by Hugh Jackson, Nevada Current
July 19, 2022
There were lots and lots of oohs and ahs last week after NASA unveiled images from the James Webb Space Telescope, and appropriately so.
What does one say about the “deep field” image of the SMACS 0723 galaxy cluster, with thousands of galaxies (each of course containing billions of stars), including glimpses of some that are almost as old as the universe. “Ooh,” I guess. And “ah.” And maybe the exclamatory expletive of your choice. I get that it’s possible to calculate the scale of space and time, mathematically. But the distances and times are still far beyond comprehension and imagination. To me anyway.
All the images are amazing (not least the Stephan’s Quintet image of galaxies tugging and pulling on each other and poised for collision). Atmospheric composition graph of the WASP 96 b gas giant.
But for the exoplanetary-minded, I gather the most intriguing image is the atmospheric composition graph of a gas giant called WASP 96 b, not for what it shows (hot water, steamy in fact) but because of what it suggests about the kind of information the telescope can and will gather about atmospheric compositions on exoplanets.
There are more telescopes in the works or under consideration, both Earth- and space-based, that will be designed specifically to look for biosignatures in exoplanet atmospheres (Webb isn’t). For a while now I’ve believed that definitive evidence of “life” (define at your leisure) beyond Earth will be found in my lifetime, not in the form of unexplained aerial phenomena captured on camera that captivated Harry Reid so, but by telescopes. (Or maybe even by the Europa Clipper, set to launch in 2024, or other probes studying moons in our solar system.)
Extraterrestrial biosignatures might even end up being as common as exoplanets. The existence of a planet outside our solar system wasn’t confirmed until 1992. Now more than 5,000 of them have been discovered, so you can see where that’s going.
The first confirmed biosignatures, whether inside or outside our solar system, will be A Big Deal.
Confirmed technosignatures though. Now there’s some ooh and ah.
I’m not confident that technosignatures indicating an extraterrestrial technology-wielding life form — intelligent life – will be discovered in my lifetime. I used to think that the sheer numbers (those of you of a certain age will recall Carl Sagan’s “billions and billions”) meant that there simply must be intelligent life out in the universe, but now I’m not so sure.
The search for technosignatures is a big thing, though, and it’s getting bigger. Maybe we’ll find evidence of a Dyson sphere – a construction project that powers a civilization by encompassing an entire star system. Or maybe the technosignatures will be like biosignatures – discovered by studying the atmospheric compositions of planets.
I was raised to believe that our broadcast signals were flying through space and someday beings on other worlds would be watching Skipper thumping Gilligan with his hat. But apparently it doesn’t work that way. SETI, you’ll recall, was famous back in the day for searching for radio signals. There’s still some of that going on of course, but the search for technosignatures is a lot broader these days.
Here’s an excerpt from a NASA overview of a 2018 conference on technosignatures:
Beings that have reached the high level of …. exo-civilization produce heat, pollutants, changes to their planets and surroundings in the process of doing that work. And so a detection of highly unusual atmospheric, thermal, surface and orbital conditions could be a signal.
One example mentioned by several speakers is the family of chemical chloroflourohydrocarbons (CFCs,) which are used as commercial refrigerants, propellants and solvents.
These CFCs are a hazardous and unnatural pollutant on Earth because they destroy the ozone layer, and they could be doing something similar on an exoplanet. And as described in the conference, the James Webb Space Telescope — once it’s launched and working — could most likely detect such an atmospheric compound if it’s in high concentration and the project was given sufficient telescope time.
A similar single finding described by (Jill) Tarter that could be revolutionary is the radioactive isotope tritium, which is a by-product of the nuclear fusion process. It has a short half-life and so any distant discovery would point to a recent use of nuclear energy (as long as it’s not associated with a recent supernova event, which can also produce tritium.)
So if there is technologically advanced life out there, and we’re looking for it, does that mean it’s looking for us? Because if it is, and that civilization has developed telescopes even more slightly advanced than ours, they’ve probably already found us.
Why even now, a rescue mission launched by the benevolent guardians of the TRAPPIST-1 system (a star system that’s on Webb’s viewing schedule, by the way) could be nearing the Earth, to save Gilligan, presumably.
Or, alternatively, the fleet of destroyers launched by the militarist regime ruling the TRAPPIST-1 system is nearing Earth. The star system is a mere (by cosmic standards) 39 light years away, and just because we haven’t figured out how to travel such distances doesn’t mean the Trappists haven’t. Have a nice day.
A version of this column originally appeared in the Daily Current newsletter, which is free, and which you can subscribe to here.
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