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Astronomer Reveals The Truth Behind Civilization: Beyond Earth‘s Exoplanets

Civilization: Beyond Earth Box Art

Firaxis’ upcoming turn-based 4X strategy game Civilization: Beyond Earth takes Sid Meier’s famous series in a unique direction: the far future. After a catastrophic event known as “The Great Mistake,” humanity must set out into the universe and found colonies on distant planets. But one strength of the series has always been its firm rooting in actual history and technological accuracy – setting aside concessions made in the name of fun, of course. How can Beyond Earth hope to retain that same semblance of being grounded in reality?

Enter Dr. Stephen Kane, Assistant Professor in the Physics & Astronomy Department at San Francisco State University. His research focuses on the detection of exoplanets – planets outside of our solar system. For the curious, he maintains a handy website that keeps track of the number of exoplanets we’ve officially found and how many reside within their star’s habitable zone – the region in which temperatures are just right for water to exist in a liquid state. In other words, he keeps a close eye on the planets that we could potentially colonize one day.

In April, Dr. Kane announced the confirmation of a new exoplanet: Kepler-186f. At the time, Firaxis was working on including exoplanets in Beyond Earth, and the announcement got the developers’ attention. They contacted Dr. Kane, and since then, there’s been an ongoing dialogue about making the information in Beyond Earth as accurate as possible and finding more planets to include in the game. We spoke to Dr. Kane about his work and how it relates to Beyond Earth.

The intersection between science fiction and science fact

A fair amount of old science fiction dealt with the mysteries of our solar system. We knew other planets were out there, and we had names for them, but we knew little else. Fiction allowed us to speculate – until science started giving us real answers. H. G. Wells’ The War of the Worlds depicts an invading alien army from Mars – today, we know there are no alien civilizations in our solar system. Ray Bradbury’s “All Summer in a Day” depicts Venus as a world of constant rainstorms, where the sun is only visible for one hour every seven years – today, we know that no rainfall hits Venus’ surface. Many of Isaac Asimov’s stories show Mercury as a world with one permanent “day side” and one permanent “night side” – today, we know the planet isn’t tidally locked like our moon.

“I think that adds an enormous extra layer of imagination for the players, knowing that these planets are out there.”

So sci-fi authors that wanted stories with aliens and wanted the freedom to craft their own extraterrestrial landscapes had to move more and more towards entirely fictional worlds set in other galaxies – or even other universes entirely. But, just as there’s a certain appeal to knowing that Civilization‘s historical settings are grounded in reality, so too is there a similar appeal in a reality-grounded sci-fi setting. The recent bounty of newly discovered exoplanets may just usher us into a new era of sci-fi.

“This is an exciting time when science fiction and science fact overlap,” said Dr. Kane. “We’ve finally reached a point that we’re able to talk about these planets in real terms.” The past two years have seen tremendous advances in the discovery of exoplanets – almost 800 were confirmed earlier this year, which almost doubled the total number of confirmed exoplanets. Both Dr. Kane and Firaxis are looking to include a number of these actual planets in Beyond Earth, and the current pre-order bonus pack for the game includes six maps based on actual exoplanets.

“Being able to put these planets into the game is something which is really exciting,” said Dr. Kane. “Instead of having planets that are randomly generated, players will be able to pick and choose the planet that they go to, knowing that that planet actually exists, and they can look up all kinds of information about the planet discovery.

“I think that adds an enormous extra layer of imagination for the players, knowing that these planets are out there. This is an incredible enhancement to the gaming experience and, in general, for science fiction.”

Dr. Kane pointed to how Star Trek and other sci-fi, for years, has had humans visiting random, fictional planets. But exoplanet discoveries may change that. “I think what we’ll start to see over the next decades is that more and more science fiction will include real planet discoveries, and that’s an exciting thing to see.”

How Beyond Earth stays true to science

Beyond Earth won’t simply include random tilesets that are named after actual exoplanets – the developers want to get as close as possible to reality.

“I know that the design team has been really excited about including exoplanet map packs,” said Dr. Kane. “They want to include more of these exoplanet discoveries, and my goal will be to make these as real-to-life as possible.”

