1. The first research project to establish contact with the aliens offered by German mathematician and astronomer Carl Friedrich Gauss: cut in the Siberian taiga forest area in the shape of a triangle and sow his wheat. The Martians will see in telescopes neat shape and realize that on earth live intelligent beings.
2. The existence of Martians in the XIX century, few doubted: in 1900 the Paris Academy of Sciences established a prize for the person who first come into contact with any extraterrestrial civilization except Mars.
3. The first coded message sent by aliens, and contained only three words, "Peace. Lenin. The USSR. " She was sent into deep space 19 and November 24, 1962 from the Center for Deep Space Communication in Yalta during radiolocation of Venus. Words coded conventional Morse code.
4. Results from the Earth was given four more meaningful interstellar messages. The first - in 1974 - was sent from the largest to date planetary radar at Arecibo (300 m antenna in Puerto Rico, USA). Beam power directed to the globular cluster M 13, exceeded the solar radio emission at 10 million times. After 25 thousand years, will cover the entire Arecibo message, No. 13, consisting of hundreds of thousands of stars. The signal was broadcast on two frequencies in a simple binary code.
5. If the pulses of one frequency to be considered zero, and the other - unity, then get a number of binary digits in 1679, in the plane of the convertible to the schedule of 73 lines and 23 points. It turns out the picture, which shows the atomic number, the person, the solar system and the actual telescope at Arecibo.
6. Three other interstellar messages were transmitted by the 70-meter radar in Yalta in 1999, 2001 and 2003. All of them were sent to surrounding solar-type stars, the earliest of them will reach the destination by 2036, and at the latest - to 2070-th.
7. The earth has sent four spacecraft beyond our solar system. The U.S. probe "Pioneer 10" and "Pioneer 11" launched in 1972-73, respectively. "Voyager 1" and "Voyager 2" started in 1977. After 40 thousand years, "Voyager 1" will be held at 1.6 light years away from the star AC +79 3888 Ophiuchus. "Pioneer 10" will reach Aldebaran in 2 million years. All probes are in themselves proof of our existence, if you suddenly fall into the hands of aliens. In addition, all of them are on board with pictures and record greetings aliens and even music.