Golden Rover #3 (E-R3) is located on level 5-18 of Angry Birds Space Red Planet. Zoom out and you will see the Rover north of the main structures. Use any bird to reach it with a straight shot. Once you hit the egg you’ll immediately be transported via a wormhole to the level, which pays homage to the Opportunity Rover. One strategy 3-starring this level is to fire a Red bird along the southern side of the gravitational field, and Terence along the northern side. Between those two shots, a fiery asteroid should destroy every piggy in space!
If you need help, the video below shows the location of the Golden Rover and a strategy for passing the level with 3 stars.