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[ljk4-1]

ADMIN NOTE: Please note that this topic was unavoidably poltical before the 'No Politics' rule. Please restrict future comments to the mission/spacecraft/news updates etc.

WHAT'S NEW Robert L. Park Friday, 6 Jan 06 Washington, DC
DEEP SPACE CLIMATE OBSERVATORY KILLED.
http://bobpark.physics.umd.edu/index.html

[fredk]

That image is the "enhanced" version. The "natural" version doesn't look quite as bad:

https://epic.gsfc.nasa.gov/archive/natural/...31014165817.png

Looking at the pixel values the blue channel drops to precisely zero in the penumbra, giving the brown hue. I suspect somewhere in the processing (combining the raw channels into the colour version) they've clipped the low end of the blue (and green) channels. Their processing probably wasn't designed for such dark levels since the Earth is normally (almost) fully sunlit from L1!

Actually limb darkening of the sun is wavelength dependent, with shorter wavelengths more attenuated than long near the rim. So around annularity the illumination should actually be shifted to the red. But most of the visible penumbra is still lit by some of the central area of the sun's disk, so I wouldn't expect a noticable effect in these images.

But near the narrow path of annularity the illumination should be shifted somewhat to the red. It would be interesting to quantify that. Sometimes people report a change in the "character" of the light near annularity - maybe the colour shift contributes to that. I didn't notice a colour shift at either the 2023 or the 2012 annular eclipses, just the dimming. Of course the eye would adapt to such a slow colour shift.