Space Junk Galaxy

The Space Junk Galaxy is a galaxy in the game Super Mario Galaxy. This Galaxy has a futuristic/space theme. A lot of the objects are silver or blue, and there is a spaceship in it.

The Pull Star is used much more than in the other known galaxies. Also, Toads are on a big platform covered in crystals; if Mario frees the Toads trapped in the crystals, the main Starshroom will appear to take Mario to the next location. There is also a wooden planet shaped like Yoshi's head.

The last unique feature of this galaxy is that it has a path that builds itself when Mario approaches it, but crumbles after he leaves. This is later re-used in Bowser's Galaxy Reactor, except the path crumbles after a few seconds automatically.

Mario fights two bosses in this galaxy: Tarantox and Kamella.

Orb Planets
The Orb Planets are three planets with Amps moving around them. There are five Star Chips on this Planet. After collecting the Star Chips, Mario can use a Launch Star to go to the Rocket Planet.

Space Ship #1
In mission 1, this planet is basically just a rocket with Star Bits on it. Mario can use Pull Stars from here to get to the Tower Planet.

Tower Planet
This Planet resembles a tower. It contains some Cosmic Scuttle Bugs. It is also where Mario finds the Toad Brigade, all of them trapped in an Item Crystal. After Mario frees them all, the Starshroom will appear. On the top of the Starshroom is a Sling Star, which will take Mario to the Space Junk Area.

Space Junk Area
Here, Mario must move around to find that Space Junk that is in the air will help him by giving him a floor to walk on. There are five Silver Stars that, once collected, will combine to create a Power Star. The player however, must be very careful as to not fall off the Space Junk and into a Black Hole.

Airships
In Mission 2, several airships appear. Members of the Toad Brigade are trapped on the airships. Mario must hit a lever on the first airship to open the bridge, leading to a Sling Star and the second airship. The second airship has a Green Shell. Mario must throw the Green Shell at the Treasure Chest to unlock a Launch Star. The third airship has green shells, which Mario should throw at a few enemies on the fourth airship to open the bridge to it. The fourth and final airship is purple and red, different than the other airships. It is also where Mario must fight Kamella (the color of her clothes match the ship's color). Mario will get a Power Star for defeating Kamella.

Crystal Planet


The Crystal Planet is a planet that is encountered shortly before the battle with Tarantox.

At first, Mario walks on top of it, which is practically a transparent crystal orb. Once he finds the passageway in, he can go under the crystal layer and explore underneath, where 1-Up Mushrooms and other treats are waiting. Here, there is a Launch Star, which will blast Mario out of its glassy suface, and take him to the Rock Planet.

Rock Planet


The Stone Planet is a planet mostly made of gray stone. It has a sort of arch, as seen in the picture. This planet is an entrance to Tarantox's lair. The pre-boss music begins when Mario lands on this planet, and the spider's Sticky Planet is nearby. Cosmic Scuttle Bugs also live here.

The Rock Planet is the first planet in the game to have a Sling Pod and is the beginning of a long path of them.

Space Ship #2


This Space Ship is a "planet" that consists mostly of just coins. It is a big, long, red-and-tan space ship floating around in space. It is encountered in Missions 1 and 3. On the route to Tarantox, in Mission 3, at the end of it is a Sling Pod, and that's literally all there is, along with a few Cosmic Scuttle Bugs. It's also thought the ship is Olimar's ship, referring to the Pikmin series, but this has not been confirmed.

Sticky Planet


The Sticky Planet is exceptionally large and looks like a giant version of the top of a Sling Pod. In fact, Mario uses a Sling Pod to get to the planet, breaking its shell open and revealing a giant sticky spider web, where he fights Tarantox, who is frozen inside the Sticky Planet. After defeating Tarantox, Mario will get a Power Star.

Yoshi Planet


The Yoshi Planet is a planet in the shape of a large, wooden Yoshi head that shoots red steam out of its nostrils. This appears to be the third reference to the Yoshi clan in Super Mario Galaxy, the first being the Yoshi game file icon, and the second the Yoshi Egg Planet that was shown earlier. Defeating all the Goombas on this planet will earn Mario a Power Star.

Enemies

 * Goombas
 * Cosmic Scuttle Bugs
 * Koopas
 * Magikoopas
 * A couple of the big Brown Electrogoombas in barrels.

Pull Star Path
As the name suggests there is a lot of pull stars. After the first path, Mario/Luigi lands at Olimar's Ship where star bits are falling as shooting stars, then go to a couple of Pull Star Plantet. After that, there is a second pull star path, then land on double-sided planet, kill the cosmic scuttle bugs, then save the Toads. The Capitain of the Toad Brigade will appear, and his heroic tune will play, Then go to the final planet through the Sling Star. At the end Mario has to get 5 Silver Stars on a place full of small bits of path, which join together to make a path for Mario to go across.

Kamella's Airship Attack
In this mission Mario has to go across airships to fight Kamella. He uses Green Shells a lot in this mission.

Tarantox's Tangled Web
The player must traverse various planets until they finally break open Tarantox's planet and fight him. Sling pods are first seen here.

Onc the player finishes the level, the Sling Pod Galaxy will be unlocked via Hungry Luma.

Pull Star Path Speed Run
The Speedy Comet mission for this Galaxy. Mario must go through Pull Star Path under a time limit.

Purple Coin Spacewalk
Mario must collect 100 Purple Coins in the area at the end of Pull Star Path. The coins come in bunches of 10 on several platforms. It is also timed.

Yoshi's Unexpected Appearance
After Mario feeds a Hungry Luma, it turns into the Yoshi Head Planet. On this planet, the player must defeat all the coinless, star-bit-less Goombas to get the Power Star to appear. A counter is kept for the amount of times Mario jumps on Goombas consecutively and if the count goes over 8 Mario will get 1ups

Trivia

 * The Spaceship encountered on the road to Tarantox looks a lot like the Hocotate Ship, which is Captain Olimar's ship.