5 Places in the Solar System Where Life Might Be Found

5. Mars

Mars has been home to extraterrestrial life in our imaginations since the earliest days of science fiction. Percival Lowell believed that the canali described by Schiaparelli were canals built by an advanced Martian civilization. H.G. Wells wrote of a Martian invasion of Victorian England.

Although the Viking landers showed us an apparently lifeless Martian surface, it is possible that Mars once supported life, and may yet do so. After all, it possesses a (thin) atmosphere, essential nutrients, and fairly abundant solar energy. There is evidence that water ice is abundant, and that liquid water once flowed across the surface. Might there be Martian microorganisms hiding beneath the surface, protected from the harsh chemicals and UV radiation?

4. Titan


After Mars, Saturn’s moon Titan may be one of the most popular places in the solar system for speculation about alien life over the past several decades. Observed by Pioneer 11 and Voyager 1 only as a hazy world surrounded by an opaque atmosphere, the Cassini probe and Huygens lander provided much more information about Titan.

Though too cold for liquid water, Titan’s surface is covered by lakes of hydrocarbons. Its atmosphere is mostly nitrogen, along with methane and other hydrocarbons. This has led astrobiologists to speculate about life forms not based on water, but instead using methane or ethane as a solvent.

3. Europa


This moon of Jupiter possesses a subsurface ocean, kept liquid by the heat from tidal forces exerted by Jupiter. This same tidal flexing could create undersea hydrothermal vents, and there is evidence to suggest that the ocean is in contact with a rocky surface. The presence of a liquid ocean, coupled with an energy source in the form of undersea vents, and a rocky undersea surface as a source of minerals, suggests that Europa is a place that could support life.

Proposals have been made for exploration of the Europan ocean, but the high-radiation environment around Jupiter, difficulties involved in boring down to the ocean, and concerns about contaminating the moon with Earth life have prevented such a mission so far.

2. Pluto


Yes, the poor non-planet at the edge of our solar system could potentially support life.

Pluto possesses a very thin atmosphere of nitrogen, methane, and carbon monoxide, and though it was once thought that the atmosphere would freeze when Pluto was farthest from the sun, scientists now believe that it remains gaseous throughout Pluto’s orbit.

Additionally, the New Horizons probe revealed the existence of tholins, a type of organic compound, on the surface of Pluto. If the extreme conditions of the surface make it uninhabitable, life might still exist deep beneath the surface, in a possible sub-surface ocean.

It should not be surprising, then, that science fiction writers have from time to time picked Pluto as a potentially life-supporting world.

Honorable Mentions

  1. Venus – Once imagined as a lush jungle world, we know now that our sister planet suffers from a stifling atmosphere with clouds of sulfuric acid and surface temperatures that can melt lead. Still, extremophiles do exist on Earth, and some speculate that life might survive high in the atmosphere of Venus.
  2. Ganymede – Another of Jupiter’s moons, Ganymede is suspected to harbor a subsurface ocean with more water than all of Earth’s oceans combined. Might something be swimming beneath the surface of this largest Galilean satellite?
  3. Jupiter – Hard as it might be to imagine life on a planet with no solid surface, Carl Sagan speculated that balloon-like organisms might float on the Jovian breezes, consuming microorganisms likewise swept around by the gale-force winds. Concept art was even created for his legendary Cosmos series.
  4. Earth. Ok, this one is a cheat. Not only does the third rock from the Sun support life, we’re also fairly certain that there’s intelligent life to be found here. Somewhere. If you’re searching for life in the solar system, Earth is your safest bet.

1. Enceladus


En-what? Enceladus, one of the larger moons of Saturn, is yet another world possessing a subsurface ocean. Observations by the Cassini spacecraft suggest a geologically active world, with geysers containing hydrocarbon compounds and indicating the presence of a high-pH ocean.

Though highly alkaline and buried deep within the moon, scientists speculate that this ocean may provide the energy sources and support the complex chemical reactions needed for life to form. Life on Enceladus may be powered by chemosynthesis, with hydrothermal vents being a source of chemical energy for the Enceladan microbes.

Incidentally, if you are ever uncertain about pronunciation, Space.com has a handy guide for pronouncing the names of all the planets and moons in our solar system. Yes, even the eighth planet…



It was too late to turn back — for all of them. Three weary explorers stared out the porthole as the spacecraft A Shot in the Dark hurtled toward Comet 266P/Christensen.

