This picture mystified Joan Dallison, 76, when she took it from ward 42 in King's Mill Hospital.
When Joan, from Coxmoor, saw the beautiful blue and pink sky on October 24, she whipped out her phone to take a picture.
It was only when she looked at the picture afterwards, that she noticed something strange.
Joan said: "The staff at the hospital said it was probably a reflection of the equipment they have on the ceiling, but it looks nothing like a reflection.
"I still can't believe it - honest to god it looks like a UFO.
"I was just looking at the sky, which was clear, and when I looked back at the picture I saw it.
"I've been so fascinated by it, it's so weird and unusual."
Joan now hopes to have the picture verified, so she can put her mind at rest.