Every day's image release from the Dawn spacecraft shows something on Vesta that is weird and cool and difficult to explain. The images come out with very little information describing what is going on to make those weird landscapes. In fact, for most images, the most useful piece of information about what in the image is interesting to scientists is in the image titles. Those titles are just long enough to tell you what in the image is especially noteworthy, but not why. Take this one, for instance. The title: "Worm-like markings on Vesta's surface." What? What could be making these "worm-like" squiggles? I've got no idea; they're wacky.
I think there's two main reasons for this crypticness. For one thing, the Dawn team is very small, and it's taxing to write long, detailed captions to images every single day. For another, Vesta is strange and different and in many cases scientists probably have no idea what's going on, or maybe they have conflicting ideas. (As the old joke goes, put n scientists in a room and you'll have n + 1 opinions.) There sure was no consensus at all among the scientists I was chatting with at either the Small Bodies Analysis Group or New Horizons meeting I attended recently.
Here's another nice cryptic one. "Unusual hill on Vesta." Why is the ground this shape? Could it be a volcano? Who knows? That's why we've got a spacecraft exploring it!