Planetary scientist puts Mars lake theory on ice with new study that offers alternate explanation

For years scientists have been debating what might lay under the Martian planet's south polar cap after bright radar reflections were discovered and initially attributed to water. But now, a new study puts that theory to rest and demonstrates for the first time that another material is most likely the answer.

source https://www.sciencedaily.com/releases/2021/07/210729143424.htm