RACHEL MARTIN, HOST:

Good morning. I'm Rachel Martin. Last week, we learned of a mysterious silver monolith spotted in the Utah desert. The story just got weirder. The 11-foot metal structure has now disappeared, less than 10 days after being discovered in drone pictures. It was removed overnight by an unknown party. Before it vanished, a few hikers were able to post selfies with it online. Maybe the strange-looking structure just didn't want its picture taken. Or maybe the aliens determined we do not deserve nice things. It's MORNING EDITION. Transcript provided by NPR, Copyright NPR.