admin If alien life on an exoplanet about 40 light-years away had its own version of the James Webb Space Telescope and pointed it at us, would they be able to detect life? The answer is yes, according to a new August 28, 2023 study conducted by Johns Hopkins astrobiologist Jacob Lustig-Yeager. And it is precisely the pollutants in our atmosphere that betray us. But the opposite could also happen. If an alien civilization had technology similar to ours, it could cause pollution in its atmosphere that we could then interpret as a sign of life.
scientists have already thought about this idea. In the new study, scientists imagined hypothetical aliens on the exoplanet TRAPPIST-1e, searching for life on Earth.
Kiona Smith wrote in Inverse on September 6, 2023 about a recent article that explored this idea. The article has not yet been peer-reviewed or published. However, you can read a preview version on arXiv, which was published online on August 28th.
Simulating Earth as seen from TRAPPIST-1e
The basic premise is that the Webb telescope could possibly find signs of biosignatures or technosignatures on nearby alien worlds. Thus, an advanced alien civilization on one of those planets could potentially find us as well. Seems logical, right? In this scenario, any aliens on TRAPPIST-1e would see Earth as a transiting exoplanet from their location. They could then analyze our atmosphere, just as we study theirs with Webb.
The study focuses largely on the detection of artificially produced pollution in a planet’s atmosphere, such as chlorofluorocarbons (CFCs) on Earth. The study used a new atmospheric data retrieval model called SMARTER. SMARTER is based on previous spectra from terrestrial planets. The paper explained:
This model has the capability to analyze UV to millimeter wave transmission, reflected light and emission data for exoplanets with a wide range of atmospheric compositions, temperatures and pressures.
Scientists used the exoplanet TRAPPIST-1e as an analog model for Earth. It is one of seven Earth-sized rocky planets orbiting the red dwarf star TRAPPIST-1, about 40 light-years away. First, they simulated Webb’s TRAPPIST-1e data. They found that Webb should be able to detect any molecules of life or technology on TRAPPIST-1e. These can include industrial pollutants such as CFCs.
Finding hints of life in messy data
The scientists then used data from Canada’s SCISAT satellite, which monitors atmospheric gases. They deliberately reduced the quality of the data and “caused chaos”. The idea was to mimic the way an alien telescope might see Earth at a distance of 40 light years. Explaining how they did it on Inverse, Smith said:
First, the team simulated what SCISAT’s view of Earth’s atmosphere would look like if the satellite were perched at the far edge of our solar system instead of in low-Earth orbit. Next, they added a bunch of ‘noise,’ or random bits of infrared light that don’t come from the star or the planet. Finally, they took samples of this noise-cluttered data at a much lower resolution, similar to how JWST would see a planet 40 light-years away.
And it worked! Scientists have managed to detect chemicals in simulated data about life and technology. The great result was that they were able to do this even with more complicated and lower quality data. The results showed that advanced aliens equipped with telescopes like Webb could find life on Earth on TRAPPIST-1e. The opposite might also be the case.For example, if Webb discovered CFCs in the atmosphere of TRAPPIST-1e or another exoplanet, it would be excellent evidence of the existence of a civilization there. At least on Earth, CFCs are only produced artificially.
Is TRAPPIST-1e a habitable exoplanet?
As for TRAPPIST-1e itself, we don’t yet know whether it can sustain life or not. This mainly depends on whether the planet has an atmosphere or not. Webb’s results for two planets closest to the star, TRAPPIST-1b and TRAPPIST-1c, showed that they had no atmosphere or, at best, an extremely thin atmosphere. That seems discouraging.
However, other research suggests that TRAPPIST-1e and TRAPPIST-1f may be the most potentially habitable of the seven planets.TRAPPIST-1e may be able to support a denser atmosphere or even water on its surface. But until we get new data from Webb, we won’t know yet. Webb has been busy studying several TRAPPIST-1 planets, so it may not be long before we learn more about TRAPPIST-1e’s conditions.
Pollution itself is obviously not a good thing. However, this could prove to be one of the first signs of advanced alien life we will ever discover.This could be one of the first ways aliens find us. We are just beginning to analyze the atmospheres of planets like TRAPPIST-1e. It will be interesting to see what Webb and other future telescopes discover. Conclusion: Scientists show how an alien civilization on TRAPPIST-1e could find us by detecting our contamination. They simulated Earth from a distance of 40 light years.
