25, 2012 9:21 am
by RedFishBlueFish
I do wonder what the (non-auroral) skyglow is from on the horizon.

The picture is taken facing north towards Polaris - so rising or setting Sun seems unlikely. K-Falls is in the wrong relative direction, as is Eugene.

Bend, though sort of in the right geographical orientation, seems both too far away and too small to account for such brightness?

Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Wed Jul 25, 2012 1:27 pm
by orin stepanek
I like it! 8-) :thumb_up: :thumb_up: :clap: :clap:

Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Wed Jul 25, 2012 2:45 pm
by Chris Peterson
RedFishBlueFish wrote:I do wonder what the (non-auroral) skyglow is from on the horizon.

The picture is taken facing north towards Polaris - so rising or setting Sun seems unlikely. K-Falls is in the wrong relative direction, as is Eugene.

Bend, though sort of in the right geographical orientation, seems both too far away and too small to account for such brightness?
Bend is exactly in the right direction for the center of the light dome (just below Capella, at an azimuth of about 30° when the picture was taken), and puts out plenty of light to produce a dome like this in a long exposure image (it's only 90 miles away). Some of the glow probably comes from little towns like Chemult and even intersection lights along Hwy 97. Just one unshielded porch light a few miles distant can produce a noticeable glow on a 30-second starfield image.

Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Wed Jul 25, 2012 3:35 pm
by Wingnut
How beautiful. Thank you for sharing this with us.

Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Wed Jul 25, 2012 4:10 pm
by dawg64
Auroras have long been objects of beauty and adoration. Why is it necessary to "accurately predict" their color and intensity? Do they cause the planet any harm? Is there some meteorlogical, financial or military benefit to be derived from predicting auroras? Like most people, I suppose, I am a curious person, but it seems that sometimes we carry scientific inquiry a bit too far. I'm just sayin'.

Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Wed Jul 25, 2012 4:32 pm
by neufer
dawg64 wrote:
Auroras have long been objects of beauty and adoration.

Why is it necessary to "accurately predict" their color and intensity?
Accurately predicting the occurrence of auroras would be a blessing to all potential observers.

Accurately predicting the colors of auroras would be a verification of our understanding of the phenomenae.

Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Wed Jul 25, 2012 4:37 pm
by Chris Peterson
dawg64 wrote:Auroras have long been objects of beauty and adoration. Why is it necessary to "accurately predict" their color and intensity? Do they cause the planet any harm? Is there some meteorlogical, financial or military benefit to be derived from predicting auroras? Like most people, I suppose, I am a curious person, but it seems that sometimes we carry scientific inquiry a bit too far. I'm just sayin'.
In addition to Art's observations, auroras are associated with solar activity that can cause damage in our high tech society, both on the ground and in space. Predicting the behavior of auroras is part of a better understanding of space weather and its interaction with the Earth, and that does have significant economic benefits.

Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Wed Jul 25, 2012 4:48 pm
by StarCuriousAero
I had the pleasure of driving through Klamath Falls about a month ago, it was actually snowing! Wish I'd had the time for a Crater Lake detour. :-/ This is an incredible shot though, at least I get to see it here! It possibly exacerbates that tinge of regret though with the exceptional beauty...

Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Wed Jul 25, 2012 6:07 pm
by neufer
Chris Peterson wrote:
RedFishBlueFish wrote:
I do wonder what the (non-auroral) skyglow is from on the horizon. The picture is taken facing north towards Polaris - so rising or setting Sun seems unlikely. K-Falls is in the wrong relative direction, as is Eugene. Bend, though sort of in the right geographical orientation, seems both too far away and too small to account for such brightness?
Bend is exactly in the right direction for the center of the light dome (just below Capella, at an azimuth of about 30° when the picture was taken), and puts out plenty of light to produce a dome like this in a long exposure image (it's only 90 miles away). Some of the glow probably comes from little towns like Chemult and even intersection lights along Hwy 97. Just one unshielded porch light a few miles distant can produce a noticeable glow on a 30-second starfield image.
http://en.wikipedia.org/wiki/Bend,_Oregon wrote: <<Bend is Central Oregon's largest city with Bend's metro population was estimated at 170,705 as of July 1, 2009. The name Bend was derived from "Farewell Bend", the designation used by early pioneers to refer to the location along the Deschutes River where the town was eventually platted, one of the few fordable points along the river. For at least 12,000 years, until the winter of 1824, the Bend area was known only to Native Americans who hunted and fished there. That year, members of a fur trapping party led by Peter Skene Ogden visited the area.

Constructed in May 1901, the Pilot Butte Development Company's little plant was the first commercial sawmill in Bend. A small community developed around the area, and in 1904, a city was incorporated by a general vote of the community's 300 residents. On January 4, 1905, the city held its first official meeting as an incorporated municipality, appointing A. H. Goodwillie as the first mayor. In 1910, Mirror Pond was created by the construction of the Bend Water, Light & Power Company dam on the Deschutes River in Bend. The dam provided the city with its initial source of electricity.

