Recent images from NASA's Perseverance Mars Rover caused a flutter of excitement on social media, specially since some of them appears to feature a rainbow on the Red Planet. The rover's Hazard Avoidance Camera picked up what looks like a perfect rainbow in the Martian sky on April 4. The image has gone viral on the Internet and sparked mass speculation online, given that rainbows should not be possible in the very dry atmosphere of Mars.
Reddit users speculated that the "rainbow" could actually be a "dustbow" caused by dust, rather than water droplets. Users also dug out an old comment from NASA Mars Program Office Chief Scientist Rich Zurek said that "icebows" could appear on Mars. "Not quite rainbows, because there is no rain, but we have seen icebows with the Pathfinder mission," he wrote in response to a query in a 2015 'Ask Me Anything' session on Reddit.
So what exactly does NASA's picture show? The space agency took to Twitter to answer the question a few hours ago.
"Many have asked: Is that a rainbow on Mars? No. Rainbows aren't possible here," NASA's Perseverance rover clarified. "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. This arc is a lens flare," it explained.
The 'rainbow' is therefore nothing more than a lens flare.
Dave Lavery from NASA Headquarters also confirmed to Forbes that it was "Definitely not a rainbow....It is just internal reflections in the camera lens."
NASA's Perseverance Mars Rover touched down on the Red Planet on February 18.
