Here's why the surface of Mercury is so dark. For years, scientists have wondered why Mercury is so dark. It doesn't have as much iron and titanium as the Moon, so it should be brighter. A team at Johns Hopkins' Applied Physics Laboratory finally has the answer, though.
March 17, 2004: NASA'S MESSENGER ENTERS MERCURY’S ORBIT - NASA's Messenger becomes the first spacecraft to enter orbit around Mercury. The probe took more than 270,000 pictures before crashing into the surface of Mercury on April 30, 2015.
Gravitational Anomalies of Mercury: NASA, GSFC's SVS, JHU's APL, Carnegie Inst. Washington: What's that under the surface of Mercury? The robotic MESSENGER spacecraft that had been orbiting planet Mercury for the past four years had been transmitting its data back to Earth with radio waves of very precise energy. The planet's gravity,