Determining the exact chances of finding microbial life on a habitable planet is challenging because we have limited data points to draw upon. However, based on what we currently understand about the conditions necessary for life and the prevalence of microbial life on Earth, it is reasonable to assume that the chances are quite high.
Microbial life is incredibly resilient and adaptable, capable of surviving in a wide range of environments on Earth, including extreme conditions such as hot springs, deep-sea hydrothermal vents, and acidic environments. This suggests that if a planet has the right conditions, such as liquid water, essential elements, and a stable environment, the chances of finding microbial life are significant.
The discovery of extremophiles (organisms that thrive in extreme environments) on Earth has expanded our understanding of the conditions under which life can exist. It has also opened up the possibility that habitable environments might exist in seemingly inhospitable places, like icy moons or exoplanets with extreme conditions.
Moreover, the abundance of potentially habitable exoplanets discovered in recent years, particularly within the habitable zone of their host stars where liquid water could exist, further increases the likelihood of finding microbial life elsewhere in the universe.
While we have yet to find definitive evidence of extraterrestrial life, ongoing and future space missions, such as the James Webb Space Telescope and the upcoming Mars sample return missions, aim to gather more data to shed light on this question. These missions will help scientists refine their understanding of habitable conditions and increase our chances of finding microbial life beyond Earth.