Antarctic expeditioners at Mawson research station have had front row seats to a rare atmospheric phenomenon – the formation of spectacular polar stratospheric clouds, also known as ‘nacreous’ or ‘mother of pearl’ clouds.
The clouds usually form over polar regions at altitudes of 15–25 km, during winter and early spring, when temperatures in the stratosphere cool to below −78°C. They are made up of ice crystals, which reflect and refract light, producing the bright, iridescent mother-of-pearl colours.
Mawson research station expeditioners took these photos between 26 and 29 July. The clouds’ natural blurriness can make them appear like “smudged soap bubbles”.