The second planet from an unnamed yellow-orange star, located within Vorlon space, some fifty eight light years from the nearest (non-Vorlon) jumpgate. The planet was orbited by a single small moon with a few metal structures on the surface and a Vorlon jumpgate.
Larger than Earth but with fewer heavy elements, the planet was approximately the same mass and so had a gravity field of near enough one standard gravity, while the oxygen/nitrogen atmosphere was habitable for humans and similar lifeforms. The planet featured extensive polar ice caps, two large continents encircled by topaz coloured oceans and supported a diversity of environments including expansive regions of forest and savannahs.
When the Vorlons eventually bombarded the planet, some areas of landmass were obliterated right down to the bedrock, kicking up massive amounts of dust and debris into the atmosphere. The resulting massive environmental upheaval reduced most of the previously verdant landscapes into desolate, arid wastelands shrouded under heavy cloud cover. The topographical disruption caused by the massive impacts caused rivers and waterways to be diverted, flooding whole areas and rapidly forming new lake systems that quickly froze over as the planet's climate entered into a nuclear winter.
The Vorlons used the planet as a breeding ground and experimental station for thousands of years, beginning at least as early as 1 million years prior to the Third Age. Retrieving samples from a hundred worlds across the galaxy where they were cloned, bred, manipulated, experimented on and pushed towards an enhanced telepathic ability. The result was a population of docile, non-sentient humanoid creatures with staggeringly powerful telepathic abilities, at a level beyond which even the Vorlons could rate. Their function was to act as hosts for the telepath gene that could be extracted and gradually introduced into their sentient "cousin" races.
In early 2257, Kevin Vacit arrived at the planet after spending the last sixty odd years travelling at near relativistic speeds from the nearest jumpgate. Though the trip took over half a century to complete thanks the effects of time dilation, from Vacit's perspective it took less than a year of subjective time. Shortly after he arrived the Vorlons began bombarding the planet with clean fusion bombs, intent on exterminating their "Nephilim" breeding stock so that the Shadows - who had recently been prematurely awoken - wouldn't be able to get their hands on them. Vacit however, was able to utilise his hybrid Vorlon consciousness to direct the immense telepathic power of the Nephilim to save a small group of about a thousand, while making the Vorlons believe they had succeeded in their genocide.
Vacit lands and finds that at least one fusion reactor is still functional, buried deep underground along with some remnant Vorlon technology that consumed his ship to grow a series of telepathically controlled dome-like structures, able to provide heat, fabricate food and distil water. With the world to himself and the surviving Nephilim willingly obedient to him, he set about studying the Vorlon's experiments.
In 2265, after partially decrypting a time-locked datafile left behind by Vacit on the Ganymede Icehouse facility, a Psi Corps expedition lead by a Mr. Diamond arrived at the planet aboard a Cyclops class cruiser in search of a way to enhance telepaths as the Vorlons once did. They take an atmospheric shuttle down but their minds are quickly overpowered by Vacit and his Nephilim. A week or so later another expedition arrived, this time the Toreador, a ship owned by Michael Garibaldi and carrying the Telepath Resistance leader Lyta Alexander, intent on preventing Psi Corps from acquiring the Vorlon's secrets. The arrived to find the Psi Corps ship deserted in orbit, it's airlocks open to space, life support shut off, no trace of the crew and the computer logs completely wiped of everything since it departed from Io. They do note the missing atmospheric shuttle and a scan of the planet quickly turns up the neutrino emissions from a large buried fusion reactor and Vacit's domes along with the debris from a missing shuttle scattered across a 20 km radius, indicating it was destroyed at high altitude.
Again using the Nephilim, Vacit fools the newcomers, even Lyta, into believing that the Vorlons had succeeded in wiping out all life and then projected a telepathic image to make them believe that Diamond had arrived and killed Vacit before being shot himself along with all of his crew members. After Lyta and Garibaldi leave, Diamond pleads with Vacit to let his group go as well. Vacit tells them that he needs them there and they still have a lot of work to do