Very simple (and not intended to be accurate) model of the sun, earth and moon to demonstrate rotations applied to circles in JavaFX.

SunEarthMoon.java

import javafx.animation.Animation;
import javafx.animation.KeyFrame;
import javafx.animation.KeyValue;
import javafx.animation.Timeline;
import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.scene.paint.Color;
import javafx.scene.shape.Circle;
import javafx.scene.transform.Rotate;
import javafx.stage.Stage;
import javafx.util.Duration;

public class SunEarthMoon extends Application {

	@Override
	public void start(Stage primaryStage) {
		final int CIRCLE_CENTER_X = 300 ;
		final int CIRCLE_CENTER_Y = 300 ;
		
		final Duration MONTH = Duration.seconds(2);
		final Duration YEAR = MONTH.multiply(13);
		
		Circle sun = new Circle(CIRCLE_CENTER_X, CIRCLE_CENTER_Y, 50, Color.GOLD);
		Circle earth = new Circle(CIRCLE_CENTER_X + 200, CIRCLE_CENTER_Y, 20, Color.CADETBLUE);
		Circle moon = new Circle(CIRCLE_CENTER_X + 240, CIRCLE_CENTER_Y, 5, Color.IVORY);
		
		Group earthAndMoon = new Group(earth, moon);
		
		Pane pane = new Pane(sun, earthAndMoon);
		pane.setMinSize(600, 600);
		
		Rotate earthRotate = new Rotate(0, CIRCLE_CENTER_X, CIRCLE_CENTER_Y);
		earthAndMoon.getTransforms().add(earthRotate);
		
		Rotate moonRotate = new Rotate(0, CIRCLE_CENTER_X + 200, CIRCLE_CENTER_Y);
		moon.getTransforms().add(moonRotate);
		
		Timeline earthTimeline = new Timeline(new KeyFrame(YEAR, new KeyValue(earthRotate.angleProperty(), 360)));
		earthTimeline.setCycleCount(Animation.INDEFINITE);
		earthTimeline.play();
		
		Timeline moonTimeline = new Timeline(new KeyFrame(MONTH, new KeyValue(moonRotate.angleProperty(), 360)));
		moonTimeline.setCycleCount(Animation.INDEFINITE);
		moonTimeline.play();
		
		primaryStage.setScene( new Scene(pane, Color.BLACK) );
		primaryStage.show();
	}

	public static void main(String[] args) {
		launch(args);
	}
}