It’s tempting to say that the announcement of liquid water on the surface of Mars heralds a new era in Martian exploration.

You might think that the first human explorers on Mars will park next to a salty stream and use it to manufacture fresh drinking water. Maybe they could even find life in damp Martian nooks and crannies, areas where the dusty red planet can still fuel microbes.

Reality is much more subtle. Finding evidence for flowing water is not the same as finding life. Right now, scientists don’t know where this water is coming from, or if the chemistry in these Martian seeps is even life-friendly. And unfortunately, chances are it will be a long time before we