NASA astronomers have released the first clear images of twilight rays and mother-of-pearl clouds in the Martian sky. The photos were posted on the Curiosity navigator’s Twitter page.
The Curiosity rover has been studying twilight clouds since January 2023. This phase of work will end in mid-March. The photo of the sun rays filtering through the clouds during the sunset is a panorama consisting of 28 separate photos. Released on March 6th. As noted by NASA, this is the first clear image of the sun’s rays on Mars.
Twilight rays occur when sunlight enters the spaces between clouds during sunset or sunrise when the star is below the horizon. Although the rays seem to converge at one point behind the cloud, they actually travel almost parallel to each other. Scientists suggest that the unusual height of the clouds allowed the rover to capture this phenomenon.
On Earth, sun rays often appear red or yellow because of the atmosphere, according to the Met Office. Due to the thin atmosphere, sunlight is scattered much less on Mars, so twilight rays are much whiter there, and Martian sunsets often take on a bluish hue.
On January 27, Curiosity also photographed a plume of mother-of-pearl cloud during another survey of twilight clouds. Previously, such clouds were observed in the sky above the North Pole. Mother-of-pearl clouds, known as polar stratospheric clouds, only form on Earth in unusually cold conditions.
Observing the color transitions in the clouds will allow scientists to better understand the composition of the Martian atmosphere and determine the particle sizes in it.