Blue Sun On Mars |
Blue Sun On Mars |
Feb 11 2004, 03:47 PM
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#1
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Senior Member Group: Members Posts: 1465 Joined: 9-February 04 From: Columbus OH USA Member No.: 13 |
...and other stupid sundial tricks.
Take a look at this NASA-calibrated sundial image: http://tinyurl.com/create.php Zoomed: From that image the following RGB values are obtained: Ambient light (direct + scattered): 200:210:207 Scattered light: 87:72:60 Sky color: 194:169:161 So the direct light (i.e., direct sunlight) would be 200:210:207 minus 87:72:60 = 113:138:147 Scaled to max brightness: 196:239:255 (Sun color) Here's a graphic showing the sky color (194:169:161) vs. the sun color (196:239:255): Who knew? Joe -------------------- |
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Feb 11 2004, 04:11 PM
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#2
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Founder Group: Chairman Posts: 14431 Joined: 8-February 04 Member No.: 1 |
Well - it's very blue at sunset. Not sure on the maths of what you've done there but it wouldnt at all suprise me.
Doug |
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Feb 11 2004, 04:20 PM
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#3
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Senior Member Group: Members Posts: 1465 Joined: 9-February 04 From: Columbus OH USA Member No.: 13 |
This is high noon--check the sundial.
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Feb 11 2004, 07:06 PM
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#4
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Junior Member Group: Members Posts: 50 Joined: 8-February 04 From: Melbourne, Australia Member No.: 5 |
Hey, y'wanna stare at the sun, here, and show us what it looks like?
IMHO, the sun is brighter, bluer than sunlight. Just it hurts to look... Maybe you need to factor in the extreme Sun filters on L8/R8? -------------------- - Nick
===================================== Nick Hoffman Mars Specialist 3D-GEO Pty Ltd Melbourne Australia http://whitemars.com "First they ignore you, then they laugh at you, then they fight you, then you win." - Mahatma Gandhi (1869-1948) ===================================== |
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Feb 11 2004, 09:23 PM
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#5
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Founder Group: Chairman Posts: 14431 Joined: 8-February 04 Member No.: 1 |
QUOTE (jmknapp @ Feb 11 2004, 04:20 PM) This is high noon--check the sundial. Oh - I know that - I was just saying that a blue coloured sun on mars isnt a new idea. BUT - i do think you're jumping to conclusions. as we've found with many many sets of images on this thing - we dont really have any clue of the real colours we're actually seing - and you have to account for things like the huge white pillar supporting pancam and navcam a few ft from the sundial that will be casting light onto the dial etc etc. Doug |
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Feb 12 2004, 01:42 AM
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#6
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Senior Member Group: Members Posts: 1465 Joined: 9-February 04 From: Columbus OH USA Member No.: 13 |
Hi Doug,
Maybe you could point to some references on the blue sun on Mars? All I can find is reference to blue sky at sunset, caused by scaterring phenomena, not that the direct sunlight itself would be bluish. As for the colors in that photo, it's NASA's calibration & so the best available. -------------------- |
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