Saturday, October 4, 2025

Eros, the site of the protomolecule experiment, in "The Expanse" TV series

Eros is the second-largest near-Earth asteroid located in the inner Asteroid Belt with dimensions of about 34 km × 11 km × 11 km, giving it an irregular, potato-like shape. It's notable as the first asteroid discovered to cross Mars' orbit, and it has been visited by NASA's NEAR Shoemaker probe in 2000, which orbited and landed on it, providing detailed images and data about its surface composition, primarily silicates and metals.

In the universe of The Expanse TV series (a political hard sci-fi drama set in mid-24th century when humans have colonized the entire Solar System), Eros hosts Eros Station, one of the earliest and most bustling outposts in the Belt. It's a major hub for shipbuilding, repairs, and entertainment, with a population of around 100'000 people. The station is spun up to create artificial gravity through centrifugal force, with levels built so that "down" is toward the outer hull, providing about 0.3g – enough for comfortable walking but still a challenge for Inners unused to it.

Eros asteroid in 'The Expanse' TV series

Unlike the more industrial Ceres, Eros is known for its lower docking fees and vibrant underbelly, featuring casinos, brothels, and shooting galleries that attract crews looking to blow off steam after long hauls. It's described as the "birthplace of the Belt," where early colonists turned raw ore into the skeletons of the first spaceships, though over time, much of the heavy shipping shifted elsewhere. The docks are clustered in five main areas, with old shipyards jutting out like massive spiderwebs of steel and carbon lace, dotted with warning lights and sensors.

Eros plays a central and tragic role in the early story of The Expanse, particularly as the site of the infamous Eros Incident. Security on the station was initially handled by Protogen, but they pulled out and installed a puppet firm to oversee operations. This was all a setup for a massive experiment with the alien protomolecule, which was unleashed on the population as a weapon test, leading to horrifying mutations and the station's eventual takeover by the entity.

Here are some shots of Eros and Eros Station exteriors from the show:

Eros asteroid in 'The Expanse' TV series
Eros Station docks:
Eros Station docks in 'The Expanse' TV series