Mercury will retrograde from Dec. 13 through Jan. 2 in the last of four times it appears to move backward in the sky this year. Every planet has in our solar system has retrograded for at least part ...

Mercury will retrograde, or appear to be moving backward in the sky, from August 23 through September 15. It's the third of four times Mercury will be moving in retrograde this year. Mercury isn't the ...

Mercury doesn't give up its secrets easily. The smallest planet in our solar system is also one of the most extreme—a sun-scorched, metal-rich world with a puzzling magnetic field and lavas unlike ...