It's the same cube from Thor. The cosmic cube/ tesseract. The Infinity Gauntlet was also in Thor. I think there was a quick shot of it on Thanos during the first end credits scene. The blue orb thing at the end of Loki's staff was a jewel from the gauntlet.
Originally Posted by TinyBird
"Astronomy offers an aesthetic indulgence not duplicated in any other field. This is not an academic or hypothetical attraction and should require no apologies, for the beauty to be found in the skies has been universally appreciated for unrecorded centuries."