As a part of its ongoing examine of Mars’ clouds, NASA’s Curiosity rover not too long ago captured a surprising picture of a Martian sundown. Because the Solar sinks over the horizon, its gentle types into solar rays that may be seen banding throughout the sky.
Technically often called crepuscular rays, that is the primary time the phenomena has been imaged in such element on Mars. And by learning the best way the rays shine by means of the clouds, scientists can be taught extra concerning the Martian environment and climate system.
Though Mars’ environment is extraordinarily skinny, at simply 1 % the density of Earth’s environment, it’s nonetheless energetic and changeable. The planet experiences excessive winds of as much as 60 miles per hour, which may choose up the tremendous mud particles coating a lot of the planet’s floor and whip them up into world mud storms. With low atmospheric strain and appreciable variation in temperatures between day and night time, dynamic occasions like mud devils are seen repeatedly.
Technically often called crepuscular rays
Additionally because of the skinny environment, there are solely occasional clouds within the Martian sky. With simply small quantities of water vapor current within the environment, the presence of clouds varies all through the seasons. The clouds which can be seen there aren’t like clouds on Earth, nonetheless, as these are composed of liquid water. On Mars, the low strain implies that clouds type from water ice or carbon dioxide (dry ice) as an alternative.
The brand new photos from Curiosity present clouds at a excessive altitude, which means that they’re composed of carbon dioxide moderately than water ice. One other picture captured not too long ago by Curiosity reveals one other necessary cloud phenomenon known as iridescence. The completely different colours seen throughout the cloud can reveal details about the particles which make it up.
“The place we see iridescence, it means a cloud’s particle sizes are an identical to their neighbors in every a part of the cloud”
“The place we see iridescence, it means a cloud’s particle sizes are an identical to their neighbors in every a part of the cloud,” mentioned Mark Lemmon, an atmospheric scientist with the Area Science Institute in Boulder, Colorado, in a press release. “By colour transitions, we’re seeing particle measurement altering throughout the cloud. That tells us about the best way the cloud is evolving and the way its particles are altering measurement over time.”
The 2 photos had been stitched collectively from 28 particular person photos every. They had been taken by Curiosity’s Mastcam instrument, which, in contrast to many earlier cloud observations made utilizing the rover’s black and white navigation cameras, can seize photos in colour. Curiosity has been performing its survey of the clouds since January and can proceed for a number of extra weeks.
Curiosity has beforehand captured different putting views of Martian climate phenomena, just like the blue sundown it imaged in 2015. The colour seen there’s additionally because of the mud within the environment, following a mud storm that had left mud suspended within the environment. This suspended mud scatters completely different colours of sunshine by completely different quantities, and it scatters the sunshine in a specific path. That leads to crimson gentle being filtered out extra, so what stays is the blue colour seen within the Martian sky.