From a table detailing the reported shapes of UFOs in sightings in the United States since 2001. The table is included in the UFO Sightings Desk Reference, which was self-published last year by Cheryl Costa and Linda Miller Costa. The authors collected and analyzed data from more than 120,000 sightings. The list is ordered from most to least common.

Circle

Sphere

Triangle

Fireball

Star

Oval

Disk

Cigar

Cylinder

Diamond

Boomerang

Chevron

Rectangle

Egg

Teardrop

Bullet

Cone

Blimp

Cross

Square