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".
