Back in August, I wrote about philanthropic funding for telescopes, both the existing instruments on Earth and those up in space — like the James Webb Space Telescope — as well as a coming generation of much larger and more powerful 30-meter telescopes currently under development. While it’s only one part of what they’re used for, one of the most exciting questions scientists are trying to answer with these telescopes is whether there’s life out there.
Many astronomers and other scientists believe there’s a good chance life exists beyond Earth. We know of at least one planet that has life (hint: this one), and there are countless planets in the universe. Already, more than 5,000 exoplanets (planets outside our solar system) have been found in our Milky Way galaxy, and we’ve only studied a tiny fraction of the billions of stars in the galaxy.
A few numbers can put things in better perspective. Astronomers figure most stars have one or more planets — our sun has eight, plus Pluto. There are 100 billion to 400 billion stars in the Milky Way alone. And there’s something like 2 trillion galaxies in the universe, each of which contains billions of stars, with their one or more planets. So even if life requires an amazingly complex and improbable set of conditions to exist, there are plenty of opportunities for those conditions to arise in our galaxy, not to mention the entire universe.
Related to this is the question of so-called intelligent life — civilizations, for example, that might have technology like radio communications. Over the last 50 or 60 years, scientists have scanned the skies for radio transmissions of intelligent origin, so far without luck. Of course, radio signals or other proof of intelligent extraterrestrial beings would be a watershed event, but in a universe where we’re only sure that life exists on our single planet, even the discovery of a blob of extraterrestrial algae would mark a new era for human understanding.
In the search for extraterrestrial life, the focus these days isn’t just confined to listening for alien-made radio signals. In recent years, newer and more powerful radio telescopes and related technologies are seeing farther than ever and giving exobiologists access to a lot more data about the universe and what, or who, may inhabit it. Not only are new planets being discovered, scientists can now determine whether they have atmospheres, and even work out the chemical makeup of those atmospheres.
But let’s say you can collect a great deal of information about the chemical makeup of a homey-looking planet 100 light-years away. What sort of information would serve as evidence of life, and how do you sort that out from non-living conditions and processes?
That’s where a recent philanthropic initiative at the Research Corporation for Science Advancement (RCSA) comes in. RCSA has the distinction of being the nation’s oldest philanthropic organization devoted to basic science. And for a second year, it has reupped one of its “Scialog” programs focused on assessing what sorts of data collected by telescopes might serve as valid signatures of life beyond Earth, among other exoplanetary topics.
RCSA launched Scialog in 2010 to support early career scientists and catalyze interdisciplinary and collaborative research. The initiative brings together interdisciplinary teams of scientists conducting high-risk, high-reward research projects and offers them funding, guidance from more senior scientists, and the ability to participate in three-day on-site conferences. RCSA runs several Scialog topics across the sciences that change as research priorities and opportunities evolve.
Within the “Signatures of Life in the Universe” Scialog category, which debuted in 2021, eight teams from the U.S. and Canada have been awarded more than $1 million in total. Support is coming from RCSA, the Heising-Simons Foundation, the Kavli Foundation and NASA.
“It’s a very challenging problem because we have to understand what is meant by ‘life’ and we have to understand what sort of signatures would count as truly compelling evidence,” said Richard Weiner, senior program director at RCSA.
While it’s probably a bad idea in science to say “never” or “impossible,” scientists don’t expect that signatures of life beyond Earth will come in a form that’s certain beyond a doubt. In other words, telescopes won’t be picking out an alien bird flying through the sky on an exoplanet circling a distant star, or a forest, or a city. What scientists may detect are chemical signatures that might indicate the presence of living organisms. A few of these signatures together would provide stronger evidence of life.
In the event that a planet is populated by beings who use technology in ways similar to humans, for example, such a “technosignature” of intelligent life might be something like atmospheric pollution from industry — that is, the presence and distribution of chemical compounds that probably wouldn’t arise naturally.
But determining what signatures of life actually look like on an alien world is a tough call. Life on another planet may look very different than life on Earth — something researchers must consider as they focus on these distant worlds. For example, a lot of life on Earth uses oxygen, but detecting the presence of oxygen on another planet doesn’t mean that potentially living organisms there even breathe it. “It’s going to be a combination of things,” Weiner said.
Some of the research projects funded under the RCSA Scialog program include efforts to understand how astronomical imaging might reveal microbes, to pick out possible biosignatures on sulfur worlds, and to study soil samples and other data from planets in our own solar system, such as Mars.
Weiner pointed out that these projects really must be interdisciplinary, involving specialists from chemistry, physics, planetary science, geology, astronomy and other areas. That makes it particularly suitable for Scialog, which puts a premium on interdisciplinary and collaborative research.
Note also that NASA is one of the supporters of the Signatures of Life in the Universe Scialog research teams. The work of the scientists could guide the use of astronomical telescopes and NASA’s study of our own solar system and beyond. It will also touch on research into the origins of life on Earth.
Beyond efforts like RCSA’s Scialog program, private and philanthropic support for the search for life beyond Earth may not be common, but it’s not unheard of. In 2015, science philanthropist and Breakthrough Foundation and Breakthrough Prize founder Yuri Milner committed a not-insignificant $100 million to launch the 10-year Breakthrough Listen initiative, markedly expanding efforts to search for extraterrestrial intelligence. And the John Templeton Foundation, a funder that often supports research with both scientific and spiritual components, has backed the search for extraterrestrial life and efforts to identify signatures of life, including with a grant of $2 million to Harvard University.
The search for life elsewhere in the universe appears likely to continue to grow. Every year, new exoplanets are found. In the coming years, newer and more powerful telescopes will not only let scientists discover more of them — they’ll also provide new levels of detail and data on those exoplanets. It is not at all inconceivable that someday soon, we’ll be able to say with a high degree of confidence that we are not alone in the universe. That will be big news for the human condition.
“It’s the kind of fundamental question that people have always wondered about, and I think it would profoundly affect people to understand that life does develop in other places, and it would force us to some extent to reconceptualize who we are,” Weiner said.