Pol

Lore & Background

In the lore of the Kerbal space program, Pol occupies a humble but essential niche. It is the first solid ground a Kerbal can set foot on after leaving Kerbin's sphere of influence and crossing the vast interplanetary void to Jool. Because it is the smallest and closest of Jool's moons, mission planners in the early days of interplanetary flight treated it as a shakedown: land, take a few photos, confirm the navigation stack holds up in Jool's gravitational well, and depart. The psychological weight of that first bootprint on a world orbiting a gas giant, however, made Pol a symbol of Kerbal ambition stretching beyond its home system.

Pol's airless, cratered surface tells a story of ancient bombardment. Without an atmosphere to burn up incoming debris, every impact left a scar, and over eons those scars layered into a dense mosaic of craters of varying sizes. The surface is geologically dead — no tectonics, no erosion, no weathering — so every feature is a fossil record of the early system's violence. Kerbal geologists who have walked its regolith describe the dust as fine, grey, and stubbornly clinging to suit boots.

The moon's strategic importance grew as Kerbal engineers developed the ability to refuel in Jool orbit. Pol became a natural logistics node: a place to stage landers, conduct EVA repairs, and calibrate instruments before the long, fuel-hungry transfer to Vall or the atmospheric entry onto Laythe. In fan communities, Pol is affectionately called 'the stepping stone' or 'the pebble,' and landing on it is considered a rite of passage for any Kerbal who aspires to the deeper Jool system.

Reader's Guide

Pol is the smallest of Jool's four major moons, with a radius of roughly 40 km. It has no atmosphere, no magnetic field of note, and a surface gravity so low that a Kerbal in a standard EVA suit can hop several meters with each step. The surface is a dense field of impact craters layered over ancient, undifferentiated basaltic rock. There are no named peaks, valleys, or geological formations of particular note — it is, in the words of one mission log, 'a very large gravel pit.'

Orbitally, Pol is the innermost major moon of Jool, meaning it can be reached from a stable Jool parking orbit with a modest retrograde burn. Because its gravity well is so shallow, the delta-v cost for both landing and ascent is minimal compared to Vall or Laythe. This makes it an ideal first target: you can practice your Jool-system navigation, confirm your fuel margins, and test your landing sequence without the penalty of a failed atmospheric entry or a long, expensive transfer.

The main hazards are mundane but real. The lack of atmosphere means no aerobraking is possible — you must use full propulsive deceleration. The low gravity makes precision control tricky; overshoot your braking burn and you'll find yourself in a wide, slow orbit that's harder to correct. The fine, electrostatically charged regolith will coat any exposed electronics, so plan for a thorough wipe-down before power-cycling instruments. And remember: with no atmosphere, there is no thermal buffer. Day-side surfaces can scorch while the night side plunges to near absolute zero. Shade management is your friend.

Pol is not a destination. It is a doorway. Treat it with the respect a landing pad deserves, and the Jool system will open before you.

Did You Know?

• Pol is the smallest of Jool's four major moons and one of the smallest solid bodies in the entire Kerbal solar system, making it a favorite target for early interplanetary test flights.
• Because Pol has no atmosphere, Kerbals cannot use aerodynamic braking to slow down; every approach must be fully propulsive, which makes fuel planning slightly more demanding than a de-orbit from Kerbin or Duna.
• The extreme low gravity on Pol means that a Kerbal in a standard EVA suit can achieve surprisingly high hops, making surface traversal feel more like slow-motion parkour than walking.
• Pol's position as the innermost Jool moon means it sits deep within Jool's gravitational influence, so the gas giant looms large in the local sky — a constant, banded reminder of how far you are from home.