But NASA cannot admit mistakes. Anyway, the objects were apparently eroded by water, not by wind, as their bottoms were uniformly flat. There has been no water on Mars for over 3 billion years, so the objects must have been hanging there like this for over 3 billion years. To repeat, no cross-bedding on Earth resembles those objects. They resemble concrete slabs. Two hundred years ago, humans could not construct concrete slabs, let alone concrete slabs that suspended in the air for over 3 billion years. Was that low-technology?