Three different color Star Bits.
Star Bits are the most common collectible items in the Super Mario Galaxy series. Unlike coins, Mario can bring them back to the Comet Observatory or Starship Mario. They come in red, yellow, green, blue, purple and white. Collecting 50 (Super Mario Galaxy) or 100 (Super Mario Galaxy 2) in a single level will have the same effect as a 1-Up Mushroom. Star Bits can be fired with the "B" button.
There are three main ways of collecting Star Bits. The most common way is finding them in galaxies. They are often used as decoration and will stay permanently until picked up. The second way is from the sky. In galaxies, Star Bits are often falling from the sky in groups of three. They only last a few seconds though. The final way is from enemies. Spinning into a enemy will result in three Star Bits rather than a coin. There are several other methods not listed.
Mario collecting many Star Bits while falling from the sky
As mentioned before, you can fire Star Bits with the "B" button. This will cause the counter to deplete and make the Star Bit irretrievable. Shooting enemies with them will stun them temporarily. Shooting at lumas will feed them. This will usually result in just a thank you message, but if you feed a Hungry Luma, they will transform into planets or galaxies after feeding them a certain amount.
Trivia
- According to Rosalina's Storybook, Star Bits taste like honey.
- Star Bits are based on the Japanese candy, konpeitō.