Four images from Perseverance’s Mastcam-Z. (IMAGE)
Caption
Four images from Perseverance’s Mastcam-Z. The left hand-side images show both detections of the aurora, on 18 March and 18 May 2024. On the right are non-detections with comparable sky illumination (from Mars’s moons) to show the contrast in colours between a night with aurora and a night with no aurora. The March event was about twice as intense as the May event. The sky was also much dustier in May, which led to fewer stars being visible. The sky is generally much brighter and warmer in color in March due to Phobos, Mars’s largest moon, being in the sky. The coloured boxes show (from top to bottom): the theoretical aurora color for these images, the average sky colour, and the bottom boxes show the sky colour with the aurora signal removed or added, for left and right column respectively. This is to show what the colour of the sky would have been, theoretically, with no aurora that night, or with aurora for the comparison images. If all conditions were identical, then the two bottom boxes should diagonally have the same color, which worked close to perfectly for the May event. Below the images is the spectra from the rover’s SuperCam that identifies the green glow as the 557.7nm atomic oxygen auroral emission, indicated by the vertical green line. The solid lines are the real measurements for the two detections, while the dashed lines show our aurora model, demonstrating that the calculations estimating the aurora’s brightness from the surface with the measured dust amount corresponds very well with the observed aurora intensity.
Credit
Elise Wright Knutsen et al.
Usage Restrictions
No restrictions.
License
Public Domain