By: Jason Shen
After over a decade of searching Mars, the Mars rover, Curiosity captured a stunning image of a sunset. The image shows rays of sunlight stretching across the horizon, lighting up clouds. This photo was captured on February 2, 2023.
“This is the first time sun rays have been so clear,” team members of Nasa’s Jet Laboratory wrote in a statement.
The sun rays captured in the image are also known as crepuscular rays. They form when the sun is just below the horizon during the twilight period, either at sunrise or sunset. On Earth, these sun rays usually appear red or yellow. That's because the particles in our thick atmosphere act like a prism, breaking the sunlight into seven colors. The shorter wavelengths that produce colors like blue and green get scattered the most. Hence, the light that reaches our eyes is mainly the longer wavelengths that produce yellow and red. However, the thin atmosphere on Mars does not scatter the sunlight as much. As a result, the sun’s rays appear whiter.
The rover also captured a set of colorful clouds shaped like a feather on January 27, 2023. When illuminated by sunlight, certain types of clouds can create a rainbow-like display called iridescence. Studying the colors in these clouds allows scientists to learn about particle size within the clouds and how they grow over time. The cloud images collected by Curiosity will provide scientists with better insights into weather patterns and conditions on the Red Planet.