Blue Sunset On Mars: NASA’s Curiosity Say ‘Let Us Go Then, You and I’

NASA’s Curiosity rover has sent back stunning images of sunset on Mars. Captured by Curiosity’s Mast Camera inside the Gale Crater, the images show blue hues of the serene sundown over the red planet’s horizon. NASA said in a statement that the images were beamed back last week. The official Twitter handle of Curiosity Rover said, “Let us go then, you and I.”

Blue Sunset On Mars: NASA's Curiosity Say 'Let Us Go Then, You and I'

Martian sunset observed over seven minutes

Curiosity recorded the sunset on Mars over a period of seven minutes during an evening of sky-watching on April 15th. The photos were captured between dust storms, but some dust was still suspended in the atmosphere, said NASA. These observations helped scientists study the vertical distribution of dust in the Martian atmosphere. Unsurprisingly, we can see a lot of rocks in these images.

The original images beamed back by Curiosity were black and white, but that’s how Mast Camera codes color into images. The color data was decoded on Earth. The color image of Martian sunset was adjusted to be an accurate representation of what human eyes would see. Curiosity’s Mast Camera is slightly less sensitive to blue color than human eyes. So, we would see an even bluer hue with a naked eye.

Blue Sunset On Mars: NASA's Curiosity Say 'Let Us Go Then, You and I'

Why does sunset appears blue on Mars?

Why does sunset on Mars appears blue, unlike red and yellow on Earth? The Martian atmosphere is thinner and has dust in it. Dust on Mars is right size to allow blue light to penetrate the atmosphere more effectively, said Mark Lemmon, a Curiosity team member. “When the blue light scatters off the dust, it stays closer to the direction of the sun than light of other colors does,” he added. The rest of the sky appears orange to yellow because red and yellow light scatter all over the sky.

Though it’s the first color image of sunset on Mars from Curiosity, it’s not the first Martian sunset we have seen. NASA’s Opportunity rover had also beamed back images of Martian sunset in 2010.