[Spice_discussion] Long-term accuracy of the IAU_MOON frame

[Ernie Wright]

I use SPICE to create renderings of the Moon's phases:

http://svs.gsfc.nasa.gov/goto?4236

I've been using DE 421 for positions.  For epochs near the present, I 
use the DE 421-derived binary PCK and the MOON_ME frame for the 
orientation of the Moon (the color and elevation maps come from LRO and 
are aligned to MOON_ME).

I'd like to do something like this for epochs hundreds of years in the 
past, but the coverage of the binary PCK only goes back to 1900, so I 
have to use IAU_MOON as the body-fixed frame.

Does anybody have a sense of the long-term accuracy of IAU_MOON?

The IAU report,

http://astropedia.astrogeology.usgs.gov/download/Docs/WGCCRE/WGCCRE2009reprint.pdf

says somewhat vaguely that the orientation equations that IAU_MOON are 
based on (see Table 2) are precise to about 150 meters, which is more 
than good enough for what I need, but it doesn't say anything about 
whether that holds up over long time spans.

- Ernie


-- 
Ernest T. Wright                                ernest.t.wright at nasa.gov
Scientific Visualization Studio                 http://svs.gsfc.nasa.gov
NASA/Goddard Space Flight Center, Code 606.4      voice: +1 301 286-1569
Greenbelt, MD 20771                                 fax: +1 301 286-1634