While we’re relatively certain that life on Earth began around 3.8 billion years ago, we’re not so sure about where life came from.
The idea that life, or the building blocks needed to create it, have extraterrestrial origins is a popular theory known as Panspermia, but it’s so far been difficult to prove because we haven’t found any evidence of life outside of Earth.
However, a team of scientists in Quebec have found more more evidence that life might have begun in space. The Canadian researchers showed that some organic molecules that form the building blocks of life could develop in icy films subjected to radiation within a vacuum, opening the possibility that life on Earth might actually be extraterrestrial in origin.
The study, published in the Journal of Chemical Physics, involved the team creating thin films of ice with methane and/or oxygen inside, and bombarded them with low-energy electrons (LEEs). These kind of electrons are when matter is hit by high-energy radiation such as UV light, X-rays, or cosmic rays.
The study was conducted by simulating a high-vacuum space environment, which allowed the researchers to perform accurate analysis techniques. In space, plenty of frozen films containing methane and oxygen actually exist, along with various types of ice (not just frozen water), which can form around dust grains in the dense and cold molecular clouds that exist in the spaces between star systems.
These types of cold environments also exist on objects in the solar system, such as comets, asteroids, and moons.
LEEs themselves have enough energy to create further chemical reactions. To put it simply, life — or rather its building blocks — could have began in icy films in space, hit by the different forms of radiation in the universe, which spurred chemical reactions that eventually formed more complex, biological matter.