There’s a giant hole on Mars, and scientists can’t figure out where it came from

Humans have now had rovers active on Mars for almost two full decades, which is enough time that we've learned plenty about the Martian landscape. We know all about the soil, the geography, and even the places where water most likely flowed free on the surface of the red planet at one time, but we still don't know everything. One place in particular, in the souther hemisphere of Mars, is giving scientists some serious grief. It's a massive pit, and nobody knows how it got there.Located in an are