Hi, I would like to see the resemblance between planet Earth and a spherical top. I draw here the x-convention Euler angles as I know them: 24 hours to complete one complete one revolution around it's own z' axes. And the 23.5° Earth axes revolves around the "sun's z axes" - the line perpendicular to the plane where the Earth orbit's the sun. So where is the nutation? does the 23.5° ever change? Thanks.