A large influx of new residents drawn by Bend's lifestyle amenities, along with the low interest rates and easy lending that fostered a national housing boom in 2001-2005, resulted in increased activity in Bend's construction and real estate sectors and have caused the rate of home price appreciation in Bend to grow substantially during that period. In June 2007 it was named the most overpriced housing market in America. In May 2010 the Federal Housing and Finance Agency released a report in which Bend had the largest price drop in the country, 23%, from first quarter of 2009 to the first quarter of 2010.>>

Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Wed Jul 25, 2012 6:58 pm
by Anthony Barreiro
dawg64 wrote:Auroras have long been objects of beauty and adoration. Why is it necessary to "accurately predict" their color and intensity? Do they cause the planet any harm? Is there some meteorlogical, financial or military benefit to be derived from predicting auroras? Like most people, I suppose, I am a curious person, but it seems that sometimes we carry scientific inquiry a bit too far. I'm just sayin'.
Fortunately this is not an either/or choice. Meteorologists and space scientists can continue to investigate the interaction between solar radiation and earth's atmosphere and develop models that can predict auroras, as well as other manifestations of space weather -- intellectual understanding possesses its own sort of beauty beyond its utilitarian value. Folks who live far enough north (or south) can continue to be surprised by and appreciate the immediate beauty of seeing an aurora. And for the rest of us who live too far from the poles, there's always apod.

Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Wed Jul 25, 2012 7:33 pm
by zbvhs
Is that in fact aurora? Is it perhaps sunlight coming over the North Pole that was diffused by air molecules and dust particles at high altitude? Around the Summer Solstice, the Sun would be seen as setting on the northern horizon from a point on "our side" of the Arctic Circle at local midnight. It is curious that the rays appear to converge on a point below the horizon. Aurora don't do that, do they? Does anyone know what time (of day) the picture was taken?

Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Wed Jul 25, 2012 8:03 pm
by Chris Peterson
zbvhs wrote:Is that in fact aurora? Is it perhaps sunlight coming over the North Pole that was diffused by air molecules and dust particles at high altitude? Around the Summer Solstice, the Sun would be seen as setting on the northern horizon from a point on "our side" of the Arctic Circle at local midnight. It is curious that the rays appear to converge on a point below the horizon. Aurora don't do that, do they? Does anyone know what time (of day) the picture was taken?
It is definitely an aurora- the colors give that away without doubt. The rays are essentially vertical- they appear to converge because of the wide field of the image (more than 90°).

The image appears to have been made on June 17 at about 4am local. That puts the Sun about 13° below the horizon, almost directly below Capella (and just a little further below the horizon than Capella is above it). The rays are not convergent on that point. However, this is right at the end of astronomical twilight, and the Sun is definitely close enough to rising to be creating that orange glow on the horizon. So it might not be light pollution at all (or it may be a mix of dawn light and Bend light).

Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Wed Jul 25, 2012 9:29 pm
by Boomer12k
I had a girl tell me I had a nice Aurora once..... :lol2:

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Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Wed Jul 25, 2012 11:58 pm
by saturno2
This image is very intersting.
With the color different of the aurora, the sky is strange.

Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Thu Jul 26, 2012 12:05 am
by TNT
Interesting...a pink aurora. Strange how they can occur like that.

Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Thu Jul 26, 2012 2:12 am
by neufer
Chris Peterson wrote:
The image appears to have been made on June 17 at about 4am local. That puts the Sun about 13° below the horizon, almost directly below Capella (and just a little further below the horizon than Capella is above it). The rays are not convergent on that point. However, this is right at the end of astronomical twilight, and the Sun is definitely close enough to rising to be creating that orange glow on the horizon. So it might not be light pollution at all (or it may be a mix of dawn light and Bend light).
The APOD taken around midnight 2 months prior gives a rough idea of
(cloud free) 90 mile distant Bend light (by the large fir tree on the left under Cepheus).

http://apod.nasa.gov/apod/ap120425.html

So what do you make of the bright light to the South East, Chris; night skiing perhaps :?:

Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Thu Jul 26, 2012 12:54 pm
by DavidLeodis
Superb photograph. I wonder how many have noticed that an annotated version is brought up on moving a cursor over the photo? :)

Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Thu Jul 26, 2012 4:30 pm
by Wing Nut
neufer wrote:
Chris Peterson wrote:
The image appears to have been made on June 17 at about 4am local. That puts the Sun about 13° below the horizon, almost directly below Capella (and just a little further below the horizon than Capella is above it). The rays are not convergent on that point. However, this is right at the end of astronomical twilight, and the Sun is definitely close enough to rising to be creating that orange glow on the horizon. So it might not be light pollution at all (or it may be a mix of dawn light and Bend light).
The APOD taken around midnight 2 months prior gives a rough idea of
(cloud free) 90 mile distant Bend light (by the large fir tree on the left under Cepheus).

http://apod.nasa.gov/apod/ap120425.html

So what do you make of the bright light to the South East, Chris; night skiing perhaps :?:
Klamath Falls, perhaps?

Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Thu Jul 26, 2012 10:29 pm
by Chris Peterson
neufer wrote:The APOD taken around midnight 2 months prior gives a rough idea of
(cloud free) 90 mile distant Bend light (by the large fir tree on the left under Cepheus).

So what do you make of the bright light to the South East, Chris; night skiing perhaps :?:
I'd make the exposure time 2am. The light to the left (azimuth 28°) is certainly Bend (90 miles away), and the light to the right (azimuth 159°) is from Klamath Falls and Altamont (totaling more than half the population of Bend, but only 50 miles from Crater Lake).

Re: APOD: Pink Aurora Over Crater Lake (2012 Jul 25)

Posted: Thu Jul 26, 2012 11:14 pm
by DavidLeodis
Regarding the time that the photo used for the APOD of July 25 2012 was taken. In the information brought up through the "auroras of unusual colors" link it states it was taken "at 3:30 a.m. local time on June 17th".