“Collision course set,” announced Michelson as the main rocket engine died. “That’s the last of our fuel.”

Dr. Grigori stared out at the stars.

“What should we tell Earth?” Dr. Markova asked.

Michelson shrugged. A world now plagued by climate shifts, mass extinction, and natural disasters too numerous to list needed hope, not more bad news.

It had started decades prior. A mysterious radio signal from the stars. “Wow!” writ large in the margin by a grad student. Astronomers worldwide tuned to 1420 MHz, but heard only silence. For decades they wondered: was the Signal merely radio noise, or the first evidence humankind is not alone?

The mystery deepened: the Signal returned, and Comet 266P/Christensen was pinpointed as its source, but against expectations, the Signal showed hints of advanced intelligence. So billions of dollars in venture capital funded A Shot in the Dark — a one-way mission of discovery. Investors dreamed of alien technologies to save the world and pad their bank accounts. If successful, the crew would be hailed (whenever future investments could fund a rescue mission) as heroes by a world desperate for hope.

But just before arrival, Dr. Grigori made a horrifying discovery. “The Signal is not from the Comet; the comet’s halo merely reflects and amplifies it.”

“From where?” Michelson asked.

“Are you familiar with the Gaia Hypothesis?” asked Markova. “That Earth is essentially a single, unified organism?”

“Decades of pollution,” muttered Grigori. “Neglect. Abuse.”

Markova looked grim as the Signal played over the speakers. “This Signal,” she explained, “is the death rattle of Planet Earth.”

Written for Cracked Flash Fiction, Year 1 Week 38, where the prompt was the first sentence of the story. This story references the famous Wow! Signal, along with recent (at the time) articles suggesting that the signal may have originated from two comets.

Dashiell vs. the Dragon Invaders, Chapter 3

The mottled orange face of the alien sun loomed large in the viewscreen. Sweating bullets and gasping for breath, Dashiell pressed his browline glasses back up his nose. Blood dripped from the clawmark across his chest. “Just a scratch.”

Leaning against the cryogenic conduit to cool himself, Dashiell checked his .38 revolver. “One bullet left.”

With a crash, the hatch deformed visibly, struck by some awesome force. “I may be a washed-up pulp writer,” he shouted, “but I’m a fighter.” Razor claws forced the hatch open. Dash took aim as the reptilian entered. “Somehow I’ll get back to Earth. Then I’ll let everyone know aliens are real.”

The quadrupedal alien approached deliberately, licking its lips. He backed away. “They say write what you know. Want to hear the title of Dashiell Pendragon’s next bestseller?”

The creature lunged at him, seeming to soar through the air. Leaping aside, Dash took aim and squeezed the trigger. The bullet whizzed past the reptilian’s crested head, striking the cryogenic conduit.

As liquid oxygen gushed onto the scaly beast, it writhed in pain. Dashiell covered his ears to muffle its death shriek.

When it fell silent, Dashiell prodded the lifeless alien’s face with the muzzle of his revolver. “Slaying the Dragon.”

Winner of Flash! Friday vol. 3-29! Photo: Buster Crabbe as Flash Gordon. Studio promotional still photo 1936, public domain.

Navajo Street Spaceport

A Flash! Friday vol. 3-23 entry. The prompt is to set the story downtown, along with the public domain photo shown.

“A thousand years ago, my people lived on these lands.” From the downtown street corner, the shirtless drifter shouts at passers-by. Humans and aliens alike ignore him; walking, slinking, and slithering past him toward the great marketplace across from the spaceport. There they trade in cultural trinkets, speak inscrutable tongues, and give no thought to the native inhabitants of this land.

“Today, no remnant but a name on a street sign, corralled by the towering skyscrapers. An ignoble tribute to a proud people.” He sighs wearily and plops down onto the curb. A medusoid creature shuffles around him into the crosswalk, in defiance of the “Don’t Walk” sign flashing in five galactic languages. Hovercars honk their displeasure at the jellyfish alien. I toss him some spare credits before entering the market.

Throughout the market square stand the Statues of the Fallen: a gallery of peoples subjugated and defeated. Khmer and Celt, Inca, Aborigine. Even the vagrant’s own Navajo nation. In the center, amidst the merchant tables of the trading post, stands an empty concrete pedestal: waiting patiently for the next to fall. Climbing upon it, I look around at the sea of faces, terrestrial and otherwise, and wonder which will be the next to stand here.

