Last month, NASA made one of the most anticipated announcements in history: we’ve confirmed the discovery of liquid water on Mars. Not only did the red planet have a watery past, leaving us with a number of distinctive features that could only arise from liquid flowing on its surface, including:

dried-up riverbeds, including some with oxbow bends,

martian spherules (or blueberries),

dozens of layers of sedimentary rock,

canyons that show evidence of being formed by water-based erosion,

and frozen lakes, icecaps and sub-surface ice,

but the detailed, recent observations of recurring slope lineae teach us that liquid exists there today.

These “gullies” that form are seen to be actively growing, and don’t come about from landslides, avalanches or dust flow. Instead, our orbiters teach us that the lineae have perchlorate salt deposits in them, evidence that liquid water dissolves them and flows there, sublimates/evaporates, and leaves them behind.

This find-of-a-lifetime opens up the possibility for current life on Mars, something I spoke about on TV last week. I’ll be recording Starts With A Bang’s first Patreon-sponsored podcast on this topic, which supporters get early access to, so ask your water-on-Mars questions!