Alien contact. Artist's impression of possible future radio contact by aliens. Radio waves (white ripples) emanate from the alien's home planet (at top). One signal from the planet's ring (vertical yellow line) passes between eyes which symbolize the aliens. The eyebrows are formed by comets, which possibly play a part in the origin of life. The signal passes through the Milky Way. The Milky Way is shown containing the chemicals needed to begin life:- ammonia (1 blue and 3 yellow circles), water (1 red and 2 yellow circles), hydrogen (2 yellow circles) and methane (1 white and 4 yellow circles). The signal is received by the Arecibo radio telescope on Earth (at bottom).