If the Earth were an exoplanet, then we would be able to see evidence of the existence of an intellectually developed civilization here.
The Earth’s atmosphere is rich in oxygen and molecules such as methane, which are a sign of the presence of life. In addition, the atmosphere contains traces of molecules such as nitrogen oxide and freons, which are strong indicators of an industrialized civilization. Using actual observations of the Earth’s atmosphere from Canada’s SCISAT satellite, the researchers studied the spectra of sunlight passing through a cloudless region of the Earth’s atmosphere. This allowed us to create a basis for what the spectra would look like when the Earth transited in front of the Sun when viewed from another star system.
James Webb could detect life on Earth
Next, the team added simulated noise to the data and reduced its resolution to simulate the observations that the James Webb (JWST) might have made had it been light-years away from Earth. Scientists have been able to identify many molecules of exoplanets similar to ours and within 50 light-years of our planet.
The researchers applied their methods to the Trappist-1 exoplanet system, which is 40 light-years from Earth and has seven known planets, several of which are potentially habitable. Using the data, the team demonstrated that JWST would be able to identify both biological and technological signatures if they were present on these exoplanets.
Although JWST will not be able to detect physical structures on other planets, its ability to detect oxygen, organic and synthetic molecules in the atmosphere of a nearby exoplanet will be an important step in the search for advanced life in the Universe.
