Activate the [Arc tool] and draw a circle.
Fill the circle with black.
Hold down the right mouse button on the circle and drag a small amount
toward the bottom right direction.
Release the right mouse button and click the [Duplicate] menu item.
Fill the circle with white.
Reduce size of the white circle.
Select both the circles.
Make the pen of the circles transparent.
Click the [Plug-in] > [Gradater] > [Control Panel] menu item, to display the Gradater control panel.
Set the parameters, described in the following graphic.
Then click the Gradate button to finish the sphere.