Finding other planets is proof of the evolution of the universe.
There are planets elsewhere in the universe. Some of these are like earth and will have evolved life on them.
The Facts Are .....
It has been stated that there are 100 billion billion (1020)planets in the universe, with 10,000 of these evolving life like Earth. To reach this number, firstly there is a guess that there are 1022 stars in the universe; then a guess that one in a million suns is like our sun; then a guess that one in a million of these sun's has a solar system like ours; then a guess that one in a million of these solar systems has a planet like Earth. These numbers are guess-work based on pure supposition, they are not facts. 
Scientists in 1983 claimed that they had discovered another solar system around Vega, the fifth brightest star in the sky. Their evidence for this was infra-red radiation detected from the sun's vicinity which had travelled the 7.4 billion miles from there. This they interpreted to represent energy re-radiated by solid particles heated up by Vega. Note that this is pure speculation based on the interpretation of data which cannot be seen to be verified. 
Claims in 1984 that the first ‘planet’ had been discovered outside the solar system has turned out to be a ball of gas orbiting star VB-8, some 21 light years away. The ball of gas is estimated to be as large as Jupiter, and to have a temperature of 2000ºF. Robert Harrington of the US Naval Observatory has stated, "Only Don McCarthy [its discoverer] would call something that warm and that big a planet". 
A planet which was reportedly the first one discovered outside our solar system in July 1991 has since been declared as a mathematical error by its discoverers. When they re-worked their analysis of the radio signals coming from Pulsar PSR1829-10 (assessed as 30,000 light years away) they found they had not taken into account the correction for the slightly oval nature of Earth's orbit. No visible sightings have actually been made of this 'planet'. 
“On July 25  the three astronomers announced in Nature their observations of the regularly-varying radio beeps from a pulsar, known as PSR1829-10. They concluded that the variations could only be explained by the pulsar wobbling from the gravitational effect of a planet about 10 times the mass of Earth circling it once every six months. This six-month figure was later to prove the undoing of the original conclusion. Nature rushed the paper into print within three weeks and forewarned science journals of something big coming up. People and institutions almost tumbled over each other to be part of the action. The Australian Academy of Science added its weight, accelerating the local media into action. The 'planet' was acclaimed around the world as "the astronomical discovery of the decade". The headquarters in Sydney of CSIRO's Australia Telescope, where Dr Bailes [the discoverer] had come to work with his mentor, Dr Dick Manchester, became the nerve centre for a major media operation. Dr Bailes was accorded star treatment. In the past week, the individual scientists involved have been impressively open and frank about the situation. In contrast, the institutions have not been rushing into print to disassociate themselves from their official promotion of the "discovery".” 
"It is an act of faith, based on rather shaky probabilistic arguments, to say that other planets like Earth exist in the universe." 
- New Scientist, January 17, 1980
- Science News, Vol. 124, August 13, 1983
- Discover, February, 1985 p:11; The Blade (Toledo, Ohio), October 5, 1986
- Nature 16/1/92 reported in Sun Herald, 26/1/92 p:46
- Written by Peter Pockley in the "Science" Section, The Sun-Herald, 26/1/92 p:46
- Written by Dr Michael Rowan-Robinson in his article "The Infrared Landscape", New Scientist, January 31, 1980 p:325