Thread: Orbiting Planets and Moons

I'm trying to make a code that has several orbiting images, a moon orbiting the earth, and then a smaller moon orbiting the moon. Getting the main moon orbiting the earth wasn't too difficult, it just requires rotating the moon image around the center of the earth. However, I can't figure out how to get the smaller moon rotating around the big one. Any ideas on how to do this? The images I'm using are attached.

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Toolkit;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class GUIs extends JFrame
{
	private Image earth = Toolkit.getDefaultToolkit().getImage("picFolder/Earth.gif");
	private Image back = Toolkit.getDefaultToolkit().getImage("picFolder/galaxy2.png");
	private Image rocket = Toolkit.getDefaultToolkit().getImage("picFolder/Rocket.gif");
	private Image moon = Toolkit.getDefaultToolkit().getImage("picFolder/Moon.png");
	public void makeEnvironment()
	{
		setTitle("This is the title");
		setBounds(0, 0, 800, 800);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		MyPanel panel = new MyPanel();
		panel.setBackground(Color.white);
		getContentPane().add(panel);
		setResizable(true);
		setVisible(true);
	}
	private class MyPanel extends JPanel
	{
		public void paintComponent(Graphics g)
		{
			super.paintComponent(g);
			g.drawImage(back,0,0,1280,1024,this);
			Graphics2D g2d = (Graphics2D)g;
			drawStuff(g, g2d);
		}
	}
	public static void main(String[] args)
	{
		GUIs gui = new GUIs();
		gui.makeEnvironment();
	}
	public int rCurrent = 0;
	public int rIncrement = 1;
	public void drawStuff(Graphics g, Graphics2D g2d)
	{
		Thread thread = new Thread();
		try{Thread.sleep(1);}
		catch(InterruptedException e){e.printStackTrace();}
		g.drawImage(earth, 200, 200, 100, 100, this);
		g2d.rotate(Math.PI*(rCurrent)/360, 250, 250);
		g.drawImage(moon, 400, 210, 60, 60, this);
		g2d.rotate(Math.PI*(rCurrent*3)/360, 250, 250);
		g.drawImage(rocket, 150, 240, 20, 20, this);
		rCurrent+=rIncrement;
		repaint();
	}
}

Moon.jpgoie_transparent.jpgRocket.jpgGalaxy2.jpg

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Good first post and an interesting project. Please keep us posted.