I talked with Shostak, a senior astronomer at SETI Institute, about the legendary science-fiction film in honor of its 40th anniversary Thursday (Nov. 16), trying to pin down its significance and why it left a lasting impression on him and the rest of society.
The scene stuck in his mind shows protagonist Roy Neary (Richard Dreyfuss), who recently stumbled upon a UFO. While sitting at dinner with his family, he builds a massive pile of mashed potatoes on his plate and begins to scrape the sides with a utensil. [The Best Space Movies in the Universe]
"It was a nifty scene," Shostak told me, praising director Steven Spielberg for creating several distinctive moments like that in the film.
Viewers quickly discover that Neary is re-creating a structure called Devils Tower in Wyoming with his potatoes; the image was haunting him in hallucinations, and re-creating it helped him deal with the stress. That's also the place where aliens choose to make official first contact with humans in the film. There, they also invite Neary to go with them to their next stop in the universe.
Music of the night
The plot of "Close Encounters" is complex, but I'll attempt to give a quick overview:
People around the world are experiencing encounters with UFOs, including Neary and Jillian Guiler (Melinda Dillon). A series of experts form a committee to investigate.
They learn that the aliens communicate using music. Once the human committee broadcasts the aliens' music to space, they receive a set of numbers that they eventually realize are coordinates to Devil's Tower. The government tries to restrict public access by saying there was a railway accident that spilled toxic gas nearby. (Shostak, a former railway employee, pointed out this would never work in real life; the nearest rail line to Devils Tower is in fact 25 miles, or 40 kilometers, away, he said.)
After everyone converges on the location — Neary somehow makes it past the barricades — the aliens arrive, some musical tones are exchanged and the aliens drop off past abductees. The film ends with Neary leaving on the ship, which flies away from Earth to parts unknown.
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Shostak does not like when films try to communicate with aliens using mathematics (such as 1997's "Contact") or, in this case, with music. "Now, this musical interlude will tell us about the pancreas?" he joked. "I don't know how you'd do that. Much better to send pictures."
It's only through language and images that we would be able to understand what Shostak calls the most interesting thing about aliens: their culture. "Do they live in cities? Do they have music? Are there gazillions of them, or just a few? Cultural stuff like that."
Little-known fact: The musical language used in "Close Encounters" was not original to the film; it resembles a language created back in the 1880s. Called Solresol, it was devised and popularized by French music teacher Francois Sudre and published in a book, "Langue musicale universelle" (The Universal Musical Language), in 1866. The hand gestures used with the music originated with Rev. John Curwen, who used the language to teach music in the 1800s. [What Makes an Alien Encounter Movie Believable?]
Evolving search for life
While we don't have definitive proof of encounters with aliens, humans have made several sorts of attempts to communicate with them in real life. (Shostak said it's hard to judge how accurate the encounters with aliens are in the film, although he still questions why the aliens needed to shine bright lights all the time.)
The real-life 1972 Pioneer 10 and 1973 Pioneer 11 spacecraft were sent to space with plaques containing pictures of a woman, a man and the location of Earth relative to several rapidly-flashing neutron stars called pulsars. Then, in 1977 — the year "Close Encounters" was released — Voyagers 1 and 2 each carried a "Golden Record" into space that held music, sounds and images from Earth.
In 1974, scientists sent a radio message to M13 containing information about Earth. That message was called "the Arecibo message" after its origin, the Arecibo Observatory in Puerto Rico.
In August 1977, just a few months before "Close Encounters" was released, astronomer Jerry Ehman discovered a signal of unexplained origin received by The Ohio State University's Big Ear radio telescope. He wrote "Wow!" beside the original data — but the signal was never replicated. The 1977 event is called "the wow signal," and its origins are still debated.
Shostak pointed out that most of today's money and energy are spent much closer to home — specifically, our own solar system.
In the 40 years since "Close Encounters" was released, there have been many missions to send spacecraft orbiting or flying by Jupiter and Saturn, each of which turned out to have several icy moons that are considered strong candidates for life. But that doesn't mean such life would be the intelligent aliens often portrayed in sci-fi films.
"If there is life there, it would be microbial," because microbes are very common, resilient and fast to evolve, Shostak said. "If the Klingons [fictional aliens from 'Star Trek'] came to Earth for most of its history, they would have found life — but it was microbial."
Mars also had water flowing on its surface in the ancient past. This was suspected in the 1970s, but water wasn't confirmed until 1998, when the Mars Global Surveyor found a mineral called hematite, which usually forms in water. The find was later backed up by rover observations on the surface. Scientists debate if Mars has liquid water today, although some say distinctive, dark streaks along the side of craters are evidence of briny water.
The NASA Mars 2020 rover is designed to look for present habitable environments on the Red Planet, and to cache promising samples for a possible sample-return mission. Meanwhile, several probes on Mars (both on the surface and flying above) continue to examine the atmosphere and ground for signs of ancient habitable environments.
Shostak said the questions he gets from the public about the search for extraterrestrial life usually don't reference "Close Encounters" directly, but the film created or popularized some of the more famous alien tropes that are still used today. These include the bright lights the aliens used and the scenes showing the aliens disabling vehicles as they flew by.
The film received numerous awards and nominations, both in its day and decades later. In 2007, on the film's 30th anniversary, the U.S. Library of Congress deemed the movie "culturally, historically or aesthetically significant" and selected it for preservation in the National Film Registry.
Personally, I've probably watched "Close Encounters" a dozen times since I first saw it in school around 1997. (Pro tip: This movie makes no sense over the racket of 40 noisy teenagers.) Two occasions stick out. The first was in July 2009, when an organization played the movie in the big field next to the National Air and Space Museum in Washington, D.C. I was there attending a special lecture delivered by all three Apollo 11 astronauts and caught a brief glimpse of the movie as I walked back to my hotel, late at night.
Then, in January 2014, I was participating in a two-week simulated Mars mission at The Mars Society's Mars Desert Research Station (MDRS) and reporting on it for Space.com. I was far from home, and as is common in isolation when you're working long hours, I felt a little cranky. But that changed on my birthday. The crew somehow produced a cake and candles, and told me I could choose whatever movie I wanted from the on-site library. "Close Encounters" on our little "Mars" mission was perfect, and reminded all of us why we were at MDRS in the first place — because we care about space.