Apple Motion 2 Tutorials - Manual (Page 210)

210 Tutorial 4 Working With Particles
3 In the Canvas, press Shift and drag a corner of the shape’s bounding box to scale down
the star, until it is about 35 percent of its original size.
4 In the Shape Dashboard, click the Fill color well.
The Colors window appears.
5 Click the color picker (the magnifying glass icon), then click one of the orange stars in
the Canvas.
The star is now a more satisfying orange color.
6 Close the Colors window.
Now, add the Orbit Around
Simulation behavior. Since the particles should orbit around
Big Star, add the behavior to the particles.
To add the Orbit Around behavior:
1 In the Layers tab, select Stars.
2 In the Toolbar, click the Add Behavior icon, choose Simulations, then choose Orbit
Around.
Nothing changes. The reason for this is that the objects do not yet know which object
around which they are to orbit. Choose this object now.