Are We All Alone?

In a new book, University of Rochester astrophysicist says we soon could finally determine whether extraterrestrial life exists.

By Mike Costanza

Astrophysicist and author Adam Frank said humanity has long faced a very important question.

“Is there life beyond Earth?” the 61-year-old asked.

“The Little Book of Aliens,” Frank’s 2023 book, describes how humanity, after speculating about the possibility of extraterrestrial life for thousands of years, could finally determine whether it exists.

“We have everything we need to start to get data relevant to it,” he said. “I wanted people to understand how remarkable that is.”

Frank‘s interest in the stars began to develop as a child growing up in Belleville, New Jersey, when he began reading his father’s collection of pulp science fiction magazines.

Those dramatic depictions of spacemen and women, rocket ships and new, mysterious worlds helped send him on a journey that eventually took him to the University of Rochester department of physics where he is the Helen F. and Fred H. Gowen professor.

During his lengthy academic career, Frank has researched the formation and development of stars and studied the evolution of planetary atmospheres. He now focuses upon astrobiology, a field that deals with the nature, existence and search for extraterrestrial life. In addition, the self-styled “evangelist for science” has penned op-eds for The New York Times, been interviewed on WXXI-AM 1370’s popular “Connections” talk show, written for National Public Radio and been a regular commentator on CNN.

Frank has also traveled the country speaking about topics of critical importance to the future of this planet and written or co-written several books, including scholarly texts and works that present their complex subjects in ways that are understandable to the general public. His 2018 book “Light of the Stars: Alien Worlds and the Fate of the Earth” examines climate change from a cosmological perspective. Its publication led to a cover story about Frank in 55-PLUS, September-October 2018 edition.

“The Little Book of Aliens” is Frank’s effort to make the search for extraterrestrial comprehensible and meaningful for readers.

“It’s one of the oldest coherent scientific questions that we’ve ever asked,” he said. “You can go back to the ancient Greeks and see them arguing over it.”

Until about 30 years ago, most astronomers did not take the question existence and search for extraterrestrial life seriously. There was scant interest in astrobiology and very little funding for research into extraterrestrial life.

“You use the word ‘alien’ and everybody kind of raises their eyebrows,” Frank said. “It’s what we call the ‘giggle factor’ that’s been prevalent in science and society for so long because of UFOs (unidentified flying objects).”

Unidentified flying objects, aerial objects or optical phenomena that are not readily identifiable, have been a subject of popular interest and sometimes subject of US government studies, since World War II. Now called “unidentified anomalous phenomena” or UAPs, they are thought in some circles to be evidence of extraterrestrial life. A 2023 NASA study found no evidence that they are of extraterrestrial origin.

Attitudes toward the search for life beyond the Earth began to change in the 1990s as technological advances in ground-based telescopes and the launching of space-based observatories like the Hubble Space Telescope opened vast parts of the cosmos to observation. Those advances led to the first discovery of planets that are orbiting stars outside of our solar system, or “exoplanets.” The light coming from those stars could reveal the presence of life on the planets orbiting them.

As starlight passes through a planet’s atmosphere, it picks up clues to the makeup of that atmosphere.

“When that light finally gets to us, that light has a fingerprint, a spectral fingerprint, of the elements, compounds, molecules that are in the atmosphere,” Frank said.

For about the past 20 years, astrophysicists and other researchers have examined those spectral fingerprints for “biosignatures,” the elements, molecules, substances or features that indicate that life exists, or once existed, on exoplanets. For example, the presence of oxygen, which is a byproduct of photosynthesis, would indicate that plant life exists.

“Twenty-one percent of the Earth’s atmosphere is oxygen, and it’s only there because of life,” Frank said.

Until recently, most researchers refused to examine the starlight that bathes exoplanets for “technosignatures,” properties or effects that are evidence of the current or past existence of technologies on those planets. Industrial pollution, for example, could indicate the existence of intelligent life. For a long time, most researchers did not take the idea of such life seriously.

“Technosignatures, because we’re talking about intelligent life, still suffered from the giggle factor,” Frank said. “NASA was almost explicit. They’d say, like ‘Oh send us proposals to study life in the universe, but not intelligent life. Intelligent life got connected to the silliness surrounding UFOs.”

That’s changed in the last few years.

“Astronomers recognized that, like, it doesn’t make any sense to somehow put a little box around the possibility of intelligent life,” Frank said.

Seeking to advance the search for intelligent life in the heavens, Frank and a small number of other astrophysicists formed Categorizing Atmospheric Technosignatures (CATS). Using nearly $1 million in NASA grants, the group plans to create a library of possible technosignatures to aid in the examination of exoplanets.

Though astronomers’ and astrophysicists’ attitudes about extraterrestrial life are changing, the technology for finding it is still catching up. The James Webb Space Telescope is the most powerful telescope ever built, but it still might not be up to detecting evidence of extraterrestrial life.

“The JWST has some of the capabilities that we need to do this, but we’d be lucky…if we actually were able to find a biosignature,” Frank said.

Recognizing the importance of the search for life beyond the Earth, NASA plans to build and launch a telescope that’s designed for that purpose, the Habitable Worlds Observatory. Frank said the telescope probably won’t be ready to launch for about 20 years.

A successful search for extraterrestrial life need not reveal the kinds of human-like creatures that populate popular science fiction television shows. Even the discovery of single-cell bacteria on Mars would be a breakthrough.

“If we found single-cell bacteria on Mars that had a different evolutionary lineage than Earth…that would show us that the formation of life is something that has happened more than once and therefore probably happens all the time,” Frank said.

A discovery of that magnitude could change the way we perceive ourselves and our world in much the same way that the theories of Polish astronomer Nicholas Copernicus catapulted the intellectual world forward in the 1500s. At a time when the Earth was thought to be the center of the solar system, Copernicus proposed that our planet orbits the sun and turns on its axis. His ideas spurred what came to be called the “Copernican Revolution.”

“The Copernican Revolution becomes a central part of the reorganization, the political, philosophical, economic reorganization, of the world,” Frank said. “It figures prominently in the Renaissance, in the Enlightenment and even in the Protestant Reformation.”

At a time when a number of crises afflict the world, the discovery of extraterrestrial life could also help us put our troubles in perspective.

“It just, in a certain way, means the universe is far more open-ended,” Frank said. “It also tells us that we’re part of a cosmic community of life.”