Evidence for falling snow - Opportunity image shows pillar of light

rgcarnes · 2004-05-04 09:22:40

A recent image of the sun near the horizon on Mars seems to show the "pillar of light" phenomenon.

This image, although apparently over exposed, shows a pillar of light above and below the sun. This may be caused by snowflakes falling flat with sunlight being scattered by their upper surfaces below the sun's disk, and from their lower surfaces above the sun's disk.

In combination with today's image of the day and the statement on the Malin site about water ice clouds over the Opportunity site, it begins to make sense.

http://www.lyle.org/mars/imagery/1N1365 … G.html]The Lyle site

Palomar · 2004-05-04 09:33:28

A recent image of the sun near the horizon on Mars seems to show the "pillar of light" phenomenon.

*Well...the sun does look a bit elongated (vertically), but besides the glare effect it seems more like some sort of photographic (equipment) distortion to me. But I'm no photographer, so...(just my 2 cents')...and I can only compare it to images of other light pillars I've seen (on Earth, of course) so...

--Cindy ???

rgcarnes · 2004-05-04 09:41:53

If it is an equipment induced effect, then the other sun images, other than this one near the horizon while there are certified water ice clouds present, should show similar effects.

Palomar · 2004-05-04 10:37:52

If it is an equipment induced effect, then the other sun images, other than this one near the horizon while there are certified water ice clouds present should show similar effects.

*Well...IIRC (spaceweather.com posts pics of them a lot), the only time the light pillar phenomenon occurs -is- when the sun is near the horizon (either). Maybe a memory lapse on my part, but I don't recall light pillar phenomenon occurring at any other time but near a horizon.

["Sun dogs" and etc., yes -- I've seen them at any time of the day, in the Midwestern winter (even fainter ones where I currently live, in the dead of winter, once in a while).]

Wish I were more knowledgeable about the subject.

--Cindy

Rxke · 2004-05-04 10:48:47

Sorry to dissapoint, but the "pillar" is digital oversaturation... IIRC, the pics get scanned vertically, line by line, and the centre must be totally overexposed, i guess...

You can see these vertical white lines on shiny surfaces on the rovers too, sometimes, like the first composite panorama of Spirit (wich is on my wall, so i see it every day...)

rgcarnes · 2004-05-05 07:48:05

Rxke and Cindy,

Thanks. Both of you are, of course, correct. I appologize for wasting time.
I was negligent in ignoring the overexposure as much as I did and jumping to the conclusion that the same filter was being used that is typically used in making the other direct solar exposures. I intend to not let such a thing happen again.

Shaun Barrett · 2004-05-05 08:23:55

Don't be too hard on yourself, Rex. We're all a little excited about these amazing new pictures - as astronaut Jim Lovell once said about the Apollo 8 crew with their noses glued to the portholes as the Moon glided beneath them, we're like kids looking in the window of a candy store!
It was an easy mistake to make, under the circumstances.

Palomar · 2004-05-05 08:56:45

Don't be too hard on yourself, Rex. We're all a little excited about these amazing new pictures - as astronaut Jim Lovell once said about the Apollo 8 crew with their noses glued to the portholes as the Moon glided beneath them, we're like kids looking in the window of a candy store!
It was an easy mistake to make, under the circumstances.

*Agreed. No need to apologize, Rex. You brought up a really interesting thread, and I enjoyed participating in it (meterology buff that I am).

It's also so interesting to see pics of Sol from off-Earth. Contrast grayish background or blackness of space with our big blue sky. Sol looks a bit whiter off-Earth, at least in pics I've seen (unless it's my imagination...could be).

--Cindy

P.S.: Jim Lovell? Did someone mention the most gorgeous astronaut ever?

Rxke · 2004-05-05 09:12:09

Look at the positive side: those water-ice clouds are *still* there! :up:

rgcarnes · 2004-05-05 12:05:31

Thanks, folks,

One thing that should be remembered is that while the image I referred to seems useless as evidence, that does not prove the negative. Also, from the image or two we have out of the Viking missions showing transient snow we know it's possible for it to happen on Mars for those (Viking) latitudes.

Palomar · 2004-05-05 12:50:47

Also, from the image or two we have out of the Viking missions showing transient snow we know it's possible for it to happen on Mars for those (Viking) latitudes.

