Last month, NASA’s Curiosity rover captured one of the best sunsets ever. A blue sunset on Mars.
The rover used its Mast Camera (Mastcam) high-resolution, color camera to capture the stunning images below.
What causes the bluish tint? Dust. The images snapped by Curiosity came during a lull in the dust storms. But, enough dust remained in Mars’ thin atmosphere for the sunset to appear blue.
The stunning sunset also provides researchers with valuable insight of the vertical distribution of dust in the atmosphere.
Mark Lemmon, the Curiosity’s team member who planned this observation, explains why the sunset appears blue.
“The colors come from the fact that the very fine dust is the right size so that blue light penetrates the atmosphere slightly more efficiently.”
Lemmon added, “when the blue light scatters off the dust, it stays closer to the direction of the sun than light of other colors does. The rest of the sky is yellow to orange, as yellow and red light scatter all over the sky instead of being absorbed or staying close to the sun.”
A Martian Detour
When not capturing beautiful sunsets, Curiosity keeps trudging along. Earlier this month, NASA announced Curiosity took a small detour from its planned mission path.
A hillside feature caught the eye of researchers. The rover made a quick stop, took some measurements, a few photos and continued its trek up Mount Sharp.
A part of a larger panorama showing several features Curiosity will study in the coming weeks and months.
“In pictures we took on the way from Pahrump Hills toward Logan Pass, some of the geologists on the team noticed a feature that looked like what’s called an ‘incised valley fill,’ which is where a valley has been cut into bedrock and then filled in with other sediment,” said Curiosity Project Scientist Ashwin Vasavada.
“We wanted to investigate what cut into the mudstone bedrock, and what process filled it back in,” Vasavada added. “The fill material looks like sand. Was the sand transported by wind or by water? What were the relative times for when the mudstone formed, when the valley was cut into it, when the cut was filled in?”
Vasavada says similar features on Earth show environmental changes. Researchers want to know what kind of changes led to another sediment being deposited. They will pour over the data collected as Curiosity continues its trek up Mount Sharp.
Here’s a bonus Mars sunset video from 2010 captured by NASA’s Opportunity rover.