Trivia: When Quill has been arrested on Xandar and his name and crimes are being reviewed, his alias is shown on the view screen but it appears as "space-lord" and not "star-lord." As ever, they've got his name wrong.
Trivia: Adam's Warlock's cocoon (also seen in Thor: The Dark World) and Eson the Searcher can be seen in the collector's place.
Chosen answer: Each realm is actually more of a dimension than a single world. So Xandar would be part of Midgard. The orb is the housing for one of the Infinity Gems. The Tesseract is also an Infinity Gem. The stone in Loki's scepter and the Aether from Thor: The Dark world are two others. All 6 gems can be combined on the Infinity Gauntlet which enables the user to do whatever he wishes just by thinking about it. Wielded by Thanos, among others, in the comics.
Grumpy Scot