We could not visually see life on other planets, but we might be able to detect life by radio transmissions or other means.
Take for example the most interesting star in the galaxy that we know about. To quote a recent article in, “Astronomers have spotted a strange mess of objects whirling around a distant star. Scientists who search for extraterrestrial civilizations are scrambling to get a closer look.”
Invisible to the naked eye but spotted by the, a star named 1,280 light years away is behaving in ways that, to some scientists, suggest a that intelligent alien life may be influencing it. No, I’m not kidding.
Something very weird is happening around that star that is blocking the star’s light in ways that seem to defy most concepts of natural phenomena. Could an alien civilization be harvesting their star’s energy to augment their own need for more energy?
In a paper published called “” (the acronym of which, not by accident, is “WTF”) they describe dips in the light from this star behave in ways not expected with a normal planet eclipsing small amounts of light from the star. A graph of this phenomenon can be seen below.
Not just a few dips, but hundreds, leading scientists to wonder what possibly could be causing this. Most standard theories don’t seem to adequately explain the data. It has been (not quite jokingly) proposed that perhaps an alien civilization is floating stuff around the star to capture energy.
Now to be honest, extraterrestrial life is the last resort of mainstream science, but the Internet has taken the idea and flown away with it. You can find literally hundreds of “what it might be” artist conceptions of this star, including these, which illustrate what might cause it – though probably not.
Now, to address your question specifically, if you’ve managed to get this far down in my reply, it might be possible one day to detect life on other planets, but we would likely never be able to actually see the aliens unless, of course, they specifically sent us some pictures.