*I agree.

http://skywheel.kangwon.ac.kr/~ahnhi/ne … Mars.jpg]I posted this pic a long time ago in the 1st "New Discoveries" thread; I'm pretty sure Astropix has it on file (with a short article accompanying it).

This thing would surely produce a bit of snow, I should think. Especially given its proximity to the polar cap. Snow...how about an occasional -blizzard- on Mars?

Well, just some speculation (occasional blizzards).

I wonder how often Mars spawns a huge cyclone like that; I didn't see/read any speculation in that regard.

--Cindy

rgcarnes · 2004-05-18 12:03:31

It is now May 18, 2004 and several of the near horizon views of the sun or setting sun show characteristics which still suggest we are observing through regular ice crystals or perhaps even falling snow somewhere in the line of sight to the sun. We don't seem to see the saturated image pixels we were seeing earlier.

One of the pseudo color images on the http://www.lyle.org]www.lyle.org site even showed a ring around the just-set sun, although I haven't measured and calculated its angular separation to confirm that that is what it actually is as observed for such situations here on earth.

There is a lot to be learned from these images.

Palomar · 2004-05-18 12:33:39

It is now May 18, 2004 and several of the near horizon views of the sun or setting sun show characteristics which still suggest we are observing through regular ice crystals or perhaps even falling snow somewhere in the line of sight to the sun. We don't seem to see the saturated image pixels we were seeing earlier.
One of the pseudo color images on the http://www.lyle.org]www.lyle.org site even showed a ring around the just-set sun, although I haven't measured and calculated its angular separation to confirm that that is what it actually is as observed for such situations here on earth.
There is a lot to be learned from these images.

*Hi Rex:

I can't get into http://www.lyle.org]www.lyle.org. I'm redirected to a web page for "Apache web server," and nary another link to lyle.

Hopefully spaceweather.com will post the pics.

Hold on...http://www.lyle.org/mars/]I just found this (hunting w/Google). This must be the site you refer to. Which link is the one to the pics you refer to? There are a lot of links, and none specified (or nearly so) to this topic.

--Cindy

atomoid · 2004-05-18 21:59:50

It is now May 18, 2004 and several of the near horizon views of the sun or setting sun show characteristics which still suggest we are observing through regular ice crystals or perhaps even falling snow somewhere in the line of sight to the sun. We don't seem to see the saturated image pixels we were seeing earlier.
One of the pseudo color images on the http://www.lyle.org]www.lyle.org site even showed a ring around the just-set sun, although I haven't measured and calculated its angular separation to confirm that that is what it actually is as observed for such situations here on earth.
There is a lot to be learned from these images.
*Hi Rex:
--Cindy

i think he was referring to http://www.lyle.org/mars/imagery/1P1378 … .html]this image or http://www.lyle.org/mars/bysol/1-109.html]others like it from sol 109
IMHO, i think the "pillar of light" is just a reflection off the inside of the camera lens or housing (the camera does happen to be pointing directly into the sun, so there should be lots of flares and other lens artifacts depending on the camera angles), the images with the vertical line pointing UP as oppsed to down, are quite odd. Also, note that you can see the pillar of light superimposed over the ground also. If it were truly an atmospheric phenomenon (such as a sundog type of effect) then it would only be seen in areas of the sky. speaking of sundogs, im sure they exist on mars and the rover should be able to get some good images if we get lucky, but i dont think this is anything like that. Sundogs are most usually seen at angles that are horizontal to the atmospheric horizon, not vertical.

i cant find that pseudocolor image of the ring around the sun, though.

rgcarnes · 2004-05-19 06:24:09

Sorry I didn't provide a link to the ring around the just set sun. I'll try to get back to it for everyone. I just saw it yesterday at my day job while cooling off.

rgcarnes · 2004-05-19 07:19:08

The pseudocolor "sun ring" image is no longer on the lyle site at the location where I saw it yesterday. I sent Lyle an e-mail requesting it's location. Interesting that it's not still there.

rgcarnes · 2004-05-19 12:49:55

http://mars.lyle.org/synth/1-101.html]Lyle site containing special sun images

Hope this provides the link for my previous comments.