Now, what does Dr. Kane mean by “real-to-life?” It’s all about realistic extrapolation of limited data. For example, one thing we know about these exoplanets is their distance from their star, so a planet that is near the inner edge of its planet’s habitable zone may be a baked desert world, while one on the outer edge may be more of an icy world.

“Of course, there is a certain point at which you’re forced to take poetic license, such as if you want to describe the surface in any detail at all,” said Dr. Kane. “But we want to try to make sure those cases where we do try to imagine what the surface is like are driven by what we do know and make that extrapolation as realistic as we can.”

Apart from the distance to their star, there are other things we know about exoplanets that can help the Beyond Earth developers integrate these worlds into the game. The techniques that we have for detecting exoplanets allow us to learn some basic things about them, and by combining the data from different techniques, we can make inferences about a planet’s nature. Specifically, one method reveals a planet’s mass, while another reveals its size, and together, these tell you the planet’s average density. “That’s when we can really start talking about characterizing these planets,” said Dr. Kane, “because once you have the mean density, you can start to think about what the interior looks like. For example, if it’s extremely dense, you imagine it has a very iron-rich core, or you can also think about how thick its atmosphere might be once you know the surface gravity.”

Will Beyond Earth run out of habitable exoplanets to include?

One concern about grounding a game in reality is the limitations that imposes. For instance, Civilization can only include so many ancient civilizations – eventually, there’s no ground left to cover. How long will it take Beyond Earth to run out of exoplanets?

“…the last thing you want to do is travel the great distance between stars, go to a planet which is the size of the Earth, but then find that it has a surface much like Venus.”

Currently, Dr. Kane’s website is tracking the orbits of 1457 exoplanets, 51 of which are in the habitable zone. If Firaxis has only covered six of those so far, it seems we’re good for at least another eight exoplanet packs. But keep in mind that Beyond Earth takes place 200 years in the future – that’s a lot of time to discover new exoplanets. Just how many may we discover by then? I turned the question to our astronomer.

“I absolutely love this question,” said Dr. Kane. “Let me start out by saying that the field of exoplanets over the past two decades has progressed so quickly and changed so radically that almost all predictions we made in 1995 about where we would be in 2005 were wrong.”

If 10 year predictions could be so far off, what hope do we have for accurately predicting the situation in 20 times that time span? Still, Dr. Kane was up for the challenge and began to lay out the facts. “We’ve figured out that there are far more smaller planets than their are larger planets,” he said. “That means there’s lots and lots of terrestrial planets out there (like Earth and Venus, as opposed to gas giants like Saturn and Neptune) – and that’s great.” When considering habitability, terrestrial planets are what we’re looking for. “The other thing that we’re concluding is that all stars have planets – that planets are a natural consequence of star formation. What this means is that every single star has terrestrial planets, and many of them probably have a terrestrial planet in the habitable zone. We just need to find them.”

Working under the assumption that habitable planets are bountiful in our universe, the question then becomes: how many can we find in the next 200 years? “I would put the answer in the hundreds of thousands – at least,” said Dr. Kane. Looks like Firaxis can sit easy – Beyond Earth essentially has no limit to the number of worlds it can allow players to colonize while remaining in the realm of possibility. But the news is even better for humanity.

“Given the rate that we’ve seen technology progress over the past 10-20 years in being able to find exoplanets,” said Dr. Kane, “200 years from now, not only are we going to have found at least hundreds of thousands of exoplanets around the nearest stars to the Earth, we’ll have been able to take images of the planets, identify which have suitable atmospheres, and know exactly which to colonize without any guesswork involved. Because the last thing you want to do is travel the great distance between stars, go to a planet which is the size of the Earth, but then find that it has a surface much like Venus. That would be very disappointing, to say the least.”

Why is it important to find exoplanets?

For the average person, the existence or non-existence of other planets will have no effect on day-to-day life – not for a long time, at least. So I asked Dr. Kane why his research is important to humanity.

“…I would hazard a guess that most planets that are habitable are inhabited – but not by advanced life.”

