Alienobacterium proximus is a species of microscopic, unicellular, silicon-based, Parabacteriaceid organism native to Aeros. It first evolved around 233 million years ago in small landlocked ocean of the planet pre-terraforming. They are now widespread throughout the planet. While it is capable to produce energy through photosynthesis, it prefers to infect a host.

It was the very first extrasolar alien life form to have ever been discovered by humans. It was first discovered in 2063 when the spacecraft Egeria, the second ship to explore the Proxima system, landed.


Alienobacterium is a composite word of two words. Alieno (from Latin Aliena) refers to the microorganism being from another planet. Bacterium is used to describe its similarities to true bacteria. Proximus refers to its place of origin.


A. proximus is a rod-shaped, silicon-based, red colored bacteria-like microorganism native to Aeros. It is capable to produce energy autonomously through photosynthesis. It has lots of organelles for different tasks. It also has a very hard, rock like membrane primarily composed of titanium and silicone which protects it from pressure and it is resistant to high temperatures. Beneath its outer membrane, there's the intermediate and inner membranes. The intermediate membrane is composed of tungsten, which protects the inner membrane from burning. And the inner membrane works as an insulator, maintaining a constant temperature inside the cell.


A. proximus is a rod-shaped, red colored, parasitic Alienobacillid. It has a nucleoid where it stores DNA. It has a Camera (an organelle where energy is stored), a Convertus (an organelle where triazene is broken for energy), a Spiritum (where nitrogen and ammonia is collected), Industria Messorem (where sunlight energy is collected), Veas (metal tubes that send energy throughout the cell to different organelles) and a Dissolutrix (where metals are broken down and sent throughout the cell for use by the Veas).


It needs nitrogen and ammonia for photosynthesis. For energy it breaks triazene (H3N3), and to maintain organelles within itself it needs metals such as iron (Fe), gold (Au), zinc (Zn), zirconium (Zr), titanium (Ti), tungsten (W), yttrium (Y), lead (Pb), palladium (Pd), copper (Cu), polonium (Po), uranium (U) and plutonium (Pu).


It ingests large amounts of triazene from other living organisms and uses it for energy.


The Messorem absorbs sunlight and the Spiritum absorbs nitrogen (N2) and ammonia (NH3). It is then converted into triazene (H3N3) by the Convertus. The Dissolutrix breaks triazene. This releases energy, which is sent throughout the organism by the Veas. Excess triazene and energy is stored into the Camera.

Sexual reproduction

Like most life of Proxima Centauri e, A. proximus has 4 sexes. 


When a member of the species is ready to reproduce, it creates a protomorph (a shell containing aquavitae, a biological liquid). The protomorph is planted inside something solid. The protomorph waits for another member of the species to detect it and "insert" its DNA inside the protomorph in the form of a liquid. The more DNA the protomorph has, the more genetically diversified it'll be. For example, if only two members of two different sexes insert their genes, the offspring will have 50% DNA of each of those members. If 3 of 3 different genders insert their DNA the offspring will have 33.3% of each and if 4 of the 4 genders sow their genes the product will have 12.5% DNA of each member. If the offspring isn't fertilized at all, it will end up being a clone of the original parent cell, having 100% of its DNA.

Life cycle

When the offspring is ready to hatch, the protomorphic shell breaks and a fully formed A. proximus comes out. The new member proceeds to find a host. While doing so, it relies on photosynthesis for energy. However, this type of photosynthesis can only produce low amounts of energy and cannot produce any nutrients and cannot create a protomorph. Therefore, it must find a host before at least 110 years before the organelles suffer oxidation and break down. Once it finds a host, it extracts triazene and metals and absorbs them, and keeps doing so until its death. Between birth and death, it produces a protomorph, and the cycle starts again.



Initial map of Aeros made by the Egeria 

A. proximus is a highly adaptable organism. It is capable of withstanding extreme temperatures (from 765 °C to -270 °C), extreme pressures (up to 10.034 bars) and even the vacuum of space. However, it seems to thrive at 2 °C. It is terrestrial but prefers to infect a multi-cellular organism. It can survive underwater, but only for a few centuries, hibernating and going into pseudo-death if in such a situation.


Because it’s an alien life form, A. proximus along with other lifeforms had to be classified in an entirely new tree of life.

Species - Alienobacterium proximus

Genus - Alienobacterium

Family - Parabacteriaceae

Order - Exsuprales

Class - Alienobacilli

Phylum - Pseudobactera

Kingdom - Ultramicrozoa

Domain - Mononucleida

Origin and evolution

The small amount of native live on Aeros prior to terraforming originated thanks to abiogenesis. However, the exact origins of A. proximus are unknown, because their bodies are microscopic and therefore extremely hard to find their ancient fossils. But new fortunate excavations have revealed their long past. It seems to have first evolved roughly 233 million years ago, and it is thought to have shared a common ancestor or even be a direct ancestor of the now extinct Protozoa marittimus (an aquatic species) around 640 million years ago.



Tim Greerson walking on the surface of Aeros

It was first discovered by astronaut and biologist Tim Greerson who was aboard the Egeria spacecraft. When he landed on Aeros, he collected and studied samples in 2063. He was helped by his other four crew members. He stored several samples aboard the spacecraft. During the half year journey back to Earth he did several experiments on it, which are recorded in this wiki page. When he came back, he gave the samples to his fellow German astrobiologist Heinrich Bergmann who observed, described and named it in 2068.


  • There are 4 other species within the Alienobecterium genus: A. aerosensis, A. bergmanni, A. abacarensis † and A. primogenitus .
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