We are facing a question that has been raised in recent months, as a scientific group has discovered the presence of phosphine in the clouds of Venus. This compound is a gas produced by microbes (on Earth) that thrive in oxygen-free conditions.
Although this does not confirm that life outside our planet is a reality, it could indicate a good way forward for future research. Of the little more than 4,000 exoplanets discovered, there are already 55 potentially habitable . Considering that there are billions of billions of planets in the Universe, it seems quite clear that we are not alone.