Moonbase One

Moonbase One, Moon Alpha, or Luna 1, is one of Cybertron's moons, with the others naturally being Moonbase Two, Moonbase 3, and Moon Base Four.

The Transformers cartoon
Moonbase One was the first Moon base built after the Decepticons' conquest of Cybertron. It appears to have been primarily a command base, and many Autobots were stationed here, including Optimus Prime, Ratchet, Ironhide, Prowl, Brawn, and the Dinobots, but only Jazz and Cliffjumper were left behind when Optimus Prime went to provide reinforcements to Autobot City. The only thing of any note that ever happened to it was getting eaten by Unicron. Moonbase Two is (well, was) its neighbor (until both of them got eaten). For a while, it spent time being slowly digested within Unicron's bowels, at least until he was obliterated by a mystical glowing thingy.

Dreamwave Generation One continuity
Grimlock had his Lightning Strike Coalition attack Starscream's Predacons at Moon Alpha Spaceport, killing Stormbringer, Pulse and Hardcase and stealing two transporters full of energon.

Prior to their disruption of the peace ceremony between the Decepticons, Ultracons and Autobots at Tyger Pax, Starscream rallied his Predacons at a staging base on Moon Alpha.

The AllSpark Almanac
Moon Base One was Cybertron's inner moon, and served as a major industrial center with plenty of energon farms and processing facilities.

Aligned novels
Moon Base One was built during the Golden Age of Cybertron. It was occupied by Starscream's Seekers during the civil war, and Sentinel Prime was imprisoned there after a disagreement with Megatron after he was kidnapped and taken to Kaon.

IDW Generation 1 continuity
Luna 1, the larger of Cybertron's two moons, vanished at some point in the ancient past. Legend has it that it was destroyed during the battle between the death god Mortilus and his fellow gods, the Guiding Hand. This religious version of events didn't roll with everyone, and instead a common belief among Cybertronians was that the "Seething Moon", as it was nicknamed, had simply been lost in space somehow. Many believed that if found, the legendary satellite would hold answers to many mysteries. Others like Trailbreaker didn't believe it existed at all.

Over the years, many attempts were made to find Luna 1, but none were successful. Tailgate claimed to have coordinated the first search in the time of Nova Prime over six million years ago. Senator Shockwave desired to find both Luna 1 and Nova's Ark, using his influence in the Senate to look for them. Dominus Ambus and Rewind also went on a hunt for it, returning empty-handed some time after the war had broken out. At least one more "Moonquest" took place during the war when Hot Rod vowed to find Luna 1, this time with Swerve partaking in it.

When Vector Sigma was reignited, Cybertron automatically began reviving its moons as well by transmitting energy to them, but the absence of Luna 1 caused its share of the energy to gather in the atmosphere instead. The atmosphere was superheated into a plasma state, causing "ball lightning" effects to strike Cybertron's surface until Wheeljack put up a temporary satellite to draw the energy away.

Where countless others had tried and failed, the crew of the Lost Light rediscovered Luna 1 after venturing through a mysterious portal in search of Ultra Magnus. To their surprise, Luna 1 was already inhabited--by no fewer then a billion people. After assembling a team of explorers and descending to the surface, Rodimus discovered that the "people" on Luna 1 were in fact dormant sparks, all of which became active once more as soon as he set foot on the ground. Luna 1 was a hot spot, a place where sparks were born, called the Seething Moon because it was seething with life.

It also turned out they weren't the first to find it when Rodimus's team was ambushed by the Titan Hunters and Pharma.

While pursued by the Titan Hunters, the team discovered an enormous field of dead Metrotitans. When flying into the Titans' corpses to escape their attackers failed, most of the team was captured and brought to face Chief Justice Tyrest, who was using Luna 1 as his own personal moonbase.

Rodimus returned to the hot spot after Tyrest's defeat but was unable to get it to re-ignite. He speculated that the field had only ignited because he held a piece of the Matrix of Leadership, and with it destroyed in the foiling of Tyrest's plans the hot spot returned to dormancy. Rodimus scattered the Matrix fragments over the spark field before departing Luna 1; Fortress Maximus and Red Alert stayed behind to deal with Decepticon activity in the region. The Lost Light departed, never discovering the five planetary engines on the dark side of the moon or the strange gear-like hieroglyph set in it...

Transformers: Unicron Trilogy
Moonbase One, or Luna 1, is a base on a moon orbiting Cybertron. It served as a major industrial center with plenty of energon farms and processing facilities.

Merchandise

 * RISK TRANSFORMERS CYBERTRON Battle Edition (2007)
 * Moon Alpha is one of the orange zones on the board.