Astrobiology uses a coalition of scientific fields to theorise the feasibility of life on exoplanets. It not only answers the pivotal human question: "Is there life out there?" but it also asks, "What type of life is there?" and "How did it evolve?".
At present, no life has been confirmed—however with every passing year, potentially habitable exoplanets continue to be confirmed, and the probability of finding extraterrestrial life increases. The real question now is: "When will we find it?"
Our knowledge of what life could be on other planets is based entirely on the life that we know here on Earth. The organisms which inhabit the Earth today are the product of millions of years of evolution, forged from the same organic compounds which populate the rest of the Universe and which were delivered to the early Earth by asteroid collisions.
Once liquid water could exist on Earth’s surface, life emerged almost straightaway from chemical processes. Early plants created all of the oxygen which exists in our atmosphere today, and with the added protection of the Ozone layer, life was able to spread onto land, aided by an atmosphere which they could breathe and metabolise.
There is nothing unique about these circumstances—and there is every chance that a planet nearby harbours the same conditions favourable to life.
Is There Life on Other Planets?
The propensity for life to exist on other planets is extremely high—and while no life has yet been found, we have only shallowly explored a minute segment of space, and this gives much promise to the possibility of life just beyond our current knowledge.
For life to exist on an Earth-like planet, there are two things that are required: water, and an atmosphere. Without water, life cannot exist, as water allows for organic chemicals to combine into proteins and genetic material, from which living organisms may spring forth.
In the absence of an atmosphere, any organic chemicals and proteins will be broken apart by radiation from the parent star—on Earth, our atmosphere shields us from this and allows life to evolve. The atmosphere also contains a mixture of gases that allow life to generate energy from its surroundings.
Life on Minerva b
The robot fleet which would explore Minerva b would be one of the most advanced ever created—with artificial intelligence capable of making on-the-spot decisions. Hundreds of autonomous probes would explore Minerva b’s surface, ensuring that the mission could continue uninhibited even if some were lost to the elements.
They would search for the faint signs of primitive life—an atmosphere of oxygen, chemical signatures in the rocks, and the presence of organic compounds in bodies of water. If lucky, they might encounter the physical presence of life in microbial colonies—or even the holy grail of astrobiology: an ecosystem composed of advanced lifeforms.