Palomar · 2004-05-19 13:11:55

http://mars.lyle.org/synth/1-101.html]Lyle site containing special sun images
Hope this provides the link for my previous comments.

*Hi Rex. I certainly hope Lyle gets back to you, regarding the pseudocolor "sun ring" image. I've found information at different sites seemingly misplaced as well, at times. Very aggravating. Anyway, would love to see that pic.

I take it the frame of Solset timed 17:52:33 is also a false-image pic (red and green/blue)? But then we had a pic come through months ago (posted in the S & O thread) showing a blue Marsian Solset...via regular media wire and "true color." But I see pics of landscapes below, in the link, with red and green, which is why I wonder.

Sol looks like an egg settled down inside a net in these pics. Lots of pretty tans, beiges and sepias in the pics above the one I question...I'm presuming those are "true color."

--Cindy

rgcarnes · 2004-05-19 15:39:25

Mr. Lyle was most helpful in showing me where to look for the image I saw yesterday.

He rightly cautioned me about taking the colors too seriously, and I sent him an e-mail that the possible presence of the ring around the just-set sun (see last "sun" image in the link) was more important than what color it was.

Cindy, the 17:52:33 image was the one containing the (partial) ring in the upper portion of the view.

rgcarnes · 2004-05-20 06:25:26

Atomoid,

I am replying to your May 18 post to point out that typically lens flares take place with the light source off axis rather than on axis. Also, the pillar of light phenomenon, similar to a rainbow, can typically appear superimposed over the ground surface. I've seen beautiful displays while living next to lake Ontario in Rochester, New York, where we got a lot of lake effect snow, even while the sun was shining.

Is there anyone from some place like Rochester, or Buffalo out there willing to concur? Rochester is, after all, a Mecca for optics.

Palomar · 2004-05-20 07:48:57

the possible presence of the ring around the just-set sun (see last "sun" image in the link) was more important than what color it was.
Cindy, the 17:52:33 image was the one containing the (partial) ring in the upper portion of the view.

*Hi Rex: Yes, I see what you mean: That faint arc-shaped band of lighter (lime-colored to my eyes) green (I had to turn my monitor up full-blast on light and contrast options). Have there been any official comments about the pic from JPL, etc.?

Marsbow?

--Cindy

rgcarnes · 2004-05-20 08:08:12

No word from official folks yet that I know about, Cindy.

Atomoid, to clarify my last post to you, the "pillar of light" is a phenomenon of reflection rather than refraction as in a rainbow, but they both can manifest themselves as superimposed over a ground-level background.

Sun dogs are likewise a refraction based effect. The sun dog would become a complete circular arc around the sun if the ice crystals responsible for the effect were uniformly distributed in the sky rather than just in a band near the horizon.

Sun dogs and rainbows separate light into its spectral colors, but the "pillar of light" should not.

atomoid · 2004-05-20 13:36:46

Are there any cases of pillars here on Earth? sundogs and such are very common, but somehow ive never heard of pillars before. thats why im initially skeptical. Not that i completely poo-poo the possibility of these types of atmospheric phenomenon in these pictures, im just thinking that its probably a certaintly that lens artifacts will occur in many of the rover images, especially when theyre pointed at the sun, its just difficult to discern what is what without being an expert. maybe the following are lens artifacts or maybe they are something else alltogether. From looking at http://www.lyle.org/mars/bysol/1-101.html]all the images of the sun from sol 101, something i notice is that:

- all the RIGHT filter images show a sun pillar http://www.lyle.org/mars/imagery/1P1371 … l]shooting UP from the sun, whereas all the LEFT filter images show a pillar http://www.lyle.org/mars/imagery/1P1371 … l]dropping DOWN from the sun. Considering these images are taken only about 20 seconds apart, i think its something about the pancam filter setup thats causing this rather than something in the atmosphere.

- the http://www.lyle.org/mars/imagery/1N1371 … ]no-filter Navcam image has an oversaturation bleed shooting up and down. perhaps the filter changes the character of the oversaturation bleed making it take on the appearance in the other images. shoudlnt we see the pillar with no filter? unless the filter is what makes it possible to see the pillar...

