Modelling the Moon - specular highlights!

[starbase1]

Hi All,
As space stuff is still very popular around here, (at least with me!), I thought other might be interested to see this - (NOT my work!). Its an animation of moon phases built from real USNO images of the Moon.

http://www.ac.wwu.edu/~stephan/phases.html

The bit I found most interesting is that there is a definite specular highlight on it, looking like a 'shiny patch' that moves along the equator as the lighting changes.

It is most obvious on the dark 'seas', but is also there on the lighter areas...

I've not seen this mentioned in modelling the moon before...

Nick

[etobiason]

I'm confused...does it mention that the images are raytraced from images of the moon mapped to a sphere with a light source moving around it? If that is the case then the specular could be a 3D artifact and not something present on the actual moon...

[starbase1]

No, it says they are images taken from the US Naval observatory - at least I assume that means they are real - I could not find the source imges on the reference site...

Nick

[etobiason]

I think what it actually says is a little more vague than that...

"I made this animated gif 12 Jul 96 using 12-hour images downloaded from the
U n i t e d * S t a t e s * N a v a l * O b s e r v a t o r y
These "Virtual Reality Moon Phases" were created from ray-traced images of the Moon. A Clementine spacecraft mosaic of the lunar surface was mapped onto a sphere, and scenes were rendered as a virtual Sun "orbited" the Moon. The depiction of lunar surface features suffers geometric distortion but the terminator is correct with respect to the spherical Moon."