[Cementjungle]

Water.

No water, just patterns in the soil which look like there was something flowing sometime in the past. This is nothing new, since we saw these from the Viking mission decades ago:

[exnavy]

The report earlier today said liquid and frozen water.

[RayChuang88]

Actually, when Mariner 9 discovered what looked like dried up river beds in 1971, the speculation immediately began on just long ago did Mars have flowing liquid water on the surface.