Universal Translator

Day 21 of the A-to-Z challenge. U is for Universal Translator, a vital but invisible part of most science fiction. Because Star Trek just wouldn’t be the same if Captain Kirk had to woo green alien women with the aid of an intepreter.

“Sorry to call you out here so late, Colonel. We’ve had a significant breakthrough.”

Colonel Loess glanced at his reflection in the mirror. He combed his disheveled hair with his fingers, then rubbed the scruffy stubble on his chin. He noticed that he’d missed a button on his uniform jacket: he buttoned it and patted the bulge in his pocket. “Not a problem, Doctor Gaines. I was just in my recliner with an old book and a glass of wine. What have you found?”

Gaines tapped an unusually long password into her laptop, then opened a gallery of images. Photographs of twisted metal, blackened but inscribed with bizarre glowing curvilinear glyphs. “You’ll remember these images?”

The Colonel nodded solemnly. “Wreckage from the alien craft. I still have those odd pictograms burned into my memory.”

“It took the cleanup crew weeks to sift through the rubble. When the alien ship crashed, it leveled four city blocks and–”

“I remember, Doctor. Your linguistics team has made a breakthrough?”

“Right.” She opened another application on her laptop. “Based on the pictograms, we’ve come up with a translation system. The alien pilot can draw on this touchscreen…” she demonstrated by tracing a circle and three lines on the screen. “And this application will display an English translation.” On the screen, the word emergency displayed in large white letters.

“It will also translate spoken English into pictograms,” continued the Doctor. “We’re ready to try it.”

“Good. Give me the laptop and open the airlock door.”

Doctor Gaines placed her hand on the Colonel’s shoulder. “Sir, are you sure…?”

“I can handle this,” Colonel Loess assured the doctor, taking the laptop and stepping into the airlock. The outer door of the alien isolation cell closed, the inner door opened, and the Colonel stood face-to-face with the alien pilot. He inhaled sharply: this was the first time he had seen the unearthly being without the barrier of the one-way mirror between them.

The alien pilot stared at him with its unblinking black eyes. Its wounds had healed in the month since the crash, so that the scars on its grey skin were barely visible.

The Colonel faced the touchscreen laptop toward the alien. He tried to draw the same glyph that Gaines had drawn, but the translator application choked on his lopsided circle and three wavy squiggles. “Write,” he said aloud to the alien being. The laptop microphone detected his speech and flashed a glyph on the screen. “Do you understand me?” More alien pictograms appeared on the screen.

With two spindly fingers, the alien drew on the touchscreen. “Yes.”

“Why did you destroy our city?”

“Accident. Engine failure.”

“Many of our people died when your reactor exploded.”

“Regret.” The alien’s stiff face seemed structurally incapable of expressing grief.

Colonel Loess swallowed hard, trying not to tremble. “My wife,” he said, his voice breaking. “My wife. My daughter… my baby girl. They were killed in the crash.”

“Sorrow. Deep sorrow.” The alien reached up and patted the Colonel lightly on the shoulder before returning to the touchscreen. “Forgiveness, please.”

In a swift motion, Colonel Loess reached into his pocket and withdrew a revolver. He pressed the barrel against the alien pilot’s chest and squeezed the trigger. From behind the one-way mirror, he heard Doctor Gaines screaming. The extraterrestrial creature in front of him fell backwards, thick blue liquid oozing from the bullet wound in its chest. It lifted its scrawny arms as though to defend itself.

“No forgiveness,” the Colonel said coldly. “I just needed you to know why I was killing you.”

He waited just long enough for a jumble of alien pictograms to appear on the laptop screen, then emptied the remaining five shots into the creature’s head, then turned around to be met by a team of armed MPs at the airlock.

Jansky Noise

This story serves double-duty. For Flash! Friday vol. 3-18, the prompt is to include a spy, along with the shown CC2.0 photo by Foto Michel. For day ten of the A-to-Z challenge, J is for Jupiter brain, a megastructure the size of Jupiter, designed for tremendous computational capabilities.

I was nervous about my first visit to the oracle, but I had a mission. With only a few coins, I entered the noisy bazaar.

