'Whirlpool' in Hawaii sky leaves scientists puzzled

Video caption, Watch the mystery swirl sweeping through the sky over Hawaii

A mysterious 'whirlpool' has been filmed flying above Hawaii at night.

The video was captured by an observatory in Mauna Kea on 18 January.

The formation started as a small dot but then changed into a spiralling shape.

Initially the swirling cloud left scientists scratching their heads, but it's now believed it may have something to do with the launch of a satellite by the private company, SpaceX.

What is SpaceX?

Image source, SpaceX

Image caption, A picture of the Starship spacecraft that SpaceX hope will carry space tourists in the future

SpaceX is a private space company part owned by the billionaire Elon Musk, which plans to one day run space tourism trips into orbit and the Moon.

Elon Musk is an inventor who also owns the electric car company Tesla and Twitter.

He made a lot of money by selling the online payment service PayPal to eBay.