Add motion blur:
1 At frame 0 select the asteroid, then right-click it and choose Object
Properties on the quad menu.
2 In the Motion Blur group, make sure that Enabled is on, and choose
Object. Click OK.
Object motion blur will blur the asteroid, but not the entire scene.
3 Move the time slider to frame 7.
4 Activate the Camera viewport and click Render Setup on the main
toolbar.
The Render Setup dialog is displayed.
5 Click the Renderer tab. On the Default Scanline Renderer rollout > Object
Motion Blur group, make sure that Apply is on, and that Duration (Frames)
is set to 0.5.
This will create a slight motion blur.
6 At the bottom of the dialog, click Render to test the result.
Motion blur on asteroid