Green Star

"AY-O! Did ya see that? Those Prankster Comets were green! That means there are Green Stars around now! Those must be the cosmic jewels I keep hearing about! Those Green Stars are pretty hard to find, so keep your eyes and ears peeled! Take it away, Captain!"

- Lubba

Green Stars (グリーンスター Gurīn Sutā, also referred to as cosmic jewels) are green-colored Power Stars that can be found in Super Mario Galaxy and Super Mario Galaxy 2.

In Super Mario Galaxy, there are only three Green Stars, each of which is hidden away in a different galaxy. Collecting all three of them grants Mario access to the three Trial Galaxies on the Planet of Trials: the Rolling Gizmo Galaxy, the Loopdeeswoop Galaxy, and the Bubble Blast Galaxy.

In Super Mario Galaxy 2, there are a total of 120 Green Stars to be found. These are only available once the player collects 120 regular Power Stars and then completes the first mission of Bowser's Galaxy Generator again. Each galaxy has the same number of Green Stars as regular Power Stars (except the Grandmaster Galaxy, which has no Green Stars at all). When collecting Green Stars, the player will have to do a certain mission of a galaxy again. In some cases the Green Stars in a galaxy can be collected in any order (i.e. "Green Star 2" can be collected during the Green Star 1 mission), but in general they can only be collected when playing a Green Star mission. Green Stars are usually found in hard to reach or hidden areas of the galaxies. Additionally, the Green Stars only appear when a galaxy is orbited by a Green Comet, which will appear once they are unlocked.

Super Mario Galaxy 2's Green Stars make a distinct twinkling sound, which is different from that of normal Power Stars and the Green Stars in Super Mario Galaxy and is meant to help players in locating them.

Super Mario Galaxy Green Star Locations

 * Battlerock Galaxy - Luigi under the Saucer: Rescuing Luigi from a cage in the first level.
 * Dusty Dune Galaxy - Treasure of the Pyramid: Collecting 5 Silver Stars in the Pyramid Planet.
 * Buoy Base Galaxy - The Secret of Buoy Base: Under the Buoy Base sealed in a cage which needs to be broken with a Bullet Bill.

Trivia

 * In Super Mario Galaxy, even though only three Green Stars are able to be recovered in the game, a total of seven Green Lumas can be found on the Comet Observatory and the Planet of Trials (counting the one that takes Mario to the Grand Finale Galaxy). Green Lumas grow up to become Green Stars, according to Polari.
 * When the Green Comets are in orbit in Super Mario Galaxy 2, a remix of the Good Egg Galaxy's music from Super Mario Galaxy is played in World 1's map.
 * When a Green Star mission is chosen (Super Mario Galaxy 2 only), the borders of the screen are green instead of black.