Last month we looked at some really strange planets astronomers have discovered outside our solar system. Which prompts a question: Could some of the odd planets known to science fiction exist in the actual universe, given its laws?

How about Tatooine from Star Wars which orbits “two scorching suns”?

Part of a binary star system, the planet orbited two scorching suns, resulting in the world lacking the necessary surface water to sustain large populations. As a result, many residents of the planet instead drew water from the atmosphere via moisture farms. The planet also had little surface vegetation. It was the homeworld to the native Jawa and Tusken Raider species and of Anakin and Luke Skywalker, who would go on to shape galactic history. – “Tatooine,”Star Wars Fandom

A meteorologist and physics student ventures an answer:

What would life be like for those living in a multiple-star system? Let’s once again start with something like Tatooine, in a binary system. As the most simple system, with a circumbinary orbit, it is quite stable. Provided that the orbit is not crazy, the next criterion is habitability.

So far we know from the Kepler Mission that more than 2100 multiple star systems, mostly binaries and some triple star systems, exist. In this list, around 8% of Kepler’s detections have a planet-hosting system. Kepler 64 is one in a quadruple system. Very recently, the Gaia dataset from the European Space Agency showed even more stars that could be in binary systems.

In 2014, Müller and Haghighipour calculated the different habitable zones for some of the multi-systems found by Kepler. The results rely on each star’s radiation reaching the exoplanet’s atmosphere. This leaves two regions of the habitable zone: the narrow habitable zone, where the greenhouse effect protects the planet from freezing, and the empirical habitable zone where the planet’s climate could range from Venus-like to early-Mars-like — i.e. it could be really hot and brutal or an environment that could reasonably sustain liquid water.

Paula Ferreira, “Is it possible for planets to orbit multiple star systems like in sci-fi?” at ZMEScience (June 17, 2022)

So it’s possible. But if we are thinking of life-hosting planets, the issue is finding the habitable zones. Ferreira doesn’t think that the planet Lagash, portrayed by Isaac Asimov (1920–1992) in Nightfall (1941) stands much of a chance in real life. It was orbiting a number of stars:

What about planets that consist entirely of living matter or their byproducts (biomass) — like Mogo, the sentient planet in the Green Lantern comics or the (exo)moon Pandora in Avatar (2009), whose many life forms are united by a global consciousness? Yes, science writers have thought of that too. Adam Hadhazy is doubtful because a planet couldn’t start out as alive. He also thinks that competition would prevent anything like the unity required for a global consciousness:

Competition between species also makes a sentient planet seem like quite a stretch.

Picture any ecosystem on Earth, such as a pond, a forest, a desert. In these environments, critters (and plants) compete for limited resources of food, water and territory in order to survive and make more of themselves.

“If you think about what life is, it has three directives,” explained [paleontologist Peter] Ward. “It has got to metabolize in order to get energy, it has to reproduce and it has to evolve, otherwise it’s a crystal and it’s not life.”

Not only do species compete against others, but the individuals within a species usually try to outmuscle their peers. Consider the fights between fiddler crabs for real estate on the beach, or rival wolf packs over prey.

All in all, creatures are not programmed to begin cooperating together like the cells in an individual’s body. “With natural selection, someone lives and someone dies,” said Ward. “How do you go from many organisms competing to one great thing which doesn’t compete?”

Adam Hadhazy , “Science Fiction or Fact: Sentient Living Planets Exist” at Live Science (March 30, 2012)

Yet Ward and Hadhazy acknowledge that “one great thing which doesn’t compete” is precisely the social organization that social insects create — and they are easily the most successful groups of insect species on Earth. However, if a single hive consciousness were to span an Earth-size planet, the principal problem would be a practical one, SETI astronomer Seth Shostak says — what about the speed of communication over long distances.

However, life forms on our own planet are so varied that it may be best not to rule out a global consciousness/hive mind on a planet where conditions favor its development.

Meanwhile, here’s a list of the 10 best science fiction planets (as of 2008) from Discover Magazine, including Solaris (1961), created by an apparently defective god. “You may or may not have liked the films, but Stanislaw Lem’s conception of a world so utterly alien that it defies any genuine human comprehension still resonates”: Note: You can see a trailer at the link; the film is age-restricted. It’s not clear how any life forms could stay alive in a world so utterly lacking in underlying order, pattern, or design as the author describes.

And here are the Star Name Registry’s top fifteen fictional planets, including “One of the more interesting worlds we saw, was Coruscant, an Ecumenopolis (planet wide city) that served as the political, cultural, and economic center of the Star Wars Galaxy before the Empire took over. We spend a lot of time on Coruscant in the prequels and it helps give those films a focus, that is essential in it’s more politically charged”:

Hmmm. If you are a nature lover, Coruscant is definitely “a nice place to visit but … ” Ecology anyone?

Tor.com offers some “truly inhospitable” science fiction planets — in the unlikely event we will run short of truly inhospitable real life ones: “Sue Burke’s Semiosis (2018) begins promisingly enough; a community of idealists sets out to found a new society far from Earth’s violence. Their problems only begin when they wake to find themselves orbiting the wrong world, which they optimistically name Pax. Older than Earth, Pax is home to a rich, diverse biosphere. It’s a world that offers the naive settlers a bewildering range of ways to die. Survival depends on convincing the dominant lifeforms that humans are worth the bother of preserving. That, in turn, depends on humans recognizing those dominant lifeforms for what they are.” (It’s not a film yet but we’re hoping… )

And finally, here’s a list of the many, many planets in Star Trek, including “Ardana – Third planet orbiting the star Rasalas (Mu Leonis A). A Federation member in 2268, despite then supporting two widely disparate castes; the privileged upper-class lived in the city of Stratos, considered the finest example of sustained anti-gravity elevation in the galaxy, while the lower-class “troglytes” were forced to stay on the surface and mine zenite. ” More at Fandom.

Perhaps the strangest place in the universe is the human imagination after all.

You may also wish to read: Among 5000 known exoplanets, there are some really strange ones Planets so strange that they prompt a rethink of the “planetary rulebook.” To sum up, whatever we see or read about planets in science fiction, something out there is likely stranger still.