Question

Is there any conclusive evidence that proves life exists beyond earth?

No, with one small exception. The astronauts of Apollo 12, as you may know, brought back Earth bacteria from the moon that had survived the harsh conditions of space for three years! These tiny earthlings had hitched a ride on camera equipment, and were (literally) living proof of the capabilities of life able to exist beyond Earth. With this discovery as well as the recent study of extremophilic life (organisms able to survive extremes in heat, cold, pressure, etc.) scientists believe that the chances of life gaining a foothold elsewhere in the universe many not be so slim. In fact, the Mars Odyssey, a spacecraft now entering lower Martian orbit, may soon tell us once and for all whether water (and perhaps life) is or was ever a reality on the Red Planet. Such data will allow us to further investigate the possibilities of life outside Earth. You may keep up with the most recent findings of the Odyssey by checking out http://mars.jpl.nasa.gov/odyssey/

Remember that we inhabit only one tiny planet around a very ordinary star, and there are roughly 400 billion other stars in our galaxy, and nearly 100 billion other galaxies. In addition, we have already directly observed over 80 planets around nearby stars in our own galaxy. The numbers alone make the idea of a lonely Earth extraordinary indeed. Could these enormous realms be truly empty? Anna Lee Strachan, NASA Astrobiology Institute
January 2, 2002