NASA’s Curiosity views first ‘sun rays’ on Mars

Martian sunsets are uniquely moody, however NASA’s Curiosity rover captured one final month that stands out. Because the sun descended over the horizon on Feb. 2, rays of sunshine illuminated a financial institution of clouds. These “sun rays” are also referred to as crepuscular rays, from the Latin phrase for “twilight.” It was the primary time sun rays have been so clearly seen on Mars.

Curiosity captured the scene throughout the rover’s latest twilight cloud survey, which builds on its 2021 observations of noctilucent, or night-shining, clouds. Whereas most Martian clouds hover not more than 37 miles (60 kilometers) above the bottom and are composed of water ice, the clouds within the newest photos seem like at a higher altitude, the place it is particularly chilly. That implies these clouds are made from carbon dioxide ice, or dry ice.

As on Earth, clouds present scientists with advanced however essential data for understanding the climate. By taking a look at when and the place clouds kind, scientists can be taught extra concerning the Martian ambiance’s composition and temperatures, and the winds inside it.

The 2021 cloud survey included extra imaging by Curiosity’s black-and-white navigation cameras, offering an in depth take a look at a cloud’s construction because it strikes. However the latest survey, which started in January and can wrap up in mid-March, depends extra usually on the rover’s colour Mast Digicam, or Mastcam, which helps scientists see how cloud particles develop over time.

Along with the picture of sun rays, Curiosity captured a set of colourful clouds formed like a feather on Jan. 27. When illuminated by daylight, sure forms of clouds can create a rainbowlike show referred to as iridescence.

“The place we see iridescence, it means a cloud’s particle sizes are equivalent to their neighbors in every a part of the cloud,” mentioned Mark Lemmon, an atmospheric scientist with the Area Science Institute in Boulder, Colorado. “By taking a look at colour transitions, we’re seeing particle size altering throughout the cloud. That tells us about the way in which the cloud is evolving and the way its particles are altering dimension over time.”

Curiosity captured each the sun rays and iridescent clouds as panoramas, every of which was stitched collectively from 28 photos despatched to Earth. The photographs have been processed to emphasise the highlights.