Sky Station Galaxy
“Our Power Stars... They're gone! Some gigantic monster stole them! If you're going after that monster, you might see our Power Stars out there too! Please bring our Power Stars back. We Lumas will help you along your way!”
Sky Station Galaxy (also known as Syncro Battle Galaxy) is a galaxy in Super Mario Galaxy 2. The level is the introductory stage of the game, taking place before Mario lands on Starship Mario. Mario is launched into the galaxy from Princess Peach's Castle. After flying through a series of clouds, Mario eventually lands on a disc-shaped planetoid. The galaxy introduces the player to the gravity based gameplay and spherical planets of Super Mario Galaxy 2. This is one of the few galaxies in the game in which different background music is used for the first and second missions.
 Starting Planet
This is the starting planet for most missions in this galaxy. It is a round, small planet divided into two sides by a big white fence; a light side and a dark side (like the Starting Planet from the Good Egg Galaxy in the first game). On the light side there are several bushes with Star Bits and Coins and several Goombas as enemies along with a big house that belongs to Yoshi. A note on the door asks Mario to come around back. Also on the top side of the planet are two Warp Pipes, one green and one orange. The orange one will lead Mario into a cage with a 1-Up Mushroom while the green one will lead him to the darker side of the planet.
The darker side is mainly a ring of dirt with numerous crystals and Goombas all around. In the middle of the ring is a giant mound of dirt with a crystal on top which, when broken, reveals a hole leading back to the top of Yoshi's House. In the second mission of the galaxy there are also Chomp Pups rolling in circles around the darker side of the planet.
 Green Hill Planet
The Green Hill Planet is a large planet covered in grass. It is home to many Octoombas. The planet has one path going through it which a Luma leads Mario through. There are, however, outcroppings with different things such as an Octoomba, a ? Coin and a Teleporter which are just off of the path. Yellow platforms which rise into the air and then disappear are introduced on this planet; they will reappear at the bottom again after they have disappear but they are used to lift the player up in various points of the planet to get to the next area. At the end of the planet the Luma that was leading the player will turn into a Launch Star and sends them to the Miniature Planets.
 Miniature Planets
The Miniature Planets are three spherical planets floating together. The first planet has several coins and is covered in grass and flowers. The second is covered in sand and has a Sling Star which sends the player in a figure 8 pattern around the Miniature Planets. There is another Sling Star along the path of the first sling star and if Mario spins while in the range of the second sling star, he will get a ? Coin. However, if he misses it, he will land on the third Miniature Planet and not be able to come back, unless he performs a backflip from the bottom of the planet and then spins. The third miniature planet is covered in dirt with a few rocks and coins and a Launch Star to the Cylindrical Planet.
 Cylindrical Planet
The Cylindrical Planet is a grass-covered area surrounded by four Black Holes and has train-like platforms encircling it. The path is littered with mud that will slow the player down and has several Paragoombas all along. The beginning of the planet has a Midway Flag and then leads down a path to a large moving stone platform going around the circle of the planet. It is possible to get a 1-Up Mushroom by staying on this platform all the way around. When the player gets off, they will have to make it through a few more Paragoombas before reaching the next moving stone platform which, if they stay on it, gives them a Comet Medal. The player will then be able to travel through a final stretch of Paragoombas and get to a Luma which will become a Launch Star to the Sided Planet.
During the speed run, the Paragoombas are replaced by the more-aggresive Octoombas.
 Sided Planet
This planet has a flat shape with a light side and a dark side. Both sides have a set of steps; the steps on the dark side are made of stone and the ground is brown. There is an Octoomba guarding a Life Mushroom and a checkpoint flag which the player can touch. The steps on the lighter side are covered in grass and there are Octoombas on each step along with a couple coins for the player to get. There is a Launch Star at the top which leads to the Geo Planet.
