NASA has released some impressive images of the first 'colour' sunset observed by its Curiosity Mars rover.

The gif below, taken at the Red Planet's Gale Crater on the mission's 965th day, consists of four colour calibrated images captured over the course of just under seven minutes.

On their website, NASA explains why the sunset appears blue, saying "dust in the Martian atmosphere has fine particles that permit blue light to penetrate the atmosphere more efficiently than longer-wavelength colors. That causes the blue colours in the mixed light coming from the sun to stay closer to sun's part of the sky, compared to the wider scattering of yellow and red colours." 

The 'blue' effect is most obvious at sunset as the sunlight passes through a longer path than it does at midday.

Image: NASA/JPL-Caltech/MSSS