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The James Webb telescope could detect aliens by looking for signs of pollution

The James Webb Space Telescope isn’t even fully operational yet, but researchers are getting more and more excited about what it can do. In a recent study, researchers claim we may be on the cusp of being able to discover other civilizations based on specific types of pollution in their planets’ atmosphere.

A total ozone map of the Earth. Image credits: NASA.

The alien ozone hole

Human society has changed a lot over the centuries, but the shifts in the past 200 years have been truly mind-bending. The Industrial Revolution changed how many things work, fueling, well, a revolution in our society. If you were a patient alien scouting the Earth from close by (or from farther away, but with a good enough telescope) you may have seen the signs of this industrial revolution happening through the emissions we produced by burning fossil fuels.

But they could see other forms of pollution even better.

Chlorofluorocarbons (CFCs) are a type of chemical notorious for causing the ozone hole in the 1980s (until regulations entered into force to address the problem). They’re produced industrially as refrigerants and cleaning agents — and if an alien civilization would resemble ours, it would likely also start producing them at some point. CFCs are also very unlikely to appear naturally so if you see them in a planet’s atmosphere, someone is producing them artificially. Furthermore, even if a civilization stops producing them or reduces their production (like we did), they still have a long life in the atmosphere, meaning they could be detected long after they’ve been produced.

This brings us to an interesting point: our most clear sign of civilization may also be one of our worst impacts on the planet — pollution. We don’t really know whether this would also be the case for an alien civilization but there’s a decent chance it is. Now, we could also have a way to detect this, thanks to the James Webb Space Telescope (JWST).

Looking for pollution on alien planets isn’t the main objective of the JWST, and its capability in this regard is limited. For instance, if a planet is too bright, it could drown out the CFC signal. So the new study focused on M-class stars — a type of dim, long-lived red dwarf. Researchers believe M-class stars make out the majority of stars in the universe.

A team of researchers led by Jacob Haqq-Misra, an astrobiologist at the Blue Marble Space Institute of Science, analyzed the JWST’s ability to detect CFC around a TRAPPIST-1, a typical red dwarf relatively close to Earth (40 light-years away). TRAPPIST-1 also has several Earth-sized planets within the habitable zone, so it would be a good place to start looking for alien civilizations (although M-stars, in general, aren’t considered to be conducive to life).

According to the study, there’s a good chance that the JWST could be able to detect CFC in this type of scenario.

“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 (such as the Arecibo Message), but consistent, passive technosignatures of the same strength as our own,” the researchers write in the study.

Funny enough, this detection isn’t necessarily reciprocal: just because we can detect potential CFCs around a planet doesn’t necessarily mean aliens could do the same for us. Remember when we said in order for the method to work, the planet needs to not be too bright? Well, the Sun is pretty bright, and it sends out enough light that it would obstruct much of the useful signal. So if an alien civilization were to exist closeby, there’s a chance we could be able to spot them without them being able to do the same thing to us. Of course, this is all speculation at this point, but it’s something that astronomers are looking into as JWST will soon become operational.

The telescope is currently in its calibration stage. James Webb is expected to offer researchers an unprecedented view of the universe, focusing on four main objectives:

  • light coming from the very first stars and galaxies that formed after the Big Bang;
  • galaxy formation and evolution;
  • star formation and planet formation;
  • planetary systems and the origins of life.

The study was published in arXiv and has not been peer-reviewed yet.

Hexagon star pattern shows James Webb is slowly getting calibrated

The James Webb telescope has completed another milestone of its journey. The so-called “Segment Image Identification” rendered one star 18 times, arranging the unfocused images into a hexagonal shape. Eventually, these 18 images will perfectly align into a single, sharp image — but for now, researchers are excited about this interim result.

This early Webb alignment image, with dots of starlight arranged in a pattern similar to the honeycomb shape of the primary mirror, is called an “image array.” Credit: NASA/STScI/J. DePasquale.

The James Webb Space Telescope’s (JWST) primary mirror, the Optical Telescope Element, consists of 18 hexagonal mirror segments made of gold-plated beryllium. Together, these mirrors combine to create a 6.5-meter (21 ft) diameter mirror — almost three times larger than Hubble’s 2.4 m (7.9 ft) mirror. But aligning them perfectly is a delicate process.

As part of this process, engineers are now using each mirror individually to create 18 unfocused copies. We’ve previously seen this happen but now, they’re organized in a shape that resembles JWST’s hexagonal mirrors.

“We steer the segment dots into this array so that they have the same relative locations as the physical mirrors,” said Matthew Lallo, systems scientist and Telescopes Branch manager at the Space Telescope Science Institute. “During global alignment and Image Stacking, this familiar arrangement gives the wavefront team an intuitive and natural way of visualizing changes in the segment spots in the context of the entire primary mirror. We can now actually watch the primary mirror slowly form into its precise, intended shape!”

A selfie taken by the James Webb telescope, showing the hexagonal arrangement of the primary mirrors. Image credits: NASA.

As Lallo mentioned, the current orientation will make it easier to further arrange and focus the mirrors. This alignment stage began on February 2 and is expected to be completed by the end of the month. After this stage, the “image stacking” stage will begin, with researchers working to bring the 18 images on top of each other into one clear, focused view. It’s expected that the telescope will become fully operational in June 2022.

It’s one of the most ambitious space missions in recent history, an “Apollo moment” that will fundamentally alter our understanding of the universe, NASA says.

James Webb is expected to offer researchers an unprecedented view of the universe, focusing on four main objectives:

  • light coming from the very first stars and galaxies that formed after the big bang;
  • galaxy formation and evolution;
  • star formation and planet formation;
  • planetary systems and the origins of life.

We expect the first images and studies to come in from JWST later this year.