If Earth were 50 light years away, the James Webb Telescope would know there is an intelligent civilization

The possibility of life on other planets has been a constant question since mankind began to observe the cosmos from a scientific point of view. Discovering that we are not alone would greatly contribute to our understanding of life in the universe. But if we search for life in other galaxies, why not start by investigating the only planet we know has life?

The Earth’s atmosphere contains a large amount of oxygen containing methane molecules, indicating the presence of life . Also, it contains traces of nitrogen dioxide molecules containing CFCs, called freon, indicating an industrial civilization.

A recent study showed that If Earth was an exoplanet, James Webb Space Telescope (JWST) could detect the presence of an intelligent civilization , since it could identify molecules in an extraterrestrial atmosphere. The study is published on the arXiv preprint server.

The study used actual observations of Earth’s atmosphere taken by Canada’s SCISAT satellite, which captured high-resolution spectra of sunlight passing through a cloudless region of Earth’s atmosphere, And from there, it detected various natural and synthetic molecules, including oxygen, methane, nitrogen dioxide, and CFCs.

The researchers used an average of the data at different atmospheric depths to simulate how these spectra would appear as Earth transits the Sun as seen from the outer solar system.

The authors then added simulated noise to the signal and reduced the resolution to mimic the type of observations the JWST might make of an exoplanet light years away. The idea was to determine whether, even when observations are weak and noisy, the telescope could capture enough data from atmospheric models.

The result: yes the signal-to-noise ratio was strong enough for JWST to capture enough data to identify atmospheric patterns and detect the presence of molecules on an Earth-like exoplanet 50 light-years from Earth.

But that wasn’t enough for the team, who applied the methodology to Trappist-1, a system 40 light-years away with seven known planets, two or three of which are potentially habitable.

The researchers introduced molecular spectra into the simulated spectra of Trappist worlds and showed that JWST could identify both biological and technological signatures if they existed in a Trappist exoplanet.

If JWST can identify oxygen, organic and synthetic molecules like CFCs in the atmosphere of a nearby exoplanet, we don’t need to go so far to search for extraterrestrial life in other systems. It is estimated that there are 4,000 planets within 50 light years of Earth. Perhaps a civilization with technology like the JWST has already seen that we are here.