Molten core on the planet Mercury, possibl

"NASA scientists working with high-precision planetary radars in California have discovered strong evidence that the planet Mercury might have a molten core.

"Scientists had not expected to find a magnetic field at Mercury," said Professor Jean-Luc Margot of Cornell University, leader of the research team. "Planetary magnetic fields are associated with molten cores, and the prevailing theory was the planet was too small to have a molten core."

Since then, multiple radar observations have ruled out a solid core, leading to the finding that Mercury's core is molten -- or at least the outer core is molten and not forced to rotate along with its shell."

I'm not sure what this means in the grand scheme of things, but it goes to explaining more of our universe. And that's a good thing.