Terrace

The Terrace is the first observatory Dome in Super Mario Galaxy.

When the black hole emerged, the Terrace broke apart from the observatory (including the strip of land that takes you to the fountain) when Peach's Castle crashed into the side of it. It was one of the last pieces of the observatory to be sucked in the black hole.

Galaxies
Good Egg Galaxy

Honeyhive Galaxy

Loopdeloop Galaxy

Flipswitch Galaxy

Bowser Jr. Robot Reactor

Sweet Sweet Galaxy Hungry Luma