The study, published in the Astrophysical Journal by scientists from the University of St. Andrews and Cornell University, shows how Earth’s atmosphere evolved over time and in what manner each stage led to the formation of new life forms.
The report included research into the various stages of geological eras, before microbes (3.9 billion years ago), after microbes and the first rise of oxygen (2 billion years ago), during the second rise of oxygen (800 million years ago), and Earth as it is today.
At each stage, oxygen, methane and carbon dioxide were in totally different quantities, so the results pointed to how life evolved in different atmospheres. This, according to the scientists can help identify early biosignatures and signs of life on Earth-sized exoplanets.
“Even looking back at our own planet, the atmosphere has changed dramatically many times,” lead researcher, Dr. Sarah Rugheimer said.
“In particular, in this paper we wanted to find out how detectable biosignature gases have been both in Earth’s history and if these planets were orbiting a different star,” Rugheimer said.
The study also included research into the varied cloud cover and surface features such as oceans and continents in order to see how these affected the models.
According to the team, in order to precisely reflect the findings on far-off exoplanets larger telescopes are required.
