Reflecting on the matter: Perhaps extraterrestrials prefer to remain unseen

It was an uncomplicated inquiry made during lunch in 1950. Enrico Fermi, the Nobel Prize laureate in physics who played a significant role in initiating the atomic era, was having a meal with peers at Los Alamos, New Mexico, when the discussion shifted to alien life. Considering the enormity of the cosmos and the statistical odds of other sentient civilizations, Fermi inquired, “Where is everybody?”

Seventy-five years later, David Charbonneau, an astronomy professor at the Center for Astrophysics | Harvard & Smithsonian, asserts that we’re closer to a resolution. 

When Fermi introduced his classic paradox, Charbonneau noted, we had not located a single planet outside our solar system. The 1995 discovery of the initial exoplanet permitted researchers to deconstruct the paradox into smaller, more manageable inquiries: How many stars exist? How many of those stars possess planets? What fraction of those planets resemble Earth? What percentage of Earth-like planets harbor life? And ultimately, what portion of that life is intelligent? 

“We have made remarkable advancements on those inquiries,” Charbonneau expressed, who co-led the National Academies of Sciences, Engineering, and Medicine’s 2018 Committee on Exoplanet Science Strategy. “We now understand that at least one in every four stars has a planet of comparable size and rock composition to Earth, located in the habitable zone. These are solid conclusions.”

Acknowledging this challenge, the National Academies’ Committee for a Decadal Survey on Astronomy and Astrophysics 2020, where Charbonneau participated as a panelist, recommended pursuing the development of the Habitable Worlds Observatory, a space telescope intended to seek out chemical indications of life on distant planets. If constructed and launched, the HWO could image at least 25 potentially habitable worlds. However, the project remains uncertain. 

The uncertainty persists regarding how prevalent life, particularly intelligent life, truly is. It’s possible, Charbonneau stated, that if one takes any habitable-zone planet, adds water, oxygen, nitrogen, and phosphorus, and allows it a billion years, life will arise. Alternatively, the same conditions might persist without any life developing. Observing the first habitable planet would provide a considerably clearer perspective on the commonality of life.

“If the initial planet lacks life, statistically speaking, one learns that life formation is not assured. You then have to consider it logarithmically. Perhaps it’s one in a thousand or maybe one in a billion, or even one in a trillion. All these options could essentially imply a lack of interactive life.” 

Avi Loeb, Frank B. Baird Jr. Professor of Science at Harvard, posits that the search for alien life should expand beyond conventional methods. Loeb is the founder of the Galileo Project, which investigates both unidentified aerial phenomena observed on Earth and tangible objects that may have originated from other solar systems. 

The project is named in honor of the Italian astronomer who faced persecution in the 17th century for advocating the Copernican theory that Earth was not the center of the universe. The existence of billions of potentially habitable planets in our galaxy serves as a reminder that we might not be as exceptional as we presume, Loeb suggests. “Nature’s message is, don’t be arrogant; you are not unique.”

Loeb garnered attention in 2018 when he suggested that ‘Oumuamua, the first known interstellar object to traverse our solar system, might be an alien lightsail or remnants from a non-Earthly vessel. Despite facing criticism over the notion, Loeb argues that we shouldn’t dismiss oddities: we should at least gather the data to ascertain the truth. He posits that Fermi was undermining himself by idly speculating about the existence of aliens, akin to someone lamenting loneliness without making efforts to meet new individuals.

 “It’s the most enchanting question on Earth,” Loeb remarked. “Do we have a companion out there?”

For Charbonneau, the likelihood of locating that companion is minimal. Even in optimal conditions — if our closest interstellar neighbor, Proxima Centauri, hosted intelligent beings with radio capabilities — exchanging messages would span nearly a decade. 

There’s also the likelihood that extraterrestrials simply aren’t interested in us.

“Upon examining Earth, there are numerous organisms, some scholars argue, intelligent beings that are not inclined to develop technology and may not have a desire to communicate,” Charbonneau noted. “Humans cherish communication and connection, which may not be a universal trait of life: Perhaps it is uniquely human.”