When I set up my telescope for public stargazing events, I enjoy talking with the people who gather around. Mostly, they ask me about the telescope targets we’re viewing. How big is the Moon? How far away is Jupiter? What are Saturn’s rings made of? Three other topics come up with surprising frequency: astrology, unidentified flying objects (UFOs), and extraterrestrial intelligence (ETI).
I’ll leave astrology in the capable hands of my Independent colleague Stefan Piscitelli. While there is some subject matter overlap with astronomy, astrology is an ancient discipline all its own. Not my department.
You might imagine that, because I’m a follower of facts, I’d take a pass on UFOs and ETI. But both are of interest to me — and to plenty of scientists as well.
The two terms encompass a wide range of subtopics. That they include strange lights in the sky, reports of abduction (including in Truro), and radio messages from advanced alien civilizations can make it hard to know where reality ends and science fiction begins. But sometimes, it’s worth noting, the latter becomes the former.
Knowledge of astronomy can help make sense of things that might otherwise seem fantastic, especially UFOs. The planet Venus is astonishingly bright in our sky. Because of its ever-shifting position relative to Earth, it’s sometimes visible just before sunrise (when it’s known as Lucifer, Latin for light-bringer, or the Morning Star) and sometimes for an hour or so after sunset, when it’s called the Evening Star. A casual observer might look up one evening and see an extremely bright object low in the west that wasn’t there the last time they looked up. Or maybe there was a stretch of bad weather between Venus’s transition from Morning to Evening Star. Investigative UFO books report countless instances of people reporting, in good faith, a “low-flying, very bright blue-white UFO” that they later realized was Venus.
Other sights that we often mistake for otherworldly objects include aircraft, satellites, and unusual cloud formations. Depending on sky conditions and your line of sight to an aircraft, it can appear to hover or move at impossible angles. A twilight sky and the aircraft’s own lights can amplify the illusion.
I know from stargazing events that many people are unaware that you can see satellites overhead at night. They look like small stars moving fast relative to the true stars, passing across the sky and out of sight within a minute or less. The International Space Station, because of its large size, is especially bright. It would be easy to imagine such a bright, fast-moving star was an alien spacecraft.
Then there are the truly unexplained lights in the sky. People report seeing things at night that appear and disappear before they can reach for a camera. A handful of people have cautiously shared with me stories of bizarre lights with none of the identifying characteristics of Venus, or satellites, or even meteors. These lights sometimes recur regularly and are sometimes witnessed by others. When they ask me what natural phenomena could possibly explain what they’ve seen, I have no good answer for them.
Which brings us to ETI. Are we alone? And if we are not, then, as physicist Enrico Fermi famously asked in 1950 over lunch at Los Alamos, “Where is everybody?”
Scientists have devoted some thinking to the first question. There’s even an equation — the Drake Equation, created by Frank Drake, an American astrophysicist — aimed at estimating how many other civilizations might be out there. But the answer, for now, depends on one’s inherent optimism.
The discovery of the first exoplanet (a planet in our galaxy orbiting a star other than our Sun) was confirmed in 1992. Since then, the technology that enables detection of exoplanets has advanced, and we’re able to find them within an increasingly wider range of constraining parameters. (The current tally is over 5,000.) The implication is that planets are everywhere, in seemingly infinite varieties, including varieties similar to Earth. Our Milky Way galaxy contains at least 100 billion stars and at least that many planets; the total is likely three or four times that. That’s a lot of opportunity for life to find a way. And that doesn’t take into account the trillions of other galaxies in the universe with many trillions of planets.
No, I don’t think we’re alone.
As to the question where is everybody? — here’s where we have to make do with wonder and imagination more than science.
Some suggest that maybe we are on a kind of interstellar probation. Maybe an advanced galactic civilization is waiting to see if we kill, starve, and poison ourselves out of existence, or if we transcend our instincts and become worthy of an invitation to join their interstellar society of like-minded beings. I wonder how many nascent space-faring species make it past this stage we’re at and how many do not. Or, on second thought, maybe it’s better not to know the odds.
In 2017, the first interstellar object originating from a different solar system to be observed passing through our own was discovered. Named Oumuamua — it was detected by the NASA-funded Pan-STARRS1 telescope at the University of Hawaii, and its name means “a messenger from afar arriving first” — its characteristics defied categorization as comet or asteroid, the only two natural objects it could plausibly be.
The NASA science website describes it as appearing to be dense, composed of rock and possibly metals, with no water or ice. But there are those who might find it uncannily similar to the fictional alien spacecraft in Arthur C. Clarke’s classic 1973 science fiction novel Rendezvous With Rama. The fact is, no one can yet say for certain; scientists still puzzle over the Oumuamua data as they watch for more interstellar visitors, natural or otherwise, which we now know are out there.
Maybe we should listen to Shakespeare on this. As Hamlet tells his friend, “Truly there are more things in Heaven and Earth, Horatio, than are dreamt of in your philosophy.” Clear skies!