Space Colony ARK

The Space Colony ARK is a fictional space station in the Sonic the Hedgehog series of video games. The ARK was classified as the first Bernal sphere space colony (mistranslated to "Bernoulli spherical" in the English translation), and was used by the government for scientific testing and experimentation. From the underside, the ARK looks like the unmistakable face of Dr. Eggman, though judging by the time it was built, it was most likely based off his grandfather Gerald Robotnik, who had an equally impressive moustache. The ARK was inspired by the Death Egg used by Dr. Eggman in Sonic the Hedgehog 2 and Sonic the Hedgehog 3, which in turn appears to be inspired by the Death Star from Star Wars.

Beginning
It was aboard Space Colony ARK that Professor Gerald Robotnik worked on "Project Shadow" in an attempt to create the "Ultimate life form" as the first step towards discovering the secret of immortality (he did this in order to find a cure for his terminally ill granddaughter, Maria Robotnik). Thus, the ARK was the "birthplace" of both the Biolizard and Shadow the Hedgehog, two results of the project.

Also on the ARK, Gerald worked with the newly discovered Gizoid, an ancient robot. He started up "Project Gizoid" and established a "Link" with the Gizoid, but in order to buy more time to finish Project Shadow, he gave up the Gizoid to the government. The Gizoid ended up destroying a large portion of the ARK after absorbing a large amount of weaponry. The government decided that what was going on with Gerald in the ARK was completely dangerous and shut down Project Shadow.

When Project Shadow was shut down, Robotnik refused to end his work before he had found the cure he sought. Thus, GUN invaded the space station to end the program by force. Maria was killed during the raid, and the news of her death sent her grandfather into despair. He plotted revenge against the entire planet. The Biolizard remained aboard ARK, having nearly decimated the invaders, and Shadow the Hedgehog was shot down to Earth in a stasis tube.

After sealing the Biolizard, GUN killed or imprisoned everyone that knew about Project Shadow. They took everyone else down to Earth, explaining that there had been an accident aboard the ARK that had rendered it uninhabitable. They then apparently sealed the "face" part of the ARK with a rock-like half-sphere, making the colony look like an asteroid, possibly to conceal its existence for years to come, though the actual reason is not known.

Sonic Adventure 2
During Sonic Adventure 2, a reawakened Shadow the Hedgehog led Doctor Eggman (Gerald's grandson), and Rouge the Bat to the ARK as part of his own plans to get vengeance for the death of Maria. They planned to activate the Eclipse Cannon, a powerful weapon of mass destruction that, when powered by Chaos Emeralds, could destroy a planet. When six of the seven emeralds were connected to the power supply, Eggman demonstrated the power of the Cannon by blowing up half of the moon and threatened to do the same to Earth in 24 hours unless the people on the planet followed his demands.

When Sonic the Hedgehog (along with his friends Tails, Knuckles, and Amy) tried to intervene, Eggman stole the seventh Chaos Emerald from them. However, when he inserted the final Emerald, rather than activating the full power of the weapon, a recording made by Gerald Robotnik appeared on several monitors, and the ARK itself began hurtling towards Earth. This was Gerald's plan for revenge: should anyone attempt to bring the Eclipse Cannon to its full power with the Chaos Emeralds, a hidden program would transfer the Emeralds' power to the ship's propulsion systems. To stop it, Sonic and Knuckles made their way to the core. However, they were waylaid by the Biolizard, which had also been awoken when the seventh Emerald had been connected to the cannon. At the same time, Amy convinced Shadow that Maria's final wish was that he should protect mankind, not destroy it, and Shadow quickly went to help by distracting the Biolizard. This allowed Knuckles enough time to deactivate the power of the Chaos Emeralds by using the Master Emerald. The Biolizard, however, was deadset on following through with the program, and used Chaos Control to merge with the Colony itself, becoming the Finalhazard, and continued its descent to the planet.

Sonic and Shadow used the power of the Chaos Emeralds to become Super Sonic and Super Shadow respectively. The two fought and defeated the Finalhazard, then used Chaos Control to teleport the entire colony a safe distance from Earth again. However, this used the last of Shadow's strength, as he had already spent a large portion of it defeating the Biolizard the first time, and he fell to Earth, believed to have died. Later games revealed that he was in fact saved by one of Eggman's robots.

Shadow the Hedgehog
In Shadow the Hedgehog, it is revealed that the true (or at least the original) purpose of the Eclipse Cannon was not to destroy Earth; instead, it was intended to destroy the alien Black Arms' base of operations, the Black Comet, in order to save the planet from the evil intentions of its leader, Black Doom.

It is also revealed in Shadow the Hedgehog that the GUN Commander was also aboard the ARK fifty years ago, and shared a sibling-esque relationship with Maria. It is unclear how he survived the GUN raid of the ARK, but he holds a strong grudge against Shadow, blaming Shadow for the death of everyone, his family and Maria included, aboard the ARK.

