Aliens are everywhere in popular culture. We’re all familiar with the conspiracy theories behind Area 51, the alleged crash at Roswell, and those shaky flying saucer videos.
Earth’s fair share of billionaires have launched themselves off the face of the Earth for interstellar jaunts, and celebrities are now beginning to join in on the cosmic trend.
This week, Star Trek actor William Shatner became the oldest person to ever go into outer space when he boarded Jeff Bezos’ Blue Origin.
With so many humans making their way into space — what are the chances we’ll attract intergalactic visitors of our own someday?
We asked award-winning astrophysicist and senior astronomer Seth Shostak of the SETI Institute, a US-based non-profit that specialises in seeking out extraterrestrial intelligence.
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If aliens visit us, will they be friendly?
Extraterrestrials are ubiquitous in books, films and games — sometimes as frightening entities intent on destroying humanity, other times cuddly and friendly like ET, who just wants to get home.
If they were to visit Earth, would we get a War of the Worlds-style encounter, or would we expect bumbling Jar Jar Binks-like entities to turn up?
Although we don’t know what they’ll be like, Shostak reckons they wouldn’t necessarily have a reason to make the trip here in the first place.
“What would motivate them to come here?” he asked. “Okay, we’ve got water, gold, plutonium, maybe something they need but that doesn’t make any sense because any scientist will tell you the whole universe is made of the same stuff, so why pay for the shipping?
“The only reason they would come here is there are a few scientists on board and it would be an exploration. It’s Captain James Cook, but in that case I don’t think they’d flatten us any more than Cook wanted to flatten Polynesia.
“They could come to look around, or to convert us all to the galactic church, but the real point is they don’t even know we’re here, they would have to pick up on some of the TV or radio transmissions we’ve been sending out willy nilly, and we’ve only been doing that since World War II.”
If they did pop around to visit, would they attack humans?
“Personally I’m not worried,” Shostak laughed. “In Hollywood’s version aliens come here and they want to flatten LA, usually, and I have to tell you, I live near San Francisco and if they want to flatten LA — that’s okay — but several million people in LA would probably feel differently. But the idea that they’re going to come here is unwarranted because they’re not here now.”
Can we communicate with aliens?
Although the movies always make it seem very easy to communicate with extraterrestrials, the likelihood of finding aliens who can speak idiomatic English is about as slim as you would imagine.
Shostak explained: “The equipment we use to try and find ET wouldn’t even pick up the message. It would be like getting a message in a bottle, but just the bottle. So you know someone tried to get in touch, or if they weren’t trying but we still picked it up — but we don’t know what the message is.”
When a signal is picked up, Shostak said you can be sure that a lot of money would be spent on investigating it further. He added: “If they would just send a picture dictionary, that would be great. It would be like decoding the hieroglyphics without the Rosetta Stone.”
Language barriers aside, one of the biggest issues we face when trying to converse with aliens is the amount of time it might take for a message to reach them.
He said: “These aliens might be 100 light-years away, which is pretty close. If we got a message that sounded interesting and you send something back like ‘are you interested in some used cars?’ it would take 100 years to reply.
“Imagine you message someone and it takes 100 years to get to them. That’s an impediment that you can’t really get around.”
Although we might not hear back from intelligent life within our lifetimes, humans did send two records full of information out into space in 1977 in the hopes that if intelligent extraterrestrial life finds them, they’ll have an understanding of humanity. The disks, named the Voyager Golden Records, include images, music, sounds, and samples of languages from planet Earth.
Even if they do find our mixtapes and still want to give us a chance, it could be a very long time until we get a response.
Why are we so fascinated with aliens in the first place?
Shostak said humans have always been interested in “who might be over the hill”, and this natural curiosity extends to our potential intergalactic neighbours, too.
Shostak said: “In terms of Stem education I think SETI is a great way to get the kids interested. You can actually get through to them and change their lives.
“Kids have a natural interest in aliens and you can use that to get them to think about astronomy and biology.”
Shostak said something that always strikes him is that between the ages of eight and 11 children begin to develop their interests.
“I think back to when I was in that age range and if someone came to my school and said ‘consider electronics’ I’d look into it. Everyone has some interest by the time they’re 11 or 12, and some of those are things they do at the weekend. That’s the critical age group.
“The big thing about SETI is that all kids are interested in aliens, much like how they’re all interested in dinosaurs — although we’re probably hard-wired to be interested in things with big teeth such as dinosaurs!”
How close are we to finding intelligent life?
It’s impossible to know, but that’s what the SETI Institute is working towards.
In recent decades, humanity has made massive strides towards understanding what goes on above the clouds. In the last 30 years alone, we discovered that there are more planets in the universe we can see than grains of sand on all the beaches on Earth.
Shostak said: “Planets are just as common as fire hydrants, they are everywhere.
“People think Earth is some kind of miracle, and I think in 10 to 20 years if we find intelligent life we’ll realise that no, it’s not all that special.”
A barrier facing scientists trying to find extraterrestrials is a very earthly problem indeed — money. As there is no government funding in the US going towards finding intelligent life, SETI’s eavesdropping antennas are run on donations.
Money is going towards trying to find biological life, however. Rovers are being sent to Mars, and even if we do only find single-celled microbes it will still be a significant milestone in how we interpret the universe, and subsequently humanity’s place in it.