 Geo Planet
The Geo Planet is a brown planet with several crystals that contain coins strewn around it. It is similar to the Dino Geo Planet from the Good Egg Galaxy in the first game. However, instead of Dino Piranha, Peewee Piranha is battled here. Peewee is in a gigantic egg on the planet when the player lands there and must defeat it.
 Sky Fleet Ship
The Sky Fleet Ship appears in the second mission and it is a cylindrical, transparent planet. The interior of the ship has several platforms, similar to the Pill Planet in the first game. The ship has a conical nose with a propeller at the tip. Banzai Bill Blasters launch Banzai Bills toward the player as they travel across the planet's glassy outside. A Rainbow Star is on the surface of the ship. Inside, there is platforming to be done and there is a warp pad and Launch Star inside.
In the first trailer of the game this planet had a lighter coloration.
 Flipswitch Fleet Planet
This planet is covered with Flipswitches. Here, the player must activate all Flipswitches while avoiding Banzai Bills being shot out of the cannon. This will cause the second section to appear. In the second section, Cosmic Clones will appear and chase the player as they activate the next set of Flipswitches. Once all the Flipswitches have been activated, the Cosmic Clones will disappear and the Launch Star to the next planet is revealed.
 Grass Fleet Planet
There are three more Banzai Bill Blasters in this planet, and mud that makes the player slower if they traverse over it. There is a long platform on one side, and at the end of it is a Spiky Piranha Plant that the player has to defeat in order to get a key to open a cage with the Power Star.
 Peewee Piranha's Temper Tantrum
Peewee Piranha's Temper Tantrum is the first level of the Sky Station Galaxy and, essentially, the first level in the game. It must be completed before reaching the Starship Mario. The player begins the level flying through several clouds and lands on the Starting Planet. A Luma tells the player that a monster stole their Power Stars and asks them to please get them back. He commits all Lumas to the player's cause. The player must travel around the starting planet to the green pipe which leads to the other, darker, side of the planet. On the darker side the player must travel up the mound in the middle, break open the crystal and jump through to find that Yoshi is not actually there along with a Luma which turns into a Launch Star for the player leading to the Platforms Planet. They can also Wall Jump and then Spin up the side of the building to get on top. On the Platforms Planet, a Luma leads the player through a path of Electrogoombas and rising platforms until they reach the end. The Luma turns into a Launch Star to the Miniature Planets. The Miniature Planets are a few planets with a ? Coin and a few Sling Stars which eventually lead the player to a Launch Star sending him off to the Cylindrical Planet.
On the Cylindrical Planet the player must travel along the only path, riding the stone platforms around the planet whenever it needs to happen and just make his way to the other side of the planet where a Luma will transform into a Launch Star to the Sided Planet. On this planet, the player must go up the stone steps and get the Midway Point along with the Life Mushroom and then travel around to the other side and climb up the green steps to a Launch Star leading to the boss battle on the Geo Planet with Peewee Piranha.
To defeat Peewee Piranha, the player must Spin the shell on its behind twice, cracking it open, and then attack its exposed bottom to damage it. While Peewee Piranha's bottom is exposed, he runs away from the player, just like what Bowser did when his tail was on fire in the first game, except Peewee Piranha is a little slower. After hitting its weak spot two times, Peewee Piranha will explode into purple smoke and release the first Power Star in the game for the player to get.
 Storming the Sky Fleet
The second level in the Sky Station Galaxy is Storming the Sky Fleet. The player once again begins on the Starting Planet, but this time around it is infested with Chomp Pups. Traveling to the darker side of the planet via the green warp pipe, the player must use the Stretch Plants strewn around to open up the chests and find a Rainbow Star. The player must then run around and destroy all of the Chomp Pups on this side of the planet (it is possible to destroy the Chomp Pups just by using the Stretch Plants) to find the key to free a captured Luma. The Luma will reward the player for freeing him by transforming into a Launch Star to the Sky Fleet Ship.
