NASA is giving earthlings the opportunity to invade Mars as the space administration’s Polar Lander touches down on the red planet Friday. During the 90-day mission to study water on Mars, virtual invaders will be able to log on to a NASA Web site where they can download Java 2D API, Java 3D API, and a Web Interface for TeleScience application; and access the sights and sounds of Mars transmitted from the Polar Lander 157 million miles away.