In the nearly six decades since Frank Drake began searching for extraterrestrial intelligence, astronomers have listened carefully and methodically, but we have heard nothing.
But that’s not to say the search for intelligent life is over. Scientists are experimenting with new ways of looking for signs of life in the universe.
The Fermi Paradox
Enrico Fermi, the architect of the atomic bomb, was also a renowned scientist who contributed to breakthroughs in quantum mechanics and theoretical physics. But he is best known for a simple three-word question that he asked one lunchtime at the Los Alamos National Laboratory in 1950: “Where is everybody?”
This query, which is known around the world as the Fermi Paradox (FP), has posed a number of scientific and philosophical questions. Some scientists believe the answer to FP is that intelligent extraterrestrial life is rarer than most people think, while others suggest that assumptions about the development of intelligent species are flawed or that the current scientific understanding of the universe itself is incomplete.
Some physicists believe that the most likely answer to FP is that human-level technological life began on an exceedingly rare planet, which has the right conditions and the ability to correctly fold proteins. This idea is called the “rare Earth solution” and has gained traction among some scientists in recent years.
The Origin of Life
The origin of life is one of the most challenging topics in science. It is the subject of many interdisciplinary research projects and it is the basis for much debate among scientists.
The most commonly accepted theory on the origin of life is based on the concept that all living organisms are descended from a single common ancestor, which formed around 3.5 billion years ago. This ancestor is thought to have emerged in very early oceans that were covered with non-living matter.
Scientists also think that this ancestor had heterotrophic nutrition, meaning that it could not synthesize its own food. This is because the environment during that time was very anaerobic and had no ozone layer, which would have been harmful to life.
Some of the earliest evidence of life’s existence can be found in the oldest zircons, which are very durable minerals that formed from magma. These 4.1 billion-year-old zircons contain traces of carbon, which is an essential element for living organisms.
The Search for Extraterrestrial Life
Scientists have long wondered if there are other planets out there that might be able to support life. It was a question that fascinated the astronomers of the ancient world — Greeks, Maya, Egyptians, and others.
That search led to the development of exobiology and astrobiology, which focus on the possible presence of extraterrestrial life. In addition to exploring the possibility of extraterrestrial life, astrobiology also addresses such questions as the origin of life on Earth and the impact of gravity on organisms.
One of the most prominent searches for extraterrestrial life involves looking for signals of technological intelligence, like radio or television signals from alien civilizations, which might indicate that they are aware of us and could potentially help our own understanding of life elsewhere in the universe. But scientists have faced some challenges, including maintaining steady funding and establishing the credibility of their work.
The Search for Extraterrestrial Intelligence
One of the most exciting areas of science is the search for extraterrestrial intelligence. This is where scientists search for radio or light signals that might be from extraterrestrial civilizations.
The first modern SETI experiment was astronomer Frank Drake’s Project Ozma, which took place in 1960. He used large radio telescopes to scan the nearby stars for signs of intelligent life.
Since then, SETI has evolved into a scientific community. Jean-Luc Margot, a UCLA professor of Earth, planetary and space sciences and of physics and astronomy, leads the SETI team at the university.
Despite the fact that SETI has been denied steady funding for years, researchers like Margot aren’t giving up on the search. Margot and her colleagues are using machine learning to classify the millions of radio signals that are sent out into space by the Sun and other planets.