Is there life beyond Earth? Scientists hope the James Webb Space Telescope may offer clues sooner rather than later

In a yet-to-be-peer-reviewed paper, a team of researchers from NASA and other institutions have suggested that the JWST may be used to uncover planets with traces of chlorofluorocarbons (CFCs) in their atmosphere.
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The James Webb Telescope.

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After journeying hundreds of thousands of miles through the void of space, the James Webb Space Telescope (JWST) arrived at its destination in late January – roughly a million miles from Earth. Following its successful deployment, preparations are already underway to provide us with a front-row seat to the cosmic dance that ensued during the earliest moments of our Universe.
With the ability to peer into the endless abyss (and effectively billions of years into the past) and reveal some of the earliest stars and galaxies to have ever formed in the universe, the JWST will allow us to understand how cosmic phenomena in our own backyard came to exist.
Although often described as a replacement for the Hubble Space Telescope launched in 1990, the JWST has some important differences and will, at least for the time being, work alongside Hubble to help astronomers unravel the mysteries of the cosmos. When Hubble was launched, it expanded our view of the universe, providing us with dazzling images, as galaxies that appeared too faint to see with the naked eye, came to life on a sprawling cosmic canvas.
Hubble was designed to capture light in the visible and ultraviolet range of the electromagnetic spectrum predominantly, and hardly any in the infrared range. The JWST, on the other hand, has been designed to focus on the infrared part of the spectrum - specifically between 600 nm to 28 microns, according to NASA's fact sheet.
The distinction is crucial because the telescope will provide us with the opportunity to directly observe individual exoplanets orbiting distant stars in novel ways that inch us closer to answering the fundamental question of whether we are truly alone in the universe or not. In a yet-to-be-peer-reviewed paper, a team of researchers from NASA and other institutions have suggested that the JWST may be used to uncover planets with traces of chlorofluorocarbons (CFCs) in their atmosphere.
Yes, you heard that correctly. Greenhouses gases like CFCs directly responsible for the warming of Earth's ozone layer are one of the key biosignatures that hint at the existence of an industrialised civilisation. Simply put, if aliens, like us humans, have managed to pollute their planet's atmosphere, the JWST may just be able to spot them.
In the paper, the team identifies TRAPPIST-1, a system comprising several Earth-like planets orbiting an M-class red dwarf star as the prime candidate for exploration. “CFCs are a notable example of a technosignature on Earth, and the detection of CFCs on a planet like TRAPPIST-1e would be difficult to explain through any biological or geologic features we know today,” the research paper reads.
There are challenges though. If a planet is orbiting a star that is too bright, then the light from the star may drown out the infrared signal the JWST is looking for. For instance, if an alien civilisation in the TRAPPIST-1 system was attempting to peer into our own solar system using a telescope with similar capabilities to the JWST, it would not be able to detect the CFCs on Earth. But the TRAPPIST-1 system has an M-class star which, although unstable, is also quite dim.
The TRAPPIST-1 system, which sits just 40 light-years away from Earth, has seven planets that scientists say may have conditions that facilitate the generation of water. The fourth in the system – TRAPPIST-1e – is of particular interest since it resides in what scientists call the Goldilocks zone, an area at an orbital distance from its star that makes it potentially habitable.
There is obviously no guarantee that the JWST will spot what scientists are hoping for but the fact that we now have the technologies to even do so is, in itself, truly exciting. As the paper concludes, “with the launch of JWST, humanity may be very close to an important milestone in SETI [the Search for Extra-Terrestrial Intelligence]: one where we are capable of detecting from nearby stars, not just powerful, deliberate, transient, and highly directional transmissions like our own, but consistent, passive technosignatures of the same strength as our own.”
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