NASA announced that there is...occasionally...flowing, liquid water on the surface of Mars. Or, at least, liquid hydrated perchlorate salts that flow down steep slopes in the warmest Martian months.
When they do this, the martian dust gets dark, a darkness we can see, and that was first spotted in 2011 and named recurring slope lineae. Or, like, lines that appear on slopes in roughly the same place every year in the warmest Martian months.
It took some time and a lot of hard work and clever tricks to determine for sure that these RSLs, as I’ll be calling them, were caused by flowing water, but indeed that is what scientists are publishing today in Nature Geoscience.