Zeronus

Zeronus is a presumably ISA controlled colony that is not directly mentioned in the Killzone games, but it appears on advertisements in the Vektan Slums.

Prior to the Second Extrasolar War
On the poster is a background of the planet's surface which appears to be covered in large, beautiful beaches and jungles; separating the beaches and the jungles are cliffs, making Zeronus a large tourist destination.

The quote of 24 hours of sunlight implies that Zeronus is either a gimmick or the colony is a moon in locked orbit around a gas giant.

Prior to the Second Extrasolar War was known as a tourist planet that was founded by the ucn in the year 2115 having to be the most ancient of the earth colonies Zeronus what's considered the most peaceful out of all Earth colonies to never suffer from a depression economic crisis or any forms of disasters it was stated that the planet's ecosystem was so beautiful that hardly prevented any acts of violence between the residents who lived on the planet since 2115.

The planet was discovered by earth explorer Jared Articus Zeronus who accidently crash landed on the planet following a fatal asteroid collision in 2105, where as a result a being rescued he would return to the planet in order to claim it for his own, until 2113 where he would eventually share it with the public.

It was stated buy the ones trapped, that even while trapped on the planet neither of them including Jared himself didn't feel like leaving, as the planet contained enough food and nourishment to basically live on.

Zeronus was eventually colonized and completed by 2115 wear as a result, the planet was made into a tourist vacationing resort where despite this, the planet was also used as a major residential world similar to Earth and many of the other colonies which would eventually follow suit a century later.

From the 22nd century all the way up to the 24th century Zeronus was never once hit with a disaster or an attack at the time of prior, during, or even after the events of the First Extrasolar War era, and was never even targeted by the Helghast it wouldn't be until the 24th century after the invasion of vekta in 2357 when Zeronus would for the first time ever experienced a planetary invasion conducted by the Helghast Empire from five of its best elite armies.

Second Extrasolar War
The Planet tragically became a sight of a Helghast Invasion during the Second Extrasolar War, following the Helghast's initiation of Operation Vengeance, as it was discovered that Zeronus, itself was located on the border, between the Solar System, and the Alpha Centauri System, and was declared one of the 5 main gate way planets into the Solar System, in order to allow the Helghast Blitz Fleet to continue their advance towards Earth.

Zeronus was known as one of the border planets of the Alpha Centauri System and Solar System, alongside Inora, Toga, Euripides, and Runekara.

The Massive Campaign that took place on Zeronus on both the planet's Continents of Terranus, and Koadeia was documented to have lasted 13 days, where despite receiving victories in the early days by the Helghast Empire, it was revealed that the ISA were relentless on Zeronus, as they would conduct suicide charges to the thousands overrunning Helghast positions, and even going as far as to wiping out 2 of the best Helghast platoons in the Helghast Imperial army. The Campaign ended on January 5th, 2358, after the UCA and ISA were able to overrun the Helghast forces on the surface of the planet, and in space eventually costing the Helghast an entire army, while at the same time causing their entire border campaign to crumble by 2361.

The Failed Helghast Invasion of Zeronus, would be credited by both sides, instating different opinions, with the ISA crediting the Engagement as the battle that saved Earth and the Solar System, while the Helghast credited the battle as the most darkest and deadliest engagement in the history of Helghast, that cost the Helghast Empire 5 of their best armies.

Zeronus after the 13 day Campaign that lasted from December 24th, 2357 to January 5th, 2358, was never Attacked or Invaded by the Helghast again, as it was stated that the Helghast people including that of the military were so traumatized by the loss of 5 of Helghans top military armies, that they feared a repeat should happen if they attempted to Invade the planet a second time.

Zeronus would begin reconstruction procedures in both Terranus, and Koadeia, where by 2370, the planet would be restored back to its beautiful state. During the course of the reconstruction era, the government on Zeronus, would provide the ISA and UCA forces with more soldiers for the remainder of the Border Campaign until 2361, when the Helghast began to shift its forces Northbound towards the Viari System, in hopes of finding another way into the Solar System.

What became of Zeronus following the Border Campaign's end in 2361, was never revealed, but it is most likely that the planet is still apart of the Alpha Centauri Theater, and might have also been one of the planets who aided the ISA during the Invasion of Helghan in 2362, as a form of retaliation for the Helghast's failed Invasion, although this was never proven.

As of 2361 to 2362, the planet's status in the Second Extrasolar War following both the Zeronus Campaign and Border Campaign's end, is left unknown.

Trivia

 * In the posters, Zeronus is portrayed as a tourist world like Gyre, but on the posters it says:
 * Guaranteed Alien Free
 * The only planet with extra oxygen for a real relaxed vacation
 * Sun 24 hours a day


 * Though not making an actual appearance within the Guerrilla Games KillZone Canon Universe, with the exception through Posters, Zeronus was never officially known terrain wise and planetwise, Zeronus makes an appearance in KillZone Helghast at War Mod, which depicts the story of the 5 Helghast Armies that Invaded Zeronus during the Border Campaign and got destroyed...


 * Zeronus has only two massive Land masses, revealing that Zeronus, has only 2 Continents, and one Island on its Surface.
 * The Continent Names are Terranus, and Koadeia...
 * The Island's name is Marshell Island...


 * Despite being a tourist world, Zeronus, has shown to be a residential planet as well, revealing cities and massive residential areas on the planet surface, including capitals amongst the 2 continents and an Island full of towns and cities...


 * Most of the ISA soldiers, that took part in the bloody 13 Day Zeronus Campaign, were all known to be Zeronusian Born citizens, with the exception of the Earth Platoon and General Oversun, who were born on Earth...