"Hello Professor Salvatore, how are you?" the Ravenclaw prefect greeted the Astronomy professor politely, before making her way to the back of the class as far away from everyone else as she could be. She had a slight cold that day and was trying to protect her classmates from getting it too. Right after class she'd go to the hospital wing for relief. For now she'd put on a brave face and try to not sneeze.

She raised her hand. "I know this isn't technically the right answer, but Pluto is a dwarf planet and used to be considered the ninth planet before it was officially downgraded."