Alien (The Man from Planet X)

This unnamed species of sapient humanoids need a life support system to operate in Earth's atmosphere. They are native to a rogue planet discovered entering the Sol System in 1951 and designated as "Planet X" by astronomers.

Biology
The aliens are humanoids who bear a Human-like body shape, but have notably large and hairless heads, also standing at a somewhat shorter stature than the average Human. Their heads have a perpetually sad or strained expression, unable to be changed, with large, constantly squinting eyes, and mouths that appear perpetually closed, only allowing them to communicate with humming sounds of musical tone. It is unknown how they eat if their mouths cannot open, but it is possible they take in sustenance other than solid food and liquid. The aliens cannot survive in Earth's atmosphere without a sealed suit, although it is unknown what their native atmosphere is comprised of.

Culture and society
Little is known of the alien society. When their planet was on the verge of extinction, they showed willingness to invade other inhabited planets in order to have a place to live, but also appeared to have been willing to peacefully coexist with other species, as they only turned to invasion and mind-control when they met hostility. Alien scouts, while known to first draw their weapons on members of other species, are also known to attempt to communicate with said members of other species if friendly contact is established, using a gesture that involves holding out their hands, although the meaning of the gesture is unknown. Due in part to their expressionless faces, aliens rarely display emotions, and are known to simply stand stoically when being addressed. As mathematics are a universal constant, and the aliens have a more advanced understanding of the concept than Humans, they are able to communicate with members of other species through mathematics.

Technology
Aliens have technology more advanced than Earth's, including interplanetary spacecraft and anti-gravity technology capable of moving entire planets. Alien spacecrafts, meant for one occupant, consist of a spherical main body with three landing gear legs on its underside and a cone protruding from its top, like the tip of a rocket. The main body has some portholes that can open up, a satellite dish shaped like target symbol, and interior lighting that pulses sickly green. Their spacecraft can also serve as the control and anchor point for alien teletransports, which can teleport entire armies between planets. Alien atmospheric probes utilize a propellant similar to Earth's rocket fuel, with the probes themselves shaped like tiny rockets and emitting lightning-like flashes as they fly.

Alien spacecraft hulls are made from a material far stronger than steel, but 50 times lighter, and the glass in spacecraft portholes is far tougher than any Human-made glass, unable to be cut by diamond, although military explosives are still capable of destroying alien crafts. Alien spacesuits consist of a dark flexible body suit with an armored torso, with a large, round, clear fishbowl-like helmet. In the front of the helmet, in front of the wearer's mouth and nose, is a tube connecting the helmet to air tanks on the wearer's backs, the airflow being regulated by a valve on the aliens' left shoulder. Also on the helmet is a black device connected to an antennae, presumably for communications and also connected via wires to headphone-like earpieces the aliens wear. On the chest of the wearers is a large, rectangular device of unknown function bears a circular light on its center, and also serves as a holster for alien pistols, which are connected to the device with a wire, possibly for power. Said alien pistols have a long, thin barrel, and have never been seen in use by Humans, so their destructive capabilities are unknown. Alien spacecraft also carry a device on them that is capable of firing energy beams that can mind-control other beings, such as Humans, making them entirely subservient to all commands given to them, although the effect wears off after a few hours if not reapplied.

History
Sometime before 1951, the homeworld of the aliens was dying and freezing over, possibly the result of their sun dimming, threatening to kill all life on the planet. In need of a new world, the aliens used an anti-gravity system to move their planet out of their system on a course to fly by Earth, using the same technology to not disturb the orbit of Earth or any other planets in the Sol System. Their planet was seen approaching by Humans, and dubbed Planet X. Both the Humans and aliens determined the location where the planets would be the closest together when they crossed, planning to use teleporters to beam them down to Earth. The aliens sent an atmospheric probe to the Scottish moors, which would be the place of closest contact, and shortly afterwards, sent an alien scout to the moors. The alien's ship was found by a woman named Enid Elliot, who saw the alien through the porthole and was scared off. Shortly afterwards, reporter John Lawrence and Professor Elliot, Enid's father, went to investigate the ship, where the alien exited the ship and confronted them with its pistol drawn. However, the alien's air supply was improperly regulated, and it began to suffocate, unable to turn the valve to increase the gas flow, but it is saved by the Humans, who see what it was trying to do and turn the valve for it. Recognizing that the Humans had helped it, the alien put its gun away and stood up, extending its hand in an apparent gesture of friendliness and making humming sounds, but the Humans were still unable to properly communicate with it. When the Humans tried to leave, returning to Professor Elliot's observatory, the alien followed them.

In the observatory, which was once a medieval castle, the alien was brought to the dungeon, where the Humans kept trying to communicate, finding all communication attempts failed, as the alien only responded with the same gesture and humming sounds. Dr. Mears, an overly ambitious scientist who worked with Professor Elliot, soon realized he could use the alien for his own gain after examining the atmospheric probe. He and Professor Elliot continued their communication attempts, until they realized that they may be able to communicate with mathematics, specifically through geometry. Despite John's protests, Dr. Mears was left alone with the alien, managing to establish communication through the complex formulas. The alien presumably told him of its homeworld within the dungeon, but while it was reading over another formula Mears gave it, Mears abruptly attacked the alien, turning its regulator valve to cut off its air supply, wanting to use the alien's formulas for their spaceship hulls to dominate Earth's industries. Dr. Mears was then called away by Professor Elliot, who was falling ill, leaving the alien behind, assuming it couldn't recover. However, the alien managed to stay conscious enough to reopen its air flow, and now deeming Humans a threat, prepared to call down an invasion force, kidnapping Enid when she entered the dungeon and taking her back to its ship, also moving its ship to a new position.

The alien then cut off the communications from the nearby seaside town, and began kidnapping men from the town and exposed them to its ship's mind control ray, using it to make the Humans build its teletransport device. The alien then kidnapped both Dr. Mears and Professor Elliot, adding them to the workers, but was unable to find John, who met with the town's constable and managed to use a heliograph to contact the mainland, summoning Scotland Yard and a garrison of the British army. The moment of Planet X passing by Earth was close, with the alien armies ready to be deployed, but John managed to free the mind-controlled Humans, including Enid, Mears, and Elliot, by giving them commands to leave for the garrison. The alien, realizing all the Humans had left, exited its ship to investigate, but John grabbed it from behind and disabled its air flow again, before fleeing to let the army begin their bombardment. The alien managed to reopen its air flow once more, and as the army began shooting explosives at the ship, also killing Dr. Mears as he desperately tried to reach the alien again, the alien started to activate the teletransport device. However, the army managed to destroy the ship and the alien before Planet X could reach its closet point. Without the teletransport device, the alien armies were unable to reach Earth, and Planet X passed by Earth, flying off into deep space.

As they were unable to reach Earth, it is possible all the aliens died off, assuming they were unable to find another world to inhabit. Although the alien's actions were hard to interpret due to its inhuman nature, Enid and John later thought about how the alien's initial interactions were seemingly friendly. They speculated that if Dr. Mears hadn't attacked the alien, things may have played out differently, as John recognized that while it was entirely possible that the aliens would have been a curse on Humanity, it was also possible that they could've been Earth's greatest blessing.

Appearances

 * The Man From Planet X (1951)