English: The first-ever time-lapse photography of an analemma on Mars.

Created using images of the MarsDial on the Opportunity (MER1) rover.

Images were taken around 12:00:00 +/- 00:05:00 Martian local mean solar time each Martian day through out the rover's mission (10+ years). The images span from sol 2 to sol 3203.

In each image the shadow cast by the gnomon is marked with a color corresponding to the solar longitude, which is a measure of the Martian year in degrees (e.g. solar longitude of 0 is the vernal equinox).

Because the images were taken on a rover, the direction the camera was pointing (North, South, East, etc.) changed frequently. The images have been processed (perspective transform + rotation) such that this change in direction has been largely eliminated. However, the fact that the rover is still moving (and tilting) from image to image and that the image isn't taken exactly at 12:00:00 each sol, leads to a slightly 'noisy' analemma.

The expected analemma (if the rover was stationary and perpendicular to the ground) is superimposed using white points in the last couple of frames of the video.