Join Date: Mar 2014
Location: Ontario, Canada
There's actually a real chance of this happening. One way life can be detected on other planets is by looking at the composition of the atmosphere and there are plans to launch and build telescopes in the 2020s and 2030s that will do this. And quite a few planets which are listed as potentially habitable have already been found, so they'll be observed in more detail in the future. I don't know if the technology in some of the upcoming telescopes will be advanced enough to give a very detailed analysis of exoplanets and their atmospheres, but the telescopes that will come after them in the coming decades could. I wouldn't be that surprised if we found life (or at least signs of it) on another planet by the end of this century, and some astronomers have predicted we could too.
It's also possible the first extraterrestrial life we find will be on a moon in our solar system. One of the theories of how life originated on Earth is that it began deep underwater around hydrothermal vents. There's evidence that moons like Europa and Enceladus have vast oceans of liquid water underneath their crust and scientists have speculated that they could have life in them because the gravity of Jupiter and Saturn causes these moons to contract and expand which could create hydrothermal vents. Scientists want to send orbiters and submarines to these moons because of this.