Celestia Forums

Would it be possible to add some more terms to the rotation formula?

It'd be nice to be able to include precession of the poles.

I'd suggest that when it's applied to the earth that the coodinate system stay at J2000, however.

You can already simulate precession with Celestia . . . Take a look at Toutatis in solarsys.ssc and you'll see this line:

PrecessionRate 48.98 # 7.35 day period

Units are degrees/Julian day . . . I haven't added precession to the Earth yet because I'm afraid it may throw off orbital calculations for the Moon (I think the ones I'm using are given in a non-precessing frame of reference.) You're welcome to experiment though--I believe the precession period of the Earth is about 26,000 years.

--Chris

Thanks!