NASA Perseverance found a phenomenon that scientists had never hoped to see on Mars — the solar halo.
"We've been looking for halos everywhere and on a lot of images. And yet it's hard to explain this phenomenon on Mars. We thought it was a false concern. There's still a lot of work to be done to figure out what's really going on," said Mark Lemmon, a planetologist at the Institute of Space Sciences, a non-profit research institute in Boulder.
On Earth, ice crystals in the atmosphere distort sunlight under suitable conditions, creating the appearance of a bright spot on either side of the sun or the halo surrounding it. Scientists believed that other planets could observe such an optical trick, but even though robot explorers on the surface of Mars had been photographing the sky for decades, scientists had not seen any signs of solar oreol until December 2021.
The carbon dioxide in the Mars atmosphere is much larger than the water, so the team checked how large an eagle could create dry ice crystals, but the calculations did not match what Perseverance observed.
They also examined whether the camera itself could create a bright ring, but this function did not match these artifacts on other images. Moreover, a strange photograph was part of a sequence of five images taken by Perseverance in the sky; the sun and the eagle appeared three times, each time in different frames. And it was definitely not dust, written by scientists.
Scientists are now continuing to study images to understand how the solar halo, which is simply impossible on Mars, appeared on the Red Planet.