Our search for extraterrestrial life is getting serious. With better telescopes and a growing scientific consensus that we’re probably not alone in the universe, we’re beginning to search farther and farther across the vast expanses of space for evidence of extraterrestrials.
But it’s possible that we’re looking for too few characters in too few places. Having evolved on Earth surrounded by terrestrial life, we assume that extraterrestrial life would look and behave like terrestrial life.
What if we’re wrong? What if ET is out there waiting to be discovered by the first astronomer willing to open up to the possibility that extraterrestrial life might seem really weird to us?
Some scientists are trying to fix our earth distortion. In a new study made available for reading on July 27, a team led by Arwen Nicholson, an astrophysicist at the University of Exeter, attacked an assumption widely held in astronomy. There is a common belief that a distant “exoplanet” – a planet outside the solar system – needs a certain amount of oxygen and hydrogen to support life. And these life forms, as they lived and died and evolved, would exude methane gas, which would accumulate in the atmosphere.
Methane is one of the big things astronomers look for when looking for evidence of extraterrestrial life. They call it a “biosignature”. But with over 5,000 confirmed exoplanets on the official list, and only a limited number of telescopes powerful enough to map them, astronomers tend to rule out planets that appear to be nutrient-poor — lacking, for example, the concentration of hydrogen we have here Earth.
To test this assumption, Nicholson and her team built an elaborate computer model of a roughly Earth-like planet, populated it with simple simulated microbes, and then began extracting hydrogen. The goal: to see if the microbes would survive and if they would still excrete detectable amounts of methane while struggling on their resource-poor planet.
Surprise! The tough little organisms held on. And yes, they still emitted enough methane for astronomical surveys to register it from light-years away. “These findings help deepen our understanding of the interactions between life and the planet,” Nicholson and her co-authors wrote. “It reduces the need to make unnecessary assumptions about extraterrestrial life based on life on Earth.”
In practical terms, Nicholson’s study, which was peer-reviewed and accepted for publication, is in Monthly Bulletins of the Royal Astronomical Society— could expand the list of exoplanets that scientists think are worth checking for signs of life.
Astronomers are lining up to take turns examining planets for biosignatures with NASA’s new James Webb Space Telescope. The priority for this first year of operation of the JWST are the seven possible Earth-sized planets in the TRAPPIST-1 star system, 40 light-years from Earth.
TRAPPIST-1’s planets are quite distant; It’s not like we’ll have any real chance of visiting potential life on these worlds any time soon. Astronomers are targeting them anyway, and not closer but seemingly more barren planets, because the TRAPPIST planets are more likely to contain all those nutrients that life on Earth really prefers. “Would you rather have relatively poor data on a hard-to-observe but truly Earth-like world — or much better data on a nearby nutrient-poor planet?” Thus described Étienne Artigau, an astrophysicist at the Université de Montréal who was not involved in Nicholson’s study , the surveyor’s dilemma.
However, if Nicholson’s model gains traction, astronomers may be willing to risk their precious telescope time on a nearby planet that has so far seemed a little hostile to life.
But the study by Nicholson and her co-authors is still just a nudge towards a more open-minded approach to the search for ET. She and her team still assume that aliens would have the same basic metabolism that is common on Earth. absorb oxygen and hydrogen and excrete methane. “Since we only know life on Earth, it’s hard not to let that affect you,” Nicholson admitted.
But at least we can introduce Life forms with completely different metabolisms. “For planets that can be very different [from] Our own different metabolism could be possible than that on Earth,” said Nicholson. “Identifying these possible metabolic pathways will be key to considering life on distant planets.”
The problem is that unless we discover a life form with a radically different metabolism, it is unlikely that a serious scientist will develop methods of investigation specifically tailored to finding signs of this type of life. It’s a chicken-and-egg problem – you can’t search for something you don’t know you’re looking for. And few scientists seem keen to design investigations into currently fictional life forms.
“We are always limited by our imagination, which is guided by our experience,” Avi Loeb, a Harvard physicist who was also not involved in Nicholson’s study, told The Daily Beast. For all their intelligence, curiosity, and training, scientists tend to be extremely conservative when it comes to strange things.
It’s this reluctance to explore the utterly unknown that keeps our quest going extraterrestrial Life so closely related to our understanding of Earth Life. The same institutional conservatism might keep us from recognizing extraterrestrials even after we found them.
Take ‘Oumuamua. That’s the name astronomers gave to a very strange, elongated object, up to 3,000 feet long and shiny, that was hurtling through our solar system in 2017. Nobody knows exactly what it was. Likewise, no one should say for sure what it is was not. But even though ‘Oumuamua is behaving as we would expect an alien spacecraft to behave, very few scientists – Loeb being one of them – urge their colleagues to at least consider the possibility that the strange object is a first contact opportunity was.
Instead, the scientific community just shrugged as ‘Oumuamua sped off. And that’s a problem, Loeb said. “Reality can surprise us, so we should just look for things or behaviors that are unfamiliar to us.” When a mysterious object zooms through the solar system and defies easy categorization, you might worry less about the categories. Investigate with an open mind.
The same applies to planetary surveys. To increase our chances of finding extraterrestrial life, we could look in places we wouldn’t normally expect life to thrive. It’s a big universe, after all. And it seems stranger to us every day as our discoveries pile up.
More and more scientists are coming up with the idea that there are aliens out there somewhere. Maybe more scientists need it Also get the idea that these aliens might be really weird.
Read more at The Daily Beast.
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