In a Tuesday tweet, the NASA Perseverance Mars rover account wrote that the agency had seen comments online wondering about the bright arc captured in the April 4 photo from the rover’s onboard Rear Left Hazard Avoidance Camera.
“Many have asked: Is that a rainbow on Mars?” they said. “No. Rainbows aren’t possible here.”
“Rainbows are created by light reflected off of round water droplets, but there isn’t enough water here to condense, and it’s too cold for liquid water in the atmosphere,” they continued. “This arc is a lens flare.”
A lens flare is caused by a non-image-forming bright light that shines into the lens.
Rainbows form when sunlight passes through raindrops in the atmosphere.
However, while a rainbow may not be possible on Mars’ thin, dry and extremely cold atmosphere, The Hill noted Tuesday that in a 2015 “Ask Me Anything” a NASA team member hinted at the prospect of “icebows” because snow has been observed at the red planet’s poles.
Nevertheless, lens flares are common in rover images.
Another April 4 image captured a lens flare and a close-up shot of Perseverance’s wheel using the same camera.