You may have seen a picture or two floating around of this cool helix spiral cloud that appeared last year over Russia, but we’ve scoured the internet for a few more. Some researchers say that it’s just a contrail formation, or in other words, long thin artificial clouds that sometimes form behind aircraft. Continue reading for more.

Depending on the temperature and humidity at the altitude the contrail forms, they may be visible for only a few seconds or minutes, or may persist for hours and spread to be several miles wide.

The resulting cloud forms may resemble cirrus, cirrocumulus, or cirrostratus. Persistent spreading contrails are thought to have a significant effect on global climate.