Left-click Add a planet. Change menu.

Right-click Change menu.

[Color] Change the color of a planet.

"?" shows a random color.

[Track] Change the type of trajectory.

line - short line

long line - long line

point - dotted line

non - hide

[Target] Add a planet to the selected direction.

1.Click the mouse to locate a planet.

2.Drag the mouse to determine the direction.

3.Release the mouse.

[Random] Add a planet to a random direction.

Click again to change the speed of the planet.

[Circle] Add a planet with a circular orbit.

[Size] Change the size of a planet.

[Star] Add and delete stars.

By clicking the blank space you'll add the stars.

By clicking on the stars, you'll delete them.

[Scale] Change the scale of the screen.

[Speed] Change the flow of the time.

From 8 to 1/4 times speed. 0 stops the time.