A strange spherical cloud has been spotted over Fujisawa, a city in Kanagawa Prefecture, Japan.

According to the resident who posted photos of the odd sighting, the cloud appeared above the train station at around 3:00 p.m. She also added that the cloud appears more round in the actual than what is seen on the photo.

Sputnik News reported that the photos have gone viral after they were posted on Twitter and that some user thought that it could be an "omen."

Meanwhile, others who refuse to believe that it's an omen and proposed that the cloud is a rare cloud which sits low in the sky.

News.com.au reported that such spherical clouds have also been spotted in Australia and that onlookers often suspect them as violent tornadoes. While the Japanese residents labeled it a "death star," the Australian news site said they are called as "morning glory" in their country. And that they often appear from September to January.

On the other hand, The Sun said the extremely rare cloud is a "roll cloud," and is shaped by the edges of a thunderstorm or cold front of weather.

But atmospheric scientist Todd Lane from the University in Melbourne, Australia says roll cloud's are cylindrical and note spherical.

"While I can't verify the origin of this image, or whether it was even of the same cloud, it appears that the cloud only appeared spherical from one direction," Lane told ScienceAlert.

"That is, the photographer was lucky to be in the right place to capture an interesting image of what is likely an uninteresting cloud. It looks to me to be some form of cumulus fractus cloud."

Weather.com defines cumulus fractus clouds as cumulus clouds that appear in irregular pieces as if it had been ripped apart from a big one.