After a decade of exploring the surface of the Red Planet, the Curiosity rover has recently been looking up. On February 2, 2023, the NASA rover captured a stunning sunset on Mars. The image shows rays of sunlight stretching across the horizon, lighting up a mass of clouds.
"It was the first time sun rays have been so clearly viewed on Mars," team members from NASA's Jet Propulsion Laboratory (JPL) 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. This could be 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 much more white.
Curiosity 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. It is 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 have a scientific purpose. They will provide scientists better insights into weather patterns and conditions on the Red Planet.
Resources: JPL.NASA.gov, CNN.com, Livescience.com