“Spare some change?” The panhandler shook his cup at me, so I tossed him some platinum. “Jupiter happily helps he who helps the needy. You seek wisdom?”

“How can I decrypt the Zoephage communications?” The Geminga Confederation had not known war in over two centuries when the Zoephages turned three border worlds into grey goo. Now it fell upon the Spy Corps to discover some weakness in our nanoscale enemy. A trillion human lives, from Earth to Antares, depended on us.

“Their communications are encrypted by one-time pad.” My heart sank. OTP encryption was uncrackable without the random shared key. As I turned to leave, I gave him my remaining coins.

“Thank you kindly for sharing with a random stranger,” said the hooded Oracle of Jupiter.

Suddenly I realized: the swarms of Zoephages needed to share a random key across a dozen parsecs. The most accessible source of randomness was Cosmic Microwave Background fluctuations. And the Spy Corps kept detailed recordings of the CMB. Smiling, I rushed to purchase my ticket back to headquarters. Random does not mean secret.

Sagitta Struck

Another Flash! Friday two-fer. The prompt is still a parking lot, along with this CC2.0 photo by Tanakawho.

I stood my ground upon the fresh asphalt. Here I would make my stand, bold as the white paint that striped this parking lot.

My journey had taken me across the known universe. I had trod barren planets beneath the million suns of a globular cluster, felt vertigo in the darkest intergalactic voids, and seen supernovae of unsurpassed brilliance.

In that time, I had learned everything except how to escape her.

She emerged from the metal sphere and immediately assumed human form to mock me. “You cannot beat me,” she taunted.

I shrugged. “Then I will not fight you.”

Now I had come full circle, falling backward through aeons of time, to Earth, to a hospital parking lot, on the very night of my birth.

“Pathetic.” She drew an ethereal weapon that transformed into a bow, then took aim with a strangelet arrow. With the merest flick of her fingers, the assassin in the Coalsack dress loosed the lethal projectile.

It struck me square in the chest. I collapsed, embracing the smooth pavement as strangelet matter consumed every atom of my human body from within. As she stood victorious over me, I laughed defiantly. Somehow, deep in my soul, I knew I was only going home.

The Date the Earth Stood Still

A Flash Friday! two-fer. The prompt was girl next door, along with this CC2 photo by Scott Ableman.

“Why so glum, Kelsea?” her manager asked as he wiped down the high top tables.

“I’unno.” she sighed, leaning against the bar during the mid-morning lull. “I guess I just thought Washington would be more exciting.”

“Exciting? Kid, we have power players coming through every day. That ain’t exciting enough for ya?”

She shrugged. “They never notice me. Except Half-Caff Soy Latte who complains that I’m too slow.”

“What about that saucer?” he nodded toward the South Lawn, where the shiny metallic disk still stood motionless near the White House on its three spindly legs. “That’s pretty exciting.”

“It’s just sitting there. Besides, any aliens are gonna talk to the President. I’ll never even see any little green men.” It took her a minute to realize that her boss’s gaze was fixated out the window. A creature approached, short, green-skinned, with a bulbous head and tentacles.

The alien being entered the coffeeshop, followed at a distance by soldiers, Secret Service, reporters, and awed onlookers. Its mouth tendrils trembled as it waddled up to Kelsea’s register and stared at her with bulging black eyes. Then it spoke in perfect English.

“Hi. I’ve seen you around, and… would you go out with me?”

A Dragon, Unmasked

Written for Flash! Friday vol. 3-3. This week’s prompt was this image by IQRemix.

His eyes aglow behind the mask, young Long rushed breathlessly toward the celebration. Since time immemorial, the Fire People had celebrated the Blood Moon Festival with the brightly hued masks of their vanquished foes.

How sad that the Draco are gone, thought Long as he circled the bonfire. Flames leapt skyward as masked revelers danced around it. So alien, yet so noble.

Though little was known about them, Long had spent many a lonely hour in the library, poring over frightening legends and imagining the stories of the planet’s aboriginal inhabitants.

I understand them better than anyone. Fiery. Passionate. Nearby, a lovely woman in a bright orange mask danced, swaying in rhythm to the music of the band.

Long pressed his feathered mask to his face. Uncertainty left him like smoke in the wind. With a confidence wholly alien to the meek young boy, a bold Draco warrior approached the woman and asked her to dance.