The movie “The Martian” has been critically acclaimed and opened over the weekend to a box-office topping $55 million domestic haul. Movie goers across America have been fascinated by the prospect of an astronaut — played by star Matt Damon — gardening and otherwise hashing out a sustainable life on a foreign planet.
But let’s get something out of the way early here: There are no alien planets yet discovered that scientists are naming “Maine 2.”
There are no planets out there — that we know of at this point — with 70-80-degree average summer temperatures and cold, snowy winters, or planets with dense forests of pine trees alongside rocky ocean coasts.
If you’re looking at that picture above of what scientists think the surface of Gliese 667 Cc might look like and saying, “That doesn’t look anything like Maine,” you need to realize there may not be any other place in the universe quite like Maine.
In fact, NASA can for the most part only make educated guesses about other so-called Earth-like planets.
The space agency has crunched the numbers to arrive at the hypothesis that there are potentially billions of planets out there capable of sustaining life as we know it — which is to say, planets that are the right temperature and makeup to host liquid water, necessary to sustain all carbon-based life.
These Earth-like planets are often referred to as being located in the “Goldilocks zones” of their respective solar systems. They’re orbiting their suns closely enough for the solar warmth to keep water from freezing, but not so closely that they overheat and all the water evaporates.
Where that sweet spot is depends on a range of factors, including the relative size and temperature of the sun in that particular solar system.
Earth-like planets also must be largely rocky or solid — we couldn’t live on an entirely gas planet — and must be vaguely similar to our planet in terms of size.
Even though NASA believes there are likely billions of these potentially habitable planets out there, they’ve only really been able to pinpoint about a couple dozen at any given time, with some promising candidates getting debunked upon further research and others being discovered as more of the galaxy is mapped out.
Without getting too technical, scientists input a range of descriptive values for each alien planet into a formula, to crank out an Earth Similarity Index, or ESI. ESIs range from 0.0 to 1.0, with 1.0 being an exact match for Earth and the lower numbers being less and less like our home planet.
There aren’t space rovers or other research tools planted on the surfaces of these Earth-like planets — like we have on Mars, for instance — so we don’t know for sure what those surfaces look like. Many of these planets are thousands of light years away and can only be studied by space-bound telescopes and mathematical calculations based on light refraction and things.
Of the Earth-like planets that have been identified thus far, two stand out as being most like the part of Earth that is Maine.
Those are KOI 3010.01 and the aforementioned Gliese 667 Cc.
Scientists are hopeful KOI 3010.01 has a composition very similar to Earth’s and believe it to be only 50-60 percent larger, which is pretty close in size all things considered.
We don’t have much to go by on many of these suspected planets, so our best bet at drawing a comparison to Maine is the surface temperatures.
Among prospective Earth-like planets, KOI 3010.01 is something like “Maine Spring/Fall,” in that regard. Researchers believe it has a surface temperature of about 67-68 degrees.
Maine is also known as being densely forested, and while we don’t have any idea whether KOI 3010.10 is covered with anything like trees, scientists have given the planet a vegetation suitability rating (a qualification based on projected temperature and humidity) even higher than that of Earth’s.
Is fall your favorite season? Want to move to KOI 3010.01? Well, this place is more than 1,200 light years away. It would take a space shuttle traveling five miles per second 37,200 years — more than three times longer than human civilization has existed — to travel just one light year.
Oh, one other teensy tiny thing. Even if you were to make that commute, you might get there and find out KOI 3010.01 never actually existed. KOI 3010.01 is currently considered an exoplanet candidate, meaning there’s some visual and mathematical evidence a planet’s there, but more research is necessary to confirm its existence.
Gliese 667 Cc
Unlike KOI 3010.01, this Earth-like planet’s existence has been confirmed, and thus, researchers know a little bit more about it. Gliese 667 Cc might be something like a weird mix between a Maine summer and a Maine winter.
Depending on what its atmosphere is like, Gliese 667 Cc is believed by scientists to have a temperature of about 86 degrees Fahrenheit. That’s a hot July or August, by Maine standards.
But it would also have Maine’s characteristic winter gloominess, as it receives about 20 percent of the visible sunlight Earth typically enjoys.
If there are anything like seasons on Gliese 667 Cc, they wouldn’t be long, protracted ones like Maine’s winters typically are. Gliese 667 Cc orbits its sun in about 28 days, so our Earth years are 13 times longer than Gliese years.
There are a lot of other wild cards, too. Gliese 667 Cc is between four and five times larger than Earth, which would make matter heavier on its surface and could create greater atmospheric pressure, etc. Then there are the prospects of dangerous solar flares, which would be more violent and more frequent coming from its red dwarf sun than they are coming from ours.
But hey, Gliese 667 Cc is right nearby, at a relatively neighborly distance away of 23.6 light years. And it’s at least conceivably similar enough to what we have on Earth for the sci-fi writers behind the “Alien vs. Predator” space thriller franchise to have named it the first planet people “terraformed,” or engineered to replicate Earth’s conditions.
How can this planet that’s so alien be one of the closest facsimiles to Maine? Well, consider that most Earth-like planets that have been studied have Arizona-like heat or near Antarctica-like cold — potentially habitable, yes, but they don’t have a relatively middle-of-the-road temperature like Maine.