|A Patch of Mercury . . . in cool blue|
No mission to any place in our solar system has ever not provided surprises. In the case of Mercury, scientists have been amazed to discover that geological activity (i.e., volcanic, tectonic) continued on the planet far, far beyond the time it was previously thought to have been possible. And measurements of the gravity of the planet on the Messenger spacecraft have revealed that the core of the plant is much, much larger than Earth's. So the mantle and crust of the planet Mercury are quite thin, like the peel on an orange compared to the interior. Who knows what other wonders await our discovery out there?
I'm wondering if there's some invisible satellite circling us . . . measuring our interiors.