As we search for a universal language, we can be sure that extraterrestrials won't be native speakers of English, Hindi, or Mandarin. What language, then, can we use to communicate with an independently evolved species, and what should we say?
If there's one thing we will have in common with any extraterrestrials we contact, it's technology. To receive our radio signals, extraterrestrials need to be good engineers. And good engineers need to know something as fundamental as 2+2 = 4, whether they live on Earth or on a planet circling Proxima Centauri. So we begin our interstellar messages with basic mathematical and scientific principles, and then move on to more complex ideas.
Historically, the creators of interstellar messages have tried to send the most comprehensive collections of information that they could. The Voyager Golden Record attempted to represent the breadth of human cultures and a sampling of life on Earth through images, sounds, and music. In 1974 a radio message was transmitted from the world’s largest radio transmitter at that time, in Arecibo, Puerto Rico. In a mere three minutes, the Arecibo message tried to explain our counting system, the essentials of terrestrial biochemistry, the shape and size of our bodies, Earth’s population, the composition of our solar system, and the technology used to transmit the message. This risk of sending a message that tries to cover everything is that you might end up communicating nothing.
It’s not enough to send intelligible messages. We need to repeat them. One of the defining characteristics of METI’s signalling program is that we’ll be repeating our messages to the same stars, to aid in signal confirmation by extraterrestrials. Our first transmissions will be at radio frequencies, relying on existing transmitters Within the next couple of years, we plan to build a dedicated laser transmitter, which will let us send information to the stars. Laser signals can pack more information into each second of transmitting time than radio signals can carry.
But which stars, precisely, will we target? In the early days of SETI, astronomers focused exclusively on stars that are more or less like our own Sun, reasoning that we know life evolved in our own solar system, so we should restrict our search to stars as close to the Sun as possible. We will continue to target Sunlike stars, but they are not the most common type of star in the galaxy, so if we want to reach the stars that are closest to Earth, we need to expand our scope of target stars. Many of the stars that METI will target are dimmer, long-lived red dwarf stars—that have been around a long time to cook up some intelligent life. The majority of stars in the neighbourhood of the Sun are red dwarfs, so this opens up a tremendous number of targets in our galactic backyard.
To increase our chances of receiving a reply in the near future, at METI our transmissions will target stars, with a preference for those known to have exoplanets within the habitable zone. This is a drastic difference from the 1974 Arecibo message, which targeted M13, a globular cluster of stars 25,000 light years away. That means it will be 50,000 years before we could possibly receive a reply.
At METI, we are transmitting to test a possible answer to the Fermi Paradox. In 1950, the physicist Enrico Fermi asked, during lunch with colleagues at the Los Alamos National Laboratory, "Where are they?"—encapsulating the puzzling question of why we haven’t made contact if life in the universe is abundant. The most straightforward answer to the Fermi Paradox is that they're out there, perhaps even signalling our direction, but we just haven't looked at enough stars. We now know that virtually all stars have planets around them, but we don't know what percentage of those planets go on to host life, and of those life-bearing planets, what fraction go on to evolve intelligent creatures with the technology for interstellar communication. And even if they have the technology, do they use it to promote First Contact?
Ultimately we need to get into the mindset of an extraterrestrial, as we look for commonalities between their civilisation and ours. To encourage this broader perspective on humankind, METI will hold a meet in Bengaluru in February 2018 in cooperation with the National Institute of Advanced Studies (NIAS), organised by philosopher Sangeetha Menon (Head, NIAS Consciousness Studies Programme) and METI director Abhik Gupta. The focus theme for the Seminar is “Altruism, Wellbeing and Purpose: Vantage Views on Planetary Life and Its Meaning from Sociobiology, Indian Philosophy and the Arts.” As we examine more deeply what it means to be human, we prepare ourselves to communicate with a species that may be radically different from us.
It’s not enough to say you are either for or against transmissions from Earth. You need to be clear about what sort of messages you favour or oppose. Though I’m a strong advocate of trying to make contact, I’m strongly opposed to any projects that send threatening messages to extraterrestrials. It’s easy to get caught in a mindset where you either favour all transmissions or oppose all of them, but reality is much more complicated. Do opponents of Active SETI really want to limit any powerful radio signals we send from Earth? Would they want to shut down radars at airports that help planes land safely? Would they shut down powerful transmissions that help us identify Earth-threatening asteroids? I certainly hope not. An added advantage of starting small and then moving to a more ambitious transmission project later is that this staged approach lets us foster broad-based, international discussion about how best to proceed. We’re currently in a Catch-22 situation. We’d like a global discussion about what to say in interstellar messages, but because there are no serious, ongoing transmission projects, it’s difficult to jumpstart those discussions. But by making clear our plans to transmit, and beginning in a modest way, we expect to generate widespread discussion from around the world about how best to move forward in the future.
The writer is president of METI (Messaging Extraterrestrial Intelligence), a nonprofit research and educational organisation.