The Sky Fleet Ship has multiple Banzai Bills for the player to avoid before he can get to a hole which leads inside the ship. To the player's advantage, however, there is another Rainbow Star for them to use so they can destroy the Banzai Bills. They need to find a hatch which leads inside the Sky Fleet Ship to proceed.
On the inside, there are numerous Amps and moving platforms. A Checkpoint Flag is just near the entrance to the inside. A 1-Up Mushroom is just above the flag. There is an area full of Star Bits where the player must fall to continue the area. There is also a Teleporter and another 1-Up Mushroom in an area which can only be reached by crawling through the tiny gap. The player must travel to the other side of the moving platforms and take the Launch Star, which is in mid air and surrounded by Amps, to the Flipswitch Fleet Planet.
There is a Banzai Bill launcher on this planet, so the player must look out for the Banzai Bills. If the player manages to get on top of the Banzai Bill launcher, they will find a small bunch of Star Bits to collect. After the player has pressed all the switches on the Flipswitch Planet, another section appears where Mario has to press the Flipswitches. However, there is a slight problem; this time the player will be chased by Cosmic Clones, meaning they shouldn't go back to a Flipswitch they've already walked over.
After pressing all the switches the clones will disappear into Star Bits and a Launch Star will appear to take the player to the Grass Fleet Planet. The Second Fleet Ship has three Banzai Bills blasting all around and a Power Star can be found in a cage. The player must travel to the end of the walkway, avoiding the Banzai Bills that case them, and reach the end of the planet which has a pole, two Piranha Plants and one Spiky Piranha Plant. Defeating the Spiky Piranha will yield a key which frees the Power Star and allows the player to go back, still avoiding the Banzai Bills, and get the star.
 Peewee Piranha's Speed Run
Peewee Piranha's Speed Run is a Prankster Comet mission in the Sky Station Galaxy. It plays out almost same way as Peewee Piranha's Temper Tantrum except there are ten green timers throughout the level which add ten seconds to the player's time. The player begins with 20 seconds on the clock and must continue collecting these timers to keep their time above zero. If the timer reaches zero, the player will lose a life. In total, there are 120 seconds, or two minutes, on the clock with all the timers added together.
 Green Star 1
The player will redo the Peewee Piranha's Temper Tantrum mission. This Green Star is located on the Starting Planet. The player should circle around Yoshi's House until they spot it. It is suspended in mid-air so the player will either have to backflip, double-jump or side-somersault to reach it.
Alternatively, the player can jump into the green pipe to the bottom side of the planet, destroy the crystal, and jump into the hole and exit out on top of Yoshi's House. From there they can walk off the edge to retrieve the Star.
 Green Star 2
The second Green Star is located near the Platforms Planet, in the abyss beyond the Launch Star. In order to reach it, the player has to simply jump off the platform with the launch star near it. The star is near the corner of the platform, so it is best to jump off around there. If they jumped correctly, they will land onto the Star before falling into the Black hole.
 Green Star 3
The player will redo the Storming the Sky Fleet mission. The last Green Star is located on the Sky Fleet Ship over the Warp Pad near the end of the planet. The player must either do a backwards somersault off the Teleporter and do a wall jump, or stand on the last rotating platform and jump onto the star.
 Other Appearances
The Sky Station appears in Mario & Sonic at the London 2012 Olympic Games as the location of the Dream Spacewalk event. The starting planet, the sided planet, and the mine cart planet appear, as well as miniature planets. It has a changed name of "Syncro Battle Galaxy." Peewee Piranha's boss planet also appears here as a planet for Dino Piranha.
 Names in Other Languages
The music used in the first mission of this galaxy is reused many other times throughout Super Mario Galaxy 2 (though usually in a different style), and is the most used music in the game. Some of these instances include: the title screen of the game, while gliding with Fluzzard in the Wild Glide Galaxy, the main theme in the Freezy Flake Galaxy and Starshine Beach Galaxy, secret Chance Cube areas hidden in many galaxies, and part of the ending credits of the game. It was also used in the E3 2009 trailer of the game.