Scientists are searching for extraterrestrial life in the far reaches of the universe, but what about our own solar system? Could alien life exist on cosmic-scale planets so close together? Portal livescience.com found it in question.
The short answer is yes, there are theoretically several potential places in our solar system where life could live, and scientists are actively studying them.
For example, although “little green men” have not yet been found on Mars, it is likely that there was at least microbial life on the planet in the past. Currently, Mars is an arid desert, but thanks to the activities of the Mars rovers, we know that in the distant past there was water on it. In addition, Perseverance has collected an interesting collection of rock samples that are expected to return to Earth on the Mars Sample Return mission. It is in the planning stages under the auspices of NASA and ESA.
At least one sample found by Perseverance has features hypothesized to be signs of ancient microbial life. And if the samples can be successfully delivered to Earth, then experts will be able to study them in detail and answer many questions.
Venus is often called “Earth's twin,” but in reality, this planet is probably not the first point of interest where one should start looking for extraterrestrial life. Venus's surface temperature is hot enough to melt lead, and its average atmospheric pressure is 90 times higher than Earth's. In addition, the planet is surrounded by dense clouds, mainly composed of sulfuric acid – an extremely caustic substance that on Earth when mixed with water turns into acid rain.
At the same time, despite the harsh conditions, extremophiles can still survive in the atmosphere of Venus – where temperatures and pressures are not too dangerous. To do this, MIT is preparing Morning Star missions to fly to Venus to take cloud samples of the planet and bring them back to Earth for analysis. And it's worth mentioning here that in 2020, the possible detection of phosphine gas in the clouds of Venus was at the center of a major scandal in the scientific community. It's a surprising finding because most of the chemical processes that lead to phosphine production involve living organisms – or the extremely high pressures in gas giants.
Finally, a little further out in the solar system, in the orbits of Saturn and Jupiter, there are satellites that may show signs of life – specifically Enceladus and Europa. Beneath its icy surface lies a vast ocean, and the planet continually spews plumes of salt water into space. And in 2023, researchers found phosphates on Enceladus – meaning there are now technically all the ingredients needed for the development of life.
Europa is a similar icy world and it also has an underground ocean. Jupiter's enormous gravity provides the satellite with the energy needed to fuel geological processes. Experts now believe this is the main reason Europa's ocean is warm enough to remain liquid. Additionally, the interaction between salty oceans and rocky terrain could support life similar to that found at hydrothermal vents on Earth.
