A spectacular and beautiful cloud formation was spotted in the skies above Australia by a passenger on an aeroplane who snapped it and posted it to his Instagram page.
Ilya Katsman, 22, saw the phenomenon on a Virgin Australia flight from Perth to Adelaide.
The photos were later re-posted on Virgin's Facebook page with the comment: "Flying above the clouds has never looked this good! These incredible cloud formations were seen on board VA714 from Perth to Adelaide."
The post has been shared more than 3,000 times.
A spokesman from the Met office explained to Britain's Telegraph that the cloud is of a type commonly seen in Australian skies, but they are rarely as beautifully distinctive as this example.
Neil Bennett, from Australia's Bureau of Meteorology, told the BBC it was likely to be a wave cloud.
"It's like skimming a stone across a lake. The air is rising up and down in a wave motion," Mr Bennett said.
"Where it's going up you're getting the cloud, and where its going down you're getting the clear lines."
Mr Katsman said he initially thought it was a rare type of wave cloud known as the "morning glory", which occurs in the country's north.
"The cloud is definitely impressive," Mr Katsman told the BBC.
"I thought it was unusual to see it so far south."