No one can hear you scream in space. But can you see rainbows in space? Especially if you may have just ‘spotted’ one in a photo posted by someone from space. For specifics, a photo taken by NASA’s Mars Perseverance Rover may have had a rainbow in the photo. NASA recently released a stunning image of the Ingenuity Mars Helicopter on the surface of Mars. Some people on social media, however, noticed something more than just the terrain – they noticed a multicoloured arc. Was it a rainbow? Could the earth-based light reflecting off water phenomenon have been replicated on Mars? Some speculated that it was caused by ice crystals in Martian high clouds. Some argued that it was a field of view artefact of the camera lens. So what is it?
Lens flare is, at present, the correct answer. NASA’s Perseverance rover on Twitter clarified that it wasn’t a rainbow. “Many have asked: Is that a rainbow on Mars? 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. This arc is a lens flare.”
Many have asked: Is that a rainbow on Mars? 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. This arc is a lens flare. pic.twitter.com/mIoSSuilJW— NASA's Perseverance Mars Rover (@NASAPersevere) April 6, 2021
Dave Lavery, a scientist at NASA Headquarters further clarified to Forbes that it was “Definitely not a rainbow….It is just internal reflections in the camera lens.” He compared it to when you get “lens flare” in any other camera system. He pointed out that, “The rover is almost due north of the helicopter, so the camera is looking almost straight south at about 2:00pm local Mars solar time when these images were taken.” According to Lavery, who is Program Executive for Solar System Exploration at the nation’s space agency, those conditions are optimal for stray light capture in the camera optics.