A mysterious UFO-shaped cloud baffled skiers when it appeared in the sky over Sweden on January 25, 2017.
The bizarre cloud floated in the sky over ski resorts Åre and Duved, prompting some to speculate that Martians had arrived for a day on the slopes.
Many rushed to take pictures of the unusual phenomenon and posted them on social media.
Experts explained it was a so-called lenticular cloud, which forms over mountain peaks when the air is forced to rise as it hits the hillside. As it cools it condenses into a cloud.
Thanks to their peculiar shape, they are often mistaken for UFOs.
Which picture of the cloud did you prefer?