Another important fact revealed was that the program that activated and set the ARK on its collision course with Earth in Sonic Adventure 2 was, like the Eclipse Cannon, also a defense mechanism. Robotnik installed it as a last resort maneuver, in case the Black Arms somehow got a hold of the Eclipse Cannon and all seven Chaos Emeralds and used them to conquer Earth. Hypothetically, the program would've activated, and the ARK would've impacted the conquered Earth, destroying it, the ARK, and the rest of the Black Arms. If the Black Arms tried to stop the collision, the Biolizard would've hindered them from doing so, as it did with Sonic and company.

Notably, the Eclipse Cannon is used against Earth in Shadow the Hedgehog. After following the Dark mission of the "The ARK" stage, Shadow and Black Doom took over the Eclipse Cannon and fired it at The President's residence in Central City. Since the cannon was only powered by five Chaos Emeralds at the point, the result was not world destruction, but an Independence Day-style explosion that devastated Central City. However, since Shadow is heroic in the true end of the game, it is very unlikely he followed the evil route, and as such Central City was most likely not destroyed. This also supported because in the true ending of the game Central City is seen to still exist, albeit in ruins because of the attacks by the Black Arms. In another of the game's endings, the Black Arms destroy the ARK; this is also not canon.

In the final story's ending, Shadow uses the Eclipse Cannon for its true purpose: destroying the Black Comet and the Black Arms with it, much to the happiness and relief of the GUN Commander and the President, who were watching from the control room of the GUN Fortress. They finally saw that Gerald did not make the Eclipse Cannon to destroy Earth but, aware of Black Doom's plot to enslave humanity, created it to destroy him and the Black Arms as a whole.

Other
It is unknown if the ARK will appear in future Sonic games, considering Shadow's story and past have now been fully resolved. It recently appeared as a collectable card in Sonic Rivals.

The Space Colony ARK also appeared in the Sonic X adaption of Sonic Adventure 2, along with the Sonic the Hedgehog comic book.

Mechanism and others
According to an eyecatcher information card from Sonic X, the ARK is 15 kilometers (9.32 miles) in diameter, and weighs 1.5 billion tons..

The ARK is crewed by robots and has six wings, three on each side (which were torn off when the ARK fell towards Earth at the end of Sonic Adventure 2, yet reappeared after Sonic and Shadow's Chaos Control). Their purpose is unknown, though they look vaguely like solar panels, which may act as the colony's power source. They are the "moustache" of the colony.It has numerous column-like buildings on its surface surrounding the Eclipse Cannon, which are likely living quarters, laboratories, and other rooms. There are also various platforms floating in space near the ARK, possibly meant for loading and unloading supplies.

The ARK is protected from intruders by a variety of GUN robots and Artificial Chaos, along with small mine-firing turrets, powerful homing missile cannons and floating green energy shields. Inside the station there are pools of strange, liquid-like green energy, and an abundance of mechanisms that control the artificial gravity.

Also, the ARK has looked slightly different each time it has been shown. In Sonic Adventure 2, the ARK had a nominally clear blue surface, the Eclipse Cannon fired a large blue beam (which was green in Shadow the Hedgehog) that had to be charged up like a super laser. There are also many large columns sticking out of the bottom, but strangely enough, when the ARK is shown in cinema scenes, these huge columns are never visible.

However, in Sonic X, the ARK is mainly a gray color and has small, round spots on it. The columns under the ARK are never visible, and the interior is drastically altered from SA2. The charging process is also drastically different, as a large collection of lightning goes to the tip of the Eclipse Cannon and creates a large, blue ball (different from the games). The Sonic X ARK also has small laser cannon turrets placed in the "eyes" of the station, which are never seen in any games.

Eclipse Cannon
The Eclipse Cannon was the ultimate weapon of mass destruction on Space Colony ARK, notably able to destroy entire planets and pierce stars. The Chaos Emeralds were the necessary energy source to activate its full power, as it needed large amounts of energy. The Eclipse Cannon has been seen to destroy a large city with five Emeralds, half a moon with six, and can supposedly destroy planets and pierce stars with all seven. (Strangely, Eggman was able to create a cannon with more potency without Emeralds in Sonic Battle, stating that several stars had been destroyed when he fired it.) In Sonic Adventure 2, Shadow claims that it was just one of the weapons created onboard the ARK.

The Eclipse Cannon is a long, slim energy cannon situated inside the "nose" of the ARK, which opens up when one is firing the cannon. When fired, the Eclipse Cannon charges up energy that moves from the four open "nose" parts to the cannon itself. After a few seconds of charging it reaches its peak, and fires a huge energy beam straight forward. The energy was light blue in Sonic Adventure 2 and Sonic X, but green in Shadow the Hedgehog. The Eclipse Cannon bares some resemblance to the main weapon on board the alien spacecrafts in the film Independence Day.

The core of the Eclipse Cannon is designed as an exact replica of shrine of the Master Emerald on Angel Island. However, the shrine in the core is intact while the real one is in ruins. This was, according to Sonic, done to harness the power of the Chaos Emeralds. The cannon itself has only been fired three times: at the moon, Central City, and at the Black Comet. In fact, the original intention of the Eclipse Cannon was to destroy the Black Comet when it returned.