- the filter L6 images all have a little blob of light just to the upper Right of the solar ball http://www.lyle.org/mars/imagery/1P1371 … .html]such as this. lens artifact or something else? Similarly, all the filter L2 images all have a little blob to the lower Left. http://www.lyle.org/mars/imagery/1P1371 … .html]such as that. hmmm... the L4 images have one to the upper left. kind of like clockwork...

- http://www.lyle.org/mars/imagery/1P1371 … .html]this image and http://www.lyle.org/mars/imagery/1P1371 … .html]this one too, both have a little white line above and to the left of the sun. might this be a lens/filter artifact, or something in the atmosphere such as a meteor trail?

Palomar · 2004-05-20 14:02:36

Are there any cases of pillars here on Earth? sundogs and such are very common, but somehow ive never heard of pillars before.

*spaceweather.com frequently (in the winter especially) posts pics (amateur and professional) of phenomenon they refer to as "light pillars" (or "sun pillars"...it's been a couple of months since they've posted those pics, of course with summer coming on).

Unless there's a major definition difference, I believe that is what Rex is referring to.

spaceweather.com has archives...

--Cindy

atomoid · 2004-05-20 14:34:10

thanks for that link Cindy,

heres an interesting http://www.sundog.clara.co.uk/halo/owmars.htm]article on Martian halos

and here's pics of sun pillars on Earth: an http://www.weather-photography.com/Phot … 1-22]upper pillar and a http://www.meteoros.de/arten/ee09e.htm]lower pillar.

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#1 2004-05-04 09:22:40

Re: Evidence for falling snow - Opportunity image shows pillar of light

#2 2004-05-04 09:33:28

Re: Evidence for falling snow - Opportunity image shows pillar of light

#3 2004-05-04 09:41:53

Re: Evidence for falling snow - Opportunity image shows pillar of light

#4 2004-05-04 10:37:52

Re: Evidence for falling snow - Opportunity image shows pillar of light

#5 2004-05-04 10:48:47

Re: Evidence for falling snow - Opportunity image shows pillar of light

#6 2004-05-05 07:48:05

Re: Evidence for falling snow - Opportunity image shows pillar of light

#7 2004-05-05 08:23:55

Re: Evidence for falling snow - Opportunity image shows pillar of light

#8 2004-05-05 08:56:45

Re: Evidence for falling snow - Opportunity image shows pillar of light

#9 2004-05-05 09:12:09

Re: Evidence for falling snow - Opportunity image shows pillar of light

#10 2004-05-05 12:05:31

Re: Evidence for falling snow - Opportunity image shows pillar of light

#11 2004-05-05 12:50:47

Re: Evidence for falling snow - Opportunity image shows pillar of light

#12 2004-05-18 12:03:31

Re: Evidence for falling snow - Opportunity image shows pillar of light

#13 2004-05-18 12:33:39

Re: Evidence for falling snow - Opportunity image shows pillar of light

#14 2004-05-18 21:59:50

Re: Evidence for falling snow - Opportunity image shows pillar of light

#15 2004-05-19 06:24:09

Re: Evidence for falling snow - Opportunity image shows pillar of light

#16 2004-05-19 07:19:08

Re: Evidence for falling snow - Opportunity image shows pillar of light

#17 2004-05-19 12:49:55

Re: Evidence for falling snow - Opportunity image shows pillar of light

#18 2004-05-19 13:11:55

Re: Evidence for falling snow - Opportunity image shows pillar of light

#19 2004-05-19 15:39:25

Re: Evidence for falling snow - Opportunity image shows pillar of light

#20 2004-05-20 06:25:26

Re: Evidence for falling snow - Opportunity image shows pillar of light

#21 2004-05-20 07:48:57

Re: Evidence for falling snow - Opportunity image shows pillar of light

#22 2004-05-20 08:08:12

Re: Evidence for falling snow - Opportunity image shows pillar of light

#23 2004-05-20 13:36:46

Re: Evidence for falling snow - Opportunity image shows pillar of light

#24 2004-05-20 14:02:36

Re: Evidence for falling snow - Opportunity image shows pillar of light

#25 2004-05-20 14:34:10

Re: Evidence for falling snow - Opportunity image shows pillar of light

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