FAIRBURY, Ill. (WCIA) – Residents in Central Illinois caught an unusual spectacle in the sky over the area Tuesday afternoon.

A collection of odd shaped clouds that resembled circular disks floated in the region.

WCIA Viewer Maria Trainor’s daughter snapped a few photos of them in the Fairbury area in Livingston County.

Some people have mistaken them for UFOs due to their smooth saucer like shape.

They are more common in mountainous terrains but more rare in areas like the Midwest.

Lenticular clouds are formed as fast air is moved over a topographic barrier, producing waves in the atmosphere, helping to develop the clouds.

While mountains are the most common topographic barrier, even buildings, bridges and valleys can help interrupt the flow of air, creating a disturbed and turbulent air pattern by swirling it around in various directions.

Lenticular clouds are often a sign of turbulence in the sky, and airplane pilots will avoid areas where these form.

The topographic influences that form these rare clouds don’t necessarily have to be nearby.

These clouds can form tens and even hundreds of miles downstream, and even can continue moving through the sky well after they have formed.