NASA Explains Why We Can’t See Aliens (Yet)

In 1950, Enrico Fermi raised an innocent but deeply unsolved question: in a galaxy full of planets and star systems, why do we see no signs of life? The question—now known as Fermi’s Paradox—has engaged astronomers, philosophers, and everyone else over the past decades. Now, a team of researchers suggests a new reason we may not have seen intelligent life in the universe.

Their solution, published in the Astrophysical Journal, is straightforward: Extraterrestrial life may not need to do all that. Researchers have tested whether a next-generation space telescope can detect solar panels on a nearby exoplanet. The team concluded that, if such intelligent life could exist and get its energy from the sun, it probably wouldn’t need the amount of energy needed to see it.

“The implication is that a civilization may not feel compelled to expand throughout the galaxy because it may reach sustainable levels of population and energy consumption even if it chooses a higher standard of living,” said Ravi Kopparapu, NASA’s Goddard Space Flight researcher. Center and lead author of the paper, on Goddard’s release. They may develop within their own star system, or even in nearby star systems, but a galactic civilization may not exist.”

In the paper, the researchers tested whether silicon-based solar panels could be found on an Earth-like exoplanet. They chose silicon-based panels because the element is more abundant than other elements used for solar energy, and (at least on Earth) it is relatively cheap to mine and use in production.

The team thought they were observing exoplanets in the Milky Way with the Habitable Worlds Observatory, a marquee project of NASA’s Great Observatories program. The first phase of development of the next-generation exoplanet-focused telescope is scheduled for 2029.

The team modeled an Earth-like planet with different levels of silicon solar panel coverage and tested whether the Habitable Worlds Observatory could detect those technical features from a distance of 30 light years. The team found that it would take at least several hundred hours to detect the technosignatures, if 23% of the exoplanet’s surface is covered by solar panels.

The team notes that only 9 percent of the Earth’s land would be needed to sustain 30 billion people at a high standard of living. About a quarter of the planet’s land covered by solar panels is, perhaps obviously, an extreme situation and would be difficult for Earth’s energy needs.

“Large-scale solar energy harvesting structures may become obsolete especially when considering technological advances,” said study co-author Vincent Kofman, a researcher at NASA Goddard and American University, in the same release. “Certainly a society that can put large structures into space will have access to nuclear fusion or other space-based energy production methods.”

The study hypothesizes that extraterrestrial civilizations will use solar energy from their host star; Yes, aliens may use any number of energy sources, including those beyond the limits of our imagination.

But, aside from some energy source, we may not see signs of intelligent life in the universe because the universe is so vast, and we only have observational tools.– indeed look-a few decades, or a century at a stretch. Our galaxy has been around for billions of years, and our universe has billions more. As stated by the SETI Institute, “The Fermi Paradox is the biggest explanation from local observations. You might look out your window and conclude that bears, as a species, cannot exist because you cannot see anything.”

Recent research makes many assumptions about alien technology and its appearance, but modeling these scenarios is important; once the Habitable Worlds Observatory and other next-generation telescopes are up and running, the projects will have several places to start searching.