Alien Civilizations Might Be Too Advanced For Us To Detect

Given the Milky Way’s age and size, we would expect to find intelligent civilizations scattered throughout. But where are they? A recent study suggests these civilizations might be so advanced that we simply can’t detect them.

Reevaluating the Detection of Extraterrestrial Life

If extraterrestrials were observing Earth, they might notice sunlight reflecting off our solar panels. With this in mind, researchers in the U.S. flipped the perspective to see if we could detect alien life similarly.

Simulation of Exoplanets and Detection of Solar Panels

The researchers simulated an Earth-like exoplanet covered with varying amounts of solar panels and examined whether a powerful telescope could spot these from 30 light-years away.

The results showed that the telescope could detect the panels, but with some conditions. To make this detection possible, we would need to cover about 23% of the planet’s surface with solar panels, and the telescope would need hundreds of hours to distinguish the signal from the background noise.

This finding implies that we could find highly advanced civilizations as challenging as finding those with less technological development.

Rather than waiting for alien contact on Earth, astronomers are proactively searching for signs of life in space. This involves looking for biosignatures, like methane in a planet’s atmosphere, or technosignatures, such as radio signals.

The study chose solar panels as a technosignature due to their strong ultraviolet light reflection, which could act as a clear marker. Solar power is also a logical choice given the abundance of silicon and starlight in the universe.

Limitations of Solar Energy as a Technosignature

However, the study revealed that solar energy might be too efficient to serve as a reliable technosignature.

The researchers discovered that to meet our energy needs using only solar power, it would be necessary to cover just 2.4% of Earth’s surface with solar panels.

With a global population of 10 billion, as suggested by the UN, the coverage would be 3%. Even with 30 billion people, less than 9% of Earth’s land would be needed for solar panels.

Since there’s no need to cover 23% of a planet with solar panels, this method is unlikely to help us detect alien civilizations, the researchers conclude.

Implications for the Fermi Paradox

This has significant implications for the Fermi Paradox, which questions why we haven’t found evidence of extraterrestrial life given the likelihood of its existence.

Statistically, the Milky Way should host numerous intelligent civilizations, some of which might have colonized their star systems or even spread across the galaxy.

Possible explanations for the silence include Earth’s location in a quiet region, inadequate search methods, deliberate exclusion, or the unsettling possibility that we might be alone.

The new study offers another possibility.

Civilizations might not need to expand across the galaxy if they maintain sustainable population and energy levels, even with a high standard of living, says Ravi Kopparapu, lead author at NASA’s Goddard Space Flight Center.

They may expand within their stellar system or nearby star systems, but galaxy-wide civilizations might not exist.

Challenging the Dyson Sphere Concept

This idea challenges the popular concept of the Dyson Sphere—a massive structure of solar panels encircling a star, once proposed as an explanation for the unusual dimming of Tabby’s Star.

Large-scale stellar energy-harvesting structures may be unnecessary with advanced technology, notes Vincent Kofman, a geochemist at NASA Goddard Space Flight Center.

A society capable of building enormous space structures would likely have access to nuclear fusion or other more space-efficient energy methods.

Read the original article on: Science Alert

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