‘Where is everybody?’ It’s the famous question about extraterrestrials, which resonates with our quiet galactic neighbors after Manhattan Project physicist Enrico Fermi asked it in 1950.
But perhaps even a highly advanced extraterrestrial civilization could find itself without the resources or key information needed to escape its home world, at least according to a new study from Spain’s Mid-Atlantic University.
Some so-called ‘Super Earths’ might be within the habitable zone of their star, but they are so massive that their gravity makes launching interplanetary rockets almost impossible.
These and other ‘Fishbowl Worlds’ are just one of several ideas introduced in the new paper, which hopes to help explain Enrico Fermi’s infamous 1950 ‘Fermi Paradox’.
The Fermi paradox has perplexed astronomers for more than six decades, wondering in short: in a universe packed with no less than 200 billion trillion stars and even more planets, many of them capable of supporting life, why Why have scientists on Earth not detected any extraterrestrials?
Even highly advanced extraterrestrial civilizations could find themselves without the resources – or key information – needed to escape their home world, according to a study from Spain’s Mid-Atlantic University. Above, Jupiter’s watery moon Europa, photographed by NASA’s Galileo spacecraft.
“The image of a planet whose gravity makes it difficult or impossible to leave suggested the metaphor of a fish tank to me,” the author of the new study, Professor Elio Quiroga, told DailyMail.com by email.
“I thought it was a powerful analogy,” said Professor Quiroga, a Mid-Atlantic professor in Spain.
For one category of his Fishbowl Worlds, Professor Quiroga calculated a value he called the “exoplanet escape factor” (Fex): a value that compares the escape velocity of a given exoplanet to the 7 miles per second (11.19 kilometers per second) of the Earth. b) escape velocity.
Escape velocity, the speed necessary for a spacecraft to break free from the gravity of any celestial body (whether a moon, planet, or asteroid) varies with the mass of that body.
Escape from potentially habitable exoplanet Proxima Centauri bFour light years from Earth, for example, is relatively easy: 5.9 miles per second, or a ‘Fex’ just 0.85 times that of Earth.
But massive, albeit hypothetically habitable, planets like Kepler-131bAt 746 light-years from Earth, they require daunting speeds to break free: 21.8 miles per second to exit Kepler-131 b, for example, or a Fex 3.13 times Earth’s.
Some of the so-called ‘Super Earths’ could be within the habitable zone of their star, but they are so massive that their gravity makes the launch of interplanetary rockets almost impossible, such as Kepler-131 b (left), 746 light years away. from the earth. Others, like Proxima Centauri b (right), are easier to launch from
“Many worlds, particularly super-Earths,” Professor Quiroga told DailyMail.com, “can be ruled out due to their prohibitive escape velocities.”
But there were also interesting extreme cases, such as the habitable world. GJ-1214b48 light years from Earth, which has an escape velocity approximately 1.5 times that of Earth.
Planets like these, which also include Kepler-103b, might prove more difficult for an advanced race to take off, but they might not trap a species on its home world.
Prof. Quiroga’s research, published last October in the Journal of the British Interplanetary Societytheorizes that any escape velocity with a Fex greater than 2.2 times that of Earth can lock a civilization to its home planet forever.
The more than 5,000 exoplanets confirmed so far in our galaxy include a variety of types, including these mysterious “super-Earths” that are larger than our world and possibly rocky.
But Professor Quiroga also pointed out unique cultural factors that could lock a species into its home planet, and in one case spoke of a more literal ‘Fishbowl World’.
An advanced civilization on an ocean planet, he speculated, could have mastered long-distance communication through its own evolution, since communication naturally travels much further in a fluid environment (think sonar) than it does outdoors. .
Dominant species on a water planet, or on a watery moon like Jupiter’s moon Europa, may have enjoyed conversations that naturally travel over hundreds of kilometers.
In those worlds, Professor Quiroga wrote, “communication between individuals could be feasible without the need for communication devices,” stifling the need to innovate in advanced communication technologies.
There were also interesting edge cases, such as the habitable world GJ-1214b (above), 48 light years from Earth, which has an escape velocity 1.5 times that of Earth: it is difficult but possible to abandon it.
“Telecommunication technology may never emerge in such a world, although it could be home to a fully developed civilization,” Quiroga argued in his article.
‘Such a civilization would not be ‘communicative’ and would not be contemplated in the Drake equation,’ the famous calculation formulated to predict the possibility of finding intelligent life in the universe, Quiroga stated.
In other words, an evolutionary feature like biological, innate underwater sonar could leave them silent and unable to hear humanity’s SETI radio transmissions.
But, as Professor Quiroga told DailyMail.com, his research is no reason for astronomers and planetary scientists to drastically change their policies or research plans just yet.
“The initial step is to look for basic life, simple life forms,” he said.
“We are moving in this direction, but we need more advanced tools (such as the future Vera Rubin telescope) and better methods to analyze the weak signals emanating from these exoplanets.”
“If we discovered a world in another star system that showed clear and indisputable signs of intelligence,” Professor Quiroga said, “then we could contemplate whether those beings have undertaken space travel, or whether it is within their capabilities or not.”
What those first successful signals, which researchers call techno-signatures, will turn out to be, remains to be seen, he noted, in part because of the truly strange possibilities of life outside our world.
“We can only affirm that we know of one civilization in the cosmos, and it is ours,” said Professor Quiroga.
‘Consequently, we tend to humanize or anthropomorphize everything; It is unavoidable.’
“However, there is something interesting to consider,” he added.
“We emerged as a species about halfway through the life of our star, the Sun, which suggests something profound: intelligence takes a considerable amount of time to evolve.”
Perhaps, Professor Quiroga suggested, one answer to Enrico Fermi’s famous paradox is that most alien species are taking as long to evolve as life here on Earth.