The Soell system is the setting for the discovery of Installation 04, the first Halo ringworld encountered by humanity.
This visualization maps all nine of the system's planets, centering on the massive violet gas giant Threshold and its primary moon, Basis. The Alpha Halo ring orbits in the lagrange point between the two, a testament to Forerunner engineering that spans the width of the system.
A massive, exceptionally bright B-class blue giant star that anchors the Soell system.
The innermost planet of the Soell system. It is a small, scorched terrestrial world baked by the blue giant.
A small natural satellite orbiting Soell I.
A small, moonless terrestrial rock.
A tiny, heavily cratered planet orbiting with two small satellites.
A terrestrial planet orbiting in the intense heat of the inner system, accompanied by three moons.
A terrestrial planet with a slight ovoid shape, likely caused by extreme tidal forces or a rapid rotation.
A relatively sparse asteroid belt separating the inner terrestrial worlds from the outer giants.
The first of the outer planets, a large, ringed gas giant orbited by five moons.
A massive Jovian world with a liquid hydrogen core. Its purplish-orange tendril-like clouds are composed of white ammonia, amber ammonium hydrosulfide, and phosphorus, whipped by raging storms and winds reaching hundreds of kilometers an hour.
An extensive band-like network of Forerunner gas mining platforms and refinery stations hanging in Threshold's upper atmosphere.
An expansive automated facility hanging from the suspension grid. Originally designed to mine hydrogen, helium, and methane, it was retrofitted to research the Flood and later occupied by Sesa 'Refumee's heretics.
An unknown Forerunner space station in high orbit over the gas giant, cataloged by the UNSC as Deep-Space Anomaly 0198.
A Forerunner ringworld megastructure suspended at the L1 Lagrange point between Threshold and Basis. From its surface, Threshold occupies nearly 1/3 of the sky.
The wreckage of the Halcyon-class light cruiser that made a blind slipspace jump to this system, inadvertently leading the Covenant to Installation 04.
One of eleven minor satellites orbiting Threshold. Positioned just outside the atmospheric suspension grid, it hosts automated Forerunner maintenance facilities.
A tightly orbiting satellite. Scans indicate hollowed-out subterranean Forerunner architecture beneath its cratered surface.
Clustered dangerously close to Minor II. Deep-penetrating scans reveal a hollowed-out interior filled with dormant Forerunner maintenance drones.
Orbiting just past Installation 04, telemetry indicates this "moon" is completely artificial—a camouflaged Forerunner facility covered in rock.
A jagged, metallic rock. It emits a faint, repeating Sentinel control signal toward the Halo ring.
Threshold's largest natural satellite. Its gravitational interaction with the planet was used by the Forerunners to stabilize the Halo's orbit.
Unlike most of Threshold's satellites, this moon is completely natural. It is a dead, cratered rock caught in a resonant orbit with Basis.
A tumbling chunk of debris containing an inactive Forerunner slipspace telemetry beacon.
A smooth, unnaturally round satellite drifting in the outer system. Its subsurface architecture suggests it was once a material refinery.
A frozen satellite that acts as a stealth-baffled armory, likely meant to supply Sentinels during a Flood outbreak.
A heavily irradiated rock making a massive, lonely orbit. It hides a dense Forerunner power relay core at its center.
The outermost minor satellite, drifting nearly 8 million kilometers out. Like Minor VI, it is completely natural and devoid of Forerunner technology.
The eighth planet is a shattered, rocky world, possibly the victim of an ancient cataclysm.
A large, cratered terrestrial planet. It has a highly elliptical orbit that occasionally brings it closer to the sun than the eighth planet.