…a few days ago.
From SPAAAACE.com
The origin of these odd features — geological or biological processes — is in TBD limbo at the moment.
Regarding trace fossils on Mars, “we don’t rule it out,” Vasavada said, “but we certainly won’t jump to that as our first interpretation.”
Close-up looks at these features show them to be angular in multiple dimensions. That could mean that they are related to crystals in the rock, perhaps “crystal molds” that are also found here on Earth, Vasavada added. Crystals in rock that are dissolved away leave crystal molds, he said.
Still, that’s just one of a few possibilities, Vasavada explained. “If we see more of them … then we begin to say that this is an important process that’s going on at Vera Rubin Ridge,” he said.
https://www.space.com/39294-mars-rover-curiosity-weird-tube-structures.html