“It’s a perfectly reasonable question,” he admits, “because there are so many distractions these days that occupy our time. But I always try and remember the writings of people from the past few hundred years – these people were talking about other planets with absolutely no data to back up their claims. Even as far back as 300 BC, the philosopher Epicurus was talking about the ‘plurality of worlds.’ It was a very philosophical exercise, but it was always something which captured the imagination.

“I think it’s extremely important for human civilization to know that we are not just a single oasis in a vast universe, but that there are other potential homes out there. And now that we’re at that point when we finally have the technology to answer these questions that people have been asking for a long time, it’s an enormous threshold in human knowledge to go from not knowing if there’s another place like the Earth, to knowing that there is.”

Laughing, Dr. Kane added, “And of course the next question is, ‘How do we get there?'”

Ultimately, there really is no practical reason for the importance of searching for exoplanets for the modern everyman – but the inspirational reasons are paramount. “In my opinion,” says Dr. Kane, “discovering planets around other stars is one of the most important research endeavours of the modern age. It’s something which is much larger than ourselves and answers some very fundamental questions about our place in the universe.”

The Drake Equation: What are the odds of finding intelligent life?

Given there may be so many habitable planets out there, we then tend to wonder how many alien civilizations may exist in our universe. In 1961, astronomer and SETI founder Frank Drake came up with a formula to estimate the number of intelligent civilizations that may exist in the Milky Way. It was never meant to be a means at arriving at a firm number, but was rather a probabilistic argument intended to provoke thought and discussion.

SIDEBAR: The Drake Equation:


N = the number of civilizations in our galaxy with which radio-communication might be possible
R* = the average rate of star formation in our galaxy
fp = the fraction of the stars in our galaxy that are orbited by planets
ne = for every star that has planets, the average number of planets it has that can potentially support life
fl = the fraction of planets that could support life that actually go on to develop life
fi = the fraction of planets with life that develop intelligent life (i.e. civilizations)
fc = the fraction of civilizations that develop a technology that releases detectable signs of their existence into space (i.e. radio waves)
L = how long such a civilization releases detectable signals into space

The equation’s parameters begin with things that we can estimate based on observation and information, such as the average rate of star formation in our galaxy, and become increasingly unknown or unknowable the deeper into the equation we get. But Dr. Kane believes that as we move toward the later parameters that revolve around intelligent life, the numbers will start to drop to zero. “It seems like all stars have planets, and most of them probably have planets with liquid water on their surface,” he says. “And I would hazard a guess that most planets that are habitable are inhabited – but not by advanced life.”

“I’m not one of those people that says, ‘Well, there are so many planets out there; of course life is common!'” Dr. Kane adds. “We can actually quantify that better because we know that life on Earth started extremely quickly.” He points to evidence that life arose on Earth as far back as four billion years ago – relatively soon after the planet’s formation. He points to the abundance of hydrogen and oxygen in our solar system (the first and third most abundant elements, respectively) as evidence that water should be extremely common on planets. “So I suspect that there’s a lot of life out there,” he says.

The Fermi Paradox: Where is everybody?

While life may be common, having life evolve into something intelligent is another issue entirely. In 1950, physicist Enrico Fermi summed up in one question the paradox that arises when we consider just how common life may be in our universe: where is everybody?

“…it’s an enormous threshold in human knowledge to go from not knowing if there’s another place like the Earth, to knowing that there is.”

If life is everywhere, why have no civilizations made contact with us? Why haven’t we detected radio signals? Why haven’t we seen any signs of colonization?

Dr. Kane believes that the solution to this paradox is that evolution rarely leads to intelligent life. “If you look at the history of life on Earth, we see all kinds of adaptations to the environment. Evolution doesn’t necessarily favor intelligence – it favors adaptation and reproduction.” As long as a creature is able to survive in its environment and give rise to viable offspring that will continue to pass on its genetic code, it is evolutionarily successful. “It’s not necessarily the case that intelligence is the peak of this evolutionary pyramid.”

The sobering reality is that it was dumb luck that allowed for the evolution of intelligent life in humans. As Dr. Kane puts it, “If the Earth hadn’t been struck by a giant impactor 66 million years ago, we’d all still be speaking dinosaur, right?”


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