Mass Effect Wiki
Mass Effect Wiki

Location: Milky WayStyx ThetaErebus System Fourth planet

Prerequisite: Noveria: Geth Interest (Mass Effect)


Chofen is an unusually small hydrogen-helium gas giant, with traces of sulphur and hydrocarbons in the atmosphere. The Alliance surveyor ship Ibn Battuta provided inconclusive evidence of hydrocarbon life in the atmosphere (over 1000 meters below the cloud tops), where pressure compresses Chofen's hydrogen into a liquid state.

Proof of life in the atmosphere would prove many long-standing theories. Unfortunately, only a probe with extremely expensive mass effect generators could survive the crushing pressure long enough to send back useful data – and the probe would be lost in the attempt. Simple expense makes investigation doubtful.


  • Chofen is too small to be a "hydrogen-helium gas giant" (William Hubbard, The New Solar System 4th ed, 1999; p. 194). In the amount of energy from the sun and in its radius, it is most like to Uranus. Hydrogen is not compressed to a liquid state in such an environment; instead, the hydrogen atmosphere merges with a water / methane / ammonia ocean.