In what could be a perfect desktop or smartphone screensaver for millions on the Earth, NASA's Curiosity rover has recorded a stunning view of the sunset from its location in Gale Crater on the Red Planet.The image shows the Sun dipping to a Martian horizon in a blue-tinged sky.Curiosity used its Mast Camera (Mastcam) to record the sunset during an evening of skywatching on April 15 this year.The imaging was done between dust storms but some dust remained suspended high in the atmosphere.The sunset observations help researchers assess the vertical distribution of dust in the atmosphere.
"The colours come from the fact that the very fine dust is the right size so that blue light penetrates the atmosphere slightly more efficiently," said Mark Lemmon from the Texas A&M University, College Station.When the blue light scatters off the dust, it stays closer to the direction of the Sun than light of other colours 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," he added.Just as colours are made more dramatic in sunsets on the Earth, Martian sunsets make the blue near the Sun's part of the sky much more prominent, while normal daylight makes the rusty colour of the dust more prominent.Since its landing inside Mars' Gale Crater, Curiosity has been studying the planet's ancient and modern environments.The image was taken at the close of the mission's 956th Martian day, the US space agency said in a statement.